Composites 101 An introduction to composites design and manufacturing.
Introduction and Classification of Composites
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Transcript of Introduction and Classification of Composites
ME 1014 ME 1014 Composite MaterialsComposite Materials
PProfVAlfred Franklin rofVAlfred Franklin StXavierrsquos Catholic College of EngineeringStXavierrsquos Catholic College of Engineering
Nagercoil IndiaNagercoil India
Composite MaterialComposite Material Two inherently different materials that when combined Two inherently different materials that when combined together produce a material with properties that exceed together produce a material with properties that exceed the constituent materialsthe constituent materials
Any combination of two or more different materials at the Any combination of two or more different materials at the macroscopic levelmacroscopic level
The constituents retain their identities ie they do not dissolve or merge into each other although they act in concert
Composites Artificially produced multiphase materials
Composite MaterialComposite Material
Composites A judicious combination of two or more materials that produces a synergistic effect
A material system composed of two or more physically distinct phases whose combination produces aggregate properties that are different from those of its constituents
Phases of Composites
Matrix Phase continuous phase surrounds other phase (eg metal (Cu Al Ti Nihellip) ceramic (SiChellip) or polymer (Thermosets thermoplastics Elastomers)
Reinforcement Phase dispersed phase discontinuous phase (eg Fibers Particles or Flakes)
1048707 rarr Interface between matrix and reinforcementInterfacial properties - the interface may be regarded as a third phase
Examplesndash Straw in mudndash Wood (cellulose fibers in hemicellulose and lignin)ndash Bones (soft protein collagen and hard apatite minerals)ndash Pearlite (ferrite and cementite)
Micro mechanics Macro mechanics
Major ConstituentsMajor Constituents
FiberMatrixFillersCoupling agentsColorants
FIBERSFIBERS
Principle Load carrying member
Main constituent and they occupy largest volume fraction
Diameter of a single fiber is about 10 microns
They may be continuous or discontinuous in length
TYPES OF GLASS FIBERTYPES OF GLASS FIBER E-Glass ndash E stands for electricalE-Glass ndash E stands for electrical S-Glass ndash S stands for high silica contentS-Glass ndash S stands for high silica content
High thermal expansion coefficientHigh thermal expansion coefficient High fatigue strengthHigh fatigue strength
C-Glass ndash C stands for CorrosionC-Glass ndash C stands for Corrosion Used in Chemical applicationsUsed in Chemical applications Storage tanksStorage tanks
R-Glass ndash R stands for RigidR-Glass ndash R stands for Rigid Structural applicationsStructural applications
D-Glass ndash D stands for DielectricD-Glass ndash D stands for Dielectric Low dielectric constantsLow dielectric constants
A-Glass ndash A Stands for appearanceA-Glass ndash A Stands for appearance To improve surface appearanceTo improve surface appearance For ornamental worksFor ornamental works
E-CR Glass ndash E-CR stands for Electrical and E-CR Glass ndash E-CR stands for Electrical and corrosion resistancecorrosion resistance
AR Glass ndash AR stands for Alkali resistanceAR Glass ndash AR stands for Alkali resistance
bull Critical fiber length for effective stiffening amp strengthening
fiber length15
fdc
fiber diameter
shear strength offiber-matrix interface
fiber strength in tension
Efficiency fiber lengthEfficiency fiber length
(x)
7
fiber length 15
fdc
Shorter thicker fiber
fiber length 15
fdc
(x)
Longer thinner fiber
Poorer fiber efficiency Better fiber efficiency
Why are Fibers of a Thin Diameter
1 Thinner fiber has higher ultimate strength because less chance
for inherent flaws Similar phenomenon in metals and alloys(Strength of a thin wire can be higher than its bulk material)
2 For the same volume of fibers thinner fibers has largersurface area thus has stronger bond with matrix (The totalsurface area of fibers is inversely proportional to the
diameterof fibers)
3 Thinner fiber has larger flexibility ( 1(EI)) and therefore isable to be bent without breaking (Woven fabric performs canbe made before impregnated with polymer matrix)
Composite Strength Longitudinal LoadingComposite Strength Longitudinal Loading
Continuous fibersContinuous fibers - - Estimate fiber-reinforced composite Estimate fiber-reinforced composite strength for long continuous fibers in a matrixstrength for long continuous fibers in a matrix
Longitudinal deformationLongitudinal deformation
cc = = mmVVmm + + ffVVff butbut cc = = mm = = ff volume fractionvolume fraction isostrainisostrain
Ec = Em Vm + EfVf longitudinal (extensional)
modulus
mm
ff
m
f
VE
VE
F
F f = fiber
m = matrixC-composite
Remembering E = and note this model corresponds to the ldquoupper boundrdquo for particulate composites
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Composite MaterialComposite Material Two inherently different materials that when combined Two inherently different materials that when combined together produce a material with properties that exceed together produce a material with properties that exceed the constituent materialsthe constituent materials
Any combination of two or more different materials at the Any combination of two or more different materials at the macroscopic levelmacroscopic level
The constituents retain their identities ie they do not dissolve or merge into each other although they act in concert
Composites Artificially produced multiphase materials
Composite MaterialComposite Material
Composites A judicious combination of two or more materials that produces a synergistic effect
A material system composed of two or more physically distinct phases whose combination produces aggregate properties that are different from those of its constituents
Phases of Composites
Matrix Phase continuous phase surrounds other phase (eg metal (Cu Al Ti Nihellip) ceramic (SiChellip) or polymer (Thermosets thermoplastics Elastomers)
Reinforcement Phase dispersed phase discontinuous phase (eg Fibers Particles or Flakes)
1048707 rarr Interface between matrix and reinforcementInterfacial properties - the interface may be regarded as a third phase
Examplesndash Straw in mudndash Wood (cellulose fibers in hemicellulose and lignin)ndash Bones (soft protein collagen and hard apatite minerals)ndash Pearlite (ferrite and cementite)
Micro mechanics Macro mechanics
Major ConstituentsMajor Constituents
FiberMatrixFillersCoupling agentsColorants
FIBERSFIBERS
Principle Load carrying member
Main constituent and they occupy largest volume fraction
Diameter of a single fiber is about 10 microns
They may be continuous or discontinuous in length
TYPES OF GLASS FIBERTYPES OF GLASS FIBER E-Glass ndash E stands for electricalE-Glass ndash E stands for electrical S-Glass ndash S stands for high silica contentS-Glass ndash S stands for high silica content
High thermal expansion coefficientHigh thermal expansion coefficient High fatigue strengthHigh fatigue strength
C-Glass ndash C stands for CorrosionC-Glass ndash C stands for Corrosion Used in Chemical applicationsUsed in Chemical applications Storage tanksStorage tanks
R-Glass ndash R stands for RigidR-Glass ndash R stands for Rigid Structural applicationsStructural applications
D-Glass ndash D stands for DielectricD-Glass ndash D stands for Dielectric Low dielectric constantsLow dielectric constants
A-Glass ndash A Stands for appearanceA-Glass ndash A Stands for appearance To improve surface appearanceTo improve surface appearance For ornamental worksFor ornamental works
E-CR Glass ndash E-CR stands for Electrical and E-CR Glass ndash E-CR stands for Electrical and corrosion resistancecorrosion resistance
AR Glass ndash AR stands for Alkali resistanceAR Glass ndash AR stands for Alkali resistance
bull Critical fiber length for effective stiffening amp strengthening
fiber length15
fdc
fiber diameter
shear strength offiber-matrix interface
fiber strength in tension
Efficiency fiber lengthEfficiency fiber length
(x)
7
fiber length 15
fdc
Shorter thicker fiber
fiber length 15
fdc
(x)
Longer thinner fiber
Poorer fiber efficiency Better fiber efficiency
Why are Fibers of a Thin Diameter
1 Thinner fiber has higher ultimate strength because less chance
for inherent flaws Similar phenomenon in metals and alloys(Strength of a thin wire can be higher than its bulk material)
2 For the same volume of fibers thinner fibers has largersurface area thus has stronger bond with matrix (The totalsurface area of fibers is inversely proportional to the
diameterof fibers)
3 Thinner fiber has larger flexibility ( 1(EI)) and therefore isable to be bent without breaking (Woven fabric performs canbe made before impregnated with polymer matrix)
Composite Strength Longitudinal LoadingComposite Strength Longitudinal Loading
Continuous fibersContinuous fibers - - Estimate fiber-reinforced composite Estimate fiber-reinforced composite strength for long continuous fibers in a matrixstrength for long continuous fibers in a matrix
Longitudinal deformationLongitudinal deformation
cc = = mmVVmm + + ffVVff butbut cc = = mm = = ff volume fractionvolume fraction isostrainisostrain
Ec = Em Vm + EfVf longitudinal (extensional)
modulus
mm
ff
m
f
VE
VE
F
F f = fiber
m = matrixC-composite
Remembering E = and note this model corresponds to the ldquoupper boundrdquo for particulate composites
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Composite MaterialComposite Material
Composites A judicious combination of two or more materials that produces a synergistic effect
A material system composed of two or more physically distinct phases whose combination produces aggregate properties that are different from those of its constituents
Phases of Composites
Matrix Phase continuous phase surrounds other phase (eg metal (Cu Al Ti Nihellip) ceramic (SiChellip) or polymer (Thermosets thermoplastics Elastomers)
Reinforcement Phase dispersed phase discontinuous phase (eg Fibers Particles or Flakes)
1048707 rarr Interface between matrix and reinforcementInterfacial properties - the interface may be regarded as a third phase
Examplesndash Straw in mudndash Wood (cellulose fibers in hemicellulose and lignin)ndash Bones (soft protein collagen and hard apatite minerals)ndash Pearlite (ferrite and cementite)
Micro mechanics Macro mechanics
Major ConstituentsMajor Constituents
FiberMatrixFillersCoupling agentsColorants
FIBERSFIBERS
Principle Load carrying member
Main constituent and they occupy largest volume fraction
Diameter of a single fiber is about 10 microns
They may be continuous or discontinuous in length
TYPES OF GLASS FIBERTYPES OF GLASS FIBER E-Glass ndash E stands for electricalE-Glass ndash E stands for electrical S-Glass ndash S stands for high silica contentS-Glass ndash S stands for high silica content
High thermal expansion coefficientHigh thermal expansion coefficient High fatigue strengthHigh fatigue strength
C-Glass ndash C stands for CorrosionC-Glass ndash C stands for Corrosion Used in Chemical applicationsUsed in Chemical applications Storage tanksStorage tanks
R-Glass ndash R stands for RigidR-Glass ndash R stands for Rigid Structural applicationsStructural applications
D-Glass ndash D stands for DielectricD-Glass ndash D stands for Dielectric Low dielectric constantsLow dielectric constants
A-Glass ndash A Stands for appearanceA-Glass ndash A Stands for appearance To improve surface appearanceTo improve surface appearance For ornamental worksFor ornamental works
E-CR Glass ndash E-CR stands for Electrical and E-CR Glass ndash E-CR stands for Electrical and corrosion resistancecorrosion resistance
AR Glass ndash AR stands for Alkali resistanceAR Glass ndash AR stands for Alkali resistance
bull Critical fiber length for effective stiffening amp strengthening
fiber length15
fdc
fiber diameter
shear strength offiber-matrix interface
fiber strength in tension
Efficiency fiber lengthEfficiency fiber length
(x)
7
fiber length 15
fdc
Shorter thicker fiber
fiber length 15
fdc
(x)
Longer thinner fiber
Poorer fiber efficiency Better fiber efficiency
Why are Fibers of a Thin Diameter
1 Thinner fiber has higher ultimate strength because less chance
for inherent flaws Similar phenomenon in metals and alloys(Strength of a thin wire can be higher than its bulk material)
2 For the same volume of fibers thinner fibers has largersurface area thus has stronger bond with matrix (The totalsurface area of fibers is inversely proportional to the
diameterof fibers)
3 Thinner fiber has larger flexibility ( 1(EI)) and therefore isable to be bent without breaking (Woven fabric performs canbe made before impregnated with polymer matrix)
Composite Strength Longitudinal LoadingComposite Strength Longitudinal Loading
Continuous fibersContinuous fibers - - Estimate fiber-reinforced composite Estimate fiber-reinforced composite strength for long continuous fibers in a matrixstrength for long continuous fibers in a matrix
Longitudinal deformationLongitudinal deformation
cc = = mmVVmm + + ffVVff butbut cc = = mm = = ff volume fractionvolume fraction isostrainisostrain
Ec = Em Vm + EfVf longitudinal (extensional)
modulus
mm
ff
m
f
VE
VE
F
F f = fiber
m = matrixC-composite
Remembering E = and note this model corresponds to the ldquoupper boundrdquo for particulate composites
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Phases of Composites
Matrix Phase continuous phase surrounds other phase (eg metal (Cu Al Ti Nihellip) ceramic (SiChellip) or polymer (Thermosets thermoplastics Elastomers)
Reinforcement Phase dispersed phase discontinuous phase (eg Fibers Particles or Flakes)
1048707 rarr Interface between matrix and reinforcementInterfacial properties - the interface may be regarded as a third phase
Examplesndash Straw in mudndash Wood (cellulose fibers in hemicellulose and lignin)ndash Bones (soft protein collagen and hard apatite minerals)ndash Pearlite (ferrite and cementite)
Micro mechanics Macro mechanics
Major ConstituentsMajor Constituents
FiberMatrixFillersCoupling agentsColorants
FIBERSFIBERS
Principle Load carrying member
Main constituent and they occupy largest volume fraction
Diameter of a single fiber is about 10 microns
They may be continuous or discontinuous in length
TYPES OF GLASS FIBERTYPES OF GLASS FIBER E-Glass ndash E stands for electricalE-Glass ndash E stands for electrical S-Glass ndash S stands for high silica contentS-Glass ndash S stands for high silica content
High thermal expansion coefficientHigh thermal expansion coefficient High fatigue strengthHigh fatigue strength
C-Glass ndash C stands for CorrosionC-Glass ndash C stands for Corrosion Used in Chemical applicationsUsed in Chemical applications Storage tanksStorage tanks
R-Glass ndash R stands for RigidR-Glass ndash R stands for Rigid Structural applicationsStructural applications
D-Glass ndash D stands for DielectricD-Glass ndash D stands for Dielectric Low dielectric constantsLow dielectric constants
A-Glass ndash A Stands for appearanceA-Glass ndash A Stands for appearance To improve surface appearanceTo improve surface appearance For ornamental worksFor ornamental works
E-CR Glass ndash E-CR stands for Electrical and E-CR Glass ndash E-CR stands for Electrical and corrosion resistancecorrosion resistance
AR Glass ndash AR stands for Alkali resistanceAR Glass ndash AR stands for Alkali resistance
bull Critical fiber length for effective stiffening amp strengthening
fiber length15
fdc
fiber diameter
shear strength offiber-matrix interface
fiber strength in tension
Efficiency fiber lengthEfficiency fiber length
(x)
7
fiber length 15
fdc
Shorter thicker fiber
fiber length 15
fdc
(x)
Longer thinner fiber
Poorer fiber efficiency Better fiber efficiency
Why are Fibers of a Thin Diameter
1 Thinner fiber has higher ultimate strength because less chance
for inherent flaws Similar phenomenon in metals and alloys(Strength of a thin wire can be higher than its bulk material)
2 For the same volume of fibers thinner fibers has largersurface area thus has stronger bond with matrix (The totalsurface area of fibers is inversely proportional to the
diameterof fibers)
3 Thinner fiber has larger flexibility ( 1(EI)) and therefore isable to be bent without breaking (Woven fabric performs canbe made before impregnated with polymer matrix)
Composite Strength Longitudinal LoadingComposite Strength Longitudinal Loading
Continuous fibersContinuous fibers - - Estimate fiber-reinforced composite Estimate fiber-reinforced composite strength for long continuous fibers in a matrixstrength for long continuous fibers in a matrix
Longitudinal deformationLongitudinal deformation
cc = = mmVVmm + + ffVVff butbut cc = = mm = = ff volume fractionvolume fraction isostrainisostrain
Ec = Em Vm + EfVf longitudinal (extensional)
modulus
mm
ff
m
f
VE
VE
F
F f = fiber
m = matrixC-composite
Remembering E = and note this model corresponds to the ldquoupper boundrdquo for particulate composites
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Micro mechanics Macro mechanics
Major ConstituentsMajor Constituents
FiberMatrixFillersCoupling agentsColorants
FIBERSFIBERS
Principle Load carrying member
Main constituent and they occupy largest volume fraction
Diameter of a single fiber is about 10 microns
They may be continuous or discontinuous in length
TYPES OF GLASS FIBERTYPES OF GLASS FIBER E-Glass ndash E stands for electricalE-Glass ndash E stands for electrical S-Glass ndash S stands for high silica contentS-Glass ndash S stands for high silica content
High thermal expansion coefficientHigh thermal expansion coefficient High fatigue strengthHigh fatigue strength
C-Glass ndash C stands for CorrosionC-Glass ndash C stands for Corrosion Used in Chemical applicationsUsed in Chemical applications Storage tanksStorage tanks
R-Glass ndash R stands for RigidR-Glass ndash R stands for Rigid Structural applicationsStructural applications
D-Glass ndash D stands for DielectricD-Glass ndash D stands for Dielectric Low dielectric constantsLow dielectric constants
A-Glass ndash A Stands for appearanceA-Glass ndash A Stands for appearance To improve surface appearanceTo improve surface appearance For ornamental worksFor ornamental works
E-CR Glass ndash E-CR stands for Electrical and E-CR Glass ndash E-CR stands for Electrical and corrosion resistancecorrosion resistance
AR Glass ndash AR stands for Alkali resistanceAR Glass ndash AR stands for Alkali resistance
bull Critical fiber length for effective stiffening amp strengthening
fiber length15
fdc
fiber diameter
shear strength offiber-matrix interface
fiber strength in tension
Efficiency fiber lengthEfficiency fiber length
(x)
7
fiber length 15
fdc
Shorter thicker fiber
fiber length 15
fdc
(x)
Longer thinner fiber
Poorer fiber efficiency Better fiber efficiency
Why are Fibers of a Thin Diameter
1 Thinner fiber has higher ultimate strength because less chance
for inherent flaws Similar phenomenon in metals and alloys(Strength of a thin wire can be higher than its bulk material)
2 For the same volume of fibers thinner fibers has largersurface area thus has stronger bond with matrix (The totalsurface area of fibers is inversely proportional to the
diameterof fibers)
3 Thinner fiber has larger flexibility ( 1(EI)) and therefore isable to be bent without breaking (Woven fabric performs canbe made before impregnated with polymer matrix)
Composite Strength Longitudinal LoadingComposite Strength Longitudinal Loading
Continuous fibersContinuous fibers - - Estimate fiber-reinforced composite Estimate fiber-reinforced composite strength for long continuous fibers in a matrixstrength for long continuous fibers in a matrix
Longitudinal deformationLongitudinal deformation
cc = = mmVVmm + + ffVVff butbut cc = = mm = = ff volume fractionvolume fraction isostrainisostrain
Ec = Em Vm + EfVf longitudinal (extensional)
modulus
mm
ff
m
f
VE
VE
F
F f = fiber
m = matrixC-composite
Remembering E = and note this model corresponds to the ldquoupper boundrdquo for particulate composites
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Major ConstituentsMajor Constituents
FiberMatrixFillersCoupling agentsColorants
FIBERSFIBERS
Principle Load carrying member
Main constituent and they occupy largest volume fraction
Diameter of a single fiber is about 10 microns
They may be continuous or discontinuous in length
TYPES OF GLASS FIBERTYPES OF GLASS FIBER E-Glass ndash E stands for electricalE-Glass ndash E stands for electrical S-Glass ndash S stands for high silica contentS-Glass ndash S stands for high silica content
High thermal expansion coefficientHigh thermal expansion coefficient High fatigue strengthHigh fatigue strength
C-Glass ndash C stands for CorrosionC-Glass ndash C stands for Corrosion Used in Chemical applicationsUsed in Chemical applications Storage tanksStorage tanks
R-Glass ndash R stands for RigidR-Glass ndash R stands for Rigid Structural applicationsStructural applications
D-Glass ndash D stands for DielectricD-Glass ndash D stands for Dielectric Low dielectric constantsLow dielectric constants
A-Glass ndash A Stands for appearanceA-Glass ndash A Stands for appearance To improve surface appearanceTo improve surface appearance For ornamental worksFor ornamental works
E-CR Glass ndash E-CR stands for Electrical and E-CR Glass ndash E-CR stands for Electrical and corrosion resistancecorrosion resistance
AR Glass ndash AR stands for Alkali resistanceAR Glass ndash AR stands for Alkali resistance
bull Critical fiber length for effective stiffening amp strengthening
fiber length15
fdc
fiber diameter
shear strength offiber-matrix interface
fiber strength in tension
Efficiency fiber lengthEfficiency fiber length
(x)
7
fiber length 15
fdc
Shorter thicker fiber
fiber length 15
fdc
(x)
Longer thinner fiber
Poorer fiber efficiency Better fiber efficiency
Why are Fibers of a Thin Diameter
1 Thinner fiber has higher ultimate strength because less chance
for inherent flaws Similar phenomenon in metals and alloys(Strength of a thin wire can be higher than its bulk material)
2 For the same volume of fibers thinner fibers has largersurface area thus has stronger bond with matrix (The totalsurface area of fibers is inversely proportional to the
diameterof fibers)
3 Thinner fiber has larger flexibility ( 1(EI)) and therefore isable to be bent without breaking (Woven fabric performs canbe made before impregnated with polymer matrix)
Composite Strength Longitudinal LoadingComposite Strength Longitudinal Loading
Continuous fibersContinuous fibers - - Estimate fiber-reinforced composite Estimate fiber-reinforced composite strength for long continuous fibers in a matrixstrength for long continuous fibers in a matrix
Longitudinal deformationLongitudinal deformation
cc = = mmVVmm + + ffVVff butbut cc = = mm = = ff volume fractionvolume fraction isostrainisostrain
Ec = Em Vm + EfVf longitudinal (extensional)
modulus
mm
ff
m
f
VE
VE
F
F f = fiber
m = matrixC-composite
Remembering E = and note this model corresponds to the ldquoupper boundrdquo for particulate composites
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
FIBERSFIBERS
Principle Load carrying member
Main constituent and they occupy largest volume fraction
Diameter of a single fiber is about 10 microns
They may be continuous or discontinuous in length
TYPES OF GLASS FIBERTYPES OF GLASS FIBER E-Glass ndash E stands for electricalE-Glass ndash E stands for electrical S-Glass ndash S stands for high silica contentS-Glass ndash S stands for high silica content
High thermal expansion coefficientHigh thermal expansion coefficient High fatigue strengthHigh fatigue strength
C-Glass ndash C stands for CorrosionC-Glass ndash C stands for Corrosion Used in Chemical applicationsUsed in Chemical applications Storage tanksStorage tanks
R-Glass ndash R stands for RigidR-Glass ndash R stands for Rigid Structural applicationsStructural applications
D-Glass ndash D stands for DielectricD-Glass ndash D stands for Dielectric Low dielectric constantsLow dielectric constants
A-Glass ndash A Stands for appearanceA-Glass ndash A Stands for appearance To improve surface appearanceTo improve surface appearance For ornamental worksFor ornamental works
E-CR Glass ndash E-CR stands for Electrical and E-CR Glass ndash E-CR stands for Electrical and corrosion resistancecorrosion resistance
AR Glass ndash AR stands for Alkali resistanceAR Glass ndash AR stands for Alkali resistance
bull Critical fiber length for effective stiffening amp strengthening
fiber length15
fdc
fiber diameter
shear strength offiber-matrix interface
fiber strength in tension
Efficiency fiber lengthEfficiency fiber length
(x)
7
fiber length 15
fdc
Shorter thicker fiber
fiber length 15
fdc
(x)
Longer thinner fiber
Poorer fiber efficiency Better fiber efficiency
Why are Fibers of a Thin Diameter
1 Thinner fiber has higher ultimate strength because less chance
for inherent flaws Similar phenomenon in metals and alloys(Strength of a thin wire can be higher than its bulk material)
2 For the same volume of fibers thinner fibers has largersurface area thus has stronger bond with matrix (The totalsurface area of fibers is inversely proportional to the
diameterof fibers)
3 Thinner fiber has larger flexibility ( 1(EI)) and therefore isable to be bent without breaking (Woven fabric performs canbe made before impregnated with polymer matrix)
Composite Strength Longitudinal LoadingComposite Strength Longitudinal Loading
Continuous fibersContinuous fibers - - Estimate fiber-reinforced composite Estimate fiber-reinforced composite strength for long continuous fibers in a matrixstrength for long continuous fibers in a matrix
Longitudinal deformationLongitudinal deformation
cc = = mmVVmm + + ffVVff butbut cc = = mm = = ff volume fractionvolume fraction isostrainisostrain
Ec = Em Vm + EfVf longitudinal (extensional)
modulus
mm
ff
m
f
VE
VE
F
F f = fiber
m = matrixC-composite
Remembering E = and note this model corresponds to the ldquoupper boundrdquo for particulate composites
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
TYPES OF GLASS FIBERTYPES OF GLASS FIBER E-Glass ndash E stands for electricalE-Glass ndash E stands for electrical S-Glass ndash S stands for high silica contentS-Glass ndash S stands for high silica content
High thermal expansion coefficientHigh thermal expansion coefficient High fatigue strengthHigh fatigue strength
C-Glass ndash C stands for CorrosionC-Glass ndash C stands for Corrosion Used in Chemical applicationsUsed in Chemical applications Storage tanksStorage tanks
R-Glass ndash R stands for RigidR-Glass ndash R stands for Rigid Structural applicationsStructural applications
D-Glass ndash D stands for DielectricD-Glass ndash D stands for Dielectric Low dielectric constantsLow dielectric constants
A-Glass ndash A Stands for appearanceA-Glass ndash A Stands for appearance To improve surface appearanceTo improve surface appearance For ornamental worksFor ornamental works
E-CR Glass ndash E-CR stands for Electrical and E-CR Glass ndash E-CR stands for Electrical and corrosion resistancecorrosion resistance
AR Glass ndash AR stands for Alkali resistanceAR Glass ndash AR stands for Alkali resistance
bull Critical fiber length for effective stiffening amp strengthening
fiber length15
fdc
fiber diameter
shear strength offiber-matrix interface
fiber strength in tension
Efficiency fiber lengthEfficiency fiber length
(x)
7
fiber length 15
fdc
Shorter thicker fiber
fiber length 15
fdc
(x)
Longer thinner fiber
Poorer fiber efficiency Better fiber efficiency
Why are Fibers of a Thin Diameter
1 Thinner fiber has higher ultimate strength because less chance
for inherent flaws Similar phenomenon in metals and alloys(Strength of a thin wire can be higher than its bulk material)
2 For the same volume of fibers thinner fibers has largersurface area thus has stronger bond with matrix (The totalsurface area of fibers is inversely proportional to the
diameterof fibers)
3 Thinner fiber has larger flexibility ( 1(EI)) and therefore isable to be bent without breaking (Woven fabric performs canbe made before impregnated with polymer matrix)
Composite Strength Longitudinal LoadingComposite Strength Longitudinal Loading
Continuous fibersContinuous fibers - - Estimate fiber-reinforced composite Estimate fiber-reinforced composite strength for long continuous fibers in a matrixstrength for long continuous fibers in a matrix
Longitudinal deformationLongitudinal deformation
cc = = mmVVmm + + ffVVff butbut cc = = mm = = ff volume fractionvolume fraction isostrainisostrain
Ec = Em Vm + EfVf longitudinal (extensional)
modulus
mm
ff
m
f
VE
VE
F
F f = fiber
m = matrixC-composite
Remembering E = and note this model corresponds to the ldquoupper boundrdquo for particulate composites
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
bull Critical fiber length for effective stiffening amp strengthening
fiber length15
fdc
fiber diameter
shear strength offiber-matrix interface
fiber strength in tension
Efficiency fiber lengthEfficiency fiber length
(x)
7
fiber length 15
fdc
Shorter thicker fiber
fiber length 15
fdc
(x)
Longer thinner fiber
Poorer fiber efficiency Better fiber efficiency
Why are Fibers of a Thin Diameter
1 Thinner fiber has higher ultimate strength because less chance
for inherent flaws Similar phenomenon in metals and alloys(Strength of a thin wire can be higher than its bulk material)
2 For the same volume of fibers thinner fibers has largersurface area thus has stronger bond with matrix (The totalsurface area of fibers is inversely proportional to the
diameterof fibers)
3 Thinner fiber has larger flexibility ( 1(EI)) and therefore isable to be bent without breaking (Woven fabric performs canbe made before impregnated with polymer matrix)
Composite Strength Longitudinal LoadingComposite Strength Longitudinal Loading
Continuous fibersContinuous fibers - - Estimate fiber-reinforced composite Estimate fiber-reinforced composite strength for long continuous fibers in a matrixstrength for long continuous fibers in a matrix
Longitudinal deformationLongitudinal deformation
cc = = mmVVmm + + ffVVff butbut cc = = mm = = ff volume fractionvolume fraction isostrainisostrain
Ec = Em Vm + EfVf longitudinal (extensional)
modulus
mm
ff
m
f
VE
VE
F
F f = fiber
m = matrixC-composite
Remembering E = and note this model corresponds to the ldquoupper boundrdquo for particulate composites
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Efficiency fiber lengthEfficiency fiber length
(x)
7
fiber length 15
fdc
Shorter thicker fiber
fiber length 15
fdc
(x)
Longer thinner fiber
Poorer fiber efficiency Better fiber efficiency
Why are Fibers of a Thin Diameter
1 Thinner fiber has higher ultimate strength because less chance
for inherent flaws Similar phenomenon in metals and alloys(Strength of a thin wire can be higher than its bulk material)
2 For the same volume of fibers thinner fibers has largersurface area thus has stronger bond with matrix (The totalsurface area of fibers is inversely proportional to the
diameterof fibers)
3 Thinner fiber has larger flexibility ( 1(EI)) and therefore isable to be bent without breaking (Woven fabric performs canbe made before impregnated with polymer matrix)
Composite Strength Longitudinal LoadingComposite Strength Longitudinal Loading
Continuous fibersContinuous fibers - - Estimate fiber-reinforced composite Estimate fiber-reinforced composite strength for long continuous fibers in a matrixstrength for long continuous fibers in a matrix
Longitudinal deformationLongitudinal deformation
cc = = mmVVmm + + ffVVff butbut cc = = mm = = ff volume fractionvolume fraction isostrainisostrain
Ec = Em Vm + EfVf longitudinal (extensional)
modulus
mm
ff
m
f
VE
VE
F
F f = fiber
m = matrixC-composite
Remembering E = and note this model corresponds to the ldquoupper boundrdquo for particulate composites
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Why are Fibers of a Thin Diameter
1 Thinner fiber has higher ultimate strength because less chance
for inherent flaws Similar phenomenon in metals and alloys(Strength of a thin wire can be higher than its bulk material)
2 For the same volume of fibers thinner fibers has largersurface area thus has stronger bond with matrix (The totalsurface area of fibers is inversely proportional to the
diameterof fibers)
3 Thinner fiber has larger flexibility ( 1(EI)) and therefore isable to be bent without breaking (Woven fabric performs canbe made before impregnated with polymer matrix)
Composite Strength Longitudinal LoadingComposite Strength Longitudinal Loading
Continuous fibersContinuous fibers - - Estimate fiber-reinforced composite Estimate fiber-reinforced composite strength for long continuous fibers in a matrixstrength for long continuous fibers in a matrix
Longitudinal deformationLongitudinal deformation
cc = = mmVVmm + + ffVVff butbut cc = = mm = = ff volume fractionvolume fraction isostrainisostrain
Ec = Em Vm + EfVf longitudinal (extensional)
modulus
mm
ff
m
f
VE
VE
F
F f = fiber
m = matrixC-composite
Remembering E = and note this model corresponds to the ldquoupper boundrdquo for particulate composites
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Composite Strength Longitudinal LoadingComposite Strength Longitudinal Loading
Continuous fibersContinuous fibers - - Estimate fiber-reinforced composite Estimate fiber-reinforced composite strength for long continuous fibers in a matrixstrength for long continuous fibers in a matrix
Longitudinal deformationLongitudinal deformation
cc = = mmVVmm + + ffVVff butbut cc = = mm = = ff volume fractionvolume fraction isostrainisostrain
Ec = Em Vm + EfVf longitudinal (extensional)
modulus
mm
ff
m
f
VE
VE
F
F f = fiber
m = matrixC-composite
Remembering E = and note this model corresponds to the ldquoupper boundrdquo for particulate composites
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Matrix Matrix RResinsesins
- - The resin or The resin or polymerpolymer is the ldquogluerdquo that is the ldquogluerdquo that
holds the composite togetherholds the composite together
-The primary functions of the resin are to -The primary functions of the resin are to transfer stress between the reinforcing fiberstransfer stress between the reinforcing fibers
Examples Polyester Epoxy Vinyl Ester PolyurethaneExamples Polyester Epoxy Vinyl Ester Polyurethane
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Transfer stresses between the fibers Provide a barrier against an adverse
environment Protect the surface of the fibers from
mechanical abrasion Determine inter-laminar shear strength Determine damage tolerance of composites Determine in-plane shear strength Determine the processibility of composites Determine heat resistance of composites
Role of Matrices in Composites
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Role of MatrixRole of Matrix The primary roles of the matrix alloy then are to provideefficient transfer of load to the fibers and to blunt cracks inthe event that fiber failure occurs and so the matrix alloy forcontinuously reinforced composites may be chosen more fortoughness than for strength
On this basis lower strength more ductile and tougher matrix alloys may be utilized in continuously reinforced
composites
For discontinuously reinforced composites the matrix may govern composite strength-Then the choice of matrix will be influenced by consideration of the required composite strength and higher strength matrix alloys may be required
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Functions of Matrix
Holds the fibres together Protects the fibres from environment
Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain
Enhances transverse properties of a laminate Improves impact and fracture resistance of a component
Helps to avoid propagation of crack growth through the fibres by providing alternate failure path along the interface between the fibres and the matrix
Carry inter-laminar shear
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Desired Properties of a Matrix
Reduced moisture absorption
Low shrinkage
Low coefficient of thermal expansion
Good flow characteristics so that it penetrates the fibre bundles completely and eliminates voids during the compactingcuring process
Must be elastic to transfer load to fibres
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Desired Properties of a Matrix
Reasonable strength modulus and elongation (elongationshould be greater than fibre)
Strength at elevated temperature (depending on application)
Low temperature capability (depending on application)
Excellent chemical resistance (depending on application)
Should be easily processable into the final composite shape
Dimensional stability (maintains its shape)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
FILLERSFILLERS
Control Compositesrsquo CostControl Compositesrsquo Cost Improved Mechanical PropertiesImproved Mechanical Properties Improved Chemical PropertiesImproved Chemical Properties Reduced Creep amp ShrinkageReduced Creep amp Shrinkage Low Tensile StrengthLow Tensile Strength Fire Retardant amp Chemical ResistantFire Retardant amp Chemical Resistant
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
TYPES OF FILLERTYPES OF FILLER Calcium CarbonateCalcium Carbonate KaolinKaolin Alumina TrihydrateAlumina Trihydrate Mica FeldsparMica Feldspar WollastoniteWollastonite Silica Talc GlassSilica Talc Glass
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
ADDITIVESADDITIVES
Improved Material PropertiesImproved Material Properties AestheticsAesthetics Enhanced WorkabilityEnhanced Workability Improved PerformanceImproved Performance
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
ADDITIVE TYPESADDITIVE TYPES
CatalystsCatalysts PromotersPromoters InhibitorsInhibitors Coloring DyesColoring Dyes Releasing AgentsReleasing Agents Antistatic AgentsAntistatic Agents Foaming AgentsFoaming Agents
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Composites OfferComposites Offer High Strength to weight ratioHigh Strength to weight ratioHigh Stiffness to weight ratioHigh Stiffness to weight ratioHigh Modulus to weight ratioHigh Modulus to weight ratioLight WeightLight WeightDirectional strength Directional strength Corrosion resistance Corrosion resistance Weather resistance Weather resistance Dimensional stability Dimensional stability -low thermal conductivity -low thermal conductivity
-low -low coefficient of thermal expansioncoefficient of thermal expansion Radar transparencyRadar transparencyNon-magnetic Non-magnetic High impact strength High impact strength High High dielectricdielectric strength (insulator) strength (insulator) Low maintenance Low maintenance Long term durability Long term durability Part consolidation Part consolidation Small to large part geometry possible Small to large part geometry possible Tailored surface finish Tailored surface finish Design FlexibilityDesign Flexibility
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Property comparisonProperty comparison
Material
Tensile modulus
(E) ( 2 mGN )
Tensile strength( u )
( 2 mGN )
Density ( )
( 3 cmg )
Specific modulus
( E )
Specific strength ( u )
E-Glass 724 53 254 285 138
Graphite 3900 21 190 2050 11
Boron 3850 28 263 1460 11
Kevlar ndash 49 130 28 150 87 187
Steel 210 034 ndash 21 78 269 0043 ndash
027
Aluminum alloys
70 014 ndash 062 27 259 0052 ndash
023
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
CompositeComposite strengthstrength depends on the following depends on the following factorsfactors
Inherent fiber Inherent fiber strength Fiber length strength Fiber length Number of flawsNumber of flaws
Fiber shape Fiber shape The bonding of the The bonding of the
fiber (equally stress fiber (equally stress distribution)distribution)
Voids Voids Moisture (coupling Moisture (coupling
agents)agents)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Classification of Composite MaterialsClassification of Composite Materials
11 Traditional compositesTraditional composites ndash composite materials ndash composite materials that occur in nature or have been produced by that occur in nature or have been produced by civilizations for many years civilizations for many years ExamplesExamples wood wood (cellulose fibers in lignin
matrix) concrete asphalt concrete asphalt
22 Synthetic compositesSynthetic composites - modern material - modern material systems normally associated with the systems normally associated with the manufacturing industries in which the manufacturing industries in which the components are first produced separately and components are first produced separately and then combined in a controlled way to achieve then combined in a controlled way to achieve the desired structure properties and part the desired structure properties and part geometry geometry
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Classification of Classification of SyntheticSynthetic Composites Composites Based on MatrixBased on Matrix
Matrix
Reinforcement
Metal Ceramic Polymer
Metal Powder metallurgy parts ndash combining immiscible metals
Cermets (ceramic-metal composite)
Brake pads
Ceramic Cermets TiC TiCNCemented carbides ndash used in toolsFiber-reinforced metals
SiC reinforced Al2O3 Tool materials
Fiberglass
Polymer Kevlar fibers in an epoxy matrix
Elemental (Carbon Boron etc)
Fiber reinforced metalsAuto partsaerospace
Rubber with carbon (tires)Boron Carbon reinforced plastics
MMCrsquos CMCrsquos PMCrsquosMetal Matrix Composites Ceramic Matrix Comprsquos Polymer Matrix Comprsquos
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Classification of Classification of SyntheticSynthetic Composites Composites Based on reinforcementsBased on reinforcements
There are five basic types of composite materials There are five basic types of composite materials FiberFiber particleparticle flakeflake laminarlaminar or layered and or layered and filledfilled composites composites
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
11 Fiber Composites Fiber Composites
In fiber composites the fibers reinforce along the line of their length Reinforcement may be mainly 1-D 2-D or 3-D Figure shows the three basic types of fiber orientation 1-D1-D gives gives maximummaximum strength strength
in one direction in one direction
2-D2-D gives strength in two gives strength in two directions directions
Isotropic gives strength Isotropic gives strength equally in all directions equally in all directions
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
22 Particle Composites Particle Composites ParticlesParticles usually reinforce a composite equally in all directions usually reinforce a composite equally in all directions
(called (called isotropicisotropic) ) PlasticsPlastics cermetscermets andand metals metals are examples of are examples of particlesparticles
ParticlesParticles used to strengthen a matrix do not do so in the same way as used to strengthen a matrix do not do so in the same way as fibers For one thing particles are not directional like fibers Spread at fibers For one thing particles are not directional like fibers Spread at random through out a matrix particles tend to reinforce in all random through out a matrix particles tend to reinforce in all directions equallydirections equally
CermetsCermets (1)(1) OxidendashBased cermetsOxidendashBased cermets(eg Combination of Al2O3 with Cr)(eg Combination of Al2O3 with Cr) (2)(2) CarbidendashBased CermetsCarbidendashBased Cermets(eg Tungstenndashcarbide titaniumndashcarbide)(eg Tungstenndashcarbide titaniumndashcarbide) Metalndashplastic particle compositesMetalndashplastic particle composites(eg Aluminum iron(eg Aluminum iron ampamp steel copper particles) steel copper particles) Metalndashinndashmetal Particle Composites and Metalndashinndashmetal Particle Composites and
Dispersion Hardened AlloysDispersion Hardened Alloys(eg Ceramicndashoxide particles)(eg Ceramicndashoxide particles)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
33 Flake Composites Flake Composites
FlakesFlakes because of their shape because of their shape usually reinforce in usually reinforce in 2-D2-D Two Two common flake materials are common flake materials are glassglass and and micamica (Also (Also aluminumaluminum is used as is used as metal flakes)metal flakes)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Flake CompositesFlake Composites
A A flakeflake composite consists of thin flat composite consists of thin flat flakes held together by a flakes held together by a binderbinder or placed or placed in a in a matrixmatrix Almost all flake composite Almost all flake composite matrixes are plastic resins The most matrixes are plastic resins The most important flake materials areimportant flake materials are
11 AluminumAluminum22 MicaMica33 GGlasslass
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Flake CompositesFlake Composites
Basically Basically flakesflakes will provide will provide Uniform mechanical properties in the Uniform mechanical properties in the
plane of the flakesplane of the flakes Higher strengthHigher strength Higher flexural modulus Higher flexural modulus Higher dielectric strength and heat Higher dielectric strength and heat
resistanceresistance Better resistance to penetration by Better resistance to penetration by
liquids and vaporliquids and vapor Lower costLower cost
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
44 Laminar Composites Laminar Composites
Laminar Composites are composed of layers of materials
held together by matrix
LaminarLaminar composites involve two or more composites involve two or more layers of the same or different layers of the same or different materials The layers can be arranged materials The layers can be arranged in different directions to give strength in different directions to give strength where neededwhere needed Speedboat hullsSpeedboat hulls are are among the very many products of this among the very many products of this
kindkind
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Laminar CompositesLaminar Composites We can divide We can divide laminar compositeslaminar composites into three basic types into three basic types Unreinforcedndashlayer compositesUnreinforcedndashlayer composites (1) (1) AllndashMetalAllndashMetal (a) Plated and coated metals (electrogalvanized (a) Plated and coated metals (electrogalvanized
steel ndash steel plated with zinc)steel ndash steel plated with zinc) (b) Clad metals (aluminumndashclad copperndashclad)(b) Clad metals (aluminumndashclad copperndashclad) (c) Multilayer metal laminates (tungsten beryllium)(c) Multilayer metal laminates (tungsten beryllium) (2) (2) MetalndashNonmetal MetalndashNonmetal (metal with plastic rubber etc)(metal with plastic rubber etc) (3) (3) Nonmetal Nonmetal (glassndashplastic laminates etc)(glassndashplastic laminates etc)
Reinforcedndashlayer compositesReinforcedndashlayer composites (laminae and laminates) (laminae and laminates)
Combined compositesCombined composites (reinforcedndashplastic laminates (reinforcedndashplastic laminates well bonded with steel aluminum copper rubber well bonded with steel aluminum copper rubber gold etc) gold etc)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Laminar CompositesLaminar Composites
Like all composites Like all composites laminar laminar compositescomposites aim at combining aim at combining constituents to produce properties constituents to produce properties that neither constituent alone would that neither constituent alone would have have
InIn laminar composites (Un laminar composites (Un reinforced) outer metal is not called reinforced) outer metal is not called a matrix but a a matrix but a faceface The inner metal The inner metal even if stronger is not called even if stronger is not called a a reinforcement It is called a reinforcement It is called a basebase
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Laminar CompositesLaminar Composites
A A laminalamina (laminae) (laminae) is any is any arrangement of arrangement of unidirectional unidirectional or or woven woven fibers in a matrix Usually fibers in a matrix Usually this arrangement is flat this arrangement is flat although it may be curved although it may be curved as in a shell as in a shell
A A laminatelaminate is a stack of is a stack of lamina arranged with their lamina arranged with their main reinforcement in main reinforcement in different directionsdifferent directions
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Laminate Sequence
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
55 Filled Composites Filled Composites
There are two types of There are two types of filledfilled composites In composites In oneone filler materials are filler materials are added to a normal composite result in added to a normal composite result in strengthening the composite and strengthening the composite and reducing weight The reducing weight The secondsecond type of type of filled composite consists of a skeletal filled composite consists of a skeletal 3-3-DD matrix holding a second material The matrix holding a second material The most widely used composites of this most widely used composites of this kind are kind are sandwich structuressandwich structures and and honeycombshoneycombs
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Sandwich Structure ndash Foam CoreSandwich Structure ndash Foam CoreConsists of a relatively thick core of low density Consists of a relatively thick core of low density
foam bonded on both faces to thin sheets of a foam bonded on both faces to thin sheets of a different material different material
Figure 97 ‑ Laminar composite structures (b) sandwich structure using foam core
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
Sandwich Structure ndash Honeycomb CoreSandwich Structure ndash Honeycomb Core An alternative to foam coreAn alternative to foam core Either foam or honeycomb achieves high Either foam or honeycomb achieves high
strength‑to‑weight and stiffness‑to‑weight ratiosstrength‑to‑weight and stiffness‑to‑weight ratios
Figure 97 ‑ Laminar composite structures (c) sandwich structure using honeycomb core
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)
66Combined CompositesCombined Composites It is possible to combine several different It is possible to combine several different
materials into a single composite It is also materials into a single composite It is also possible to combine several different possible to combine several different composites into a single product A good composites into a single product A good example is a example is a modern skimodern ski (combination of wood (combination of wood as natural fiber and layers as laminar as natural fiber and layers as laminar composites)composites)