Hindawi Publishing CorporationJournal of Powder TechnologyVolume 2013 Article ID 183713 14 pageshttpdxdoiorg1011552013183713

Research ArticleInvestigations into Deformation Characteristics duringOpen-Die Forging of SiCp Reinforced Aluminium MetalMatrix Composites

Deep Verma1 P Chandrasekhar1 S Singh1 and S Kar2

1 School of Mechanical Engineering KIIT University Bhubaneswar 751024 Odisha India2 Research Scholar IIT Kharagpur Paschim Midnapur West Bengal 721302 India

Correspondence should be addressed to P Chandrasekhar chandrasekhar34gmailcom

Received 27 March 2013 Accepted 23 August 2013

Academic Editor Thierry Barriere

Copyright copy 2013 Deep Verma et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

The deformation characteristics during open-die forging of silicon carbide particulate reinforced aluminium metal matrixcomposites (SiC119901 AMC) at cold conditions are investigated The material was fabricated by liquid stir casting method in whichpreheated SiC particles were mixed with molten LM6 aluminium casting alloy and casted in the silicon mould Finally preformsobtained weremachined in required dimensions Two separate cases of deformation that is open-die forging of solid disc and solidrectangular preforms were considered Both upper bound theoretical analysis and experimental investigations were performedfollowed by finite element simulation using DEFORM considering composite interfacial friction law barreling of preform verticalsides and inertia effects that is effect of die velocity on various deformation characteristics like effective stress strain strainrate forging load energy dissipations and height reduction Results have been presented graphically and critically investigatedto evaluate the concurrence among theoretical experimental and finite element based computational findings

1 Introduction

Metal matrix composite (MMC) as hybrid materials hasattracted attention of many researchers in recent yearsMMCs provide significantly enhanced properties over con-ventional monolithic materials for example higher strengthstiffness hardness elastic modulus and wear resistanceand thus may be subjected to various forming operationslike rolling extrusion forging and so forth to manufac-ture numerous engineering components Sulaiman et aland Murashkevich et al [1 2] Automobile pistons valvescylinder liners piston rings connecting rods crankshaftgear parts suspension arms turbocharger impellers guidevanes in gas turbines ventral fins and fuel-access coverdoors in military aircrafts rotor blade sleeves in helicoptersflight-control hydraulic manifolds brake discs of transportvehicles bicycle frames and so forth are the most commonengineering applications seen as cited by Kainer et al andMatejka et al [3 4] Various composite products tailored-made to the demands of different industrial applications by

suitable combinations of matrix materials reinforcementsand processing routes were also reported by Surappa [5]The present paper is an attempt to investigate the variousdeformation characteristics during open-die forging of SiCpreinforced aluminium metal matrix composites (AMC) Theobjective was to synthesize ametalmatrix compositematerialand further process it mechanically to manufacture engi-neering components with superior mechanical properties ascompared to individual elements

Investigations during mechanical processing of conven-tional monolithic materials have been reported from variousaspects but very little work has been reported on the forgingof metal matrix composites The production of metal matrixcomposites from aluminium and copper alloy chips throughhot extrusion process is demonstrated by Gronostajski et aland Kaczmar et al [6 7] A numerical mathematical modelformulated for the prediction of the stress during forgingof AMC and possible damage zones were predicted basedon the simple relationship for generation and relaxation ofinternal stresses by Roberts et al [8] The effect of forging by

2 Journal of Powder Technology

temperature and heat treatment on themechanical propertiesof Al-Cu metal matrix composites were investigated and itwas found that conditions of heat treatment have an essentialinfluence on their mechanical properties as reported byszczepanik et al [9] Extensive studies have been carriedout on the mechanical properties like tensile strength yieldstrength hardness and ductility of SiC particle reinforcedaluminium metal matrix composites Chung and Lau [10]The closed-die hot forging of aluminium-silicon alloy (Al-5 Si-02 Mg) with different volume fractions of SiCparticulate and microstructure as well as the mechanicalproperties of the matrix alloy as-cast state and after theforging operation was critically investigated by Ozdemiret al [11] The forging behavior of 2124SiCp aluminiumcomposites having 26 vol of reinforcements both at roomtemperature and elevated temperature been studied andfurther tensile testing microphotographic study was per-formed to investigate the mechanism controlling the frac-ture of specimens by Badini [12] Youngrsquos modulus tensilestrength strain-to-fracture fatigue strength of sinter-forgedSiC particle reinforced matrix composites and the fatiguefractography were conducted and it was found that Fe-rich inclusions were extremely detrimental to the fatiguelife of the composites which were investigated by Chawlaet al [13] The isothermal forging of 2618 aluminium alloyreinforced with 20 vol of Al2O3 particles and reportedon the recrystallization behavior of composites by meansof deformation efficiency was carried out by Cavaliere andEvangelista [14] The effect of forging temperature on themicrostructure and mechanical properties of in situ TiTiCmatrix composites by performing hot forging experimentswas reported by Ma et al [15] Investigations on the cold-forging aspects of iron and aluminiummetal alloy compositesfabricated by powder metallurgy route were carried out andtheir behaviour against the relative density and barrel radiushas been systematically analyzed by Narayanasamy et al[16] The forging of AA618Al2O3 particulate compositeshaving 20 vol of reinforcements and studying the effects offormability characteristics on the microstructure and tensileproperties of composites were performed by Ceschini et al[17] The combination of forging and extrusion process onSiCpAZ91 magnesium matrix composites fabricated by stircasting technology and investigated the effect of deforma-tion characteristics on the yield stress and ultimate tensilestrength of material by Wu et al [18] Formability analysis ofaluminium metal matrix composite specimen manufacturedthrough PM route was analyzed by finite element methodMaterial factors like volume fraction of reinforcements shapeand size of reinforced particles compaction pressure andsintering temperature along with process parameters like die-wall friction friction between particles matrix powder andforming limits were investigated by Ramesh and Senthil-velan [19] Preliminary experimental investigations into theformability and machinability analysis of SiCp reinforcedaluminium metal matrix composites were carried out bySutradhar et al [20] Though Singh et al Jha et al andChandrasekhar et al [21ndash23] reported the analysis of dynamiceffects during open-die forging of sinteredmaterials no workhas been reported to analyze these effects that is effect of

die velocity on various deformation characteristics duringmechanical processing of metal matrix composites

In the present work various deformation characteristicslike effective stress effective strain effective strain rate flowof material strain rates energy dissipations and die loadsduring open-die forging of SiCp AMCs at cold conditionshave been analyzed Experimental investigations and upperbound theoretical analysis along with finite element simula-tion (FEM) of forging of SiCp AMC have been performedThe SiCp AMC has been prepared by stir casting methodand preforms of required dimensions were machined fromthe cast specimen The present investigations consideredheterogeneous deformation due to barreling of vertical sidescomposite die-workpiece interfacial friction conditions andinertia effects It is expected that the present work will beuseful for assessment of various deformation characteristicsduring mechanical processing of AMCs

2 Experimental Investigations

In general metal matrix composite material consists ofmetal matrix and reinforcements where metal matrix mainfunction is to transfer and distribute load to reinforcementswhich are commonly boron silicon carbide or graphiteparticles In the present research work aluminium metalmatrix composite has been produced by liquid metal stircasting process from LM6 aluminium casting alloy (havinghigh silicon content of 10ndash13wt) with SiC particles as rein-forcements with an idea to synthesize a composite materialwith superiormechanical properties Liquidmetal stir castingprocess was preferred due to simplicity in operation andlower processing cost which was also established by Mithunand Devaraj [24] in their research work They fabricatedaluminum based composite material with aluminum as basealloy (AA4430) and silicon carbide and magnesium oxide asreinforcement materials through stir casting method It wasfound out that although aluminummetal in its pure form hasexcellent mechanical properties its strength is too low to beused as functional component and hence its properties needto be modified to increase its capabilities

In the present case also SiC particles have been added pri-marily to increase the strength and stiffness of the aluminiummatrix During liquid stir casting process LM6 aluminiumcasting alloy was melted in a clay-graphite crucible usingan electric resistance furnace and 5wt of magnesiumwas added to the molten metal to have strong bondingbetween matrix metal and reinforcement particles Additionofmagnesium decreases the surface energy andwetting angleas well as increases the flowability of the molten metal TheSiC powder particles havingmesh size +400120583were preheatedin the temperature range of 850 to 900∘C and were addedto the molten metal The mixture was stirred briskly usinga mechanical impeller installed on the electric resistancefurnace (refer to Figure 1) at a speed of about 500 rpmand an optimum mixing temperature of about 720∘C wasmaintained Two groups of AMC samples having 5wt and13wt SiCp were prepared by this manufacturing route Themoltenmixturewas immediately poured into the silicamould

Journal of Powder Technology 3

Figure 1 Electric resistance furnace with mechanical impeller(stirrer)

Table 1 Specifications of 5 wt and 13wt SiCp AMC preforms

Preform shape DimensionsSolid disc preforms 1198630 = 15mm1198670 = 10mm

Solid rectangular preforms 1198710 = 20mm 1198610 = 10mm1198670 = 10mm

and subsequently cooled to the room temperatureThemouldwas prepared prior to casting using core sand bentonitecharcoal powder and parting sand Parting gate structurewas preferred for simplicity and alignment as well as sealingof the mould was done with utmost care to decrease thechance of mould erosion air entrapment run out and drossformation The cast was obtained by breaking the core andgently tapping it after cooling which was later machined toobtain preformswith desired dimensions (refer to Table 1) forfurther experiments

The cold-forging experiments on SiCp AMC preformswere conducted at room temperature employing hydraulicpress havingmaximum load capacity of 200 tonswith station-ary upper die platen till the onset of fracture The SiCp AMCpreforms placed on the lower die platen were compressedand data for deformation and corresponding forging loadwere recorded from the digital display of data acquisitionsystem of the press In all the experiment run deformationswere carried out under dry interfacial friction conditions(without any lubricant) till the onset of fracture that ismaximum forgeability at room temperatureThe engineeringstress and strain data were calculated from the correspondingrecorded data of forging load and deformation and were lateralso uploaded in the material library of DEFORM softwareas shown in Figure 2 for further FEM analysis Figures 3 and4 show the solid disc and solid rectangular preforms beforeand after open-die forging respectively for both 5wt and13wt SiCp reinforcements It can be seen that for the samedeformation conditions AMC preforms having higher wt

of SiCp were observed to have less forgeability and thosepreform surfaces showed severe cracking at equatorial bulgedregionsThe photomicrographs for SiCp AMC preforms wereobtained at 500X to illustrate the distribution of SiCp rein-forcements within the aluminium metal matrix As evidentfrom Figure 5 13 wt SiCp AMC is having higher density ofsilicon carbides particulate distribution as compared to 5wtSiCp AMC

3 Theoretical Analysis

The present theoretical analysis based on upper boundapproach for open-die forging of SiCp AMC solid discand solid rectangular preforms has been performed usingaxisymmetric and plane strain conditions of deformationrespectively The following assumptions were consideredduring the present analysis

(i) Die platens are incompressible rigid and parallel(ii) Deformation is homogeneous and insensitive to

hydrostatic stress component and hence von-Mises yieldcriterion was considered which is given as

120590119900 = lfloorradic311986910158402rfloor (1)

(iii) Die-preform interfacial friction conditions are com-posite in nature including both sliding and sticking frictionswhere sticking friction is a function of adhesion factorAccording to Downey et al [25] such composite interfacialfriction laws can be given mathematically as

solid disc preform

120591 = 120583119875av + 1206010 [1 minus (119877119898 minus 119877

1198991198770

)] (2)

solid rectangle preform

120591 = 120583119875av + 1206010 [1 minus (119861119898 minus 119861

1198991198610

)] (3)

Sticking zone distances ldquo119877119898rdquo and ldquo119861119898rdquo can be approximatedby modified Rooks [26] equations as

119877119898 = 1198770 minus1198670

2120583effln( 1

120583effradic3) (4)

119861119898 = 1198610 minus1198670

2120583effln( 1

120583effradic3) (5)

(iv) Compatibility equations have been derived fromvolume constancy principle based on the work done by Jhaet al [27] as

solid disc preform

120576119903119903 + 120576120579120579 + 120576119911119911 = 0 (6)

solid rectangle preform

120576119909119909 + 120576119910119910 + 120576119911119911 = 0 (7)

4 Journal of Powder Technology

Figure 2 Flow stress curve of SiCp AMC uploaded in DEFORM software

5wt13 wt

(a) Before forging

13 wt5wt

(b) After forging

Figure 3 Solid disc SiCp AMC preforms

(v) Bulging of workpiece vertical sides has been consid-ered by including a barreling parameter ldquo120573rdquo in the kinemati-cally admissible exponential velocity fields

(vi) Redundant energy dissipation due to velocity discon-tinuities has been neglected

(vii) Quarter portion of the preform has been consideredduring the analysis due to symmetry along the horizontal andvertical axes

(viii) Circumferential flow of preform vertical sides hasbeen neglected in case of solid disc preforms and deforma-tion conditions are essentially axisymmetric in nature

(ix) Lateral flow of preform vertical sides in the longitudi-nal direction has been neglected in case of solid rectangularpreforms and deformation is essentially plane-strain innature

Kinematically admissible velocity field and correspond-ing strain rates were formulated for both cases separatelysatisfying compatibility conditions and flow rule (refer to

Appendix) According to Avitzur [28] total energy dissi-pations during plastic deformation based on upper boundapproach are given as

119869lowast= 119882119894 +119882119891 +119882119886

=2

radic3

1205900 int

V

radic1

2120576119894119895 120576119894119895

119889119881 + int

119878119879

120591 |Δ119880| 119889119904 + int

119881

120588 (119886119894119880119894) 119889119881

(8)

31 Solid Disc Preform Internal energy dissipation ldquo119882119894rdquo aftersubstituting strain rates in (8) integrating and simplifying isgiven as

119882119894 = [

120587radic31205732119867012059001198770119890

minus1205732(1 + 120573

212)119880

32 Sin ℎ(1205734)2] (9)

Journal of Powder Technology 5

13wt5wt

(a) Before forging

13wt5wt

(b) After forging

Figure 4 Solid rectangular SiCp AMC preforms

(a) 5 wt SiCp (b) 13 wt SiCp

Figure 5 Photomicrograph of SiCp AMC preforms

Frictional shear energy dissipation at die-preform interfaceldquo119882119891rdquo after substituting frictional stress equation and velocityfield in (8) integrating and simplifying is given as

119882119891 = [2120587120583120573119877

3

0119890minus1205732

1206010119880

1198670 (1 minus 119890minus1205732

)] [(

119875av1206010

) + (1 +2

3119899minus119877119898

1198991198770

)]

(10)

Energy dissipation due to inertia forces ldquo119882119886rdquo after substi-tuting velocity field and corresponding strain rates in (1)integrating and simplifying is given as

119882119886 = [1205871205731205880119877

2

01198803

3 (1 minus 119890minus1205732

)]

times [

(1 + 119890minus1205732

+ 120573119890minus31205732

)

2]

+ [(1198772

0

311986720

)(31198670

1198770

minus 2) (1 + 119890minus1205732

+ 119890minus120573)]

+[

1205731198770 (1 + 119890minus1205732

minus 3119890minus31205732

)

(1 minus 119890minus1205732

)31198802

]

(11)

32 Solid Rectangular Preform Internal energy dissipationldquo119882119894rdquo after substituting strain rates in (8) integrating andsimplifying is given as

119882119894 = [

radic312057321198612

01205900119880

48 (1 minus 119890minus1205732

)]

times [(41198672

0

11986120

) + 1205732(1 +

81198670

12057321198610

) (1 minus 119890minus1205732

)]

(12)

Frictional shear energy dissipation at die-preform interfaceldquo119882119891rdquo after substituting frictional stress equation and velocityfield in (8) integrating and simplifying is given as

119882119891 = [1205831205731198613

0119890minus1205732

1206010119880

81198670 (1 minus 119890minus1205732

)] [(

119875av1206010

) + (1 +1

3119899minus119861119898

1198991198610

)]

(13)

Energy dissipation due to inertia forces ldquo119882119886rdquo after substi-tuting velocity field and corresponding strain rates in (8)integrating and simplifying is given as

119882119886 = [120573412058801198672

01198803

(1 minus 119890minus1205732

)2]

times [

(2 + 119890minus1205732

+ 119890minus120573)

1205733

]

+ (1 + 119890minus1205732

)(2

1205732minus1198612

0

11986720

) + [1198610119890minus120573

1205731198802

]

(14)

6 Journal of Powder Technology

2D model 3D model

(a) Solid disc preforms

2D model 3D model

(b) Solid rectangular preforms

Figure 6 Modeling of SiCp AMC preforms

The average forging load for both cases was computed sepa-rately by substituting the above energy dissipation equationsin (15)

119865av = 4119869lowast(119880)minus1119860av (15)

Dynamic effects that is effect of die velocity on relativemagnitudes of various energy dissipations involved duringopen-die forging of SiCp AMC preforms are illustrated usinginertia factor ldquo120585rdquo which is defined as the ratio of inertiaenergy dissipated to total energy supplied by die platen duringdeformation and given as

120585 () = (119882119886

119869) 100 (16)

4 Finite Element Analysis

Finite element simulation of open-die forging of SiCp AMCpreforms has been performed using DEFORM-3D which isbased on the implicit Lagrangian finite element code In thepresent solution preform mesh deforms under the die loadand elasticity of the material has been neglected as plasticstrains outweigh elastic strains and material behaves like anelastic-viscoplastic material as stated by Kobayashi et al [29]

The stress-strain curve of type120590 = 119886120576119887MPa for SiCpAMC

material was uploaded in the material library of software asdescribed in the previous section The material properties ofSiCp AMC used in the present analysis are given in Table 2The geometry of die platens was generated in DEFORM andthe die platens were modeled as rigid parallel and flat bodieswith plastic preform placed in between them The geometryof preforms was generated using CATIA using part designmoduleworkbench and data was imported to DEFORM inform of STL files Figures 6(a) and 6(b) show the 2D and3D models of the solid disc and solid rectangular preformsrespectively The composite frictional law was considered tomodel the interfacial frictional conditions represented bysuitable composite interfacial frictional shear stress (referto (3) and (4)) Tetrahedral elements were used to meshthe preforms and small meshes were generated close tothe edges of preforms in order to better scope the forgingprocess The complete forging simulation was performedin 120 steps having time for movement of die platens ineach step equal to 0064 seconds The deformation criterion

Table 2 Material property of stir-casted SiCp AMC

Material property 5wt SiCp 13 wt SiCp

Poissonrsquos ratio gt033 gt033Ultimate tensile strength (MPA) 112 138Hardness (HRC) 54 62Stress-strain relationship 120590 = 119886120576

119887MPa

consideredwasmaximum forgeability of SiCpAMCpreformsat room temperature which was experimentally found to beabout 49 and 47 respectively for 5 wt and 13wt SiCpreinforced AMC preforms

5 Results and Discussions

Figure 7 shows that the maximum deformation of preformsis about 47ndash49 at room temperature under dry interfacialfriction conditions and preforms start cracking at maximumstress of about 14ndash15 GPa The stress required to producethe same amount of strain is higher in case of 13 wtSiCp preforms as well as higher in case of solid rectangularpreformsThis indicates that the increases in the perecentageof SiCp increases the stress required to deform the preformsAlso solid rectangular preforms exhibit higher constraintdeformation due to existence of sharp corners as comparedto solid disc preforms

Figure 8 shows that the percentage of height reductionof preform increases gradually during the initial phase ofdeformation and only after forging load attains a magnitudeof about 5ndash7 tons it increases exponentially This continuestill cracks start appearing on the outer surfaces of preformsthat is maximum forgeability of preforms In both axisym-metric and plane strain deformations the height reductionfor preforms having 5wt SiCp is found to be more ascompared to 13 wt SiCp preforms which indicates that thepercentage of increase in SiCp decreases the forgeability ofpreforms Also the load requirements are higher for thesame amount of deformation in case of solid disc preformsindicating better flow of material The experimental data arefound to be in close agreement with the theoretical oneswhich validates the present upper bound approach used tosolve the forging problems considered in the present paper

Journal of Powder Technology 7

00 01 02 03 04 0500

02

04

06

08

10

12

14

16

Solid disc preformSolid rectangular preform

Engineering strain

Engi

neer

ing

stres

s (G

Pa)

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

5wt SiCp13wt SiCp

Figure 7 Experimental variation of engineering stress (GPa) withengineering strain (mmmm)

0 3 6 9 12 15 18 210

10

20

30

40

50

Forging load (tons)

Hei

ght r

educ

tion

()

Solid rectangular preform

Solid disc preform

R0 = 10mm H0 = 10mm L0 = 20mmB0 = 10mm Uav = 01ms 120583eff = 05

Experimental dataExperimental data

5wt SiCp

13wt SiCp

Figure 8 Experimental and theoretical variations of height reduc-tion () with forging load (tons)

Figure 9 shows the variation of strain rate (mmmmsec) with forging load (tons) for SiCp AMC preforms Asevident from the figure maximum strain rate of magnitude0024 secminus1 is being observed at forging load of about 20tons for both 5wt and 13wt SiCp Initially strain ratesare higher for solid rectangular preforms but after theload attains a magnitude of about 10 tons strain rates for13 wt SiCp preforms are higher irrespective of the shape ofpreforms Also at the end of forging operations strain ratesare found to decrease slightly after attaining the highest value

0 5 10 15 20 25 300000

0005

0010

0015

0020

0025

Forging load (Tons)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

Stra

in ra

te (s

minus1)

5wt SiCp

13wt SiCp

Figure 9 Experimental variation of strain rate (mmmm sec) withforging load (tons)

These two behaviors are attributed due to the consolidationof SiCp particles within the AMC preforms during the end offorging operation It can be concluded that the effect of SiCpparticles on stress strain and strain rate is predominant upto 40 of height reduction at forging load of about 20 tonsand thereafter these particles consolidate within the matrixand hence they least influence the forging characteristics

It can be seen from Figure 10 that the energy dissipationincreases with the increase in the forging load and defor-mation The total energy requirement for deformation ofAMC preforms having higher SiCp is found to be higherdue to higher strength of material and is also higher if theprocess is carried at higher die acceleration leading to higherinertia energy dissipation (refer to (11) and (14)) Also energyrequirements are higher for solid rectangular preforms ascompared to solid disc preforms due to more constraintdeformation in the former case

The variation of inertia factor with die velocity for SiCpAMC preforms is shown in Figure 11 It is clearly evidentthat inertia factor increases exponentially with increase in thedie velocity and is higher for higher die acceleration in solidrectangular preforms Also it can be noticed that proportionof inertia energy can be as high as 30 of the total energydissipation and hence cannot be neglected during the presentinvestigation

Figure 12 shows that both axial and radial strains increaseexponentially with increases in the forging load Also thecorresponding values of axial strains are higher than radialstrains for same forging load and higher percentage of SiCpIt also depicts the measure of Poissonrsquos ratio that is ratio ofradial strain to axial strain for present SiCp AMCmaterial

Figure 13 shows the effective stress (MPa) distribution onSiCp AMC preforms It is clearly evident that magnitudesof effective stresses are higher in 13 wt SiCp preforms ascompared to 5wt SiCp preforms in the corresponding

8 Journal of Powder Technology

0 3 6 9 12 15 18 210

2

4

6

8

10

12

Average forging load (tons)

Tota

l ene

rgy

diss

ipat

ion

(kJ)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav Uav = 01ms 120583eff = 05

13wt SiCp accel = 025mms2

5wt SiCp accel = 025mms213wt SiCp accel = 01mms2

5wt SiCp accel = 01mms2

Figure 10Theoretical variation of total energy dissipation (kJ) withaverage forging load (tons)

0 4 8 12 16 20 240

5

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Die velocity (mms)

Iner

tia fa

ctor

()

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav 120583eff = 05 SiCp = 5wt

Accel = 025mms2Accel = 005mms2Accel = 010mms2

Figure 11Theoretical variation of inertia factor ()with die velocity(mms)

regions The edges are subjected to higher stresses whereasthe centremost regions are having lower stresses of magni-tude about 150MPa and 300MPa for solid disc and solidrectangular preforms respectively This indicates that as thepercentage of SiCp increases stress also increases due toincrease in the strength of preforms

Figure 14 shows the effective strain (mmmm) distribu-tion on SiCp AMC preforms It can be seen that the major

00010203040506

5 40Average forging load (tons)

Solid rectangular preformSolid disc preform

10 20 30

R0 = 10mm H0 = 10mm

L0 = 20mm B0 = 10mm

120573 = 04 1206010 = 030 Pav 120583eff = 05

minus05

minus06

minus04

minus02

minus03

minus01

Axi

al st

rain

998400 120576998400 z

Radi

al st

rain

998400 120576998400 r

13 wt SiCp5 wt SiCp

Figure 12Theoretical variation of radial strain and axial strain withaverage forging load (tons)

portion of preform is subjected to strain in the order 03ndash06 magnitude except at the edges The strains are higher in5wt SiCp preforms as compared to 13 wt SiCp preformswhich indicate that ductility of 5 wt SiCp is higher In case of5 wt SiCp preforms the edges are subjected to severe strainof magnitude about 07ndash09 which leads to the fracture ofvertical surfaces and is also confirmed from Figure 3 In thiscase no appreciable variation in the strain distribution hasbeen observed for preforms having 13 wt and 5wt SiCpAlso the strains at the central region of preform are low andeventually almost zero at the centermost regions near to theupper and bottom flat surfaces The dissected section alsoreveals that the variation of strain in the central region isin the form of an inverted cone This confirms the presenceof sticking friction zone at those regions which confirmsand validates the variable interfacial composite friction lawconsidered during the present theoretical analysis

The distribution of effective strain rate (mmmm-sec)on SiCp AMC preforms is shown in Figure 15 It can beclearly seen that the major portion of solid disc preforms issubjected to strain rate of about 2mmmm-sec and only theedges are subjected to higher strain rates in the order 32ndash35mmmm-sec In case of solid rectangular preforms theedges are subjected to strain rate of 25ndash29mmmm-secThesolid disc preforms are having higher strain rates as comparedto solid rectangular preforms indicating better metal flow inthe former case as well as presence of constraint deformationin case of solid rectangular preforms

The velocity (mmsec) distribution on SiCp AMC pre-forms is shown in Figure 16 It can be observed that soliddisc and solid rectangular preforms are subjected to the high-est flow velocity of about 10ndash13mmsec and 15ndash17mmsecrespectively Also the outer regions of preform are havinghigher flow velocity as compared to the inner regions whichis in close agreement with the composite interfacial friction

Journal of Powder Technology 9

995

871

746

622

498

373

249

124

0000

MinMax

1140

1000

857

715

572

429

286

143

00006891140

(a) 5 wt SiCp

1010

885

759

632

506

379

253

126

0000

MinMax

857

750

643

536

429

322

214

107

0000659857

(b) 13 wt SiCp

Figure 13 Distribution of effective stress (MPa)

0888

0777

0666

0555

0444

0333

0222

0111

0000

MinMax

0761

0666

0571

0476

0380

0285

0190

00951

000004550761

(a) 5 wt SiCp

0918

0803

0689

0574

0459

0344

0230

0115

0000

0779

0682

0584

0487

0390

0292

0195

00974

000004500779

MinMax

(b) 13 wt SiCp

Figure 14 Distribution of effective strain (mmmm)

10 Journal of Powder Technology

318278238198159119079403970000

2592271941621290971064703240000141259

MinMax

(a) 5 wt SiCp

359314269225180135089804490000

279244209174139105069703490000133278

MinMax

(b) 13 wt SiCp

Figure 15 Distribution of effective strain rate (mmmm-sec)

1311171028757295834372921460000

157

157

137

118

979

784

588

392

196

0000

000818MinMax

(a) 5 wt SiCp

1311181059167856545233932621310000

MinMax

172

151

129

108

862

647

431

216

00000308159

(b) 13 wt SiCp

Figure 16 Velocity (mmsec) distribution on SiCp preforms

Journal of Powder Technology 11

00 01 02 03 04 050

200

400

600

800

1000

Solid rectangular preformSolid disc preform

Forging time (s)

Effec

tive s

tress

(MPa

)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 17 Computational variations of effective stress (MPa) withforging time (sec)

law considered in the present paper The strain rates arehigher in case of 5 wt SiCp preforms as compared to 13 wtSiCp which indicates that ductility of preform decreases withthe increase in the perecentage of SiCp The variation of flowvelocity in the vertical direction leads to the barreling of pre-forms which confirms the inclusion of barreling parameterldquo120573rdquo during the present theoretical analysis

Figure 17 shows the variation of effective stress (MPa)with forging time (sec) for SiCp AMC preforms It canbe observed that stress requirement for preforms having13 wt SiCp is higher as compared to preforms having 5wtSiCp which indicates that the percentage of increase in SiCpincreases the hardness of preforms It can be also seen thatsolid rectangular preforms are subjected to higher effectivestresses as compared to solid disc preforms indicating bettermaterial flow in case of solid disc preforms as well asconstraint deformation in case of solid rectangular preforms

The variation of effective strain (mmmm) with forgingtime (sec) is shown in Figure 18 and it was found that itincreased exponentially with respect to forging time Alsoit is clearly evident that effective strains for solid rectangularpreforms are higher as compared to solid disc preforms dueto constraint deformation

Figure 19 shows the variation of effective strain rate(mmmm-sec) with forging time (sec) for SiCp AMC pre-forms The strain rate for 5wt SiCp preforms is foundhigher than preforms having 13 wt SiCp which indicatesthat percentage of increase in SiCp decreases the ductility andforgeability of preforms Also the strain rates are higher forsolid disc preforms as compared to solid rectangular preformdue to constraint deformation in the latter case

Figure 20 shows the variation of forging load (kN) withforging time (sec) for solid disc and solid rectangular pre-forms which is found to increase rapidly with forging time Itcan be clearly seen that the preforms canwithstandmaximum

00 01 02 03 04 0500

02

04

06

08

10

Effec

tive s

trai

n (m

mm

m)

Forging time (s)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 18 Computational variations of effective strain (mmmm)with forging time (sec)

00 01 02 03 04 0500

05

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Effec

tive s

trai

n ra

te (s

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp

13wt SiCp

Figure 19 Computational variations of effective strain rate(mmmm-sec) with forging time (sec)

load of about 270ndash300 kNwithout the onset of fracture It canalso be noted that solid rectangular preforms require higherload to deform as compared to solid disc preforms

6 Conclusions

Themajor conclusions may be summarized as follows

(i) Maximum formability of AMC material at roomtemperature and under dry interfacial frictional con-ditions was found to be about 47-47 of height reduc-tion The deformations in AMC preforms having5wt SiCp were found to be higher as compared

12 Journal of Powder Technology

00 01 02 03 04 050

50

100

150

200

250

300

Forg

ing

load

(kN

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm

Solid rectangular preformSolid disc preform

120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp13wt SiCp

Figure 20 Computational variations of forging load (kN) withforging time (sec)

Upper die

Lower die

(0 0)

r (xlowast)

r (xlowast)

dr (dxlowast)

z

H0

Figure 21 Open-die forging of SiCp AMC preform

to 13 wt SiCp indicating that as the percentage ofSiCp particulate increases forgeability of the preformsdecreases The experimental result was found to bein close agreement with theoretical ones and hencevalidates the present theoretical analysis based onupper bound approach

(ii) Engineering stress required to produce the sameamount of strain was found to be higher in case ofAMC preforms having higher weight of SiCp aswell as higher for solid rectangular preformsThis wasattributed due to the fact that the increase in weight of SiCp increases the hardness of the preform Alsosolid rectangular preforms exhibit higher constraintdeformation due to the presence of sharp corners

(iii) The highest strain rate in the order of 024 wasexperienced during the open-die forging of AMCpreforms irrespective of the percentage of SiCp Theeffect of SiCp particles over various deformationcharacteristics like strain stress and strain rate ispredominant only up to nearly 44 of height reduc-tion and thereafter these particles consolidate within

the metal matrix and have the least influence on thevarious forging parameters

(iv) Total energy requirements during open-die forging ofAMC preforms having higher SiCp are found to behigher due to higher strength of the material Alsothe energy requirements are higher if the processis carried out at higher die acceleration due toinertia effects Also the effect of die velocity wasclearly depicted using inertia factor which indicatedthat energy dissipation due to inertia effects maybe as high as 30 of the total energy dissipationsand thus must be considered during the analysis offorging operations carried out especially at higher dievelocities

(v) Lower magnitude of strains was observed at thecentral region of preforms andwas found to be almostzero at the centermost region near to top and bot-tom flat surfaces indicating the presence of variableinterfacial friction zone in the form of inverted coneThis confirmed the composite interfacial friction lawconsidered during the present investigationsThiswasalso confirmed by the results of velocity distributionwhere flow velocity was found to be zero at the cen-termost regions of preforms indicating the existenceof nondeforming zone due to the presence of highsticking friction conditions

(vi) Simulation of open-die forging of SiCp AMCmaterialwas performed using DEFORM and the distributionof effective stress effective strain effective strain rateand velocity vector profile was generated for bothsolid disc and solid rectangular preforms Highermagnitudes of effective stress strain and strain ratewere found at the corners and edges of preformsindicating that the onset of fracture will take placeat those regions only This was also confirmed by thepresence of severe cracks at those regions during thepresent experimental investigations

(vii) Validation of simulation was done by comparing itsresults with the theoretical and experimental resultsand was found to reasonably agree with each otherwhich indicated that present finite element simulationrepresents fairly well the present open-die forging ofSiCp AMC

It is expected that the present work will be useful forthe assessment of various deformation characteristics duringmechanical processing of AMCs

Appendix

Consider open-die forging of a SiCp AMC between two per-fectly flat parallel and rigid die platens at room temperaturewith lower die platen moving upwards with velocity ldquo119880rdquo andupper die platen stationary as shown in Figure 21

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

2 Journal of Powder Technology

temperature and heat treatment on themechanical propertiesof Al-Cu metal matrix composites were investigated and itwas found that conditions of heat treatment have an essentialinfluence on their mechanical properties as reported byszczepanik et al [9] Extensive studies have been carriedout on the mechanical properties like tensile strength yieldstrength hardness and ductility of SiC particle reinforcedaluminium metal matrix composites Chung and Lau [10]The closed-die hot forging of aluminium-silicon alloy (Al-5 Si-02 Mg) with different volume fractions of SiCparticulate and microstructure as well as the mechanicalproperties of the matrix alloy as-cast state and after theforging operation was critically investigated by Ozdemiret al [11] The forging behavior of 2124SiCp aluminiumcomposites having 26 vol of reinforcements both at roomtemperature and elevated temperature been studied andfurther tensile testing microphotographic study was per-formed to investigate the mechanism controlling the frac-ture of specimens by Badini [12] Youngrsquos modulus tensilestrength strain-to-fracture fatigue strength of sinter-forgedSiC particle reinforced matrix composites and the fatiguefractography were conducted and it was found that Fe-rich inclusions were extremely detrimental to the fatiguelife of the composites which were investigated by Chawlaet al [13] The isothermal forging of 2618 aluminium alloyreinforced with 20 vol of Al2O3 particles and reportedon the recrystallization behavior of composites by meansof deformation efficiency was carried out by Cavaliere andEvangelista [14] The effect of forging temperature on themicrostructure and mechanical properties of in situ TiTiCmatrix composites by performing hot forging experimentswas reported by Ma et al [15] Investigations on the cold-forging aspects of iron and aluminiummetal alloy compositesfabricated by powder metallurgy route were carried out andtheir behaviour against the relative density and barrel radiushas been systematically analyzed by Narayanasamy et al[16] The forging of AA618Al2O3 particulate compositeshaving 20 vol of reinforcements and studying the effects offormability characteristics on the microstructure and tensileproperties of composites were performed by Ceschini et al[17] The combination of forging and extrusion process onSiCpAZ91 magnesium matrix composites fabricated by stircasting technology and investigated the effect of deforma-tion characteristics on the yield stress and ultimate tensilestrength of material by Wu et al [18] Formability analysis ofaluminium metal matrix composite specimen manufacturedthrough PM route was analyzed by finite element methodMaterial factors like volume fraction of reinforcements shapeand size of reinforced particles compaction pressure andsintering temperature along with process parameters like die-wall friction friction between particles matrix powder andforming limits were investigated by Ramesh and Senthil-velan [19] Preliminary experimental investigations into theformability and machinability analysis of SiCp reinforcedaluminium metal matrix composites were carried out bySutradhar et al [20] Though Singh et al Jha et al andChandrasekhar et al [21ndash23] reported the analysis of dynamiceffects during open-die forging of sinteredmaterials no workhas been reported to analyze these effects that is effect of

die velocity on various deformation characteristics duringmechanical processing of metal matrix composites

In the present work various deformation characteristicslike effective stress effective strain effective strain rate flowof material strain rates energy dissipations and die loadsduring open-die forging of SiCp AMCs at cold conditionshave been analyzed Experimental investigations and upperbound theoretical analysis along with finite element simula-tion (FEM) of forging of SiCp AMC have been performedThe SiCp AMC has been prepared by stir casting methodand preforms of required dimensions were machined fromthe cast specimen The present investigations consideredheterogeneous deformation due to barreling of vertical sidescomposite die-workpiece interfacial friction conditions andinertia effects It is expected that the present work will beuseful for assessment of various deformation characteristicsduring mechanical processing of AMCs

2 Experimental Investigations

In general metal matrix composite material consists ofmetal matrix and reinforcements where metal matrix mainfunction is to transfer and distribute load to reinforcementswhich are commonly boron silicon carbide or graphiteparticles In the present research work aluminium metalmatrix composite has been produced by liquid metal stircasting process from LM6 aluminium casting alloy (havinghigh silicon content of 10ndash13wt) with SiC particles as rein-forcements with an idea to synthesize a composite materialwith superiormechanical properties Liquidmetal stir castingprocess was preferred due to simplicity in operation andlower processing cost which was also established by Mithunand Devaraj [24] in their research work They fabricatedaluminum based composite material with aluminum as basealloy (AA4430) and silicon carbide and magnesium oxide asreinforcement materials through stir casting method It wasfound out that although aluminummetal in its pure form hasexcellent mechanical properties its strength is too low to beused as functional component and hence its properties needto be modified to increase its capabilities

In the present case also SiC particles have been added pri-marily to increase the strength and stiffness of the aluminiummatrix During liquid stir casting process LM6 aluminiumcasting alloy was melted in a clay-graphite crucible usingan electric resistance furnace and 5wt of magnesiumwas added to the molten metal to have strong bondingbetween matrix metal and reinforcement particles Additionofmagnesium decreases the surface energy andwetting angleas well as increases the flowability of the molten metal TheSiC powder particles havingmesh size +400120583were preheatedin the temperature range of 850 to 900∘C and were addedto the molten metal The mixture was stirred briskly usinga mechanical impeller installed on the electric resistancefurnace (refer to Figure 1) at a speed of about 500 rpmand an optimum mixing temperature of about 720∘C wasmaintained Two groups of AMC samples having 5wt and13wt SiCp were prepared by this manufacturing route Themoltenmixturewas immediately poured into the silicamould

Journal of Powder Technology 3

Figure 1 Electric resistance furnace with mechanical impeller(stirrer)

Table 1 Specifications of 5 wt and 13wt SiCp AMC preforms

Preform shape DimensionsSolid disc preforms 1198630 = 15mm1198670 = 10mm

Solid rectangular preforms 1198710 = 20mm 1198610 = 10mm1198670 = 10mm

and subsequently cooled to the room temperatureThemouldwas prepared prior to casting using core sand bentonitecharcoal powder and parting sand Parting gate structurewas preferred for simplicity and alignment as well as sealingof the mould was done with utmost care to decrease thechance of mould erosion air entrapment run out and drossformation The cast was obtained by breaking the core andgently tapping it after cooling which was later machined toobtain preformswith desired dimensions (refer to Table 1) forfurther experiments

The cold-forging experiments on SiCp AMC preformswere conducted at room temperature employing hydraulicpress havingmaximum load capacity of 200 tonswith station-ary upper die platen till the onset of fracture The SiCp AMCpreforms placed on the lower die platen were compressedand data for deformation and corresponding forging loadwere recorded from the digital display of data acquisitionsystem of the press In all the experiment run deformationswere carried out under dry interfacial friction conditions(without any lubricant) till the onset of fracture that ismaximum forgeability at room temperatureThe engineeringstress and strain data were calculated from the correspondingrecorded data of forging load and deformation and were lateralso uploaded in the material library of DEFORM softwareas shown in Figure 2 for further FEM analysis Figures 3 and4 show the solid disc and solid rectangular preforms beforeand after open-die forging respectively for both 5wt and13wt SiCp reinforcements It can be seen that for the samedeformation conditions AMC preforms having higher wt

of SiCp were observed to have less forgeability and thosepreform surfaces showed severe cracking at equatorial bulgedregionsThe photomicrographs for SiCp AMC preforms wereobtained at 500X to illustrate the distribution of SiCp rein-forcements within the aluminium metal matrix As evidentfrom Figure 5 13 wt SiCp AMC is having higher density ofsilicon carbides particulate distribution as compared to 5wtSiCp AMC

3 Theoretical Analysis

The present theoretical analysis based on upper boundapproach for open-die forging of SiCp AMC solid discand solid rectangular preforms has been performed usingaxisymmetric and plane strain conditions of deformationrespectively The following assumptions were consideredduring the present analysis

(i) Die platens are incompressible rigid and parallel(ii) Deformation is homogeneous and insensitive to

hydrostatic stress component and hence von-Mises yieldcriterion was considered which is given as

120590119900 = lfloorradic311986910158402rfloor (1)

(iii) Die-preform interfacial friction conditions are com-posite in nature including both sliding and sticking frictionswhere sticking friction is a function of adhesion factorAccording to Downey et al [25] such composite interfacialfriction laws can be given mathematically as

solid disc preform

120591 = 120583119875av + 1206010 [1 minus (119877119898 minus 119877

1198991198770

)] (2)

solid rectangle preform

120591 = 120583119875av + 1206010 [1 minus (119861119898 minus 119861

1198991198610

)] (3)

Sticking zone distances ldquo119877119898rdquo and ldquo119861119898rdquo can be approximatedby modified Rooks [26] equations as

119877119898 = 1198770 minus1198670

2120583effln( 1

120583effradic3) (4)

119861119898 = 1198610 minus1198670

2120583effln( 1

120583effradic3) (5)

(iv) Compatibility equations have been derived fromvolume constancy principle based on the work done by Jhaet al [27] as

solid disc preform

120576119903119903 + 120576120579120579 + 120576119911119911 = 0 (6)

solid rectangle preform

120576119909119909 + 120576119910119910 + 120576119911119911 = 0 (7)

4 Journal of Powder Technology

Figure 2 Flow stress curve of SiCp AMC uploaded in DEFORM software

5wt13 wt

(a) Before forging

13 wt5wt

(b) After forging

Figure 3 Solid disc SiCp AMC preforms

(v) Bulging of workpiece vertical sides has been consid-ered by including a barreling parameter ldquo120573rdquo in the kinemati-cally admissible exponential velocity fields

(vi) Redundant energy dissipation due to velocity discon-tinuities has been neglected

(vii) Quarter portion of the preform has been consideredduring the analysis due to symmetry along the horizontal andvertical axes

(viii) Circumferential flow of preform vertical sides hasbeen neglected in case of solid disc preforms and deforma-tion conditions are essentially axisymmetric in nature

(ix) Lateral flow of preform vertical sides in the longitudi-nal direction has been neglected in case of solid rectangularpreforms and deformation is essentially plane-strain innature

Kinematically admissible velocity field and correspond-ing strain rates were formulated for both cases separatelysatisfying compatibility conditions and flow rule (refer to

Appendix) According to Avitzur [28] total energy dissi-pations during plastic deformation based on upper boundapproach are given as

119869lowast= 119882119894 +119882119891 +119882119886

=2

radic3

1205900 int

V

radic1

2120576119894119895 120576119894119895

119889119881 + int

119878119879

120591 |Δ119880| 119889119904 + int

119881

120588 (119886119894119880119894) 119889119881

(8)

31 Solid Disc Preform Internal energy dissipation ldquo119882119894rdquo aftersubstituting strain rates in (8) integrating and simplifying isgiven as

119882119894 = [

120587radic31205732119867012059001198770119890

minus1205732(1 + 120573

212)119880

32 Sin ℎ(1205734)2] (9)

Journal of Powder Technology 5

13wt5wt

(a) Before forging

13wt5wt

(b) After forging

Figure 4 Solid rectangular SiCp AMC preforms

(a) 5 wt SiCp (b) 13 wt SiCp

Figure 5 Photomicrograph of SiCp AMC preforms

Frictional shear energy dissipation at die-preform interfaceldquo119882119891rdquo after substituting frictional stress equation and velocityfield in (8) integrating and simplifying is given as

119882119891 = [2120587120583120573119877

3

0119890minus1205732

1206010119880

1198670 (1 minus 119890minus1205732

)] [(

119875av1206010

) + (1 +2

3119899minus119877119898

1198991198770

)]

(10)

Energy dissipation due to inertia forces ldquo119882119886rdquo after substi-tuting velocity field and corresponding strain rates in (1)integrating and simplifying is given as

119882119886 = [1205871205731205880119877

2

01198803

3 (1 minus 119890minus1205732

)]

times [

(1 + 119890minus1205732

+ 120573119890minus31205732

)

2]

+ [(1198772

0

311986720

)(31198670

1198770

minus 2) (1 + 119890minus1205732

+ 119890minus120573)]

+[

1205731198770 (1 + 119890minus1205732

minus 3119890minus31205732

)

(1 minus 119890minus1205732

)31198802

]

(11)

32 Solid Rectangular Preform Internal energy dissipationldquo119882119894rdquo after substituting strain rates in (8) integrating andsimplifying is given as

119882119894 = [

radic312057321198612

01205900119880

48 (1 minus 119890minus1205732

)]

times [(41198672

0

11986120

) + 1205732(1 +

81198670

12057321198610

) (1 minus 119890minus1205732

)]

(12)

Frictional shear energy dissipation at die-preform interfaceldquo119882119891rdquo after substituting frictional stress equation and velocityfield in (8) integrating and simplifying is given as

119882119891 = [1205831205731198613

0119890minus1205732

1206010119880

81198670 (1 minus 119890minus1205732

)] [(

119875av1206010

) + (1 +1

3119899minus119861119898

1198991198610

)]

(13)

Energy dissipation due to inertia forces ldquo119882119886rdquo after substi-tuting velocity field and corresponding strain rates in (8)integrating and simplifying is given as

119882119886 = [120573412058801198672

01198803

(1 minus 119890minus1205732

)2]

times [

(2 + 119890minus1205732

+ 119890minus120573)

1205733

]

+ (1 + 119890minus1205732

)(2

1205732minus1198612

0

11986720

) + [1198610119890minus120573

1205731198802

]

(14)

6 Journal of Powder Technology

2D model 3D model

(a) Solid disc preforms

2D model 3D model

(b) Solid rectangular preforms

Figure 6 Modeling of SiCp AMC preforms

The average forging load for both cases was computed sepa-rately by substituting the above energy dissipation equationsin (15)

119865av = 4119869lowast(119880)minus1119860av (15)

Dynamic effects that is effect of die velocity on relativemagnitudes of various energy dissipations involved duringopen-die forging of SiCp AMC preforms are illustrated usinginertia factor ldquo120585rdquo which is defined as the ratio of inertiaenergy dissipated to total energy supplied by die platen duringdeformation and given as

120585 () = (119882119886

119869) 100 (16)

4 Finite Element Analysis

Finite element simulation of open-die forging of SiCp AMCpreforms has been performed using DEFORM-3D which isbased on the implicit Lagrangian finite element code In thepresent solution preform mesh deforms under the die loadand elasticity of the material has been neglected as plasticstrains outweigh elastic strains and material behaves like anelastic-viscoplastic material as stated by Kobayashi et al [29]

The stress-strain curve of type120590 = 119886120576119887MPa for SiCpAMC

material was uploaded in the material library of software asdescribed in the previous section The material properties ofSiCp AMC used in the present analysis are given in Table 2The geometry of die platens was generated in DEFORM andthe die platens were modeled as rigid parallel and flat bodieswith plastic preform placed in between them The geometryof preforms was generated using CATIA using part designmoduleworkbench and data was imported to DEFORM inform of STL files Figures 6(a) and 6(b) show the 2D and3D models of the solid disc and solid rectangular preformsrespectively The composite frictional law was considered tomodel the interfacial frictional conditions represented bysuitable composite interfacial frictional shear stress (referto (3) and (4)) Tetrahedral elements were used to meshthe preforms and small meshes were generated close tothe edges of preforms in order to better scope the forgingprocess The complete forging simulation was performedin 120 steps having time for movement of die platens ineach step equal to 0064 seconds The deformation criterion

Table 2 Material property of stir-casted SiCp AMC

Material property 5wt SiCp 13 wt SiCp

Poissonrsquos ratio gt033 gt033Ultimate tensile strength (MPA) 112 138Hardness (HRC) 54 62Stress-strain relationship 120590 = 119886120576

119887MPa

consideredwasmaximum forgeability of SiCpAMCpreformsat room temperature which was experimentally found to beabout 49 and 47 respectively for 5 wt and 13wt SiCpreinforced AMC preforms

5 Results and Discussions

Figure 7 shows that the maximum deformation of preformsis about 47ndash49 at room temperature under dry interfacialfriction conditions and preforms start cracking at maximumstress of about 14ndash15 GPa The stress required to producethe same amount of strain is higher in case of 13 wtSiCp preforms as well as higher in case of solid rectangularpreformsThis indicates that the increases in the perecentageof SiCp increases the stress required to deform the preformsAlso solid rectangular preforms exhibit higher constraintdeformation due to existence of sharp corners as comparedto solid disc preforms

Figure 8 shows that the percentage of height reductionof preform increases gradually during the initial phase ofdeformation and only after forging load attains a magnitudeof about 5ndash7 tons it increases exponentially This continuestill cracks start appearing on the outer surfaces of preformsthat is maximum forgeability of preforms In both axisym-metric and plane strain deformations the height reductionfor preforms having 5wt SiCp is found to be more ascompared to 13 wt SiCp preforms which indicates that thepercentage of increase in SiCp decreases the forgeability ofpreforms Also the load requirements are higher for thesame amount of deformation in case of solid disc preformsindicating better flow of material The experimental data arefound to be in close agreement with the theoretical oneswhich validates the present upper bound approach used tosolve the forging problems considered in the present paper

Journal of Powder Technology 7

00 01 02 03 04 0500

02

04

06

08

10

12

14

16

Solid disc preformSolid rectangular preform

Engineering strain

Engi

neer

ing

stres

s (G

Pa)

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

5wt SiCp13wt SiCp

Figure 7 Experimental variation of engineering stress (GPa) withengineering strain (mmmm)

0 3 6 9 12 15 18 210

10

20

30

40

50

Forging load (tons)

Hei

ght r

educ

tion

()

Solid rectangular preform

Solid disc preform

R0 = 10mm H0 = 10mm L0 = 20mmB0 = 10mm Uav = 01ms 120583eff = 05

Experimental dataExperimental data

5wt SiCp

13wt SiCp

Figure 8 Experimental and theoretical variations of height reduc-tion () with forging load (tons)

Figure 9 shows the variation of strain rate (mmmmsec) with forging load (tons) for SiCp AMC preforms Asevident from the figure maximum strain rate of magnitude0024 secminus1 is being observed at forging load of about 20tons for both 5wt and 13wt SiCp Initially strain ratesare higher for solid rectangular preforms but after theload attains a magnitude of about 10 tons strain rates for13 wt SiCp preforms are higher irrespective of the shape ofpreforms Also at the end of forging operations strain ratesare found to decrease slightly after attaining the highest value

0 5 10 15 20 25 300000

0005

0010

0015

0020

0025

Forging load (Tons)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

Stra

in ra

te (s

minus1)

5wt SiCp

13wt SiCp

Figure 9 Experimental variation of strain rate (mmmm sec) withforging load (tons)

These two behaviors are attributed due to the consolidationof SiCp particles within the AMC preforms during the end offorging operation It can be concluded that the effect of SiCpparticles on stress strain and strain rate is predominant upto 40 of height reduction at forging load of about 20 tonsand thereafter these particles consolidate within the matrixand hence they least influence the forging characteristics

It can be seen from Figure 10 that the energy dissipationincreases with the increase in the forging load and defor-mation The total energy requirement for deformation ofAMC preforms having higher SiCp is found to be higherdue to higher strength of material and is also higher if theprocess is carried at higher die acceleration leading to higherinertia energy dissipation (refer to (11) and (14)) Also energyrequirements are higher for solid rectangular preforms ascompared to solid disc preforms due to more constraintdeformation in the former case

The variation of inertia factor with die velocity for SiCpAMC preforms is shown in Figure 11 It is clearly evidentthat inertia factor increases exponentially with increase in thedie velocity and is higher for higher die acceleration in solidrectangular preforms Also it can be noticed that proportionof inertia energy can be as high as 30 of the total energydissipation and hence cannot be neglected during the presentinvestigation

Figure 12 shows that both axial and radial strains increaseexponentially with increases in the forging load Also thecorresponding values of axial strains are higher than radialstrains for same forging load and higher percentage of SiCpIt also depicts the measure of Poissonrsquos ratio that is ratio ofradial strain to axial strain for present SiCp AMCmaterial

Figure 13 shows the effective stress (MPa) distribution onSiCp AMC preforms It is clearly evident that magnitudesof effective stresses are higher in 13 wt SiCp preforms ascompared to 5wt SiCp preforms in the corresponding

8 Journal of Powder Technology

0 3 6 9 12 15 18 210

2

4

6

8

10

12

Average forging load (tons)

Tota

l ene

rgy

diss

ipat

ion

(kJ)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav Uav = 01ms 120583eff = 05

13wt SiCp accel = 025mms2

5wt SiCp accel = 025mms213wt SiCp accel = 01mms2

5wt SiCp accel = 01mms2

Figure 10Theoretical variation of total energy dissipation (kJ) withaverage forging load (tons)

0 4 8 12 16 20 240

5

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Die velocity (mms)

Iner

tia fa

ctor

()

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav 120583eff = 05 SiCp = 5wt

Accel = 025mms2Accel = 005mms2Accel = 010mms2

Figure 11Theoretical variation of inertia factor ()with die velocity(mms)

regions The edges are subjected to higher stresses whereasthe centremost regions are having lower stresses of magni-tude about 150MPa and 300MPa for solid disc and solidrectangular preforms respectively This indicates that as thepercentage of SiCp increases stress also increases due toincrease in the strength of preforms

Figure 14 shows the effective strain (mmmm) distribu-tion on SiCp AMC preforms It can be seen that the major

00010203040506

5 40Average forging load (tons)

Solid rectangular preformSolid disc preform

10 20 30

R0 = 10mm H0 = 10mm

L0 = 20mm B0 = 10mm

120573 = 04 1206010 = 030 Pav 120583eff = 05

minus05

minus06

minus04

minus02

minus03

minus01

Axi

al st

rain

998400 120576998400 z

Radi

al st

rain

998400 120576998400 r

13 wt SiCp5 wt SiCp

Figure 12Theoretical variation of radial strain and axial strain withaverage forging load (tons)

portion of preform is subjected to strain in the order 03ndash06 magnitude except at the edges The strains are higher in5wt SiCp preforms as compared to 13 wt SiCp preformswhich indicate that ductility of 5 wt SiCp is higher In case of5 wt SiCp preforms the edges are subjected to severe strainof magnitude about 07ndash09 which leads to the fracture ofvertical surfaces and is also confirmed from Figure 3 In thiscase no appreciable variation in the strain distribution hasbeen observed for preforms having 13 wt and 5wt SiCpAlso the strains at the central region of preform are low andeventually almost zero at the centermost regions near to theupper and bottom flat surfaces The dissected section alsoreveals that the variation of strain in the central region isin the form of an inverted cone This confirms the presenceof sticking friction zone at those regions which confirmsand validates the variable interfacial composite friction lawconsidered during the present theoretical analysis

The distribution of effective strain rate (mmmm-sec)on SiCp AMC preforms is shown in Figure 15 It can beclearly seen that the major portion of solid disc preforms issubjected to strain rate of about 2mmmm-sec and only theedges are subjected to higher strain rates in the order 32ndash35mmmm-sec In case of solid rectangular preforms theedges are subjected to strain rate of 25ndash29mmmm-secThesolid disc preforms are having higher strain rates as comparedto solid rectangular preforms indicating better metal flow inthe former case as well as presence of constraint deformationin case of solid rectangular preforms

The velocity (mmsec) distribution on SiCp AMC pre-forms is shown in Figure 16 It can be observed that soliddisc and solid rectangular preforms are subjected to the high-est flow velocity of about 10ndash13mmsec and 15ndash17mmsecrespectively Also the outer regions of preform are havinghigher flow velocity as compared to the inner regions whichis in close agreement with the composite interfacial friction

Journal of Powder Technology 9

995

871

746

622

498

373

249

124

0000

MinMax

1140

1000

857

715

572

429

286

143

00006891140

(a) 5 wt SiCp

1010

885

759

632

506

379

253

126

0000

MinMax

857

750

643

536

429

322

214

107

0000659857

(b) 13 wt SiCp

Figure 13 Distribution of effective stress (MPa)

0888

0777

0666

0555

0444

0333

0222

0111

0000

MinMax

0761

0666

0571

0476

0380

0285

0190

00951

000004550761

(a) 5 wt SiCp

0918

0803

0689

0574

0459

0344

0230

0115

0000

0779

0682

0584

0487

0390

0292

0195

00974

000004500779

MinMax

(b) 13 wt SiCp

Figure 14 Distribution of effective strain (mmmm)

10 Journal of Powder Technology

318278238198159119079403970000

2592271941621290971064703240000141259

MinMax

(a) 5 wt SiCp

359314269225180135089804490000

279244209174139105069703490000133278

MinMax

(b) 13 wt SiCp

Figure 15 Distribution of effective strain rate (mmmm-sec)

1311171028757295834372921460000

157

157

137

118

979

784

588

392

196

0000

000818MinMax

(a) 5 wt SiCp

1311181059167856545233932621310000

MinMax

172

151

129

108

862

647

431

216

00000308159

(b) 13 wt SiCp

Figure 16 Velocity (mmsec) distribution on SiCp preforms

Journal of Powder Technology 11

00 01 02 03 04 050

200

400

600

800

1000

Solid rectangular preformSolid disc preform

Forging time (s)

Effec

tive s

tress

(MPa

)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 17 Computational variations of effective stress (MPa) withforging time (sec)

law considered in the present paper The strain rates arehigher in case of 5 wt SiCp preforms as compared to 13 wtSiCp which indicates that ductility of preform decreases withthe increase in the perecentage of SiCp The variation of flowvelocity in the vertical direction leads to the barreling of pre-forms which confirms the inclusion of barreling parameterldquo120573rdquo during the present theoretical analysis

Figure 17 shows the variation of effective stress (MPa)with forging time (sec) for SiCp AMC preforms It canbe observed that stress requirement for preforms having13 wt SiCp is higher as compared to preforms having 5wtSiCp which indicates that the percentage of increase in SiCpincreases the hardness of preforms It can be also seen thatsolid rectangular preforms are subjected to higher effectivestresses as compared to solid disc preforms indicating bettermaterial flow in case of solid disc preforms as well asconstraint deformation in case of solid rectangular preforms

The variation of effective strain (mmmm) with forgingtime (sec) is shown in Figure 18 and it was found that itincreased exponentially with respect to forging time Alsoit is clearly evident that effective strains for solid rectangularpreforms are higher as compared to solid disc preforms dueto constraint deformation

Figure 19 shows the variation of effective strain rate(mmmm-sec) with forging time (sec) for SiCp AMC pre-forms The strain rate for 5wt SiCp preforms is foundhigher than preforms having 13 wt SiCp which indicatesthat percentage of increase in SiCp decreases the ductility andforgeability of preforms Also the strain rates are higher forsolid disc preforms as compared to solid rectangular preformdue to constraint deformation in the latter case

Figure 20 shows the variation of forging load (kN) withforging time (sec) for solid disc and solid rectangular pre-forms which is found to increase rapidly with forging time Itcan be clearly seen that the preforms canwithstandmaximum

00 01 02 03 04 0500

02

04

06

08

10

Effec

tive s

trai

n (m

mm

m)

Forging time (s)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 18 Computational variations of effective strain (mmmm)with forging time (sec)

00 01 02 03 04 0500

05

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Effec

tive s

trai

n ra

te (s

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp

13wt SiCp

Figure 19 Computational variations of effective strain rate(mmmm-sec) with forging time (sec)

load of about 270ndash300 kNwithout the onset of fracture It canalso be noted that solid rectangular preforms require higherload to deform as compared to solid disc preforms

6 Conclusions

Themajor conclusions may be summarized as follows

(i) Maximum formability of AMC material at roomtemperature and under dry interfacial frictional con-ditions was found to be about 47-47 of height reduc-tion The deformations in AMC preforms having5wt SiCp were found to be higher as compared

12 Journal of Powder Technology

00 01 02 03 04 050

50

100

150

200

250

300

Forg

ing

load

(kN

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm

Solid rectangular preformSolid disc preform

120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp13wt SiCp

Figure 20 Computational variations of forging load (kN) withforging time (sec)

Upper die

Lower die

(0 0)

r (xlowast)

r (xlowast)

dr (dxlowast)

z

H0

Figure 21 Open-die forging of SiCp AMC preform

to 13 wt SiCp indicating that as the percentage ofSiCp particulate increases forgeability of the preformsdecreases The experimental result was found to bein close agreement with theoretical ones and hencevalidates the present theoretical analysis based onupper bound approach

(ii) Engineering stress required to produce the sameamount of strain was found to be higher in case ofAMC preforms having higher weight of SiCp aswell as higher for solid rectangular preformsThis wasattributed due to the fact that the increase in weight of SiCp increases the hardness of the preform Alsosolid rectangular preforms exhibit higher constraintdeformation due to the presence of sharp corners

(iii) The highest strain rate in the order of 024 wasexperienced during the open-die forging of AMCpreforms irrespective of the percentage of SiCp Theeffect of SiCp particles over various deformationcharacteristics like strain stress and strain rate ispredominant only up to nearly 44 of height reduc-tion and thereafter these particles consolidate within

the metal matrix and have the least influence on thevarious forging parameters

(iv) Total energy requirements during open-die forging ofAMC preforms having higher SiCp are found to behigher due to higher strength of the material Alsothe energy requirements are higher if the processis carried out at higher die acceleration due toinertia effects Also the effect of die velocity wasclearly depicted using inertia factor which indicatedthat energy dissipation due to inertia effects maybe as high as 30 of the total energy dissipationsand thus must be considered during the analysis offorging operations carried out especially at higher dievelocities

(v) Lower magnitude of strains was observed at thecentral region of preforms andwas found to be almostzero at the centermost region near to top and bot-tom flat surfaces indicating the presence of variableinterfacial friction zone in the form of inverted coneThis confirmed the composite interfacial friction lawconsidered during the present investigationsThiswasalso confirmed by the results of velocity distributionwhere flow velocity was found to be zero at the cen-termost regions of preforms indicating the existenceof nondeforming zone due to the presence of highsticking friction conditions

(vi) Simulation of open-die forging of SiCp AMCmaterialwas performed using DEFORM and the distributionof effective stress effective strain effective strain rateand velocity vector profile was generated for bothsolid disc and solid rectangular preforms Highermagnitudes of effective stress strain and strain ratewere found at the corners and edges of preformsindicating that the onset of fracture will take placeat those regions only This was also confirmed by thepresence of severe cracks at those regions during thepresent experimental investigations

(vii) Validation of simulation was done by comparing itsresults with the theoretical and experimental resultsand was found to reasonably agree with each otherwhich indicated that present finite element simulationrepresents fairly well the present open-die forging ofSiCp AMC

It is expected that the present work will be useful forthe assessment of various deformation characteristics duringmechanical processing of AMCs

Appendix

Consider open-die forging of a SiCp AMC between two per-fectly flat parallel and rigid die platens at room temperaturewith lower die platen moving upwards with velocity ldquo119880rdquo andupper die platen stationary as shown in Figure 21

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Journal of Powder Technology 3

Figure 1 Electric resistance furnace with mechanical impeller(stirrer)

Table 1 Specifications of 5 wt and 13wt SiCp AMC preforms

Preform shape DimensionsSolid disc preforms 1198630 = 15mm1198670 = 10mm

Solid rectangular preforms 1198710 = 20mm 1198610 = 10mm1198670 = 10mm

and subsequently cooled to the room temperatureThemouldwas prepared prior to casting using core sand bentonitecharcoal powder and parting sand Parting gate structurewas preferred for simplicity and alignment as well as sealingof the mould was done with utmost care to decrease thechance of mould erosion air entrapment run out and drossformation The cast was obtained by breaking the core andgently tapping it after cooling which was later machined toobtain preformswith desired dimensions (refer to Table 1) forfurther experiments

The cold-forging experiments on SiCp AMC preformswere conducted at room temperature employing hydraulicpress havingmaximum load capacity of 200 tonswith station-ary upper die platen till the onset of fracture The SiCp AMCpreforms placed on the lower die platen were compressedand data for deformation and corresponding forging loadwere recorded from the digital display of data acquisitionsystem of the press In all the experiment run deformationswere carried out under dry interfacial friction conditions(without any lubricant) till the onset of fracture that ismaximum forgeability at room temperatureThe engineeringstress and strain data were calculated from the correspondingrecorded data of forging load and deformation and were lateralso uploaded in the material library of DEFORM softwareas shown in Figure 2 for further FEM analysis Figures 3 and4 show the solid disc and solid rectangular preforms beforeand after open-die forging respectively for both 5wt and13wt SiCp reinforcements It can be seen that for the samedeformation conditions AMC preforms having higher wt

of SiCp were observed to have less forgeability and thosepreform surfaces showed severe cracking at equatorial bulgedregionsThe photomicrographs for SiCp AMC preforms wereobtained at 500X to illustrate the distribution of SiCp rein-forcements within the aluminium metal matrix As evidentfrom Figure 5 13 wt SiCp AMC is having higher density ofsilicon carbides particulate distribution as compared to 5wtSiCp AMC

3 Theoretical Analysis

The present theoretical analysis based on upper boundapproach for open-die forging of SiCp AMC solid discand solid rectangular preforms has been performed usingaxisymmetric and plane strain conditions of deformationrespectively The following assumptions were consideredduring the present analysis

(i) Die platens are incompressible rigid and parallel(ii) Deformation is homogeneous and insensitive to

hydrostatic stress component and hence von-Mises yieldcriterion was considered which is given as

120590119900 = lfloorradic311986910158402rfloor (1)

(iii) Die-preform interfacial friction conditions are com-posite in nature including both sliding and sticking frictionswhere sticking friction is a function of adhesion factorAccording to Downey et al [25] such composite interfacialfriction laws can be given mathematically as

solid disc preform

120591 = 120583119875av + 1206010 [1 minus (119877119898 minus 119877

1198991198770

)] (2)

solid rectangle preform

120591 = 120583119875av + 1206010 [1 minus (119861119898 minus 119861

1198991198610

)] (3)

Sticking zone distances ldquo119877119898rdquo and ldquo119861119898rdquo can be approximatedby modified Rooks [26] equations as

119877119898 = 1198770 minus1198670

2120583effln( 1

120583effradic3) (4)

119861119898 = 1198610 minus1198670

2120583effln( 1

120583effradic3) (5)

(iv) Compatibility equations have been derived fromvolume constancy principle based on the work done by Jhaet al [27] as

solid disc preform

120576119903119903 + 120576120579120579 + 120576119911119911 = 0 (6)

solid rectangle preform

120576119909119909 + 120576119910119910 + 120576119911119911 = 0 (7)

4 Journal of Powder Technology

Figure 2 Flow stress curve of SiCp AMC uploaded in DEFORM software

5wt13 wt

(a) Before forging

13 wt5wt

(b) After forging

Figure 3 Solid disc SiCp AMC preforms

(v) Bulging of workpiece vertical sides has been consid-ered by including a barreling parameter ldquo120573rdquo in the kinemati-cally admissible exponential velocity fields

(vi) Redundant energy dissipation due to velocity discon-tinuities has been neglected

(vii) Quarter portion of the preform has been consideredduring the analysis due to symmetry along the horizontal andvertical axes

(viii) Circumferential flow of preform vertical sides hasbeen neglected in case of solid disc preforms and deforma-tion conditions are essentially axisymmetric in nature

(ix) Lateral flow of preform vertical sides in the longitudi-nal direction has been neglected in case of solid rectangularpreforms and deformation is essentially plane-strain innature

Kinematically admissible velocity field and correspond-ing strain rates were formulated for both cases separatelysatisfying compatibility conditions and flow rule (refer to

Appendix) According to Avitzur [28] total energy dissi-pations during plastic deformation based on upper boundapproach are given as

119869lowast= 119882119894 +119882119891 +119882119886

=2

radic3

1205900 int

V

radic1

2120576119894119895 120576119894119895

119889119881 + int

119878119879

120591 |Δ119880| 119889119904 + int

119881

120588 (119886119894119880119894) 119889119881

(8)

31 Solid Disc Preform Internal energy dissipation ldquo119882119894rdquo aftersubstituting strain rates in (8) integrating and simplifying isgiven as

119882119894 = [

120587radic31205732119867012059001198770119890

minus1205732(1 + 120573

212)119880

32 Sin ℎ(1205734)2] (9)

Journal of Powder Technology 5

13wt5wt

(a) Before forging

13wt5wt

(b) After forging

Figure 4 Solid rectangular SiCp AMC preforms

(a) 5 wt SiCp (b) 13 wt SiCp

Figure 5 Photomicrograph of SiCp AMC preforms

Frictional shear energy dissipation at die-preform interfaceldquo119882119891rdquo after substituting frictional stress equation and velocityfield in (8) integrating and simplifying is given as

119882119891 = [2120587120583120573119877

3

0119890minus1205732

1206010119880

1198670 (1 minus 119890minus1205732

)] [(

119875av1206010

) + (1 +2

3119899minus119877119898

1198991198770

)]

(10)

Energy dissipation due to inertia forces ldquo119882119886rdquo after substi-tuting velocity field and corresponding strain rates in (1)integrating and simplifying is given as

119882119886 = [1205871205731205880119877

2

01198803

3 (1 minus 119890minus1205732

)]

times [

(1 + 119890minus1205732

+ 120573119890minus31205732

)

2]

+ [(1198772

0

311986720

)(31198670

1198770

minus 2) (1 + 119890minus1205732

+ 119890minus120573)]

+[

1205731198770 (1 + 119890minus1205732

minus 3119890minus31205732

)

(1 minus 119890minus1205732

)31198802

]

(11)

32 Solid Rectangular Preform Internal energy dissipationldquo119882119894rdquo after substituting strain rates in (8) integrating andsimplifying is given as

119882119894 = [

radic312057321198612

01205900119880

48 (1 minus 119890minus1205732

)]

times [(41198672

0

11986120

) + 1205732(1 +

81198670

12057321198610

) (1 minus 119890minus1205732

)]

(12)

Frictional shear energy dissipation at die-preform interfaceldquo119882119891rdquo after substituting frictional stress equation and velocityfield in (8) integrating and simplifying is given as

119882119891 = [1205831205731198613

0119890minus1205732

1206010119880

81198670 (1 minus 119890minus1205732

)] [(

119875av1206010

) + (1 +1

3119899minus119861119898

1198991198610

)]

(13)

Energy dissipation due to inertia forces ldquo119882119886rdquo after substi-tuting velocity field and corresponding strain rates in (8)integrating and simplifying is given as

119882119886 = [120573412058801198672

01198803

(1 minus 119890minus1205732

)2]

times [

(2 + 119890minus1205732

+ 119890minus120573)

1205733

]

+ (1 + 119890minus1205732

)(2

1205732minus1198612

0

11986720

) + [1198610119890minus120573

1205731198802

]

(14)

6 Journal of Powder Technology

2D model 3D model

(a) Solid disc preforms

2D model 3D model

(b) Solid rectangular preforms

Figure 6 Modeling of SiCp AMC preforms

The average forging load for both cases was computed sepa-rately by substituting the above energy dissipation equationsin (15)

119865av = 4119869lowast(119880)minus1119860av (15)

Dynamic effects that is effect of die velocity on relativemagnitudes of various energy dissipations involved duringopen-die forging of SiCp AMC preforms are illustrated usinginertia factor ldquo120585rdquo which is defined as the ratio of inertiaenergy dissipated to total energy supplied by die platen duringdeformation and given as

120585 () = (119882119886

119869) 100 (16)

4 Finite Element Analysis

Finite element simulation of open-die forging of SiCp AMCpreforms has been performed using DEFORM-3D which isbased on the implicit Lagrangian finite element code In thepresent solution preform mesh deforms under the die loadand elasticity of the material has been neglected as plasticstrains outweigh elastic strains and material behaves like anelastic-viscoplastic material as stated by Kobayashi et al [29]

The stress-strain curve of type120590 = 119886120576119887MPa for SiCpAMC

material was uploaded in the material library of software asdescribed in the previous section The material properties ofSiCp AMC used in the present analysis are given in Table 2The geometry of die platens was generated in DEFORM andthe die platens were modeled as rigid parallel and flat bodieswith plastic preform placed in between them The geometryof preforms was generated using CATIA using part designmoduleworkbench and data was imported to DEFORM inform of STL files Figures 6(a) and 6(b) show the 2D and3D models of the solid disc and solid rectangular preformsrespectively The composite frictional law was considered tomodel the interfacial frictional conditions represented bysuitable composite interfacial frictional shear stress (referto (3) and (4)) Tetrahedral elements were used to meshthe preforms and small meshes were generated close tothe edges of preforms in order to better scope the forgingprocess The complete forging simulation was performedin 120 steps having time for movement of die platens ineach step equal to 0064 seconds The deformation criterion

Table 2 Material property of stir-casted SiCp AMC

Material property 5wt SiCp 13 wt SiCp

Poissonrsquos ratio gt033 gt033Ultimate tensile strength (MPA) 112 138Hardness (HRC) 54 62Stress-strain relationship 120590 = 119886120576

119887MPa

consideredwasmaximum forgeability of SiCpAMCpreformsat room temperature which was experimentally found to beabout 49 and 47 respectively for 5 wt and 13wt SiCpreinforced AMC preforms

5 Results and Discussions

Figure 7 shows that the maximum deformation of preformsis about 47ndash49 at room temperature under dry interfacialfriction conditions and preforms start cracking at maximumstress of about 14ndash15 GPa The stress required to producethe same amount of strain is higher in case of 13 wtSiCp preforms as well as higher in case of solid rectangularpreformsThis indicates that the increases in the perecentageof SiCp increases the stress required to deform the preformsAlso solid rectangular preforms exhibit higher constraintdeformation due to existence of sharp corners as comparedto solid disc preforms

Figure 8 shows that the percentage of height reductionof preform increases gradually during the initial phase ofdeformation and only after forging load attains a magnitudeof about 5ndash7 tons it increases exponentially This continuestill cracks start appearing on the outer surfaces of preformsthat is maximum forgeability of preforms In both axisym-metric and plane strain deformations the height reductionfor preforms having 5wt SiCp is found to be more ascompared to 13 wt SiCp preforms which indicates that thepercentage of increase in SiCp decreases the forgeability ofpreforms Also the load requirements are higher for thesame amount of deformation in case of solid disc preformsindicating better flow of material The experimental data arefound to be in close agreement with the theoretical oneswhich validates the present upper bound approach used tosolve the forging problems considered in the present paper

Journal of Powder Technology 7

00 01 02 03 04 0500

02

04

06

08

10

12

14

16

Solid disc preformSolid rectangular preform

Engineering strain

Engi

neer

ing

stres

s (G

Pa)

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

5wt SiCp13wt SiCp

Figure 7 Experimental variation of engineering stress (GPa) withengineering strain (mmmm)

0 3 6 9 12 15 18 210

10

20

30

40

50

Forging load (tons)

Hei

ght r

educ

tion

()

Solid rectangular preform

Solid disc preform

R0 = 10mm H0 = 10mm L0 = 20mmB0 = 10mm Uav = 01ms 120583eff = 05

Experimental dataExperimental data

5wt SiCp

13wt SiCp

Figure 8 Experimental and theoretical variations of height reduc-tion () with forging load (tons)

Figure 9 shows the variation of strain rate (mmmmsec) with forging load (tons) for SiCp AMC preforms Asevident from the figure maximum strain rate of magnitude0024 secminus1 is being observed at forging load of about 20tons for both 5wt and 13wt SiCp Initially strain ratesare higher for solid rectangular preforms but after theload attains a magnitude of about 10 tons strain rates for13 wt SiCp preforms are higher irrespective of the shape ofpreforms Also at the end of forging operations strain ratesare found to decrease slightly after attaining the highest value

0 5 10 15 20 25 300000

0005

0010

0015

0020

0025

Forging load (Tons)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

Stra

in ra

te (s

minus1)

5wt SiCp

13wt SiCp

Figure 9 Experimental variation of strain rate (mmmm sec) withforging load (tons)

These two behaviors are attributed due to the consolidationof SiCp particles within the AMC preforms during the end offorging operation It can be concluded that the effect of SiCpparticles on stress strain and strain rate is predominant upto 40 of height reduction at forging load of about 20 tonsand thereafter these particles consolidate within the matrixand hence they least influence the forging characteristics

It can be seen from Figure 10 that the energy dissipationincreases with the increase in the forging load and defor-mation The total energy requirement for deformation ofAMC preforms having higher SiCp is found to be higherdue to higher strength of material and is also higher if theprocess is carried at higher die acceleration leading to higherinertia energy dissipation (refer to (11) and (14)) Also energyrequirements are higher for solid rectangular preforms ascompared to solid disc preforms due to more constraintdeformation in the former case

The variation of inertia factor with die velocity for SiCpAMC preforms is shown in Figure 11 It is clearly evidentthat inertia factor increases exponentially with increase in thedie velocity and is higher for higher die acceleration in solidrectangular preforms Also it can be noticed that proportionof inertia energy can be as high as 30 of the total energydissipation and hence cannot be neglected during the presentinvestigation

Figure 12 shows that both axial and radial strains increaseexponentially with increases in the forging load Also thecorresponding values of axial strains are higher than radialstrains for same forging load and higher percentage of SiCpIt also depicts the measure of Poissonrsquos ratio that is ratio ofradial strain to axial strain for present SiCp AMCmaterial

Figure 13 shows the effective stress (MPa) distribution onSiCp AMC preforms It is clearly evident that magnitudesof effective stresses are higher in 13 wt SiCp preforms ascompared to 5wt SiCp preforms in the corresponding

8 Journal of Powder Technology

0 3 6 9 12 15 18 210

2

4

6

8

10

12

Average forging load (tons)

Tota

l ene

rgy

diss

ipat

ion

(kJ)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav Uav = 01ms 120583eff = 05

13wt SiCp accel = 025mms2

5wt SiCp accel = 025mms213wt SiCp accel = 01mms2

5wt SiCp accel = 01mms2

Figure 10Theoretical variation of total energy dissipation (kJ) withaverage forging load (tons)

0 4 8 12 16 20 240

5

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Die velocity (mms)

Iner

tia fa

ctor

()

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav 120583eff = 05 SiCp = 5wt

Accel = 025mms2Accel = 005mms2Accel = 010mms2

Figure 11Theoretical variation of inertia factor ()with die velocity(mms)

regions The edges are subjected to higher stresses whereasthe centremost regions are having lower stresses of magni-tude about 150MPa and 300MPa for solid disc and solidrectangular preforms respectively This indicates that as thepercentage of SiCp increases stress also increases due toincrease in the strength of preforms

Figure 14 shows the effective strain (mmmm) distribu-tion on SiCp AMC preforms It can be seen that the major

00010203040506

5 40Average forging load (tons)

Solid rectangular preformSolid disc preform

10 20 30

R0 = 10mm H0 = 10mm

L0 = 20mm B0 = 10mm

120573 = 04 1206010 = 030 Pav 120583eff = 05

minus05

minus06

minus04

minus02

minus03

minus01

Axi

al st

rain

998400 120576998400 z

Radi

al st

rain

998400 120576998400 r

13 wt SiCp5 wt SiCp

Figure 12Theoretical variation of radial strain and axial strain withaverage forging load (tons)

portion of preform is subjected to strain in the order 03ndash06 magnitude except at the edges The strains are higher in5wt SiCp preforms as compared to 13 wt SiCp preformswhich indicate that ductility of 5 wt SiCp is higher In case of5 wt SiCp preforms the edges are subjected to severe strainof magnitude about 07ndash09 which leads to the fracture ofvertical surfaces and is also confirmed from Figure 3 In thiscase no appreciable variation in the strain distribution hasbeen observed for preforms having 13 wt and 5wt SiCpAlso the strains at the central region of preform are low andeventually almost zero at the centermost regions near to theupper and bottom flat surfaces The dissected section alsoreveals that the variation of strain in the central region isin the form of an inverted cone This confirms the presenceof sticking friction zone at those regions which confirmsand validates the variable interfacial composite friction lawconsidered during the present theoretical analysis

The distribution of effective strain rate (mmmm-sec)on SiCp AMC preforms is shown in Figure 15 It can beclearly seen that the major portion of solid disc preforms issubjected to strain rate of about 2mmmm-sec and only theedges are subjected to higher strain rates in the order 32ndash35mmmm-sec In case of solid rectangular preforms theedges are subjected to strain rate of 25ndash29mmmm-secThesolid disc preforms are having higher strain rates as comparedto solid rectangular preforms indicating better metal flow inthe former case as well as presence of constraint deformationin case of solid rectangular preforms

The velocity (mmsec) distribution on SiCp AMC pre-forms is shown in Figure 16 It can be observed that soliddisc and solid rectangular preforms are subjected to the high-est flow velocity of about 10ndash13mmsec and 15ndash17mmsecrespectively Also the outer regions of preform are havinghigher flow velocity as compared to the inner regions whichis in close agreement with the composite interfacial friction

Journal of Powder Technology 9

995

871

746

622

498

373

249

124

0000

MinMax

1140

1000

857

715

572

429

286

143

00006891140

(a) 5 wt SiCp

1010

885

759

632

506

379

253

126

0000

MinMax

857

750

643

536

429

322

214

107

0000659857

(b) 13 wt SiCp

Figure 13 Distribution of effective stress (MPa)

0888

0777

0666

0555

0444

0333

0222

0111

0000

MinMax

0761

0666

0571

0476

0380

0285

0190

00951

000004550761

(a) 5 wt SiCp

0918

0803

0689

0574

0459

0344

0230

0115

0000

0779

0682

0584

0487

0390

0292

0195

00974

000004500779

MinMax

(b) 13 wt SiCp

Figure 14 Distribution of effective strain (mmmm)

10 Journal of Powder Technology

318278238198159119079403970000

2592271941621290971064703240000141259

MinMax

(a) 5 wt SiCp

359314269225180135089804490000

279244209174139105069703490000133278

MinMax

(b) 13 wt SiCp

Figure 15 Distribution of effective strain rate (mmmm-sec)

1311171028757295834372921460000

157

157

137

118

979

784

588

392

196

0000

000818MinMax

(a) 5 wt SiCp

1311181059167856545233932621310000

MinMax

172

151

129

108

862

647

431

216

00000308159

(b) 13 wt SiCp

Figure 16 Velocity (mmsec) distribution on SiCp preforms

Journal of Powder Technology 11

00 01 02 03 04 050

200

400

600

800

1000

Solid rectangular preformSolid disc preform

Forging time (s)

Effec

tive s

tress

(MPa

)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 17 Computational variations of effective stress (MPa) withforging time (sec)

law considered in the present paper The strain rates arehigher in case of 5 wt SiCp preforms as compared to 13 wtSiCp which indicates that ductility of preform decreases withthe increase in the perecentage of SiCp The variation of flowvelocity in the vertical direction leads to the barreling of pre-forms which confirms the inclusion of barreling parameterldquo120573rdquo during the present theoretical analysis

Figure 17 shows the variation of effective stress (MPa)with forging time (sec) for SiCp AMC preforms It canbe observed that stress requirement for preforms having13 wt SiCp is higher as compared to preforms having 5wtSiCp which indicates that the percentage of increase in SiCpincreases the hardness of preforms It can be also seen thatsolid rectangular preforms are subjected to higher effectivestresses as compared to solid disc preforms indicating bettermaterial flow in case of solid disc preforms as well asconstraint deformation in case of solid rectangular preforms

The variation of effective strain (mmmm) with forgingtime (sec) is shown in Figure 18 and it was found that itincreased exponentially with respect to forging time Alsoit is clearly evident that effective strains for solid rectangularpreforms are higher as compared to solid disc preforms dueto constraint deformation

Figure 19 shows the variation of effective strain rate(mmmm-sec) with forging time (sec) for SiCp AMC pre-forms The strain rate for 5wt SiCp preforms is foundhigher than preforms having 13 wt SiCp which indicatesthat percentage of increase in SiCp decreases the ductility andforgeability of preforms Also the strain rates are higher forsolid disc preforms as compared to solid rectangular preformdue to constraint deformation in the latter case

Figure 20 shows the variation of forging load (kN) withforging time (sec) for solid disc and solid rectangular pre-forms which is found to increase rapidly with forging time Itcan be clearly seen that the preforms canwithstandmaximum

00 01 02 03 04 0500

02

04

06

08

10

Effec

tive s

trai

n (m

mm

m)

Forging time (s)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 18 Computational variations of effective strain (mmmm)with forging time (sec)

00 01 02 03 04 0500

05

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Effec

tive s

trai

n ra

te (s

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp

13wt SiCp

Figure 19 Computational variations of effective strain rate(mmmm-sec) with forging time (sec)

load of about 270ndash300 kNwithout the onset of fracture It canalso be noted that solid rectangular preforms require higherload to deform as compared to solid disc preforms

6 Conclusions

Themajor conclusions may be summarized as follows

(i) Maximum formability of AMC material at roomtemperature and under dry interfacial frictional con-ditions was found to be about 47-47 of height reduc-tion The deformations in AMC preforms having5wt SiCp were found to be higher as compared

12 Journal of Powder Technology

00 01 02 03 04 050

50

100

150

200

250

300

Forg

ing

load

(kN

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm

Solid rectangular preformSolid disc preform

120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp13wt SiCp

Figure 20 Computational variations of forging load (kN) withforging time (sec)

Upper die

Lower die

(0 0)

r (xlowast)

r (xlowast)

dr (dxlowast)

z

H0

Figure 21 Open-die forging of SiCp AMC preform

to 13 wt SiCp indicating that as the percentage ofSiCp particulate increases forgeability of the preformsdecreases The experimental result was found to bein close agreement with theoretical ones and hencevalidates the present theoretical analysis based onupper bound approach

(ii) Engineering stress required to produce the sameamount of strain was found to be higher in case ofAMC preforms having higher weight of SiCp aswell as higher for solid rectangular preformsThis wasattributed due to the fact that the increase in weight of SiCp increases the hardness of the preform Alsosolid rectangular preforms exhibit higher constraintdeformation due to the presence of sharp corners

(iii) The highest strain rate in the order of 024 wasexperienced during the open-die forging of AMCpreforms irrespective of the percentage of SiCp Theeffect of SiCp particles over various deformationcharacteristics like strain stress and strain rate ispredominant only up to nearly 44 of height reduc-tion and thereafter these particles consolidate within

the metal matrix and have the least influence on thevarious forging parameters

(iv) Total energy requirements during open-die forging ofAMC preforms having higher SiCp are found to behigher due to higher strength of the material Alsothe energy requirements are higher if the processis carried out at higher die acceleration due toinertia effects Also the effect of die velocity wasclearly depicted using inertia factor which indicatedthat energy dissipation due to inertia effects maybe as high as 30 of the total energy dissipationsand thus must be considered during the analysis offorging operations carried out especially at higher dievelocities

(v) Lower magnitude of strains was observed at thecentral region of preforms andwas found to be almostzero at the centermost region near to top and bot-tom flat surfaces indicating the presence of variableinterfacial friction zone in the form of inverted coneThis confirmed the composite interfacial friction lawconsidered during the present investigationsThiswasalso confirmed by the results of velocity distributionwhere flow velocity was found to be zero at the cen-termost regions of preforms indicating the existenceof nondeforming zone due to the presence of highsticking friction conditions

(vi) Simulation of open-die forging of SiCp AMCmaterialwas performed using DEFORM and the distributionof effective stress effective strain effective strain rateand velocity vector profile was generated for bothsolid disc and solid rectangular preforms Highermagnitudes of effective stress strain and strain ratewere found at the corners and edges of preformsindicating that the onset of fracture will take placeat those regions only This was also confirmed by thepresence of severe cracks at those regions during thepresent experimental investigations

(vii) Validation of simulation was done by comparing itsresults with the theoretical and experimental resultsand was found to reasonably agree with each otherwhich indicated that present finite element simulationrepresents fairly well the present open-die forging ofSiCp AMC

It is expected that the present work will be useful forthe assessment of various deformation characteristics duringmechanical processing of AMCs

Appendix

Consider open-die forging of a SiCp AMC between two per-fectly flat parallel and rigid die platens at room temperaturewith lower die platen moving upwards with velocity ldquo119880rdquo andupper die platen stationary as shown in Figure 21

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

4 Journal of Powder Technology

Figure 2 Flow stress curve of SiCp AMC uploaded in DEFORM software

5wt13 wt

(a) Before forging

13 wt5wt

(b) After forging

Figure 3 Solid disc SiCp AMC preforms

(v) Bulging of workpiece vertical sides has been consid-ered by including a barreling parameter ldquo120573rdquo in the kinemati-cally admissible exponential velocity fields

(vi) Redundant energy dissipation due to velocity discon-tinuities has been neglected

(vii) Quarter portion of the preform has been consideredduring the analysis due to symmetry along the horizontal andvertical axes

(viii) Circumferential flow of preform vertical sides hasbeen neglected in case of solid disc preforms and deforma-tion conditions are essentially axisymmetric in nature

(ix) Lateral flow of preform vertical sides in the longitudi-nal direction has been neglected in case of solid rectangularpreforms and deformation is essentially plane-strain innature

Kinematically admissible velocity field and correspond-ing strain rates were formulated for both cases separatelysatisfying compatibility conditions and flow rule (refer to

Appendix) According to Avitzur [28] total energy dissi-pations during plastic deformation based on upper boundapproach are given as

119869lowast= 119882119894 +119882119891 +119882119886

=2

radic3

1205900 int

V

radic1

2120576119894119895 120576119894119895

119889119881 + int

119878119879

120591 |Δ119880| 119889119904 + int

119881

120588 (119886119894119880119894) 119889119881

(8)

31 Solid Disc Preform Internal energy dissipation ldquo119882119894rdquo aftersubstituting strain rates in (8) integrating and simplifying isgiven as

119882119894 = [

120587radic31205732119867012059001198770119890

minus1205732(1 + 120573

212)119880

32 Sin ℎ(1205734)2] (9)

Journal of Powder Technology 5

13wt5wt

(a) Before forging

13wt5wt

(b) After forging

Figure 4 Solid rectangular SiCp AMC preforms

(a) 5 wt SiCp (b) 13 wt SiCp

Figure 5 Photomicrograph of SiCp AMC preforms

Frictional shear energy dissipation at die-preform interfaceldquo119882119891rdquo after substituting frictional stress equation and velocityfield in (8) integrating and simplifying is given as

119882119891 = [2120587120583120573119877

3

0119890minus1205732

1206010119880

1198670 (1 minus 119890minus1205732

)] [(

119875av1206010

) + (1 +2

3119899minus119877119898

1198991198770

)]

(10)

Energy dissipation due to inertia forces ldquo119882119886rdquo after substi-tuting velocity field and corresponding strain rates in (1)integrating and simplifying is given as

119882119886 = [1205871205731205880119877

2

01198803

3 (1 minus 119890minus1205732

)]

times [

(1 + 119890minus1205732

+ 120573119890minus31205732

)

2]

+ [(1198772

0

311986720

)(31198670

1198770

minus 2) (1 + 119890minus1205732

+ 119890minus120573)]

+[

1205731198770 (1 + 119890minus1205732

minus 3119890minus31205732

)

(1 minus 119890minus1205732

)31198802

]

(11)

32 Solid Rectangular Preform Internal energy dissipationldquo119882119894rdquo after substituting strain rates in (8) integrating andsimplifying is given as

119882119894 = [

radic312057321198612

01205900119880

48 (1 minus 119890minus1205732

)]

times [(41198672

0

11986120

) + 1205732(1 +

81198670

12057321198610

) (1 minus 119890minus1205732

)]

(12)

Frictional shear energy dissipation at die-preform interfaceldquo119882119891rdquo after substituting frictional stress equation and velocityfield in (8) integrating and simplifying is given as

119882119891 = [1205831205731198613

0119890minus1205732

1206010119880

81198670 (1 minus 119890minus1205732

)] [(

119875av1206010

) + (1 +1

3119899minus119861119898

1198991198610

)]

(13)

Energy dissipation due to inertia forces ldquo119882119886rdquo after substi-tuting velocity field and corresponding strain rates in (8)integrating and simplifying is given as

119882119886 = [120573412058801198672

01198803

(1 minus 119890minus1205732

)2]

times [

(2 + 119890minus1205732

+ 119890minus120573)

1205733

]

+ (1 + 119890minus1205732

)(2

1205732minus1198612

0

11986720

) + [1198610119890minus120573

1205731198802

]

(14)

6 Journal of Powder Technology

2D model 3D model

(a) Solid disc preforms

2D model 3D model

(b) Solid rectangular preforms

Figure 6 Modeling of SiCp AMC preforms

The average forging load for both cases was computed sepa-rately by substituting the above energy dissipation equationsin (15)

119865av = 4119869lowast(119880)minus1119860av (15)

Dynamic effects that is effect of die velocity on relativemagnitudes of various energy dissipations involved duringopen-die forging of SiCp AMC preforms are illustrated usinginertia factor ldquo120585rdquo which is defined as the ratio of inertiaenergy dissipated to total energy supplied by die platen duringdeformation and given as

120585 () = (119882119886

119869) 100 (16)

4 Finite Element Analysis

Finite element simulation of open-die forging of SiCp AMCpreforms has been performed using DEFORM-3D which isbased on the implicit Lagrangian finite element code In thepresent solution preform mesh deforms under the die loadand elasticity of the material has been neglected as plasticstrains outweigh elastic strains and material behaves like anelastic-viscoplastic material as stated by Kobayashi et al [29]

The stress-strain curve of type120590 = 119886120576119887MPa for SiCpAMC

material was uploaded in the material library of software asdescribed in the previous section The material properties ofSiCp AMC used in the present analysis are given in Table 2The geometry of die platens was generated in DEFORM andthe die platens were modeled as rigid parallel and flat bodieswith plastic preform placed in between them The geometryof preforms was generated using CATIA using part designmoduleworkbench and data was imported to DEFORM inform of STL files Figures 6(a) and 6(b) show the 2D and3D models of the solid disc and solid rectangular preformsrespectively The composite frictional law was considered tomodel the interfacial frictional conditions represented bysuitable composite interfacial frictional shear stress (referto (3) and (4)) Tetrahedral elements were used to meshthe preforms and small meshes were generated close tothe edges of preforms in order to better scope the forgingprocess The complete forging simulation was performedin 120 steps having time for movement of die platens ineach step equal to 0064 seconds The deformation criterion

Table 2 Material property of stir-casted SiCp AMC

Material property 5wt SiCp 13 wt SiCp

Poissonrsquos ratio gt033 gt033Ultimate tensile strength (MPA) 112 138Hardness (HRC) 54 62Stress-strain relationship 120590 = 119886120576

119887MPa

consideredwasmaximum forgeability of SiCpAMCpreformsat room temperature which was experimentally found to beabout 49 and 47 respectively for 5 wt and 13wt SiCpreinforced AMC preforms

5 Results and Discussions

Figure 7 shows that the maximum deformation of preformsis about 47ndash49 at room temperature under dry interfacialfriction conditions and preforms start cracking at maximumstress of about 14ndash15 GPa The stress required to producethe same amount of strain is higher in case of 13 wtSiCp preforms as well as higher in case of solid rectangularpreformsThis indicates that the increases in the perecentageof SiCp increases the stress required to deform the preformsAlso solid rectangular preforms exhibit higher constraintdeformation due to existence of sharp corners as comparedto solid disc preforms

Figure 8 shows that the percentage of height reductionof preform increases gradually during the initial phase ofdeformation and only after forging load attains a magnitudeof about 5ndash7 tons it increases exponentially This continuestill cracks start appearing on the outer surfaces of preformsthat is maximum forgeability of preforms In both axisym-metric and plane strain deformations the height reductionfor preforms having 5wt SiCp is found to be more ascompared to 13 wt SiCp preforms which indicates that thepercentage of increase in SiCp decreases the forgeability ofpreforms Also the load requirements are higher for thesame amount of deformation in case of solid disc preformsindicating better flow of material The experimental data arefound to be in close agreement with the theoretical oneswhich validates the present upper bound approach used tosolve the forging problems considered in the present paper

Journal of Powder Technology 7

00 01 02 03 04 0500

02

04

06

08

10

12

14

16

Solid disc preformSolid rectangular preform

Engineering strain

Engi

neer

ing

stres

s (G

Pa)

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

5wt SiCp13wt SiCp

Figure 7 Experimental variation of engineering stress (GPa) withengineering strain (mmmm)

0 3 6 9 12 15 18 210

10

20

30

40

50

Forging load (tons)

Hei

ght r

educ

tion

()

Solid rectangular preform

Solid disc preform

R0 = 10mm H0 = 10mm L0 = 20mmB0 = 10mm Uav = 01ms 120583eff = 05

Experimental dataExperimental data

5wt SiCp

13wt SiCp

Figure 8 Experimental and theoretical variations of height reduc-tion () with forging load (tons)

Figure 9 shows the variation of strain rate (mmmmsec) with forging load (tons) for SiCp AMC preforms Asevident from the figure maximum strain rate of magnitude0024 secminus1 is being observed at forging load of about 20tons for both 5wt and 13wt SiCp Initially strain ratesare higher for solid rectangular preforms but after theload attains a magnitude of about 10 tons strain rates for13 wt SiCp preforms are higher irrespective of the shape ofpreforms Also at the end of forging operations strain ratesare found to decrease slightly after attaining the highest value

0 5 10 15 20 25 300000

0005

0010

0015

0020

0025

Forging load (Tons)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

Stra

in ra

te (s

minus1)

5wt SiCp

13wt SiCp

Figure 9 Experimental variation of strain rate (mmmm sec) withforging load (tons)

These two behaviors are attributed due to the consolidationof SiCp particles within the AMC preforms during the end offorging operation It can be concluded that the effect of SiCpparticles on stress strain and strain rate is predominant upto 40 of height reduction at forging load of about 20 tonsand thereafter these particles consolidate within the matrixand hence they least influence the forging characteristics

It can be seen from Figure 10 that the energy dissipationincreases with the increase in the forging load and defor-mation The total energy requirement for deformation ofAMC preforms having higher SiCp is found to be higherdue to higher strength of material and is also higher if theprocess is carried at higher die acceleration leading to higherinertia energy dissipation (refer to (11) and (14)) Also energyrequirements are higher for solid rectangular preforms ascompared to solid disc preforms due to more constraintdeformation in the former case

The variation of inertia factor with die velocity for SiCpAMC preforms is shown in Figure 11 It is clearly evidentthat inertia factor increases exponentially with increase in thedie velocity and is higher for higher die acceleration in solidrectangular preforms Also it can be noticed that proportionof inertia energy can be as high as 30 of the total energydissipation and hence cannot be neglected during the presentinvestigation

Figure 12 shows that both axial and radial strains increaseexponentially with increases in the forging load Also thecorresponding values of axial strains are higher than radialstrains for same forging load and higher percentage of SiCpIt also depicts the measure of Poissonrsquos ratio that is ratio ofradial strain to axial strain for present SiCp AMCmaterial

Figure 13 shows the effective stress (MPa) distribution onSiCp AMC preforms It is clearly evident that magnitudesof effective stresses are higher in 13 wt SiCp preforms ascompared to 5wt SiCp preforms in the corresponding

8 Journal of Powder Technology

0 3 6 9 12 15 18 210

2

4

6

8

10

12

Average forging load (tons)

Tota

l ene

rgy

diss

ipat

ion

(kJ)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav Uav = 01ms 120583eff = 05

13wt SiCp accel = 025mms2

5wt SiCp accel = 025mms213wt SiCp accel = 01mms2

5wt SiCp accel = 01mms2

Figure 10Theoretical variation of total energy dissipation (kJ) withaverage forging load (tons)

0 4 8 12 16 20 240

5

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Die velocity (mms)

Iner

tia fa

ctor

()

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav 120583eff = 05 SiCp = 5wt

Accel = 025mms2Accel = 005mms2Accel = 010mms2

Figure 11Theoretical variation of inertia factor ()with die velocity(mms)

regions The edges are subjected to higher stresses whereasthe centremost regions are having lower stresses of magni-tude about 150MPa and 300MPa for solid disc and solidrectangular preforms respectively This indicates that as thepercentage of SiCp increases stress also increases due toincrease in the strength of preforms

Figure 14 shows the effective strain (mmmm) distribu-tion on SiCp AMC preforms It can be seen that the major

00010203040506

5 40Average forging load (tons)

Solid rectangular preformSolid disc preform

10 20 30

R0 = 10mm H0 = 10mm

L0 = 20mm B0 = 10mm

120573 = 04 1206010 = 030 Pav 120583eff = 05

minus05

minus06

minus04

minus02

minus03

minus01

Axi

al st

rain

998400 120576998400 z

Radi

al st

rain

998400 120576998400 r

13 wt SiCp5 wt SiCp

Figure 12Theoretical variation of radial strain and axial strain withaverage forging load (tons)

portion of preform is subjected to strain in the order 03ndash06 magnitude except at the edges The strains are higher in5wt SiCp preforms as compared to 13 wt SiCp preformswhich indicate that ductility of 5 wt SiCp is higher In case of5 wt SiCp preforms the edges are subjected to severe strainof magnitude about 07ndash09 which leads to the fracture ofvertical surfaces and is also confirmed from Figure 3 In thiscase no appreciable variation in the strain distribution hasbeen observed for preforms having 13 wt and 5wt SiCpAlso the strains at the central region of preform are low andeventually almost zero at the centermost regions near to theupper and bottom flat surfaces The dissected section alsoreveals that the variation of strain in the central region isin the form of an inverted cone This confirms the presenceof sticking friction zone at those regions which confirmsand validates the variable interfacial composite friction lawconsidered during the present theoretical analysis

The distribution of effective strain rate (mmmm-sec)on SiCp AMC preforms is shown in Figure 15 It can beclearly seen that the major portion of solid disc preforms issubjected to strain rate of about 2mmmm-sec and only theedges are subjected to higher strain rates in the order 32ndash35mmmm-sec In case of solid rectangular preforms theedges are subjected to strain rate of 25ndash29mmmm-secThesolid disc preforms are having higher strain rates as comparedto solid rectangular preforms indicating better metal flow inthe former case as well as presence of constraint deformationin case of solid rectangular preforms

The velocity (mmsec) distribution on SiCp AMC pre-forms is shown in Figure 16 It can be observed that soliddisc and solid rectangular preforms are subjected to the high-est flow velocity of about 10ndash13mmsec and 15ndash17mmsecrespectively Also the outer regions of preform are havinghigher flow velocity as compared to the inner regions whichis in close agreement with the composite interfacial friction

Journal of Powder Technology 9

995

871

746

622

498

373

249

124

0000

MinMax

1140

1000

857

715

572

429

286

143

00006891140

(a) 5 wt SiCp

1010

885

759

632

506

379

253

126

0000

MinMax

857

750

643

536

429

322

214

107

0000659857

(b) 13 wt SiCp

Figure 13 Distribution of effective stress (MPa)

0888

0777

0666

0555

0444

0333

0222

0111

0000

MinMax

0761

0666

0571

0476

0380

0285

0190

00951

000004550761

(a) 5 wt SiCp

0918

0803

0689

0574

0459

0344

0230

0115

0000

0779

0682

0584

0487

0390

0292

0195

00974

000004500779

MinMax

(b) 13 wt SiCp

Figure 14 Distribution of effective strain (mmmm)

10 Journal of Powder Technology

318278238198159119079403970000

2592271941621290971064703240000141259

MinMax

(a) 5 wt SiCp

359314269225180135089804490000

279244209174139105069703490000133278

MinMax

(b) 13 wt SiCp

Figure 15 Distribution of effective strain rate (mmmm-sec)

1311171028757295834372921460000

157

157

137

118

979

784

588

392

196

0000

000818MinMax

(a) 5 wt SiCp

1311181059167856545233932621310000

MinMax

172

151

129

108

862

647

431

216

00000308159

(b) 13 wt SiCp

Figure 16 Velocity (mmsec) distribution on SiCp preforms

Journal of Powder Technology 11

00 01 02 03 04 050

200

400

600

800

1000

Solid rectangular preformSolid disc preform

Forging time (s)

Effec

tive s

tress

(MPa

)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 17 Computational variations of effective stress (MPa) withforging time (sec)

law considered in the present paper The strain rates arehigher in case of 5 wt SiCp preforms as compared to 13 wtSiCp which indicates that ductility of preform decreases withthe increase in the perecentage of SiCp The variation of flowvelocity in the vertical direction leads to the barreling of pre-forms which confirms the inclusion of barreling parameterldquo120573rdquo during the present theoretical analysis

Figure 17 shows the variation of effective stress (MPa)with forging time (sec) for SiCp AMC preforms It canbe observed that stress requirement for preforms having13 wt SiCp is higher as compared to preforms having 5wtSiCp which indicates that the percentage of increase in SiCpincreases the hardness of preforms It can be also seen thatsolid rectangular preforms are subjected to higher effectivestresses as compared to solid disc preforms indicating bettermaterial flow in case of solid disc preforms as well asconstraint deformation in case of solid rectangular preforms

The variation of effective strain (mmmm) with forgingtime (sec) is shown in Figure 18 and it was found that itincreased exponentially with respect to forging time Alsoit is clearly evident that effective strains for solid rectangularpreforms are higher as compared to solid disc preforms dueto constraint deformation

Figure 19 shows the variation of effective strain rate(mmmm-sec) with forging time (sec) for SiCp AMC pre-forms The strain rate for 5wt SiCp preforms is foundhigher than preforms having 13 wt SiCp which indicatesthat percentage of increase in SiCp decreases the ductility andforgeability of preforms Also the strain rates are higher forsolid disc preforms as compared to solid rectangular preformdue to constraint deformation in the latter case

Figure 20 shows the variation of forging load (kN) withforging time (sec) for solid disc and solid rectangular pre-forms which is found to increase rapidly with forging time Itcan be clearly seen that the preforms canwithstandmaximum

00 01 02 03 04 0500

02

04

06

08

10

Effec

tive s

trai

n (m

mm

m)

Forging time (s)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 18 Computational variations of effective strain (mmmm)with forging time (sec)

00 01 02 03 04 0500

05

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Effec

tive s

trai

n ra

te (s

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp

13wt SiCp

Figure 19 Computational variations of effective strain rate(mmmm-sec) with forging time (sec)

load of about 270ndash300 kNwithout the onset of fracture It canalso be noted that solid rectangular preforms require higherload to deform as compared to solid disc preforms

6 Conclusions

Themajor conclusions may be summarized as follows

(i) Maximum formability of AMC material at roomtemperature and under dry interfacial frictional con-ditions was found to be about 47-47 of height reduc-tion The deformations in AMC preforms having5wt SiCp were found to be higher as compared

12 Journal of Powder Technology

00 01 02 03 04 050

50

100

150

200

250

300

Forg

ing

load

(kN

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm

Solid rectangular preformSolid disc preform

120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp13wt SiCp

Figure 20 Computational variations of forging load (kN) withforging time (sec)

Upper die

Lower die

(0 0)

r (xlowast)

r (xlowast)

dr (dxlowast)

z

H0

Figure 21 Open-die forging of SiCp AMC preform

to 13 wt SiCp indicating that as the percentage ofSiCp particulate increases forgeability of the preformsdecreases The experimental result was found to bein close agreement with theoretical ones and hencevalidates the present theoretical analysis based onupper bound approach

(ii) Engineering stress required to produce the sameamount of strain was found to be higher in case ofAMC preforms having higher weight of SiCp aswell as higher for solid rectangular preformsThis wasattributed due to the fact that the increase in weight of SiCp increases the hardness of the preform Alsosolid rectangular preforms exhibit higher constraintdeformation due to the presence of sharp corners

(iii) The highest strain rate in the order of 024 wasexperienced during the open-die forging of AMCpreforms irrespective of the percentage of SiCp Theeffect of SiCp particles over various deformationcharacteristics like strain stress and strain rate ispredominant only up to nearly 44 of height reduc-tion and thereafter these particles consolidate within

the metal matrix and have the least influence on thevarious forging parameters

(iv) Total energy requirements during open-die forging ofAMC preforms having higher SiCp are found to behigher due to higher strength of the material Alsothe energy requirements are higher if the processis carried out at higher die acceleration due toinertia effects Also the effect of die velocity wasclearly depicted using inertia factor which indicatedthat energy dissipation due to inertia effects maybe as high as 30 of the total energy dissipationsand thus must be considered during the analysis offorging operations carried out especially at higher dievelocities

(v) Lower magnitude of strains was observed at thecentral region of preforms andwas found to be almostzero at the centermost region near to top and bot-tom flat surfaces indicating the presence of variableinterfacial friction zone in the form of inverted coneThis confirmed the composite interfacial friction lawconsidered during the present investigationsThiswasalso confirmed by the results of velocity distributionwhere flow velocity was found to be zero at the cen-termost regions of preforms indicating the existenceof nondeforming zone due to the presence of highsticking friction conditions

(vi) Simulation of open-die forging of SiCp AMCmaterialwas performed using DEFORM and the distributionof effective stress effective strain effective strain rateand velocity vector profile was generated for bothsolid disc and solid rectangular preforms Highermagnitudes of effective stress strain and strain ratewere found at the corners and edges of preformsindicating that the onset of fracture will take placeat those regions only This was also confirmed by thepresence of severe cracks at those regions during thepresent experimental investigations

(vii) Validation of simulation was done by comparing itsresults with the theoretical and experimental resultsand was found to reasonably agree with each otherwhich indicated that present finite element simulationrepresents fairly well the present open-die forging ofSiCp AMC

It is expected that the present work will be useful forthe assessment of various deformation characteristics duringmechanical processing of AMCs

Appendix

Consider open-die forging of a SiCp AMC between two per-fectly flat parallel and rigid die platens at room temperaturewith lower die platen moving upwards with velocity ldquo119880rdquo andupper die platen stationary as shown in Figure 21

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Journal of Powder Technology 5

13wt5wt

(a) Before forging

13wt5wt

(b) After forging

Figure 4 Solid rectangular SiCp AMC preforms

(a) 5 wt SiCp (b) 13 wt SiCp

Figure 5 Photomicrograph of SiCp AMC preforms

Frictional shear energy dissipation at die-preform interfaceldquo119882119891rdquo after substituting frictional stress equation and velocityfield in (8) integrating and simplifying is given as

119882119891 = [2120587120583120573119877

3

0119890minus1205732

1206010119880

1198670 (1 minus 119890minus1205732

)] [(

119875av1206010

) + (1 +2

3119899minus119877119898

1198991198770

)]

(10)

Energy dissipation due to inertia forces ldquo119882119886rdquo after substi-tuting velocity field and corresponding strain rates in (1)integrating and simplifying is given as

119882119886 = [1205871205731205880119877

2

01198803

3 (1 minus 119890minus1205732

)]

times [

(1 + 119890minus1205732

+ 120573119890minus31205732

)

2]

+ [(1198772

0

311986720

)(31198670

1198770

minus 2) (1 + 119890minus1205732

+ 119890minus120573)]

+[

1205731198770 (1 + 119890minus1205732

minus 3119890minus31205732

)

(1 minus 119890minus1205732

)31198802

]

(11)

32 Solid Rectangular Preform Internal energy dissipationldquo119882119894rdquo after substituting strain rates in (8) integrating andsimplifying is given as

119882119894 = [

radic312057321198612

01205900119880

48 (1 minus 119890minus1205732

)]

times [(41198672

0

11986120

) + 1205732(1 +

81198670

12057321198610

) (1 minus 119890minus1205732

)]

(12)

Frictional shear energy dissipation at die-preform interfaceldquo119882119891rdquo after substituting frictional stress equation and velocityfield in (8) integrating and simplifying is given as

119882119891 = [1205831205731198613

0119890minus1205732

1206010119880

81198670 (1 minus 119890minus1205732

)] [(

119875av1206010

) + (1 +1

3119899minus119861119898

1198991198610

)]

(13)

Energy dissipation due to inertia forces ldquo119882119886rdquo after substi-tuting velocity field and corresponding strain rates in (8)integrating and simplifying is given as

119882119886 = [120573412058801198672

01198803

(1 minus 119890minus1205732

)2]

times [

(2 + 119890minus1205732

+ 119890minus120573)

1205733

]

+ (1 + 119890minus1205732

)(2

1205732minus1198612

0

11986720

) + [1198610119890minus120573

1205731198802

]

(14)

6 Journal of Powder Technology

2D model 3D model

(a) Solid disc preforms

2D model 3D model

(b) Solid rectangular preforms

Figure 6 Modeling of SiCp AMC preforms

The average forging load for both cases was computed sepa-rately by substituting the above energy dissipation equationsin (15)

119865av = 4119869lowast(119880)minus1119860av (15)

Dynamic effects that is effect of die velocity on relativemagnitudes of various energy dissipations involved duringopen-die forging of SiCp AMC preforms are illustrated usinginertia factor ldquo120585rdquo which is defined as the ratio of inertiaenergy dissipated to total energy supplied by die platen duringdeformation and given as

120585 () = (119882119886

119869) 100 (16)

4 Finite Element Analysis

Finite element simulation of open-die forging of SiCp AMCpreforms has been performed using DEFORM-3D which isbased on the implicit Lagrangian finite element code In thepresent solution preform mesh deforms under the die loadand elasticity of the material has been neglected as plasticstrains outweigh elastic strains and material behaves like anelastic-viscoplastic material as stated by Kobayashi et al [29]

The stress-strain curve of type120590 = 119886120576119887MPa for SiCpAMC

material was uploaded in the material library of software asdescribed in the previous section The material properties ofSiCp AMC used in the present analysis are given in Table 2The geometry of die platens was generated in DEFORM andthe die platens were modeled as rigid parallel and flat bodieswith plastic preform placed in between them The geometryof preforms was generated using CATIA using part designmoduleworkbench and data was imported to DEFORM inform of STL files Figures 6(a) and 6(b) show the 2D and3D models of the solid disc and solid rectangular preformsrespectively The composite frictional law was considered tomodel the interfacial frictional conditions represented bysuitable composite interfacial frictional shear stress (referto (3) and (4)) Tetrahedral elements were used to meshthe preforms and small meshes were generated close tothe edges of preforms in order to better scope the forgingprocess The complete forging simulation was performedin 120 steps having time for movement of die platens ineach step equal to 0064 seconds The deformation criterion

Table 2 Material property of stir-casted SiCp AMC

Material property 5wt SiCp 13 wt SiCp

Poissonrsquos ratio gt033 gt033Ultimate tensile strength (MPA) 112 138Hardness (HRC) 54 62Stress-strain relationship 120590 = 119886120576

119887MPa

consideredwasmaximum forgeability of SiCpAMCpreformsat room temperature which was experimentally found to beabout 49 and 47 respectively for 5 wt and 13wt SiCpreinforced AMC preforms

5 Results and Discussions

Figure 7 shows that the maximum deformation of preformsis about 47ndash49 at room temperature under dry interfacialfriction conditions and preforms start cracking at maximumstress of about 14ndash15 GPa The stress required to producethe same amount of strain is higher in case of 13 wtSiCp preforms as well as higher in case of solid rectangularpreformsThis indicates that the increases in the perecentageof SiCp increases the stress required to deform the preformsAlso solid rectangular preforms exhibit higher constraintdeformation due to existence of sharp corners as comparedto solid disc preforms

Figure 8 shows that the percentage of height reductionof preform increases gradually during the initial phase ofdeformation and only after forging load attains a magnitudeof about 5ndash7 tons it increases exponentially This continuestill cracks start appearing on the outer surfaces of preformsthat is maximum forgeability of preforms In both axisym-metric and plane strain deformations the height reductionfor preforms having 5wt SiCp is found to be more ascompared to 13 wt SiCp preforms which indicates that thepercentage of increase in SiCp decreases the forgeability ofpreforms Also the load requirements are higher for thesame amount of deformation in case of solid disc preformsindicating better flow of material The experimental data arefound to be in close agreement with the theoretical oneswhich validates the present upper bound approach used tosolve the forging problems considered in the present paper

Journal of Powder Technology 7

00 01 02 03 04 0500

02

04

06

08

10

12

14

16

Solid disc preformSolid rectangular preform

Engineering strain

Engi

neer

ing

stres

s (G

Pa)

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

5wt SiCp13wt SiCp

Figure 7 Experimental variation of engineering stress (GPa) withengineering strain (mmmm)

0 3 6 9 12 15 18 210

10

20

30

40

50

Forging load (tons)

Hei

ght r

educ

tion

()

Solid rectangular preform

Solid disc preform

R0 = 10mm H0 = 10mm L0 = 20mmB0 = 10mm Uav = 01ms 120583eff = 05

Experimental dataExperimental data

5wt SiCp

13wt SiCp

Figure 8 Experimental and theoretical variations of height reduc-tion () with forging load (tons)

Figure 9 shows the variation of strain rate (mmmmsec) with forging load (tons) for SiCp AMC preforms Asevident from the figure maximum strain rate of magnitude0024 secminus1 is being observed at forging load of about 20tons for both 5wt and 13wt SiCp Initially strain ratesare higher for solid rectangular preforms but after theload attains a magnitude of about 10 tons strain rates for13 wt SiCp preforms are higher irrespective of the shape ofpreforms Also at the end of forging operations strain ratesare found to decrease slightly after attaining the highest value

0 5 10 15 20 25 300000

0005

0010

0015

0020

0025

Forging load (Tons)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

Stra

in ra

te (s

minus1)

5wt SiCp

13wt SiCp

Figure 9 Experimental variation of strain rate (mmmm sec) withforging load (tons)

These two behaviors are attributed due to the consolidationof SiCp particles within the AMC preforms during the end offorging operation It can be concluded that the effect of SiCpparticles on stress strain and strain rate is predominant upto 40 of height reduction at forging load of about 20 tonsand thereafter these particles consolidate within the matrixand hence they least influence the forging characteristics

It can be seen from Figure 10 that the energy dissipationincreases with the increase in the forging load and defor-mation The total energy requirement for deformation ofAMC preforms having higher SiCp is found to be higherdue to higher strength of material and is also higher if theprocess is carried at higher die acceleration leading to higherinertia energy dissipation (refer to (11) and (14)) Also energyrequirements are higher for solid rectangular preforms ascompared to solid disc preforms due to more constraintdeformation in the former case

The variation of inertia factor with die velocity for SiCpAMC preforms is shown in Figure 11 It is clearly evidentthat inertia factor increases exponentially with increase in thedie velocity and is higher for higher die acceleration in solidrectangular preforms Also it can be noticed that proportionof inertia energy can be as high as 30 of the total energydissipation and hence cannot be neglected during the presentinvestigation

Figure 12 shows that both axial and radial strains increaseexponentially with increases in the forging load Also thecorresponding values of axial strains are higher than radialstrains for same forging load and higher percentage of SiCpIt also depicts the measure of Poissonrsquos ratio that is ratio ofradial strain to axial strain for present SiCp AMCmaterial

Figure 13 shows the effective stress (MPa) distribution onSiCp AMC preforms It is clearly evident that magnitudesof effective stresses are higher in 13 wt SiCp preforms ascompared to 5wt SiCp preforms in the corresponding

8 Journal of Powder Technology

0 3 6 9 12 15 18 210

2

4

6

8

10

12

Average forging load (tons)

Tota

l ene

rgy

diss

ipat

ion

(kJ)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav Uav = 01ms 120583eff = 05

13wt SiCp accel = 025mms2

5wt SiCp accel = 025mms213wt SiCp accel = 01mms2

5wt SiCp accel = 01mms2

Figure 10Theoretical variation of total energy dissipation (kJ) withaverage forging load (tons)

0 4 8 12 16 20 240

5

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Die velocity (mms)

Iner

tia fa

ctor

()

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav 120583eff = 05 SiCp = 5wt

Accel = 025mms2Accel = 005mms2Accel = 010mms2

Figure 11Theoretical variation of inertia factor ()with die velocity(mms)

regions The edges are subjected to higher stresses whereasthe centremost regions are having lower stresses of magni-tude about 150MPa and 300MPa for solid disc and solidrectangular preforms respectively This indicates that as thepercentage of SiCp increases stress also increases due toincrease in the strength of preforms

Figure 14 shows the effective strain (mmmm) distribu-tion on SiCp AMC preforms It can be seen that the major

00010203040506

5 40Average forging load (tons)

Solid rectangular preformSolid disc preform

10 20 30

R0 = 10mm H0 = 10mm

L0 = 20mm B0 = 10mm

120573 = 04 1206010 = 030 Pav 120583eff = 05

minus05

minus06

minus04

minus02

minus03

minus01

Axi

al st

rain

998400 120576998400 z

Radi

al st

rain

998400 120576998400 r

13 wt SiCp5 wt SiCp

Figure 12Theoretical variation of radial strain and axial strain withaverage forging load (tons)

portion of preform is subjected to strain in the order 03ndash06 magnitude except at the edges The strains are higher in5wt SiCp preforms as compared to 13 wt SiCp preformswhich indicate that ductility of 5 wt SiCp is higher In case of5 wt SiCp preforms the edges are subjected to severe strainof magnitude about 07ndash09 which leads to the fracture ofvertical surfaces and is also confirmed from Figure 3 In thiscase no appreciable variation in the strain distribution hasbeen observed for preforms having 13 wt and 5wt SiCpAlso the strains at the central region of preform are low andeventually almost zero at the centermost regions near to theupper and bottom flat surfaces The dissected section alsoreveals that the variation of strain in the central region isin the form of an inverted cone This confirms the presenceof sticking friction zone at those regions which confirmsand validates the variable interfacial composite friction lawconsidered during the present theoretical analysis

The distribution of effective strain rate (mmmm-sec)on SiCp AMC preforms is shown in Figure 15 It can beclearly seen that the major portion of solid disc preforms issubjected to strain rate of about 2mmmm-sec and only theedges are subjected to higher strain rates in the order 32ndash35mmmm-sec In case of solid rectangular preforms theedges are subjected to strain rate of 25ndash29mmmm-secThesolid disc preforms are having higher strain rates as comparedto solid rectangular preforms indicating better metal flow inthe former case as well as presence of constraint deformationin case of solid rectangular preforms

The velocity (mmsec) distribution on SiCp AMC pre-forms is shown in Figure 16 It can be observed that soliddisc and solid rectangular preforms are subjected to the high-est flow velocity of about 10ndash13mmsec and 15ndash17mmsecrespectively Also the outer regions of preform are havinghigher flow velocity as compared to the inner regions whichis in close agreement with the composite interfacial friction

Journal of Powder Technology 9

995

871

746

622

498

373

249

124

0000

MinMax

1140

1000

857

715

572

429

286

143

00006891140

(a) 5 wt SiCp

1010

885

759

632

506

379

253

126

0000

MinMax

857

750

643

536

429

322

214

107

0000659857

(b) 13 wt SiCp

Figure 13 Distribution of effective stress (MPa)

0888

0777

0666

0555

0444

0333

0222

0111

0000

MinMax

0761

0666

0571

0476

0380

0285

0190

00951

000004550761

(a) 5 wt SiCp

0918

0803

0689

0574

0459

0344

0230

0115

0000

0779

0682

0584

0487

0390

0292

0195

00974

000004500779

MinMax

(b) 13 wt SiCp

Figure 14 Distribution of effective strain (mmmm)

10 Journal of Powder Technology

318278238198159119079403970000

2592271941621290971064703240000141259

MinMax

(a) 5 wt SiCp

359314269225180135089804490000

279244209174139105069703490000133278

MinMax

(b) 13 wt SiCp

Figure 15 Distribution of effective strain rate (mmmm-sec)

1311171028757295834372921460000

157

157

137

118

979

784

588

392

196

0000

000818MinMax

(a) 5 wt SiCp

1311181059167856545233932621310000

MinMax

172

151

129

108

862

647

431

216

00000308159

(b) 13 wt SiCp

Figure 16 Velocity (mmsec) distribution on SiCp preforms

Journal of Powder Technology 11

00 01 02 03 04 050

200

400

600

800

1000

Solid rectangular preformSolid disc preform

Forging time (s)

Effec

tive s

tress

(MPa

)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 17 Computational variations of effective stress (MPa) withforging time (sec)

law considered in the present paper The strain rates arehigher in case of 5 wt SiCp preforms as compared to 13 wtSiCp which indicates that ductility of preform decreases withthe increase in the perecentage of SiCp The variation of flowvelocity in the vertical direction leads to the barreling of pre-forms which confirms the inclusion of barreling parameterldquo120573rdquo during the present theoretical analysis

Figure 17 shows the variation of effective stress (MPa)with forging time (sec) for SiCp AMC preforms It canbe observed that stress requirement for preforms having13 wt SiCp is higher as compared to preforms having 5wtSiCp which indicates that the percentage of increase in SiCpincreases the hardness of preforms It can be also seen thatsolid rectangular preforms are subjected to higher effectivestresses as compared to solid disc preforms indicating bettermaterial flow in case of solid disc preforms as well asconstraint deformation in case of solid rectangular preforms

The variation of effective strain (mmmm) with forgingtime (sec) is shown in Figure 18 and it was found that itincreased exponentially with respect to forging time Alsoit is clearly evident that effective strains for solid rectangularpreforms are higher as compared to solid disc preforms dueto constraint deformation

Figure 19 shows the variation of effective strain rate(mmmm-sec) with forging time (sec) for SiCp AMC pre-forms The strain rate for 5wt SiCp preforms is foundhigher than preforms having 13 wt SiCp which indicatesthat percentage of increase in SiCp decreases the ductility andforgeability of preforms Also the strain rates are higher forsolid disc preforms as compared to solid rectangular preformdue to constraint deformation in the latter case

Figure 20 shows the variation of forging load (kN) withforging time (sec) for solid disc and solid rectangular pre-forms which is found to increase rapidly with forging time Itcan be clearly seen that the preforms canwithstandmaximum

00 01 02 03 04 0500

02

04

06

08

10

Effec

tive s

trai

n (m

mm

m)

Forging time (s)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 18 Computational variations of effective strain (mmmm)with forging time (sec)

00 01 02 03 04 0500

05

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Effec

tive s

trai

n ra

te (s

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp

13wt SiCp

Figure 19 Computational variations of effective strain rate(mmmm-sec) with forging time (sec)

load of about 270ndash300 kNwithout the onset of fracture It canalso be noted that solid rectangular preforms require higherload to deform as compared to solid disc preforms

6 Conclusions

Themajor conclusions may be summarized as follows

(i) Maximum formability of AMC material at roomtemperature and under dry interfacial frictional con-ditions was found to be about 47-47 of height reduc-tion The deformations in AMC preforms having5wt SiCp were found to be higher as compared

12 Journal of Powder Technology

00 01 02 03 04 050

50

100

150

200

250

300

Forg

ing

load

(kN

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm

Solid rectangular preformSolid disc preform

120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp13wt SiCp

Figure 20 Computational variations of forging load (kN) withforging time (sec)

Upper die

Lower die

(0 0)

r (xlowast)

r (xlowast)

dr (dxlowast)

z

H0

Figure 21 Open-die forging of SiCp AMC preform

to 13 wt SiCp indicating that as the percentage ofSiCp particulate increases forgeability of the preformsdecreases The experimental result was found to bein close agreement with theoretical ones and hencevalidates the present theoretical analysis based onupper bound approach

(ii) Engineering stress required to produce the sameamount of strain was found to be higher in case ofAMC preforms having higher weight of SiCp aswell as higher for solid rectangular preformsThis wasattributed due to the fact that the increase in weight of SiCp increases the hardness of the preform Alsosolid rectangular preforms exhibit higher constraintdeformation due to the presence of sharp corners

(iii) The highest strain rate in the order of 024 wasexperienced during the open-die forging of AMCpreforms irrespective of the percentage of SiCp Theeffect of SiCp particles over various deformationcharacteristics like strain stress and strain rate ispredominant only up to nearly 44 of height reduc-tion and thereafter these particles consolidate within

the metal matrix and have the least influence on thevarious forging parameters

(iv) Total energy requirements during open-die forging ofAMC preforms having higher SiCp are found to behigher due to higher strength of the material Alsothe energy requirements are higher if the processis carried out at higher die acceleration due toinertia effects Also the effect of die velocity wasclearly depicted using inertia factor which indicatedthat energy dissipation due to inertia effects maybe as high as 30 of the total energy dissipationsand thus must be considered during the analysis offorging operations carried out especially at higher dievelocities

(v) Lower magnitude of strains was observed at thecentral region of preforms andwas found to be almostzero at the centermost region near to top and bot-tom flat surfaces indicating the presence of variableinterfacial friction zone in the form of inverted coneThis confirmed the composite interfacial friction lawconsidered during the present investigationsThiswasalso confirmed by the results of velocity distributionwhere flow velocity was found to be zero at the cen-termost regions of preforms indicating the existenceof nondeforming zone due to the presence of highsticking friction conditions

(vi) Simulation of open-die forging of SiCp AMCmaterialwas performed using DEFORM and the distributionof effective stress effective strain effective strain rateand velocity vector profile was generated for bothsolid disc and solid rectangular preforms Highermagnitudes of effective stress strain and strain ratewere found at the corners and edges of preformsindicating that the onset of fracture will take placeat those regions only This was also confirmed by thepresence of severe cracks at those regions during thepresent experimental investigations

(vii) Validation of simulation was done by comparing itsresults with the theoretical and experimental resultsand was found to reasonably agree with each otherwhich indicated that present finite element simulationrepresents fairly well the present open-die forging ofSiCp AMC

It is expected that the present work will be useful forthe assessment of various deformation characteristics duringmechanical processing of AMCs

Appendix

Consider open-die forging of a SiCp AMC between two per-fectly flat parallel and rigid die platens at room temperaturewith lower die platen moving upwards with velocity ldquo119880rdquo andupper die platen stationary as shown in Figure 21

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Biomaterials

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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

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Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

6 Journal of Powder Technology

2D model 3D model

(a) Solid disc preforms

2D model 3D model

(b) Solid rectangular preforms

Figure 6 Modeling of SiCp AMC preforms

The average forging load for both cases was computed sepa-rately by substituting the above energy dissipation equationsin (15)

119865av = 4119869lowast(119880)minus1119860av (15)

Dynamic effects that is effect of die velocity on relativemagnitudes of various energy dissipations involved duringopen-die forging of SiCp AMC preforms are illustrated usinginertia factor ldquo120585rdquo which is defined as the ratio of inertiaenergy dissipated to total energy supplied by die platen duringdeformation and given as

120585 () = (119882119886

119869) 100 (16)

4 Finite Element Analysis

Finite element simulation of open-die forging of SiCp AMCpreforms has been performed using DEFORM-3D which isbased on the implicit Lagrangian finite element code In thepresent solution preform mesh deforms under the die loadand elasticity of the material has been neglected as plasticstrains outweigh elastic strains and material behaves like anelastic-viscoplastic material as stated by Kobayashi et al [29]

The stress-strain curve of type120590 = 119886120576119887MPa for SiCpAMC

material was uploaded in the material library of software asdescribed in the previous section The material properties ofSiCp AMC used in the present analysis are given in Table 2The geometry of die platens was generated in DEFORM andthe die platens were modeled as rigid parallel and flat bodieswith plastic preform placed in between them The geometryof preforms was generated using CATIA using part designmoduleworkbench and data was imported to DEFORM inform of STL files Figures 6(a) and 6(b) show the 2D and3D models of the solid disc and solid rectangular preformsrespectively The composite frictional law was considered tomodel the interfacial frictional conditions represented bysuitable composite interfacial frictional shear stress (referto (3) and (4)) Tetrahedral elements were used to meshthe preforms and small meshes were generated close tothe edges of preforms in order to better scope the forgingprocess The complete forging simulation was performedin 120 steps having time for movement of die platens ineach step equal to 0064 seconds The deformation criterion

Table 2 Material property of stir-casted SiCp AMC

Material property 5wt SiCp 13 wt SiCp

Poissonrsquos ratio gt033 gt033Ultimate tensile strength (MPA) 112 138Hardness (HRC) 54 62Stress-strain relationship 120590 = 119886120576

119887MPa

consideredwasmaximum forgeability of SiCpAMCpreformsat room temperature which was experimentally found to beabout 49 and 47 respectively for 5 wt and 13wt SiCpreinforced AMC preforms

5 Results and Discussions

Figure 7 shows that the maximum deformation of preformsis about 47ndash49 at room temperature under dry interfacialfriction conditions and preforms start cracking at maximumstress of about 14ndash15 GPa The stress required to producethe same amount of strain is higher in case of 13 wtSiCp preforms as well as higher in case of solid rectangularpreformsThis indicates that the increases in the perecentageof SiCp increases the stress required to deform the preformsAlso solid rectangular preforms exhibit higher constraintdeformation due to existence of sharp corners as comparedto solid disc preforms

Figure 8 shows that the percentage of height reductionof preform increases gradually during the initial phase ofdeformation and only after forging load attains a magnitudeof about 5ndash7 tons it increases exponentially This continuestill cracks start appearing on the outer surfaces of preformsthat is maximum forgeability of preforms In both axisym-metric and plane strain deformations the height reductionfor preforms having 5wt SiCp is found to be more ascompared to 13 wt SiCp preforms which indicates that thepercentage of increase in SiCp decreases the forgeability ofpreforms Also the load requirements are higher for thesame amount of deformation in case of solid disc preformsindicating better flow of material The experimental data arefound to be in close agreement with the theoretical oneswhich validates the present upper bound approach used tosolve the forging problems considered in the present paper

Journal of Powder Technology 7

00 01 02 03 04 0500

02

04

06

08

10

12

14

16

Solid disc preformSolid rectangular preform

Engineering strain

Engi

neer

ing

stres

s (G

Pa)

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

5wt SiCp13wt SiCp

Figure 7 Experimental variation of engineering stress (GPa) withengineering strain (mmmm)

0 3 6 9 12 15 18 210

10

20

30

40

50

Forging load (tons)

Hei

ght r

educ

tion

()

Solid rectangular preform

Solid disc preform

R0 = 10mm H0 = 10mm L0 = 20mmB0 = 10mm Uav = 01ms 120583eff = 05

Experimental dataExperimental data

5wt SiCp

13wt SiCp

Figure 8 Experimental and theoretical variations of height reduc-tion () with forging load (tons)

Figure 9 shows the variation of strain rate (mmmmsec) with forging load (tons) for SiCp AMC preforms Asevident from the figure maximum strain rate of magnitude0024 secminus1 is being observed at forging load of about 20tons for both 5wt and 13wt SiCp Initially strain ratesare higher for solid rectangular preforms but after theload attains a magnitude of about 10 tons strain rates for13 wt SiCp preforms are higher irrespective of the shape ofpreforms Also at the end of forging operations strain ratesare found to decrease slightly after attaining the highest value

0 5 10 15 20 25 300000

0005

0010

0015

0020

0025

Forging load (Tons)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

Stra

in ra

te (s

minus1)

5wt SiCp

13wt SiCp

Figure 9 Experimental variation of strain rate (mmmm sec) withforging load (tons)

These two behaviors are attributed due to the consolidationof SiCp particles within the AMC preforms during the end offorging operation It can be concluded that the effect of SiCpparticles on stress strain and strain rate is predominant upto 40 of height reduction at forging load of about 20 tonsand thereafter these particles consolidate within the matrixand hence they least influence the forging characteristics

It can be seen from Figure 10 that the energy dissipationincreases with the increase in the forging load and defor-mation The total energy requirement for deformation ofAMC preforms having higher SiCp is found to be higherdue to higher strength of material and is also higher if theprocess is carried at higher die acceleration leading to higherinertia energy dissipation (refer to (11) and (14)) Also energyrequirements are higher for solid rectangular preforms ascompared to solid disc preforms due to more constraintdeformation in the former case

The variation of inertia factor with die velocity for SiCpAMC preforms is shown in Figure 11 It is clearly evidentthat inertia factor increases exponentially with increase in thedie velocity and is higher for higher die acceleration in solidrectangular preforms Also it can be noticed that proportionof inertia energy can be as high as 30 of the total energydissipation and hence cannot be neglected during the presentinvestigation

Figure 12 shows that both axial and radial strains increaseexponentially with increases in the forging load Also thecorresponding values of axial strains are higher than radialstrains for same forging load and higher percentage of SiCpIt also depicts the measure of Poissonrsquos ratio that is ratio ofradial strain to axial strain for present SiCp AMCmaterial

Figure 13 shows the effective stress (MPa) distribution onSiCp AMC preforms It is clearly evident that magnitudesof effective stresses are higher in 13 wt SiCp preforms ascompared to 5wt SiCp preforms in the corresponding

8 Journal of Powder Technology

0 3 6 9 12 15 18 210

2

4

6

8

10

12

Average forging load (tons)

Tota

l ene

rgy

diss

ipat

ion

(kJ)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav Uav = 01ms 120583eff = 05

13wt SiCp accel = 025mms2

5wt SiCp accel = 025mms213wt SiCp accel = 01mms2

5wt SiCp accel = 01mms2

Figure 10Theoretical variation of total energy dissipation (kJ) withaverage forging load (tons)

0 4 8 12 16 20 240

5

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Die velocity (mms)

Iner

tia fa

ctor

()

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav 120583eff = 05 SiCp = 5wt

Accel = 025mms2Accel = 005mms2Accel = 010mms2

Figure 11Theoretical variation of inertia factor ()with die velocity(mms)

regions The edges are subjected to higher stresses whereasthe centremost regions are having lower stresses of magni-tude about 150MPa and 300MPa for solid disc and solidrectangular preforms respectively This indicates that as thepercentage of SiCp increases stress also increases due toincrease in the strength of preforms

Figure 14 shows the effective strain (mmmm) distribu-tion on SiCp AMC preforms It can be seen that the major

00010203040506

5 40Average forging load (tons)

Solid rectangular preformSolid disc preform

10 20 30

R0 = 10mm H0 = 10mm

L0 = 20mm B0 = 10mm

120573 = 04 1206010 = 030 Pav 120583eff = 05

minus05

minus06

minus04

minus02

minus03

minus01

Axi

al st

rain

998400 120576998400 z

Radi

al st

rain

998400 120576998400 r

13 wt SiCp5 wt SiCp

Figure 12Theoretical variation of radial strain and axial strain withaverage forging load (tons)

portion of preform is subjected to strain in the order 03ndash06 magnitude except at the edges The strains are higher in5wt SiCp preforms as compared to 13 wt SiCp preformswhich indicate that ductility of 5 wt SiCp is higher In case of5 wt SiCp preforms the edges are subjected to severe strainof magnitude about 07ndash09 which leads to the fracture ofvertical surfaces and is also confirmed from Figure 3 In thiscase no appreciable variation in the strain distribution hasbeen observed for preforms having 13 wt and 5wt SiCpAlso the strains at the central region of preform are low andeventually almost zero at the centermost regions near to theupper and bottom flat surfaces The dissected section alsoreveals that the variation of strain in the central region isin the form of an inverted cone This confirms the presenceof sticking friction zone at those regions which confirmsand validates the variable interfacial composite friction lawconsidered during the present theoretical analysis

The distribution of effective strain rate (mmmm-sec)on SiCp AMC preforms is shown in Figure 15 It can beclearly seen that the major portion of solid disc preforms issubjected to strain rate of about 2mmmm-sec and only theedges are subjected to higher strain rates in the order 32ndash35mmmm-sec In case of solid rectangular preforms theedges are subjected to strain rate of 25ndash29mmmm-secThesolid disc preforms are having higher strain rates as comparedto solid rectangular preforms indicating better metal flow inthe former case as well as presence of constraint deformationin case of solid rectangular preforms

The velocity (mmsec) distribution on SiCp AMC pre-forms is shown in Figure 16 It can be observed that soliddisc and solid rectangular preforms are subjected to the high-est flow velocity of about 10ndash13mmsec and 15ndash17mmsecrespectively Also the outer regions of preform are havinghigher flow velocity as compared to the inner regions whichis in close agreement with the composite interfacial friction

Journal of Powder Technology 9

995

871

746

622

498

373

249

124

0000

MinMax

1140

1000

857

715

572

429

286

143

00006891140

(a) 5 wt SiCp

1010

885

759

632

506

379

253

126

0000

MinMax

857

750

643

536

429

322

214

107

0000659857

(b) 13 wt SiCp

Figure 13 Distribution of effective stress (MPa)

0888

0777

0666

0555

0444

0333

0222

0111

0000

MinMax

0761

0666

0571

0476

0380

0285

0190

00951

000004550761

(a) 5 wt SiCp

0918

0803

0689

0574

0459

0344

0230

0115

0000

0779

0682

0584

0487

0390

0292

0195

00974

000004500779

MinMax

(b) 13 wt SiCp

Figure 14 Distribution of effective strain (mmmm)

10 Journal of Powder Technology

318278238198159119079403970000

2592271941621290971064703240000141259

MinMax

(a) 5 wt SiCp

359314269225180135089804490000

279244209174139105069703490000133278

MinMax

(b) 13 wt SiCp

Figure 15 Distribution of effective strain rate (mmmm-sec)

1311171028757295834372921460000

157

157

137

118

979

784

588

392

196

0000

000818MinMax

(a) 5 wt SiCp

1311181059167856545233932621310000

MinMax

172

151

129

108

862

647

431

216

00000308159

(b) 13 wt SiCp

Figure 16 Velocity (mmsec) distribution on SiCp preforms

Journal of Powder Technology 11

00 01 02 03 04 050

200

400

600

800

1000

Solid rectangular preformSolid disc preform

Forging time (s)

Effec

tive s

tress

(MPa

)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 17 Computational variations of effective stress (MPa) withforging time (sec)

law considered in the present paper The strain rates arehigher in case of 5 wt SiCp preforms as compared to 13 wtSiCp which indicates that ductility of preform decreases withthe increase in the perecentage of SiCp The variation of flowvelocity in the vertical direction leads to the barreling of pre-forms which confirms the inclusion of barreling parameterldquo120573rdquo during the present theoretical analysis

Figure 17 shows the variation of effective stress (MPa)with forging time (sec) for SiCp AMC preforms It canbe observed that stress requirement for preforms having13 wt SiCp is higher as compared to preforms having 5wtSiCp which indicates that the percentage of increase in SiCpincreases the hardness of preforms It can be also seen thatsolid rectangular preforms are subjected to higher effectivestresses as compared to solid disc preforms indicating bettermaterial flow in case of solid disc preforms as well asconstraint deformation in case of solid rectangular preforms

The variation of effective strain (mmmm) with forgingtime (sec) is shown in Figure 18 and it was found that itincreased exponentially with respect to forging time Alsoit is clearly evident that effective strains for solid rectangularpreforms are higher as compared to solid disc preforms dueto constraint deformation

Figure 19 shows the variation of effective strain rate(mmmm-sec) with forging time (sec) for SiCp AMC pre-forms The strain rate for 5wt SiCp preforms is foundhigher than preforms having 13 wt SiCp which indicatesthat percentage of increase in SiCp decreases the ductility andforgeability of preforms Also the strain rates are higher forsolid disc preforms as compared to solid rectangular preformdue to constraint deformation in the latter case

Figure 20 shows the variation of forging load (kN) withforging time (sec) for solid disc and solid rectangular pre-forms which is found to increase rapidly with forging time Itcan be clearly seen that the preforms canwithstandmaximum

00 01 02 03 04 0500

02

04

06

08

10

Effec

tive s

trai

n (m

mm

m)

Forging time (s)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 18 Computational variations of effective strain (mmmm)with forging time (sec)

00 01 02 03 04 0500

05

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Effec

tive s

trai

n ra

te (s

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp

13wt SiCp

Figure 19 Computational variations of effective strain rate(mmmm-sec) with forging time (sec)

load of about 270ndash300 kNwithout the onset of fracture It canalso be noted that solid rectangular preforms require higherload to deform as compared to solid disc preforms

6 Conclusions

Themajor conclusions may be summarized as follows

(i) Maximum formability of AMC material at roomtemperature and under dry interfacial frictional con-ditions was found to be about 47-47 of height reduc-tion The deformations in AMC preforms having5wt SiCp were found to be higher as compared

12 Journal of Powder Technology

00 01 02 03 04 050

50

100

150

200

250

300

Forg

ing

load

(kN

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm

Solid rectangular preformSolid disc preform

120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp13wt SiCp

Figure 20 Computational variations of forging load (kN) withforging time (sec)

Upper die

Lower die

(0 0)

r (xlowast)

r (xlowast)

dr (dxlowast)

z

H0

Figure 21 Open-die forging of SiCp AMC preform

to 13 wt SiCp indicating that as the percentage ofSiCp particulate increases forgeability of the preformsdecreases The experimental result was found to bein close agreement with theoretical ones and hencevalidates the present theoretical analysis based onupper bound approach

(ii) Engineering stress required to produce the sameamount of strain was found to be higher in case ofAMC preforms having higher weight of SiCp aswell as higher for solid rectangular preformsThis wasattributed due to the fact that the increase in weight of SiCp increases the hardness of the preform Alsosolid rectangular preforms exhibit higher constraintdeformation due to the presence of sharp corners

(iii) The highest strain rate in the order of 024 wasexperienced during the open-die forging of AMCpreforms irrespective of the percentage of SiCp Theeffect of SiCp particles over various deformationcharacteristics like strain stress and strain rate ispredominant only up to nearly 44 of height reduc-tion and thereafter these particles consolidate within

the metal matrix and have the least influence on thevarious forging parameters

(iv) Total energy requirements during open-die forging ofAMC preforms having higher SiCp are found to behigher due to higher strength of the material Alsothe energy requirements are higher if the processis carried out at higher die acceleration due toinertia effects Also the effect of die velocity wasclearly depicted using inertia factor which indicatedthat energy dissipation due to inertia effects maybe as high as 30 of the total energy dissipationsand thus must be considered during the analysis offorging operations carried out especially at higher dievelocities

(v) Lower magnitude of strains was observed at thecentral region of preforms andwas found to be almostzero at the centermost region near to top and bot-tom flat surfaces indicating the presence of variableinterfacial friction zone in the form of inverted coneThis confirmed the composite interfacial friction lawconsidered during the present investigationsThiswasalso confirmed by the results of velocity distributionwhere flow velocity was found to be zero at the cen-termost regions of preforms indicating the existenceof nondeforming zone due to the presence of highsticking friction conditions

(vi) Simulation of open-die forging of SiCp AMCmaterialwas performed using DEFORM and the distributionof effective stress effective strain effective strain rateand velocity vector profile was generated for bothsolid disc and solid rectangular preforms Highermagnitudes of effective stress strain and strain ratewere found at the corners and edges of preformsindicating that the onset of fracture will take placeat those regions only This was also confirmed by thepresence of severe cracks at those regions during thepresent experimental investigations

(vii) Validation of simulation was done by comparing itsresults with the theoretical and experimental resultsand was found to reasonably agree with each otherwhich indicated that present finite element simulationrepresents fairly well the present open-die forging ofSiCp AMC

It is expected that the present work will be useful forthe assessment of various deformation characteristics duringmechanical processing of AMCs

Appendix

Consider open-die forging of a SiCp AMC between two per-fectly flat parallel and rigid die platens at room temperaturewith lower die platen moving upwards with velocity ldquo119880rdquo andupper die platen stationary as shown in Figure 21

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Journal of Powder Technology 7

00 01 02 03 04 0500

02

04

06

08

10

12

14

16

Solid disc preformSolid rectangular preform

Engineering strain

Engi

neer

ing

stres

s (G

Pa)

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

5wt SiCp13wt SiCp

Figure 7 Experimental variation of engineering stress (GPa) withengineering strain (mmmm)

0 3 6 9 12 15 18 210

10

20

30

40

50

Forging load (tons)

Hei

ght r

educ

tion

()

Solid rectangular preform

Solid disc preform

R0 = 10mm H0 = 10mm L0 = 20mmB0 = 10mm Uav = 01ms 120583eff = 05

Experimental dataExperimental data

5wt SiCp

13wt SiCp

Figure 8 Experimental and theoretical variations of height reduc-tion () with forging load (tons)

Figure 9 shows the variation of strain rate (mmmmsec) with forging load (tons) for SiCp AMC preforms Asevident from the figure maximum strain rate of magnitude0024 secminus1 is being observed at forging load of about 20tons for both 5wt and 13wt SiCp Initially strain ratesare higher for solid rectangular preforms but after theload attains a magnitude of about 10 tons strain rates for13 wt SiCp preforms are higher irrespective of the shape ofpreforms Also at the end of forging operations strain ratesare found to decrease slightly after attaining the highest value

0 5 10 15 20 25 300000

0005

0010

0015

0020

0025

Forging load (Tons)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mmL0 = 20mm B0 = 10mmUav = 01ms dry friction conditions

Stra

in ra

te (s

minus1)

5wt SiCp

13wt SiCp

Figure 9 Experimental variation of strain rate (mmmm sec) withforging load (tons)

These two behaviors are attributed due to the consolidationof SiCp particles within the AMC preforms during the end offorging operation It can be concluded that the effect of SiCpparticles on stress strain and strain rate is predominant upto 40 of height reduction at forging load of about 20 tonsand thereafter these particles consolidate within the matrixand hence they least influence the forging characteristics

It can be seen from Figure 10 that the energy dissipationincreases with the increase in the forging load and defor-mation The total energy requirement for deformation ofAMC preforms having higher SiCp is found to be higherdue to higher strength of material and is also higher if theprocess is carried at higher die acceleration leading to higherinertia energy dissipation (refer to (11) and (14)) Also energyrequirements are higher for solid rectangular preforms ascompared to solid disc preforms due to more constraintdeformation in the former case

The variation of inertia factor with die velocity for SiCpAMC preforms is shown in Figure 11 It is clearly evidentthat inertia factor increases exponentially with increase in thedie velocity and is higher for higher die acceleration in solidrectangular preforms Also it can be noticed that proportionof inertia energy can be as high as 30 of the total energydissipation and hence cannot be neglected during the presentinvestigation

Figure 12 shows that both axial and radial strains increaseexponentially with increases in the forging load Also thecorresponding values of axial strains are higher than radialstrains for same forging load and higher percentage of SiCpIt also depicts the measure of Poissonrsquos ratio that is ratio ofradial strain to axial strain for present SiCp AMCmaterial

Figure 13 shows the effective stress (MPa) distribution onSiCp AMC preforms It is clearly evident that magnitudesof effective stresses are higher in 13 wt SiCp preforms ascompared to 5wt SiCp preforms in the corresponding

8 Journal of Powder Technology

0 3 6 9 12 15 18 210

2

4

6

8

10

12

Average forging load (tons)

Tota

l ene

rgy

diss

ipat

ion

(kJ)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav Uav = 01ms 120583eff = 05

13wt SiCp accel = 025mms2

5wt SiCp accel = 025mms213wt SiCp accel = 01mms2

5wt SiCp accel = 01mms2

Figure 10Theoretical variation of total energy dissipation (kJ) withaverage forging load (tons)

0 4 8 12 16 20 240

5

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Die velocity (mms)

Iner

tia fa

ctor

()

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav 120583eff = 05 SiCp = 5wt

Accel = 025mms2Accel = 005mms2Accel = 010mms2

Figure 11Theoretical variation of inertia factor ()with die velocity(mms)

regions The edges are subjected to higher stresses whereasthe centremost regions are having lower stresses of magni-tude about 150MPa and 300MPa for solid disc and solidrectangular preforms respectively This indicates that as thepercentage of SiCp increases stress also increases due toincrease in the strength of preforms

Figure 14 shows the effective strain (mmmm) distribu-tion on SiCp AMC preforms It can be seen that the major

00010203040506

5 40Average forging load (tons)

Solid rectangular preformSolid disc preform

10 20 30

R0 = 10mm H0 = 10mm

L0 = 20mm B0 = 10mm

120573 = 04 1206010 = 030 Pav 120583eff = 05

minus05

minus06

minus04

minus02

minus03

minus01

Axi

al st

rain

998400 120576998400 z

Radi

al st

rain

998400 120576998400 r

13 wt SiCp5 wt SiCp

Figure 12Theoretical variation of radial strain and axial strain withaverage forging load (tons)

portion of preform is subjected to strain in the order 03ndash06 magnitude except at the edges The strains are higher in5wt SiCp preforms as compared to 13 wt SiCp preformswhich indicate that ductility of 5 wt SiCp is higher In case of5 wt SiCp preforms the edges are subjected to severe strainof magnitude about 07ndash09 which leads to the fracture ofvertical surfaces and is also confirmed from Figure 3 In thiscase no appreciable variation in the strain distribution hasbeen observed for preforms having 13 wt and 5wt SiCpAlso the strains at the central region of preform are low andeventually almost zero at the centermost regions near to theupper and bottom flat surfaces The dissected section alsoreveals that the variation of strain in the central region isin the form of an inverted cone This confirms the presenceof sticking friction zone at those regions which confirmsand validates the variable interfacial composite friction lawconsidered during the present theoretical analysis

The distribution of effective strain rate (mmmm-sec)on SiCp AMC preforms is shown in Figure 15 It can beclearly seen that the major portion of solid disc preforms issubjected to strain rate of about 2mmmm-sec and only theedges are subjected to higher strain rates in the order 32ndash35mmmm-sec In case of solid rectangular preforms theedges are subjected to strain rate of 25ndash29mmmm-secThesolid disc preforms are having higher strain rates as comparedto solid rectangular preforms indicating better metal flow inthe former case as well as presence of constraint deformationin case of solid rectangular preforms

The velocity (mmsec) distribution on SiCp AMC pre-forms is shown in Figure 16 It can be observed that soliddisc and solid rectangular preforms are subjected to the high-est flow velocity of about 10ndash13mmsec and 15ndash17mmsecrespectively Also the outer regions of preform are havinghigher flow velocity as compared to the inner regions whichis in close agreement with the composite interfacial friction

Journal of Powder Technology 9

995

871

746

622

498

373

249

124

0000

MinMax

1140

1000

857

715

572

429

286

143

00006891140

(a) 5 wt SiCp

1010

885

759

632

506

379

253

126

0000

MinMax

857

750

643

536

429

322

214

107

0000659857

(b) 13 wt SiCp

Figure 13 Distribution of effective stress (MPa)

0888

0777

0666

0555

0444

0333

0222

0111

0000

MinMax

0761

0666

0571

0476

0380

0285

0190

00951

000004550761

(a) 5 wt SiCp

0918

0803

0689

0574

0459

0344

0230

0115

0000

0779

0682

0584

0487

0390

0292

0195

00974

000004500779

MinMax

(b) 13 wt SiCp

Figure 14 Distribution of effective strain (mmmm)

10 Journal of Powder Technology

318278238198159119079403970000

2592271941621290971064703240000141259

MinMax

(a) 5 wt SiCp

359314269225180135089804490000

279244209174139105069703490000133278

MinMax

(b) 13 wt SiCp

Figure 15 Distribution of effective strain rate (mmmm-sec)

1311171028757295834372921460000

157

157

137

118

979

784

588

392

196

0000

000818MinMax

(a) 5 wt SiCp

1311181059167856545233932621310000

MinMax

172

151

129

108

862

647

431

216

00000308159

(b) 13 wt SiCp

Figure 16 Velocity (mmsec) distribution on SiCp preforms

Journal of Powder Technology 11

00 01 02 03 04 050

200

400

600

800

1000

Solid rectangular preformSolid disc preform

Forging time (s)

Effec

tive s

tress

(MPa

)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 17 Computational variations of effective stress (MPa) withforging time (sec)

law considered in the present paper The strain rates arehigher in case of 5 wt SiCp preforms as compared to 13 wtSiCp which indicates that ductility of preform decreases withthe increase in the perecentage of SiCp The variation of flowvelocity in the vertical direction leads to the barreling of pre-forms which confirms the inclusion of barreling parameterldquo120573rdquo during the present theoretical analysis

Figure 17 shows the variation of effective stress (MPa)with forging time (sec) for SiCp AMC preforms It canbe observed that stress requirement for preforms having13 wt SiCp is higher as compared to preforms having 5wtSiCp which indicates that the percentage of increase in SiCpincreases the hardness of preforms It can be also seen thatsolid rectangular preforms are subjected to higher effectivestresses as compared to solid disc preforms indicating bettermaterial flow in case of solid disc preforms as well asconstraint deformation in case of solid rectangular preforms

The variation of effective strain (mmmm) with forgingtime (sec) is shown in Figure 18 and it was found that itincreased exponentially with respect to forging time Alsoit is clearly evident that effective strains for solid rectangularpreforms are higher as compared to solid disc preforms dueto constraint deformation

Figure 19 shows the variation of effective strain rate(mmmm-sec) with forging time (sec) for SiCp AMC pre-forms The strain rate for 5wt SiCp preforms is foundhigher than preforms having 13 wt SiCp which indicatesthat percentage of increase in SiCp decreases the ductility andforgeability of preforms Also the strain rates are higher forsolid disc preforms as compared to solid rectangular preformdue to constraint deformation in the latter case

Figure 20 shows the variation of forging load (kN) withforging time (sec) for solid disc and solid rectangular pre-forms which is found to increase rapidly with forging time Itcan be clearly seen that the preforms canwithstandmaximum

00 01 02 03 04 0500

02

04

06

08

10

Effec

tive s

trai

n (m

mm

m)

Forging time (s)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 18 Computational variations of effective strain (mmmm)with forging time (sec)

00 01 02 03 04 0500

05

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Effec

tive s

trai

n ra

te (s

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp

13wt SiCp

Figure 19 Computational variations of effective strain rate(mmmm-sec) with forging time (sec)

load of about 270ndash300 kNwithout the onset of fracture It canalso be noted that solid rectangular preforms require higherload to deform as compared to solid disc preforms

6 Conclusions

Themajor conclusions may be summarized as follows

(i) Maximum formability of AMC material at roomtemperature and under dry interfacial frictional con-ditions was found to be about 47-47 of height reduc-tion The deformations in AMC preforms having5wt SiCp were found to be higher as compared

12 Journal of Powder Technology

00 01 02 03 04 050

50

100

150

200

250

300

Forg

ing

load

(kN

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm

Solid rectangular preformSolid disc preform

120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp13wt SiCp

Figure 20 Computational variations of forging load (kN) withforging time (sec)

Upper die

Lower die

(0 0)

r (xlowast)

r (xlowast)

dr (dxlowast)

z

H0

Figure 21 Open-die forging of SiCp AMC preform

to 13 wt SiCp indicating that as the percentage ofSiCp particulate increases forgeability of the preformsdecreases The experimental result was found to bein close agreement with theoretical ones and hencevalidates the present theoretical analysis based onupper bound approach

(ii) Engineering stress required to produce the sameamount of strain was found to be higher in case ofAMC preforms having higher weight of SiCp aswell as higher for solid rectangular preformsThis wasattributed due to the fact that the increase in weight of SiCp increases the hardness of the preform Alsosolid rectangular preforms exhibit higher constraintdeformation due to the presence of sharp corners

(iii) The highest strain rate in the order of 024 wasexperienced during the open-die forging of AMCpreforms irrespective of the percentage of SiCp Theeffect of SiCp particles over various deformationcharacteristics like strain stress and strain rate ispredominant only up to nearly 44 of height reduc-tion and thereafter these particles consolidate within

the metal matrix and have the least influence on thevarious forging parameters

(iv) Total energy requirements during open-die forging ofAMC preforms having higher SiCp are found to behigher due to higher strength of the material Alsothe energy requirements are higher if the processis carried out at higher die acceleration due toinertia effects Also the effect of die velocity wasclearly depicted using inertia factor which indicatedthat energy dissipation due to inertia effects maybe as high as 30 of the total energy dissipationsand thus must be considered during the analysis offorging operations carried out especially at higher dievelocities

(v) Lower magnitude of strains was observed at thecentral region of preforms andwas found to be almostzero at the centermost region near to top and bot-tom flat surfaces indicating the presence of variableinterfacial friction zone in the form of inverted coneThis confirmed the composite interfacial friction lawconsidered during the present investigationsThiswasalso confirmed by the results of velocity distributionwhere flow velocity was found to be zero at the cen-termost regions of preforms indicating the existenceof nondeforming zone due to the presence of highsticking friction conditions

(vi) Simulation of open-die forging of SiCp AMCmaterialwas performed using DEFORM and the distributionof effective stress effective strain effective strain rateand velocity vector profile was generated for bothsolid disc and solid rectangular preforms Highermagnitudes of effective stress strain and strain ratewere found at the corners and edges of preformsindicating that the onset of fracture will take placeat those regions only This was also confirmed by thepresence of severe cracks at those regions during thepresent experimental investigations

(vii) Validation of simulation was done by comparing itsresults with the theoretical and experimental resultsand was found to reasonably agree with each otherwhich indicated that present finite element simulationrepresents fairly well the present open-die forging ofSiCp AMC

It is expected that the present work will be useful forthe assessment of various deformation characteristics duringmechanical processing of AMCs

Appendix

Consider open-die forging of a SiCp AMC between two per-fectly flat parallel and rigid die platens at room temperaturewith lower die platen moving upwards with velocity ldquo119880rdquo andupper die platen stationary as shown in Figure 21

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

8 Journal of Powder Technology

0 3 6 9 12 15 18 210

2

4

6

8

10

12

Average forging load (tons)

Tota

l ene

rgy

diss

ipat

ion

(kJ)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav Uav = 01ms 120583eff = 05

13wt SiCp accel = 025mms2

5wt SiCp accel = 025mms213wt SiCp accel = 01mms2

5wt SiCp accel = 01mms2

Figure 10Theoretical variation of total energy dissipation (kJ) withaverage forging load (tons)

0 4 8 12 16 20 240

5

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Die velocity (mms)

Iner

tia fa

ctor

()

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 1206010 = 030 Pav 120583eff = 05 SiCp = 5wt

Accel = 025mms2Accel = 005mms2Accel = 010mms2

Figure 11Theoretical variation of inertia factor ()with die velocity(mms)

regions The edges are subjected to higher stresses whereasthe centremost regions are having lower stresses of magni-tude about 150MPa and 300MPa for solid disc and solidrectangular preforms respectively This indicates that as thepercentage of SiCp increases stress also increases due toincrease in the strength of preforms

Figure 14 shows the effective strain (mmmm) distribu-tion on SiCp AMC preforms It can be seen that the major

00010203040506

5 40Average forging load (tons)

Solid rectangular preformSolid disc preform

10 20 30

R0 = 10mm H0 = 10mm

L0 = 20mm B0 = 10mm

120573 = 04 1206010 = 030 Pav 120583eff = 05

minus05

minus06

minus04

minus02

minus03

minus01

Axi

al st

rain

998400 120576998400 z

Radi

al st

rain

998400 120576998400 r

13 wt SiCp5 wt SiCp

Figure 12Theoretical variation of radial strain and axial strain withaverage forging load (tons)

portion of preform is subjected to strain in the order 03ndash06 magnitude except at the edges The strains are higher in5wt SiCp preforms as compared to 13 wt SiCp preformswhich indicate that ductility of 5 wt SiCp is higher In case of5 wt SiCp preforms the edges are subjected to severe strainof magnitude about 07ndash09 which leads to the fracture ofvertical surfaces and is also confirmed from Figure 3 In thiscase no appreciable variation in the strain distribution hasbeen observed for preforms having 13 wt and 5wt SiCpAlso the strains at the central region of preform are low andeventually almost zero at the centermost regions near to theupper and bottom flat surfaces The dissected section alsoreveals that the variation of strain in the central region isin the form of an inverted cone This confirms the presenceof sticking friction zone at those regions which confirmsand validates the variable interfacial composite friction lawconsidered during the present theoretical analysis

The distribution of effective strain rate (mmmm-sec)on SiCp AMC preforms is shown in Figure 15 It can beclearly seen that the major portion of solid disc preforms issubjected to strain rate of about 2mmmm-sec and only theedges are subjected to higher strain rates in the order 32ndash35mmmm-sec In case of solid rectangular preforms theedges are subjected to strain rate of 25ndash29mmmm-secThesolid disc preforms are having higher strain rates as comparedto solid rectangular preforms indicating better metal flow inthe former case as well as presence of constraint deformationin case of solid rectangular preforms

The velocity (mmsec) distribution on SiCp AMC pre-forms is shown in Figure 16 It can be observed that soliddisc and solid rectangular preforms are subjected to the high-est flow velocity of about 10ndash13mmsec and 15ndash17mmsecrespectively Also the outer regions of preform are havinghigher flow velocity as compared to the inner regions whichis in close agreement with the composite interfacial friction

Journal of Powder Technology 9

995

871

746

622

498

373

249

124

0000

MinMax

1140

1000

857

715

572

429

286

143

00006891140

(a) 5 wt SiCp

1010

885

759

632

506

379

253

126

0000

MinMax

857

750

643

536

429

322

214

107

0000659857

(b) 13 wt SiCp

Figure 13 Distribution of effective stress (MPa)

0888

0777

0666

0555

0444

0333

0222

0111

0000

MinMax

0761

0666

0571

0476

0380

0285

0190

00951

000004550761

(a) 5 wt SiCp

0918

0803

0689

0574

0459

0344

0230

0115

0000

0779

0682

0584

0487

0390

0292

0195

00974

000004500779

MinMax

(b) 13 wt SiCp

Figure 14 Distribution of effective strain (mmmm)

10 Journal of Powder Technology

318278238198159119079403970000

2592271941621290971064703240000141259

MinMax

(a) 5 wt SiCp

359314269225180135089804490000

279244209174139105069703490000133278

MinMax

(b) 13 wt SiCp

Figure 15 Distribution of effective strain rate (mmmm-sec)

1311171028757295834372921460000

157

157

137

118

979

784

588

392

196

0000

000818MinMax

(a) 5 wt SiCp

1311181059167856545233932621310000

MinMax

172

151

129

108

862

647

431

216

00000308159

(b) 13 wt SiCp

Figure 16 Velocity (mmsec) distribution on SiCp preforms

Journal of Powder Technology 11

00 01 02 03 04 050

200

400

600

800

1000

Solid rectangular preformSolid disc preform

Forging time (s)

Effec

tive s

tress

(MPa

)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 17 Computational variations of effective stress (MPa) withforging time (sec)

law considered in the present paper The strain rates arehigher in case of 5 wt SiCp preforms as compared to 13 wtSiCp which indicates that ductility of preform decreases withthe increase in the perecentage of SiCp The variation of flowvelocity in the vertical direction leads to the barreling of pre-forms which confirms the inclusion of barreling parameterldquo120573rdquo during the present theoretical analysis

Figure 17 shows the variation of effective stress (MPa)with forging time (sec) for SiCp AMC preforms It canbe observed that stress requirement for preforms having13 wt SiCp is higher as compared to preforms having 5wtSiCp which indicates that the percentage of increase in SiCpincreases the hardness of preforms It can be also seen thatsolid rectangular preforms are subjected to higher effectivestresses as compared to solid disc preforms indicating bettermaterial flow in case of solid disc preforms as well asconstraint deformation in case of solid rectangular preforms

The variation of effective strain (mmmm) with forgingtime (sec) is shown in Figure 18 and it was found that itincreased exponentially with respect to forging time Alsoit is clearly evident that effective strains for solid rectangularpreforms are higher as compared to solid disc preforms dueto constraint deformation

Figure 19 shows the variation of effective strain rate(mmmm-sec) with forging time (sec) for SiCp AMC pre-forms The strain rate for 5wt SiCp preforms is foundhigher than preforms having 13 wt SiCp which indicatesthat percentage of increase in SiCp decreases the ductility andforgeability of preforms Also the strain rates are higher forsolid disc preforms as compared to solid rectangular preformdue to constraint deformation in the latter case

Figure 20 shows the variation of forging load (kN) withforging time (sec) for solid disc and solid rectangular pre-forms which is found to increase rapidly with forging time Itcan be clearly seen that the preforms canwithstandmaximum

00 01 02 03 04 0500

02

04

06

08

10

Effec

tive s

trai

n (m

mm

m)

Forging time (s)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 18 Computational variations of effective strain (mmmm)with forging time (sec)

00 01 02 03 04 0500

05

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Effec

tive s

trai

n ra

te (s

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp

13wt SiCp

Figure 19 Computational variations of effective strain rate(mmmm-sec) with forging time (sec)

load of about 270ndash300 kNwithout the onset of fracture It canalso be noted that solid rectangular preforms require higherload to deform as compared to solid disc preforms

6 Conclusions

Themajor conclusions may be summarized as follows

(i) Maximum formability of AMC material at roomtemperature and under dry interfacial frictional con-ditions was found to be about 47-47 of height reduc-tion The deformations in AMC preforms having5wt SiCp were found to be higher as compared

12 Journal of Powder Technology

00 01 02 03 04 050

50

100

150

200

250

300

Forg

ing

load

(kN

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm

Solid rectangular preformSolid disc preform

120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp13wt SiCp

Figure 20 Computational variations of forging load (kN) withforging time (sec)

Upper die

Lower die

(0 0)

r (xlowast)

r (xlowast)

dr (dxlowast)

z

H0

Figure 21 Open-die forging of SiCp AMC preform

to 13 wt SiCp indicating that as the percentage ofSiCp particulate increases forgeability of the preformsdecreases The experimental result was found to bein close agreement with theoretical ones and hencevalidates the present theoretical analysis based onupper bound approach

(ii) Engineering stress required to produce the sameamount of strain was found to be higher in case ofAMC preforms having higher weight of SiCp aswell as higher for solid rectangular preformsThis wasattributed due to the fact that the increase in weight of SiCp increases the hardness of the preform Alsosolid rectangular preforms exhibit higher constraintdeformation due to the presence of sharp corners

(iii) The highest strain rate in the order of 024 wasexperienced during the open-die forging of AMCpreforms irrespective of the percentage of SiCp Theeffect of SiCp particles over various deformationcharacteristics like strain stress and strain rate ispredominant only up to nearly 44 of height reduc-tion and thereafter these particles consolidate within

the metal matrix and have the least influence on thevarious forging parameters

(iv) Total energy requirements during open-die forging ofAMC preforms having higher SiCp are found to behigher due to higher strength of the material Alsothe energy requirements are higher if the processis carried out at higher die acceleration due toinertia effects Also the effect of die velocity wasclearly depicted using inertia factor which indicatedthat energy dissipation due to inertia effects maybe as high as 30 of the total energy dissipationsand thus must be considered during the analysis offorging operations carried out especially at higher dievelocities

(v) Lower magnitude of strains was observed at thecentral region of preforms andwas found to be almostzero at the centermost region near to top and bot-tom flat surfaces indicating the presence of variableinterfacial friction zone in the form of inverted coneThis confirmed the composite interfacial friction lawconsidered during the present investigationsThiswasalso confirmed by the results of velocity distributionwhere flow velocity was found to be zero at the cen-termost regions of preforms indicating the existenceof nondeforming zone due to the presence of highsticking friction conditions

(vi) Simulation of open-die forging of SiCp AMCmaterialwas performed using DEFORM and the distributionof effective stress effective strain effective strain rateand velocity vector profile was generated for bothsolid disc and solid rectangular preforms Highermagnitudes of effective stress strain and strain ratewere found at the corners and edges of preformsindicating that the onset of fracture will take placeat those regions only This was also confirmed by thepresence of severe cracks at those regions during thepresent experimental investigations

(vii) Validation of simulation was done by comparing itsresults with the theoretical and experimental resultsand was found to reasonably agree with each otherwhich indicated that present finite element simulationrepresents fairly well the present open-die forging ofSiCp AMC

It is expected that the present work will be useful forthe assessment of various deformation characteristics duringmechanical processing of AMCs

Appendix

Consider open-die forging of a SiCp AMC between two per-fectly flat parallel and rigid die platens at room temperaturewith lower die platen moving upwards with velocity ldquo119880rdquo andupper die platen stationary as shown in Figure 21

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Journal of Powder Technology 9

995

871

746

622

498

373

249

124

0000

MinMax

1140

1000

857

715

572

429

286

143

00006891140

(a) 5 wt SiCp

1010

885

759

632

506

379

253

126

0000

MinMax

857

750

643

536

429

322

214

107

0000659857

(b) 13 wt SiCp

Figure 13 Distribution of effective stress (MPa)

0888

0777

0666

0555

0444

0333

0222

0111

0000

MinMax

0761

0666

0571

0476

0380

0285

0190

00951

000004550761

(a) 5 wt SiCp

0918

0803

0689

0574

0459

0344

0230

0115

0000

0779

0682

0584

0487

0390

0292

0195

00974

000004500779

MinMax

(b) 13 wt SiCp

Figure 14 Distribution of effective strain (mmmm)

10 Journal of Powder Technology

318278238198159119079403970000

2592271941621290971064703240000141259

MinMax

(a) 5 wt SiCp

359314269225180135089804490000

279244209174139105069703490000133278

MinMax

(b) 13 wt SiCp

Figure 15 Distribution of effective strain rate (mmmm-sec)

1311171028757295834372921460000

157

157

137

118

979

784

588

392

196

0000

000818MinMax

(a) 5 wt SiCp

1311181059167856545233932621310000

MinMax

172

151

129

108

862

647

431

216

00000308159

(b) 13 wt SiCp

Figure 16 Velocity (mmsec) distribution on SiCp preforms

Journal of Powder Technology 11

00 01 02 03 04 050

200

400

600

800

1000

Solid rectangular preformSolid disc preform

Forging time (s)

Effec

tive s

tress

(MPa

)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 17 Computational variations of effective stress (MPa) withforging time (sec)

law considered in the present paper The strain rates arehigher in case of 5 wt SiCp preforms as compared to 13 wtSiCp which indicates that ductility of preform decreases withthe increase in the perecentage of SiCp The variation of flowvelocity in the vertical direction leads to the barreling of pre-forms which confirms the inclusion of barreling parameterldquo120573rdquo during the present theoretical analysis

Figure 17 shows the variation of effective stress (MPa)with forging time (sec) for SiCp AMC preforms It canbe observed that stress requirement for preforms having13 wt SiCp is higher as compared to preforms having 5wtSiCp which indicates that the percentage of increase in SiCpincreases the hardness of preforms It can be also seen thatsolid rectangular preforms are subjected to higher effectivestresses as compared to solid disc preforms indicating bettermaterial flow in case of solid disc preforms as well asconstraint deformation in case of solid rectangular preforms

The variation of effective strain (mmmm) with forgingtime (sec) is shown in Figure 18 and it was found that itincreased exponentially with respect to forging time Alsoit is clearly evident that effective strains for solid rectangularpreforms are higher as compared to solid disc preforms dueto constraint deformation

Figure 19 shows the variation of effective strain rate(mmmm-sec) with forging time (sec) for SiCp AMC pre-forms The strain rate for 5wt SiCp preforms is foundhigher than preforms having 13 wt SiCp which indicatesthat percentage of increase in SiCp decreases the ductility andforgeability of preforms Also the strain rates are higher forsolid disc preforms as compared to solid rectangular preformdue to constraint deformation in the latter case

Figure 20 shows the variation of forging load (kN) withforging time (sec) for solid disc and solid rectangular pre-forms which is found to increase rapidly with forging time Itcan be clearly seen that the preforms canwithstandmaximum

00 01 02 03 04 0500

02

04

06

08

10

Effec

tive s

trai

n (m

mm

m)

Forging time (s)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 18 Computational variations of effective strain (mmmm)with forging time (sec)

00 01 02 03 04 0500

05

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Effec

tive s

trai

n ra

te (s

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp

13wt SiCp

Figure 19 Computational variations of effective strain rate(mmmm-sec) with forging time (sec)

load of about 270ndash300 kNwithout the onset of fracture It canalso be noted that solid rectangular preforms require higherload to deform as compared to solid disc preforms

6 Conclusions

Themajor conclusions may be summarized as follows

(i) Maximum formability of AMC material at roomtemperature and under dry interfacial frictional con-ditions was found to be about 47-47 of height reduc-tion The deformations in AMC preforms having5wt SiCp were found to be higher as compared

12 Journal of Powder Technology

00 01 02 03 04 050

50

100

150

200

250

300

Forg

ing

load

(kN

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm

Solid rectangular preformSolid disc preform

120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp13wt SiCp

Figure 20 Computational variations of forging load (kN) withforging time (sec)

Upper die

Lower die

(0 0)

r (xlowast)

r (xlowast)

dr (dxlowast)

z

H0

Figure 21 Open-die forging of SiCp AMC preform

to 13 wt SiCp indicating that as the percentage ofSiCp particulate increases forgeability of the preformsdecreases The experimental result was found to bein close agreement with theoretical ones and hencevalidates the present theoretical analysis based onupper bound approach

(ii) Engineering stress required to produce the sameamount of strain was found to be higher in case ofAMC preforms having higher weight of SiCp aswell as higher for solid rectangular preformsThis wasattributed due to the fact that the increase in weight of SiCp increases the hardness of the preform Alsosolid rectangular preforms exhibit higher constraintdeformation due to the presence of sharp corners

(iii) The highest strain rate in the order of 024 wasexperienced during the open-die forging of AMCpreforms irrespective of the percentage of SiCp Theeffect of SiCp particles over various deformationcharacteristics like strain stress and strain rate ispredominant only up to nearly 44 of height reduc-tion and thereafter these particles consolidate within

the metal matrix and have the least influence on thevarious forging parameters

(iv) Total energy requirements during open-die forging ofAMC preforms having higher SiCp are found to behigher due to higher strength of the material Alsothe energy requirements are higher if the processis carried out at higher die acceleration due toinertia effects Also the effect of die velocity wasclearly depicted using inertia factor which indicatedthat energy dissipation due to inertia effects maybe as high as 30 of the total energy dissipationsand thus must be considered during the analysis offorging operations carried out especially at higher dievelocities

(v) Lower magnitude of strains was observed at thecentral region of preforms andwas found to be almostzero at the centermost region near to top and bot-tom flat surfaces indicating the presence of variableinterfacial friction zone in the form of inverted coneThis confirmed the composite interfacial friction lawconsidered during the present investigationsThiswasalso confirmed by the results of velocity distributionwhere flow velocity was found to be zero at the cen-termost regions of preforms indicating the existenceof nondeforming zone due to the presence of highsticking friction conditions

(vi) Simulation of open-die forging of SiCp AMCmaterialwas performed using DEFORM and the distributionof effective stress effective strain effective strain rateand velocity vector profile was generated for bothsolid disc and solid rectangular preforms Highermagnitudes of effective stress strain and strain ratewere found at the corners and edges of preformsindicating that the onset of fracture will take placeat those regions only This was also confirmed by thepresence of severe cracks at those regions during thepresent experimental investigations

(vii) Validation of simulation was done by comparing itsresults with the theoretical and experimental resultsand was found to reasonably agree with each otherwhich indicated that present finite element simulationrepresents fairly well the present open-die forging ofSiCp AMC

It is expected that the present work will be useful forthe assessment of various deformation characteristics duringmechanical processing of AMCs

Appendix

Consider open-die forging of a SiCp AMC between two per-fectly flat parallel and rigid die platens at room temperaturewith lower die platen moving upwards with velocity ldquo119880rdquo andupper die platen stationary as shown in Figure 21

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

10 Journal of Powder Technology

318278238198159119079403970000

2592271941621290971064703240000141259

MinMax

(a) 5 wt SiCp

359314269225180135089804490000

279244209174139105069703490000133278

MinMax

(b) 13 wt SiCp

Figure 15 Distribution of effective strain rate (mmmm-sec)

1311171028757295834372921460000

157

157

137

118

979

784

588

392

196

0000

000818MinMax

(a) 5 wt SiCp

1311181059167856545233932621310000

MinMax

172

151

129

108

862

647

431

216

00000308159

(b) 13 wt SiCp

Figure 16 Velocity (mmsec) distribution on SiCp preforms

Journal of Powder Technology 11

00 01 02 03 04 050

200

400

600

800

1000

Solid rectangular preformSolid disc preform

Forging time (s)

Effec

tive s

tress

(MPa

)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 17 Computational variations of effective stress (MPa) withforging time (sec)

law considered in the present paper The strain rates arehigher in case of 5 wt SiCp preforms as compared to 13 wtSiCp which indicates that ductility of preform decreases withthe increase in the perecentage of SiCp The variation of flowvelocity in the vertical direction leads to the barreling of pre-forms which confirms the inclusion of barreling parameterldquo120573rdquo during the present theoretical analysis

Figure 17 shows the variation of effective stress (MPa)with forging time (sec) for SiCp AMC preforms It canbe observed that stress requirement for preforms having13 wt SiCp is higher as compared to preforms having 5wtSiCp which indicates that the percentage of increase in SiCpincreases the hardness of preforms It can be also seen thatsolid rectangular preforms are subjected to higher effectivestresses as compared to solid disc preforms indicating bettermaterial flow in case of solid disc preforms as well asconstraint deformation in case of solid rectangular preforms

The variation of effective strain (mmmm) with forgingtime (sec) is shown in Figure 18 and it was found that itincreased exponentially with respect to forging time Alsoit is clearly evident that effective strains for solid rectangularpreforms are higher as compared to solid disc preforms dueto constraint deformation

Figure 19 shows the variation of effective strain rate(mmmm-sec) with forging time (sec) for SiCp AMC pre-forms The strain rate for 5wt SiCp preforms is foundhigher than preforms having 13 wt SiCp which indicatesthat percentage of increase in SiCp decreases the ductility andforgeability of preforms Also the strain rates are higher forsolid disc preforms as compared to solid rectangular preformdue to constraint deformation in the latter case

Figure 20 shows the variation of forging load (kN) withforging time (sec) for solid disc and solid rectangular pre-forms which is found to increase rapidly with forging time Itcan be clearly seen that the preforms canwithstandmaximum

00 01 02 03 04 0500

02

04

06

08

10

Effec

tive s

trai

n (m

mm

m)

Forging time (s)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 18 Computational variations of effective strain (mmmm)with forging time (sec)

00 01 02 03 04 0500

05

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Effec

tive s

trai

n ra

te (s

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp

13wt SiCp

Figure 19 Computational variations of effective strain rate(mmmm-sec) with forging time (sec)

load of about 270ndash300 kNwithout the onset of fracture It canalso be noted that solid rectangular preforms require higherload to deform as compared to solid disc preforms

6 Conclusions

Themajor conclusions may be summarized as follows

(i) Maximum formability of AMC material at roomtemperature and under dry interfacial frictional con-ditions was found to be about 47-47 of height reduc-tion The deformations in AMC preforms having5wt SiCp were found to be higher as compared

12 Journal of Powder Technology

00 01 02 03 04 050

50

100

150

200

250

300

Forg

ing

load

(kN

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm

Solid rectangular preformSolid disc preform

120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp13wt SiCp

Figure 20 Computational variations of forging load (kN) withforging time (sec)

Upper die

Lower die

(0 0)

r (xlowast)

r (xlowast)

dr (dxlowast)

z

H0

Figure 21 Open-die forging of SiCp AMC preform

to 13 wt SiCp indicating that as the percentage ofSiCp particulate increases forgeability of the preformsdecreases The experimental result was found to bein close agreement with theoretical ones and hencevalidates the present theoretical analysis based onupper bound approach

(ii) Engineering stress required to produce the sameamount of strain was found to be higher in case ofAMC preforms having higher weight of SiCp aswell as higher for solid rectangular preformsThis wasattributed due to the fact that the increase in weight of SiCp increases the hardness of the preform Alsosolid rectangular preforms exhibit higher constraintdeformation due to the presence of sharp corners

(iii) The highest strain rate in the order of 024 wasexperienced during the open-die forging of AMCpreforms irrespective of the percentage of SiCp Theeffect of SiCp particles over various deformationcharacteristics like strain stress and strain rate ispredominant only up to nearly 44 of height reduc-tion and thereafter these particles consolidate within

the metal matrix and have the least influence on thevarious forging parameters

(iv) Total energy requirements during open-die forging ofAMC preforms having higher SiCp are found to behigher due to higher strength of the material Alsothe energy requirements are higher if the processis carried out at higher die acceleration due toinertia effects Also the effect of die velocity wasclearly depicted using inertia factor which indicatedthat energy dissipation due to inertia effects maybe as high as 30 of the total energy dissipationsand thus must be considered during the analysis offorging operations carried out especially at higher dievelocities

(v) Lower magnitude of strains was observed at thecentral region of preforms andwas found to be almostzero at the centermost region near to top and bot-tom flat surfaces indicating the presence of variableinterfacial friction zone in the form of inverted coneThis confirmed the composite interfacial friction lawconsidered during the present investigationsThiswasalso confirmed by the results of velocity distributionwhere flow velocity was found to be zero at the cen-termost regions of preforms indicating the existenceof nondeforming zone due to the presence of highsticking friction conditions

(vi) Simulation of open-die forging of SiCp AMCmaterialwas performed using DEFORM and the distributionof effective stress effective strain effective strain rateand velocity vector profile was generated for bothsolid disc and solid rectangular preforms Highermagnitudes of effective stress strain and strain ratewere found at the corners and edges of preformsindicating that the onset of fracture will take placeat those regions only This was also confirmed by thepresence of severe cracks at those regions during thepresent experimental investigations

(vii) Validation of simulation was done by comparing itsresults with the theoretical and experimental resultsand was found to reasonably agree with each otherwhich indicated that present finite element simulationrepresents fairly well the present open-die forging ofSiCp AMC

It is expected that the present work will be useful forthe assessment of various deformation characteristics duringmechanical processing of AMCs

Appendix

Consider open-die forging of a SiCp AMC between two per-fectly flat parallel and rigid die platens at room temperaturewith lower die platen moving upwards with velocity ldquo119880rdquo andupper die platen stationary as shown in Figure 21

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Journal of Powder Technology 11

00 01 02 03 04 050

200

400

600

800

1000

Solid rectangular preformSolid disc preform

Forging time (s)

Effec

tive s

tress

(MPa

)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 17 Computational variations of effective stress (MPa) withforging time (sec)

law considered in the present paper The strain rates arehigher in case of 5 wt SiCp preforms as compared to 13 wtSiCp which indicates that ductility of preform decreases withthe increase in the perecentage of SiCp The variation of flowvelocity in the vertical direction leads to the barreling of pre-forms which confirms the inclusion of barreling parameterldquo120573rdquo during the present theoretical analysis

Figure 17 shows the variation of effective stress (MPa)with forging time (sec) for SiCp AMC preforms It canbe observed that stress requirement for preforms having13 wt SiCp is higher as compared to preforms having 5wtSiCp which indicates that the percentage of increase in SiCpincreases the hardness of preforms It can be also seen thatsolid rectangular preforms are subjected to higher effectivestresses as compared to solid disc preforms indicating bettermaterial flow in case of solid disc preforms as well asconstraint deformation in case of solid rectangular preforms

The variation of effective strain (mmmm) with forgingtime (sec) is shown in Figure 18 and it was found that itincreased exponentially with respect to forging time Alsoit is clearly evident that effective strains for solid rectangularpreforms are higher as compared to solid disc preforms dueto constraint deformation

Figure 19 shows the variation of effective strain rate(mmmm-sec) with forging time (sec) for SiCp AMC pre-forms The strain rate for 5wt SiCp preforms is foundhigher than preforms having 13 wt SiCp which indicatesthat percentage of increase in SiCp decreases the ductility andforgeability of preforms Also the strain rates are higher forsolid disc preforms as compared to solid rectangular preformdue to constraint deformation in the latter case

Figure 20 shows the variation of forging load (kN) withforging time (sec) for solid disc and solid rectangular pre-forms which is found to increase rapidly with forging time Itcan be clearly seen that the preforms canwithstandmaximum

00 01 02 03 04 0500

02

04

06

08

10

Effec

tive s

trai

n (m

mm

m)

Forging time (s)

Solid rectangular preformSolid disc preform

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

13wt SiCp

5wt SiCp

Figure 18 Computational variations of effective strain (mmmm)with forging time (sec)

00 01 02 03 04 0500

05

10

15

20

25

30

35

Solid rectangular preformSolid disc preform

Effec

tive s

trai

n ra

te (s

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp

13wt SiCp

Figure 19 Computational variations of effective strain rate(mmmm-sec) with forging time (sec)

load of about 270ndash300 kNwithout the onset of fracture It canalso be noted that solid rectangular preforms require higherload to deform as compared to solid disc preforms

6 Conclusions

Themajor conclusions may be summarized as follows

(i) Maximum formability of AMC material at roomtemperature and under dry interfacial frictional con-ditions was found to be about 47-47 of height reduc-tion The deformations in AMC preforms having5wt SiCp were found to be higher as compared

12 Journal of Powder Technology

00 01 02 03 04 050

50

100

150

200

250

300

Forg

ing

load

(kN

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm

Solid rectangular preformSolid disc preform

120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp13wt SiCp

Figure 20 Computational variations of forging load (kN) withforging time (sec)

Upper die

Lower die

(0 0)

r (xlowast)

r (xlowast)

dr (dxlowast)

z

H0

Figure 21 Open-die forging of SiCp AMC preform

to 13 wt SiCp indicating that as the percentage ofSiCp particulate increases forgeability of the preformsdecreases The experimental result was found to bein close agreement with theoretical ones and hencevalidates the present theoretical analysis based onupper bound approach

(ii) Engineering stress required to produce the sameamount of strain was found to be higher in case ofAMC preforms having higher weight of SiCp aswell as higher for solid rectangular preformsThis wasattributed due to the fact that the increase in weight of SiCp increases the hardness of the preform Alsosolid rectangular preforms exhibit higher constraintdeformation due to the presence of sharp corners

(iii) The highest strain rate in the order of 024 wasexperienced during the open-die forging of AMCpreforms irrespective of the percentage of SiCp Theeffect of SiCp particles over various deformationcharacteristics like strain stress and strain rate ispredominant only up to nearly 44 of height reduc-tion and thereafter these particles consolidate within

the metal matrix and have the least influence on thevarious forging parameters

(iv) Total energy requirements during open-die forging ofAMC preforms having higher SiCp are found to behigher due to higher strength of the material Alsothe energy requirements are higher if the processis carried out at higher die acceleration due toinertia effects Also the effect of die velocity wasclearly depicted using inertia factor which indicatedthat energy dissipation due to inertia effects maybe as high as 30 of the total energy dissipationsand thus must be considered during the analysis offorging operations carried out especially at higher dievelocities

(v) Lower magnitude of strains was observed at thecentral region of preforms andwas found to be almostzero at the centermost region near to top and bot-tom flat surfaces indicating the presence of variableinterfacial friction zone in the form of inverted coneThis confirmed the composite interfacial friction lawconsidered during the present investigationsThiswasalso confirmed by the results of velocity distributionwhere flow velocity was found to be zero at the cen-termost regions of preforms indicating the existenceof nondeforming zone due to the presence of highsticking friction conditions

(vi) Simulation of open-die forging of SiCp AMCmaterialwas performed using DEFORM and the distributionof effective stress effective strain effective strain rateand velocity vector profile was generated for bothsolid disc and solid rectangular preforms Highermagnitudes of effective stress strain and strain ratewere found at the corners and edges of preformsindicating that the onset of fracture will take placeat those regions only This was also confirmed by thepresence of severe cracks at those regions during thepresent experimental investigations

(vii) Validation of simulation was done by comparing itsresults with the theoretical and experimental resultsand was found to reasonably agree with each otherwhich indicated that present finite element simulationrepresents fairly well the present open-die forging ofSiCp AMC

It is expected that the present work will be useful forthe assessment of various deformation characteristics duringmechanical processing of AMCs

Appendix

Consider open-die forging of a SiCp AMC between two per-fectly flat parallel and rigid die platens at room temperaturewith lower die platen moving upwards with velocity ldquo119880rdquo andupper die platen stationary as shown in Figure 21

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

12 Journal of Powder Technology

00 01 02 03 04 050

50

100

150

200

250

300

Forg

ing

load

(kN

)

Forging time (s)

R0 = 10mm H0 = 10mm L0 = 20mm B0 = 10mm

Solid rectangular preformSolid disc preform

120573 = 04 Uav = 01ms 120583eff = 05

5wt SiCp13wt SiCp

Figure 20 Computational variations of forging load (kN) withforging time (sec)

Upper die

Lower die

(0 0)

r (xlowast)

r (xlowast)

dr (dxlowast)

z

H0

Figure 21 Open-die forging of SiCp AMC preform

to 13 wt SiCp indicating that as the percentage ofSiCp particulate increases forgeability of the preformsdecreases The experimental result was found to bein close agreement with theoretical ones and hencevalidates the present theoretical analysis based onupper bound approach

(ii) Engineering stress required to produce the sameamount of strain was found to be higher in case ofAMC preforms having higher weight of SiCp aswell as higher for solid rectangular preformsThis wasattributed due to the fact that the increase in weight of SiCp increases the hardness of the preform Alsosolid rectangular preforms exhibit higher constraintdeformation due to the presence of sharp corners

(iii) The highest strain rate in the order of 024 wasexperienced during the open-die forging of AMCpreforms irrespective of the percentage of SiCp Theeffect of SiCp particles over various deformationcharacteristics like strain stress and strain rate ispredominant only up to nearly 44 of height reduc-tion and thereafter these particles consolidate within

the metal matrix and have the least influence on thevarious forging parameters

(iv) Total energy requirements during open-die forging ofAMC preforms having higher SiCp are found to behigher due to higher strength of the material Alsothe energy requirements are higher if the processis carried out at higher die acceleration due toinertia effects Also the effect of die velocity wasclearly depicted using inertia factor which indicatedthat energy dissipation due to inertia effects maybe as high as 30 of the total energy dissipationsand thus must be considered during the analysis offorging operations carried out especially at higher dievelocities

(v) Lower magnitude of strains was observed at thecentral region of preforms andwas found to be almostzero at the centermost region near to top and bot-tom flat surfaces indicating the presence of variableinterfacial friction zone in the form of inverted coneThis confirmed the composite interfacial friction lawconsidered during the present investigationsThiswasalso confirmed by the results of velocity distributionwhere flow velocity was found to be zero at the cen-termost regions of preforms indicating the existenceof nondeforming zone due to the presence of highsticking friction conditions

(vi) Simulation of open-die forging of SiCp AMCmaterialwas performed using DEFORM and the distributionof effective stress effective strain effective strain rateand velocity vector profile was generated for bothsolid disc and solid rectangular preforms Highermagnitudes of effective stress strain and strain ratewere found at the corners and edges of preformsindicating that the onset of fracture will take placeat those regions only This was also confirmed by thepresence of severe cracks at those regions during thepresent experimental investigations

(vii) Validation of simulation was done by comparing itsresults with the theoretical and experimental resultsand was found to reasonably agree with each otherwhich indicated that present finite element simulationrepresents fairly well the present open-die forging ofSiCp AMC

It is expected that the present work will be useful forthe assessment of various deformation characteristics duringmechanical processing of AMCs

Appendix

Consider open-die forging of a SiCp AMC between two per-fectly flat parallel and rigid die platens at room temperaturewith lower die platen moving upwards with velocity ldquo119880rdquo andupper die platen stationary as shown in Figure 21

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Journal of Powder Technology 13

The boundary conditions velocity field and correspond-ing strain rate equations for solid disc preforms are given as

119880119911 = 0 at 119911 = 0

119880119911 = 119880 at 119911 =1198670

2

119880119903 =120573119890minus120573119911ℎ

119880119903

2 (1 minus 119890minus1205732

) ℎ

119880119911 = minus

(1 minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)

119880120579 = 0

120576119903119903 =120597119880119903

120597119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576120579120579 =119880119903

119903=

120573119890minus120573119911ℎ

119880

2 (1 minus 119890minus1205732

) ℎ

120576119911119911 =120597119880119903

120597119911= minus

120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ

120576119903119911 =1

2[120597119880119911

120597119903+120597119880119903

120597119911] = minus

1205732119890minus120573119911ℎ

119880119903

4 (1 minus 119890minus1205732

) ℎ2

120576119903120579 = 120576120579119911= 0

(A1)

The boundary conditions velocity field and correspond-ing strain rate equations for solid rectangular preforms aregiven as

119880119911 = 119880 at 119911 = 0

119880119911 = 0 at 119911 = 1198670

119880119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus1205732

) ℎ]

119880119911 = minus[

(119890minus1205732

minus 119890minus120573119911ℎ

)119880

(1 minus 119890minus1205732

)]

119880119910 = 0

120576119909119909 = [120573119890minus120573119911ℎ

119880119909

(1 minus 119890minus120573) ℎ

]

120576119911119911 = minus[120573119890minus120573119911ℎ

119880

(1 minus 119890minus1205732

) ℎ]

120576119910119910 = 0

120576119909119911 =1

2(120597119880119909

120597119911+120597119880119911

120597119909) = minus[

1205732119890minus120573119911ℎ

119880119909

2 (1 minus 119890minus1205732

) ℎ2]

120576119909119910 = 120576119910119911 = 0

(A2)

Nomenclature

119886119894119895 Acceleration field120576119894119895 Strain rate fieldΔ119880 Interfacial relative velocity119901 Die pressure119865av Average forging load119878 Surface area1198770 Radius of solid disc preform1198610 Width of solid rectangular preform1198710 Length of solid rectangular preform119882119894 Internal energy dissipation119882119886 Inertia energy dissipation120590119900 Flow stress of SiCp AMCmaterial120591 Frictional shear stress120583eff Effective coefficient of friction120573 Barreling factor119880119894119895 Velocity field119880 Die velocity Die acceleration119875av Average pressure119860av Average cross sectional area119881 Volume119877119898 Sticking zone radius119861119898 Sticking zone width1198670 Height of preform119882119891 Friction energy dissipation119869lowast External energy supplied120588 Density of SiCp AMC preform1198692 Second invariant of stress120601119900 Specific cohesion factor120577 Inertia factor

References

[1] S Sulaiman M Sayuti and R Samin ldquoMechanical propertiesof the as-cast quartz particulate reinforced LM6 alloy matrixcompositesrdquo Journal ofMaterials Processing Technology vol 201Proceedings of the 10th International Conference on Advancesin Materials and Processing Technologies (AMPT rsquo07) no 1-3pp 731ndash735 2008

[2] A NMurashkevich A S Lavitskaya O A Alisienok and I MZharskii ldquoFabrication and properties of SiO2TiO2 compositesrdquoInorganic Materials vol 45 no 10 pp 1146ndash1152 2009

[3] K U Kainer Basics of Metal Matrix Composites MetalMatrix Composites Custom-Made Materials for Automotiveand Aerospace Engineering Wiley-VCH Gmbh and Co KGaAWeinheim Germany 2006

[4] V Matejka Y Lu L Jiao L Huang G Simha Martynkova andV Tomasek ldquoEffects of silicon carbide particle sizes on friction-wear properties of friction composites designed for car brakelining applicationsrdquo Tribology International vol 43 no 1-2 pp144ndash151 2010

[5] M K Surappa ldquoAluminum matrix composites challenges andopportunitiesrdquo Sadhana vol 28 no 1-2 pp 319ndash334 2003

[6] J Z Gronostajski H Marciniak and A Matuszak ldquoProductionof composites on the base of AlCu4 alloy chipsrdquo Journal ofMaterials Processing Technology vol 60 no 1ndash4 pp 719ndash7221996

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

14 Journal of Powder Technology

[7] J Z Gronostajski J W Kaczmar H Marciniak and AMatuszak ldquoProduction of composites from Al and AlMg2 alloychipsrdquo Journal of Materials Processing Technology vol 300 no3-4 pp 37ndash41 1998

[8] S M Roberts J Kusiak P J Withers S J Barnes and P BPrangnell ldquoNumerical prediction of the development of particlestress in the forging of aluminium metal matrix compositesrdquoJournal of Materials Processing Technology vol 60 no 1ndash4 pp711ndash718 1996

[9] S Szczepanik and T Sleboda ldquoThe influence of the hot defor-mation and heat treatment on the properties of PM Al-Cucompositesrdquo Journal of Materials Processing Technology vol 60no 1-4 pp 729ndash733 1996

[10] C Y Chung and K C Lau ldquoMechanical characteristicsof hipped SiC particulate-reinforced Aluminum alloy metalmatrix compositesrdquo in Proceedings of the 2nd International Con-ference on Intelligent Processing and Manufacturing of Materials(IPMM rsquo99) vol 2 pp 1023ndash1028 1999

[11] I Ozdemir U Cocen and K Onel ldquoThe effect of forging onthe properties of particulate-SiC-reinforced aluminium-alloycompositesrdquo Composites Science and Technology vol 60 no 3pp 411ndash419 2000

[12] C Badini G M La Vecchia P Fino and T Valente ldquoForgingof 2124SiCp composite preliminary studies of the effects onmicrostructure and strengthrdquo Journal of Materials ProcessingTechnology vol 116 no 2-3 pp 289ndash297 2001

[13] N Chawla J J Williams and R Saha ldquoMechanical behaviorand microstructure characterization of sinter-forged SiC parti-cle reinforced aluminum matrix compositesrdquo Journal of LightMetals vol 2 no 4 pp 215ndash227 2002

[14] P Cavaliere and E Evangelista ldquoIsothermal forging of metalmatrix composites recrystallization behaviour by means ofdeformation efficiencyrdquoComposites Science and Technology vol66 no 2 pp 357ndash362 2006

[15] F-C Ma W-J Lu J-N Qin D Zhang and B Ji ldquoTheeffect of forging temperature onmicrostructure andmechanicalproperties of in situ TiCTi compositesrdquo Materials and Designvol 28 no 4 pp 1339ndash1342 2007

[16] R Narayanasamy T Ramesh and K S Pandey ldquoSome aspectson cold forging of aluminium-iron powdermetallurgy compos-ite under triaxial stress state conditionrdquo Materials and Designvol 29 no 4 pp 891ndash903 2008

[17] L Ceschini GMinak andAMorri ldquoForging of theAA261820vol Al2O3p composite effects on microstructure and tensilepropertiesrdquo Composites Science and Technology vol 69 no 11-12 pp 1783ndash1789 2009

[18] K Wu K Deng K Nie et al ldquoMicrostructure and mechanicalproperties of SiCpAZ91 composite deformed through a combi-nation of forging and extrusion processrdquoMaterials and Designvol 31 no 8 pp 3929ndash3932 2010

[19] B Ramesh and T Senthilvelan ldquoFormability characteristics ofAluminium based compositesmdasha reviewrdquo International Journalof Engineering and Technology vol 2 no 1 pp 1ndash6 2010

[20] G Sutradhar R Behera A Dutta S Das K Majumdar andD Chatterjee ldquoAn experimental study on the effect of siliconcarbide particulates (SiCp) on the mechanical properties likemachinability and forgeability of stir-cast aluminum alloymetalmatrix compositesrdquo Indian Foundry Journal vol 56 no 5 pp43ndash50 2010

[21] S Singh A K Jha and S Kumar ldquoAnalysis of dynamic effectsduring high-speed forging of sintered preformsrdquo Journal ofMaterials Processing Technology vol 112 pp 53ndash62 2001

[22] S Singh A K Jha and S Kumar ldquoDynamic effects during sinterforging of axi-symmetric hollow disc preformsrdquo InternationalJournal of Machine Tools and Manufacture vol 47 no 7-8 pp1101ndash1113 2007

[23] P Chandrasekhar and S Singh ldquoInvestigation of dynamiceffects during cold upset-forging of sintered aluminium trun-cated conical preformsrdquo Journal ofMaterials Processing Technol-ogy vol 211 no 7 pp 1285ndash1295 2011

[24] P S Mithun and M R Devaraj ldquoDevelopment of Aluminumbased composite materialrdquo International Journal of AppliedScience and Engineering Research vol 6 no 1 pp 121ndash130 2011

[25] C L Downey and H A Kuhn ldquoDeformation characteristicsand plastic theory of sintered powder materialsrdquo InternationalJournal of Powder Metallurgy vol 7 pp 15ndash21 1971

[26] A W Rooks ldquoThe effect of die temperature on metal flow anddie wear during high-speed hot forgingrdquo in Proceedings of 15thInternational MTDR Conference p 487 1974

[27] A K Jha and S Kumar ldquoCompatibility of sintered materialsduring cold forgingrdquo International Journal of Materials andProduct Technology vol 9 pp 281ndash299 1994

[28] B AvitzurMetal Forming Processes and Analysis McGraw HillNew York Ny USA 1968

[29] S Kobayashi S Oh and T AltanMetal Forming and the FiniteElement Method Oxford University Press Oxford UK 1989

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials