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Unformatted text preview: Metal Matrix Composites (bilingual teaching) College of materials science and engineering Jilin University Professor Yu­guang ZHAO Chapter 1, Introduction (2 class hours) Chapter 1, ( 绪绪 ,2 绪绪) Chapter 2, Theory of composites (2 class hours) )绪绪绪绪 ,2 绪绪) Chapter 3, solidification Theory of particulates reinforced MMCs (2 class hours) 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 ,2 绪绪绪 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 Chapter 4, Interface and compatibility of composites (2 class hours) ( 绪绪绪绪绪绪绪绪绪绪绪绪绪 ,2 绪绪 ) Chapter 5, Reinforcements and matrices of MMCs (2 class hours) ( 绪绪绪绪绪绪绪绪绪绪绪 ,2 绪绪 ) Chapter 6, fabricated methods of MMCs I (2 class hours) 绪绪绪绪绪绪绪绪绪绪绪绪绪 I 绪 2 绪绪 绪绪绪绪绪绪绪绪绪绪绪绪绪 Chapter 7, fabricated methods of MMCs II (2 class hours) Chapter 7, 绪绪绪绪绪绪绪绪绪绪绪绪绪 II 绪 2 绪绪 绪绪绪绪绪绪绪绪绪绪绪绪绪 Chapter 8, fabricated methods of MMCs III (2 class hours) 绪绪绪绪绪绪绪绪绪绪绪绪绪 III 绪 2 绪绪 绪绪绪绪绪绪绪绪绪绪绪绪绪 Chapter 9, Reclaim and Reprocessing of MMCs (2 class hours) 绪绪绪绪绪绪绪绪绪绪绪绪绪绪 2 绪绪 Chapter 10, Functional MMCs (2 class hours) 绪绪绪绪绪绪绪绪绪 2 绪绪 绪绪绪绪绪绪绪绪绪 Chapter 11, Biomimetic composites materials (2 class hours) 绪绪绪绪绪绪 2 绪绪 Chapter 12, Prospect and Development of Metal matrix composites (2 class hours) 绪绪绪绪绪绪绪绪绪绪绪 2 绪绪 Teaching materials and references Teaching materials and references [1] Metal Matrix Composites Edited by Karl U. Kainer 2006 WILEY­VCH Verlag GmbH & Co. KGaA, Weinheim ISBN: 3­527­31360­5 [2] Composites manufacturing: materials, product, and process engineering / by Sandjay K. Mazumdar. CRC Press LLC, 2000 N.W. Corporate Blvd., Boca Raton, Florida 33431. [3] Microstructural and mechanical characteristics of in situ metal matrix composites, S.C. Tjong, Z.Y. Ma, Materials Science and Engineering, 29 (2000) 49­113 Reports: A Review Journal. If you have some difficulties to read English teaching materials, you can look up Chinese book as follow: [4] )))))))绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 1996 绪 7 绪绪 [5] )))))))绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 1995 绪 5 绪绪 [6] )))) , 绪绪绪 绪绪 , 绪绪绪绪绪绪绪绪 2000.12 [7] ))))))) , T.W. 绪绪绪绪 P.J. 绪绪绪 绪绪绪绪绪绪绪绪绪绪绪 绪绪绪绪绪绪绪绪绪绪 1996.11 [8] ))))))) , 绪绪绪 .G.. 绪绪绪 绪绪绪绪绪绪 绪绪绪绪绪绪 绪绪绪绪绪绪绪绪绪绪 1982.11 [9] )))))))) , 绪绪绪 , 绪绪绪 绪绪 , 绪绪绪绪绪绪绪 , 2004.01 [10] )))))))))))) , 绪绪绪 .[M]. 绪绪绪绪绪绪绪绪绪绪绪 2003. [11] )))))))) 绪 10 绪 )))))) [M]. 绪绪绪绪绪绪绪绪绪绪绪 . 绪绪绪绪绪绪绪绪绪绪绪 2006. )))))) Chapter 2, Theory of composites (2s hours) Chapter 2, 2.1 Preface( )) ) The characteristics of metal matrix composite materials are determined by their microstructure and internal interfaces, which are affected by their production and thermal mechanical prehistory. The microstructure covers the structure of the matrix and the reinforced phase. The chemical composition, grain and/or sub­grain size, texture, precipitation behavior and lattice defects are of importance to the matrix. The second phase is characterised by its volume percentage, its kind, size, distribution and orientation. Local varying internal tension due to the different thermal expansion behavior of the two phases is an additional influencing factor. Fig.2.1 Schematic presentation of three shapes of metal matrix composite materials 2.2 Mixed Rule of Mechanical Properties 2.2 Mixed Rule of Mechanical Properties )))))))))) ) 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 绪绪绪绪绪绪绪 Strengthening by Particles The influence of ceramic particles on the strength properties of particle reinforced light metals can be described by using the following micromechanical model ⊿Rpc = ⊿ σα + ⊿ σkG + ⊿ σskG + ⊿ σkf where ⊿Rpc is the increase in tensile strength of aluminum materials by particle addition. The influence of induced dislocations⊿ σαis given by: ⊿ σα = α ∙G∙ b ∙ ρ1/2 . with ρ= 12 ⊿T ⊿CVp/ b d where ⊿ σα is the yield strength contribution due to geometrical necessary dislocations and inner tension, α is a constant (values 0.5–1), G is the shear modulus, b the Burger’s vector, ρ the dislocation density, ⊿T the temperature difference, ⊿C the difference in thermal expansion coefficient between matrix and particle, Vp the particle volume content and d the particle size. The influence of the grain size ⊿ σkG is given by: ⊿ σkG = kY1D–1/2 (17) With D = d [(1­Vp)/Vp] 1/3 where ⊿ σkG is the yield strength contribution from changes in grain size (for example recrystallization during thermomechanical treatment of composite materials, analogue Hall­Petch); kY1 is a constant, D is the resulting grain size and Vp is the particle volume content. The influence of the subgrain size ⊿ σ is given by: skG ⊿ σskG = kY2Ds–1/2 with Ds = d (πd2/6Vp) 1/2 where ⊿ σskG is the yield strength contribution due to changes in subgrain size (for example in a relaxation process during thermomechanical treatment of composite materials), kY2 is a constant (typical value 0.05 MN m–3/2 ), Ds is the resulting subgrain size and Vp is the particle volume content. The yield point is usually measured as the yield strength with 0.2 % remaining elongation. A significant strain hardening occurs, which is dependent on the particle diameter and content. The strain hardening contribution ⊿ σkf is given by ⊿ σkf = KGVp(2b/d) 1/2 ∙ε1/2 where K is a constant, G the shear modulus, Vp the particle volume content, b the Burger’s vector, d the particle diameter and εthe elongation. According to whether the particle size or the particle content is the dominant effect, different characteristic tension contributions of the individual mechanisms to the technical yield strength RP0.2 of the particle strengthened light metal alloys result. The example of a particle­ strengthened composite material with two different particle diameters in Fig. 1.22 clarifies this in principle. Generally higher hardening contributions are made by smaller particle diameters than by coarser particles. For smaller particle diameters the work hardening and the grain size influence contributes the most to the increase in the yield strength. Figure 1.23 shows schematically the change in the substantial hardening contributions with increasing particle content for a constant particle diameter. 1) Principle of Dispersion Strengthening 1) ))))))) ) ))))))) 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 0.01-0.1μm 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 Orowan 绪绪绪绪绪绪绪绪绪 绪绪绪绪绪绪绪绪绪 τ =G b/[ d (2/3V )1/2(1-V )] y m p p τ —— 绪绪绪绪绪 G —— 绪绪绪绪绪绪绪 b—— 绪绪绪绪绪 —— 绪绪绪绪绪 y m d—— 绪绪绪绪绪 V —— 绪绪绪绪绪绪绪 —— 绪绪绪绪绪 p —— 绪绪绪绪绪绪绪 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 V = 0.01-0.15 绪 d = 0.1-0.01μm 绪 p 2 ) Principle of Particles Reinforced Composites ))))))) ) )))))))))))))))))) >1μm )))))))))))))))))))))))))))))))))) )))))))))))))))))))))))))))))))))))))))))) σy ={ (31/2GmGpbVp1/2)/[ 2d(1-Vp)C] }1/2 σ y—— ))))) Gp—— )))))))))))))))))))))))))))))))))) ))))))))))) 1-50μm )))))) 1-25μm )))))))) 0.05-0.5 ) 3 ) Principle of Fiber Reinforced Composites )))))) )) Long Fiber Reinforcement For the optimal case of a single orientation in the direction of the stress, no fiber contact and optimal interface formation (Fig. 1.11), it is possible to use the linear mixture rule to calculate the strength of an ideal long fiber reinforced composite material with stress in the fiber orientation. σ c = σ fVf + σ m (1-Vf) where σ c is the strength of the composite, Vf the fiber volume content, σ f the fiber tensile strength and σ m the matrix yield strength. From this basic correlation the critical fiber content Vfc, which must be exceeded to reach an effective strengthening effect, can be determined. This specific value is important for the development of long fiber composites: Limit of reinforcement: σ m = σ fVfc + σ my (1-Vfc) Critical fiber content: Vfc=(σ m – σ my )/(σ f – σ m ) Approximation of high fiber strength: Vfc=(σ m – σ my )/σ f Short Fiber Reinforcement The effect of short fibers as reinforcement in metallic matrixes can be clarified with the help of a micromechanical model (shear lay model). The influence of the fiber length and the fiber orientation on the expected strength can be shown as a function of the fiber content and the fiber and matrix characteristics with the help of simple model calculations. The starting point is the mixture rule for the calculation of the strength of an ideal long­ fiber­reinforced composite material with load in the fiber direction. For short­fiber reinforcement the fiber length has to be considered. During the loading of the composite materials, e.g. by tensions, the individual short fibers do not carry the full tension over their entire length. Only with over tension and predominantly shear stresses at the fiber/ matrix interface will the load transfer partly to the fiber. Figure 1.16 shows the modeling of the load of a single fiber, which is embedded in a ductile matrix and stressed in the fiber direction. The effective tension on the fiber in dependence on the fiber length can be calculated as follows: (dσf / dx)∙ rf2 ∙π + 2π∙τfmrfdx = 0 Fig.2.2 Model of loading of a single fiber, embedded in a ductile matrix (a) Stress field in the matrix, (b) shear stress distribution at the interface fiber/matrix and tensile strength contribution in the fiber. σ f = (2/rf)∙ τfm∙[(2/rf)­X], lc= σ f ∙rf/τfm Where σ f = fiber tension, rf = fiber radius, τfm = shear stress at the fiber/matrix interface. A critical fiber length lc results, at which the fiber can be loaded to its maximum .The shear strength at the interface matrix/fiber is τfm= 0.5 σ m where σ m = matrix yield point. The effective fiber strength σ f ,eff in dependence on the fiber length is σ f ,eff = k∙σ f ∙(1­ lc /2lm) where = k,fiber efficiency (deviation from optimum 0<k<1) ; lm = average fiber length. According to three cases, depending on the fiber length, can be distinguished 1)Fiber length lm>lc: σc = k∙C∙σf ∙Vf ∙[1­ (rf ∙σf / lm ∙σm)] where C = orientation factor [26] (orientated C = 1, irregular C = 1/5, planar isotropic C = 3/8). Fiber length lm = lc: σc = 0.5∙k∙C∙σf ∙Vf +(1­ Vf) ∙σm Fiber length lm < lc: σc = k∙C∙σm∙(1­ (lm / 4rf )+(1­ Vf) ∙σm At a fiber length below the critical fiber length lc the tensile strength of the fiber under load cannot be completely utilized. The reinforcement effect is lower: lc = 2rf ∙(σ f ­ σ m ) / ∙σ m The models are based on idealised conditions: ideal adhesion between fiber and matrix and ideal adjustment and distribution of the long fibers or the arranged short fibers. Figure 1.18 shows schematically the influence of the length/thickness relationship of the fibers on the reinforcement effect under optimal conditions. By increasing the fiber length the potential of long fibers (l/ d 100) will be approached. For irregular or planar­isotropically arranged short fibers an optimal distribution is the basic condition for applicability. 3 ) Principle of Fiber Reinforced Composites ))))))) ) 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 Ec 绪绪绪绪绪绪 c 绪绪绪绪绪绪绪绪绪绪绪绪绪 Ec = k1[ EfVf+Em(1-Vf) ] σc = k2[ σfVf + σm (1-Vf) ] k1 绪 k2 —— 绪绪绪 Em 绪绪 m—— 绪绪绪绪绪绪绪绪绪绪 绪 绪绪绪 Ef 绪绪 f—— 绪绪绪绪绪绪绪绪绪绪绪 kinds of Composite effect kinds of Composite effect ))))))) 1. Linear effect ( )))) ) Average effect )))))) Also call the mixed effect ))))))) ))))) Also call the mixed effect ∑K V ——parallel model( )))) ) 1/K =∑V /K ——series model( )))) ) Kc= i c i i i Juxtapose effect )))))) , Also call the parallel effect ( )))) ) Also call the parallel effect Kc ≌ Ki Complementary effect )))))) Kc= A×B Mutual counteract effect )))))) ∑ KV Kc ) Here: i i 2. Nonlinear effect( ))))) ) 2. Nonlinear effect System effect ( )))) ) Subjugation effect( )))) ) Induce effect( )))) ) Resonance effect( )))) ) 2.3 Ratio-strength between composite and matrix 2.3 )))))) ) )))))) ))))) F )))))))))))))))) F = σ c /σ m )))))))))))))) 1 绪绪绪绪绪绪绪绪绪绪绪绪绪绪 Fs = τc /τm= Gmb/[ d (2/3Vp)1/2(1-Vp)] τm 绪 绪绪 τm = Gm / 绪绪 100 绪 Fs = 100b ) 3Vp)1/2/[21/2(1-Vp) d] ) 100b d] 绪绪绪绪绪绪绪绪绪绪绪 F 绪绪绪绪绪绪绪绪绪绪 0.01-0.1μm 绪绪绪绪 F 绪绪 4-15 绪绪绪绪绪绪绪绪绪绪绪 绪绪绪绪绪绪绪绪绪绪绪 0.1-1μm 绪 F=1-3 绪绪绪绪绪绪绪绪绪绪 2 )))))))))))) Fp = σ y /σ m = { (31/2GmGpbVp1/2)/[ 2d(1-Vp)C] }1/2σ m 绪绪绪 m = Gm /100, 绪绪 绪绪 Fp = 100{ (3Vp1/2)Gpb/[ 2d(1-Vp)C] }1/2 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 0.1-1μm 绪 F=1-3 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 3 )))))))))))) Ff = σ c /σ m = k[σ fVf/σ m+(1-Vf) ] 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪绪 30­50 绪 )))))) )))))) Composite materials —— )))) Reinforcement —— ))) , Matrix —— )) )) Interface —— ))) compatibility —— )))) Interface —— ))) compatibility —— )))) Ceramic matrix composite —— ))))))) Ceramic matrix composite —— Metal matrix composite —— ))))))) Polymer matrix composite —— )))))))) Fiber —— ))) short fiber —— )))) ))) short fiber —— mono filaments —— ))) continuous fiber —— )))) ))) continuous fiber —— Carbon fiber —— )))) Boron fiber —— )))) )))) Boron fiber —— Kevlar fiber —— ))))) ))))) Whisker —— )) , Particulate , particle —— )) Whisker —— ceramic particles —— ))))) oxide —— )))) Carbide —— )))) Boride —— )))) Nitride —— ))) Fiber reinforced metal ) ceramic ) rubber ) plastics —— ))))))))))))))) ceramic rubber hybrid reinforcement —— )))) hybrid reinforcement particle­reinforced brake discs Ex­situ methods, In situ methods Powder metallurgical processes Melting metallurgical processes Infiltration, squeeze casting, vacuum infiltration or pressure infiltration; reaction infiltration of fiber­ or particle preforms Thixocasting, rheocasting, extrusion , forging, compo­casting or melt stirring solid­liquid reaction process vapor­liquid­solid reaction process Self­propagating high­temperature synthesis (SHS) combustion wave thermodynamics and kinetics exothermic dispersion (XD) process reactive hot pressing (RHP) Combustion assisted cast (CAC) solidification )) solidification crystallization )) nucleation )) growth )) solidification temperature region )))))) solute concentration )))) wetting )) wetting filling )) melting back )) solidification heat latent )))) homogeneous nucleation )))) heterogeneous nucleation )))) nucleation substrate )))) critical nucleus radius )))))) nucleation activation energy ))))) inoculation period ) inoculation time ))) constitutional fluctuation )))) structural fluctuation )))) supercooing, undercooling ))) constitutional undercooling )))) growth rate )))) cooling rate )))) solid fraction )))) solid fraction liquid fraction )))) dynamitic solidification curve )))))) solidification interface )))) L/S interface energy, L/S interface tension )))))))))))) solute partition ratio,solute partition coefficient ))))))) initial transient region ))))) steady state region ))))) final transient region ))))) liquid­solid interface morphology, )))))) planar growth interface,planar liquid­solid interface )))))) dendrite growth,dendritic crystal,dendrite morphology ))) columnar crystal ))) equiaxed grain, equi­axed grain ))) constrained crystal growth, constrained crystallization ))))) free crystal growth, non­constrained crystal growth )))))) interface stability ))))) planar­cellular ) interface transition ))))) cellular­dendrite interface transition ))))) absolute stability ))))) dendrite tip radius )))))) dendrite spacing )))) dendrite coarsening )))) eutectic solidification )))) eutectic spacing )))) lamellar eutectic )))) lamellar eutectic regular eutectic )))) )))) non­regular eutectic ))))) non­regular eutectic hypoeutectic, hypo­eutectic ))))) hypereutectic,hyper­eutectic ))))) pseudo­eutectic,pseudoeutectic ))) divorced eutectic )))) coupled growth zone ))) leading phase ))) primary phase ))) second phase ))) bridging growth of lamellar eutectic )))))) peritectic solidification, peritectic reaction )))) monotectic solidification, monotectic reaction )))) )))) local solidification time ))))))) local solidification time unidirectional solidification, directional solidification )))) exothermic powder method )))) (EP ) ) power down method ))))) (PD ) ) high rate solidification ))))) (HRS ) ) liquid metal cooling method ))))))) (LMC ) ) continuous directional solidification )))))) directional solidification furnace ))))) directional solidification furnace single crystal growth )))) seeded single crystal growth ))) Selective single crystal growth ))) electromagnetic shaping )))))) zone melting ))) melting interface )))) rapid solidification )))) near rapid solidification ))))) ))))) equilibrium solidification )))) equilibrium solidification non­equilibrium solidification ))))) near­equilibrium solidification ))))) metastable phase )))) chilling )) single roller process, single roller chilling, chill block melt spinning ))))) double­roller quenching, twin roller process, twin roller casting ))))) planar flow casting ))))))) gas atomization ))))) water atomization )))) rotating electrode process ))))) rotating disk / cup /screen (mesh) )))) / )) / )))) Taylor method ))) piston­anvil quenching method ))) melt overflow process ))) melt extraction ))))) ))))) deep undercooling ))) deep undercooling deep undercooling rapid solidification ))))))) ))))))) glass fluxing technique ))))))) glass fluxing technique levitation melting ))))) electromagnetic levitation )))) acoustic levitation ))) gas flow levitation )))) spray deposition )))) melt drop diameter )))) micro­gravity solidification ))))) high­gravity solidification ))))) ))))) double diffusion convection ))))) double diffusion convection levitation )) dropping pipe )) high pressure solidification )))) casting )) mold, mould )) mould making, mold making )) core making )) melting )) proportional solidification )))) Sand casting )))) special casting )))) lost­wax casting ))))))))))) shell mold casting )))) permanent mold casting ))))) centrifugal casting )))) bimetal casting ))))) cast­in process, insert method ))) plaster mould casting ))))) plaster mould casting continuous casting )))) counter­gravity casting ))))) low pressure casting )))) adjusted pressure casting )))) pressure differential casting )))) vacuum suction casting )))) die­casting )) full mold casting, vacuum evaporation pattern casting ) V­ EPC )) lost foam casting (LFC) )))))))“)))))” magnetic mold casting )))) castability )))) filling capacity )))) recycling materials ))) master alloy )))))))“)))” flux )) modification )))) inoculation process, inoculation treatment )))) grain refinement )))) mechanical grain refinement )))) chemical grain refinement )))) surface grain refinement )))) grain refiner ))) grain refiner modifier ))) inoculants,inoculation addition ))) temperature treatment )))) superheating,superheat treatment )))) Pouring temperature )))) holding )) pre­heating )) On­site analyses )))) pouring )) superheating temperature ))) filling )) pressure head )) static pressure head ))) mushy solidification, solidification with mushy zone ))))))))))) shell solidification ))))))))))) mushy zone ))))))))))) solidification front )))) chill zone ))) columnar zone )))) equiaxed zone )))) grain size­­ )))) grain size­­ equivalent thickness­ ))))))))))))))))))) square root relationship­ ))))) feeding bounary­ )))) feeding channel­ )))) feeding difficulty zone­ ))))) effective feeding distance­ )))))) casting defects­ )))) porosity, micro­porosity­ )))))“))))” shrinkage cavity­ )) grain multiplication­ )))) crystal shower­ ))) macro­segregation­ )))) micro­segregation­ )))) positive segregation­ ))) negative segregation­ ))) normal segregation­ )))) inverse segregation­ ))) grain boundary segregation­ )))) hot­top­segregation= )))) A type segregation ) A­segregation ­A ))) ...
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This note was uploaded on 10/15/2011 for the course ENG 209 taught by Professor Zhao during the Spring '10 term at Tsinghua University.

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