Post on 06-Feb-2018
MATERIALS I Professor Catalin POPA, Dr.Eng.
REFERENCES
http://www.sim.utcluj.ro/wp/ → Download cursuri: Popa Catalin; password = PopaCatalin
• H. Colan, V. C. Cândea, s.a. - Ştiinţa materialelor Vol. 1, U.T. Press 2013;
• V. Cândea, C. Popa, T. Marcu - Atlas, structuri metalografice, U.T.Press 2012;
• V.Candea, C.Popa, N.Sechel, V.Buharu – Clasificarea si simbolizarea
aliajelor feroase si neferoase, UTPress, 2010;
• C. Popa, V. Cândea, V. Şimon, D. Lucaciu, O. Rotaru - Ştiinţa biomaterialelor.
Biomateriale metalice, U.T.Press 2008;
• V.Candea, C.Popa – Initiere in Stiinta Metalelor, Bucuresti, Ed.Vega 1995;
• H.Colan, s.a. – Studiul Metalelor, Bucuresti, EDP 1983;
• D.Askeland – Introduction to Materials Science, J.Wiley & Sons, 1993
• C. Paul – Materials Science and Engineering, ASM 1991
• W. D. Callister, D. G. Rethwisch - Fundamentals of materials science and
engineering, John Wiley and Sons, 2013;
• W. F. Hosford, Elementary materials science , ASM International 2013;
• D.L. Chung - Composite materials: science and applications : functional
materials for modern technologies, Springer 2003;
INTRODUCTION TO MATERIALS SCIENCE
Materials Science : Branch of Technical Sciences that studies the
chemical composition
structure ratio for engineering materials
properties
• Age : as a science, after 1840
(optical microscope)
Nature / chemical
composition
of the material
Structure:
macrostructure (1-50x)
microstructure (50-1500x)
atoms scale (0.1 nm)
Manufacturing
technology
Properties chemical
physical
mechanical
USES
Content of the lecture course Introduction to Materials Science. Classes of engineering materials
Properties of materials.
Corrosion resistance. Corrosion protection methods.
Interatomic bonding. Crystalline and amorphous structure.
Crystallisation of metals.
Plastic deformation of metals.
Cold hardening, recrystallisation. Fracture.
Alloys theory.
Fe-C diagram. Unalloyed steels. Foundry cast irons.
Heat treatments.
Alloy steels.
Non-ferrous alloys: Al and Cu based alloys.
Polymers.
Ceramics.
Composite materials.
Properties of materials
• Mechanical
• Physical
• Chemical
Technological Machinability
Weldability
Castability
[ Formability ]
…
→ functional properties
Materials Processing
- Casting -
Materials Processing
- Plastic forming -
Forging (hot)
Materials Processing
- Plastic forming -
Rolling (hot)
Materials Processing
- Plastic forming -
Wire drawing
Materials Processing
- Plastic forming -
Deep drawing
Materials Processing
- Machining-
Turning
Materials Processing
- Welding -
Electric arc welding
Materials Processing - Powder aggregation-
Materials Processing - Additive manufacturing-
Effect of structure upon properties
Ex.: graphite
Effect of structure upon properties
Ex.: graphite fibers
Effect of structure upon properties
Ex.: graphite fibers
Effect of structure upon properties
Ex.: graphite fibers
Effect of structure upon properties
Ex.: graphite nanotubes
Effect of structure upon properties
Ex.: graphene
Extremely light: surface of a football field ̴ 1g
The strongest material:
More than 130 times stronger than a high strength steel
CLASSES OF MATERIALS
A. Origin
natural (bone, rock, wood, proteins, etc.)
synthesis
Spider silk
CLASSES OF MATERIALS
B – NATURE
• Metals
• Ceramics
• Polymers
• Multimaterials
• Composites
• Multi-layered materials
C – USE
• Structural
• Functional
• Automotive
• Aerospace
• Electronics
• Optoelectronics
• Biomaterials
• Energy storage
• Sports equipment
….
METALS
• 89 in periodic table –electropositive character,
common energy levels between conduction /
valence bands;
• Practically not pure metals - alloys
contain other elements, based on (a) metal
• Most used – Fe, Al, Cu, Mg, Zn, Ti, Ni, ...
• Metallic state: electric conductors, resistivity
increases with temperature; thermal conductors;
metallic shine; thermo-electronic effect;
CERAMICS
Definition: Materials containing anorganic compounds, without metallic character.
General: contain metallic elements, combined with strong non-metallic elements (O, Cl, F, ....)
Exceptions: C, B
Classification: A. Classic (porcelain, clay, usual glass,....)
Engineering (alumina, zirconia, TiN,...)
B. Amorphous – glasses
Crystalline
POLYMERS
Definition: Macro-molecular organic materials, made of long atom chains
(C + H, O, N)
(M = 104 – 106)
Classification: thermoplasts (plastics)
thermosets
elastomers
COMPOSITES
Constituted of: matrix (majority of volume, maintains part’s shape)
+ reinforcing constituent
Classification: A. Matrix material Polimeric (Organic)
Metallic
Ceramic
B. Shape of reinforcing constituent
Fibres long short
Tissues
Particles
MULTILAYERED MATERIALS
Made of layers of different materials, strongly bonded, that
behave as a single material
Example:
skis
PROPERTIES OF MATERIALS
PHYSICAL PROPERTIES
Density metals: Li(0.53) …Mg(1.74)…Al(2.7)…Fe(7.8)… Os(22.5) [kg/m3] ceramics: Grafit(2.28)….WC(13-15.3)
polymers: 0.83 – 2.15 values related to water [kg/m3 x 10-3]
Electrical conductivity σ Metals: conductors Ag – Cu – Au – Al - ... – Mn Ceramics: insulators (in general); exceptions: C, semiconductors, superconductors Polymers: insulators (in general) exceptions: conductive polymers Thermal conductivity λ = thermal energy transferred through the material to increase the
temperature with 1K at a distance of 1m for a time of 1s; Similar to σ (in general) metals: conductors Au – Cu – Ag – Al - .... ceramics, polymers: insulators
Vm /
PHYSICAL PROPERTIES
Thermal expansion coefficient α (approx.)
In general: polymers / metals > ceramics
exceptions: invar alloys
Magnetic properties χm = magnetic susceptibility;
μ = magnetic permeability;
Materials: dia-magnetic (χm < 0) (Cu, Ag, Au, ...)
para-magnetic (χm >0, mic) (Feγ, Al, Ti, ...)
ferro-magnetic (χm >>0)
(Feα, Ni, Co, under Curie temperature)
tll 10
Glossary • Casting = turnare; • Plastic forming = deformare plastica (proces); • Forging = forjare; • Rolling = laminare; • Deep drawing = ambutisare; • Wire drawing = trefilare; • Welding = sudare; • Machining = aschiere; • Turning = strunjire; • Composite = compozit; • Part = piesa; • Strength = rezistenta (mecanica); • Stiffness = rigiditate; • Toughness = tenacitate; • Alloy = aliaj; • Steel = otel; • Multilayered material = multimaterial stratificat; • Engineering ceramic = ceramica tehnica • Thermoplast = termoplast; • Thermoset = termorigid; • Reinforcing constituent = constituent de armare;