Study On Microstructure And Mechanical Properties Of Aluminum Alloy/Aluminum Matrix Composite Laminated Composites

The conventional aluminum matrix composites(AMCs)have many applications in aerospace and automobile manufacturing due to their high strength,elastic modulus and wear resistance.However,the reduced ductility and instantaneous failure of AMCs severely limit its application.Therefore,it is necessary to develop laminated composites which have both high strength of AMCs and good plasticity of aluminum alloy to improve its application.In this paper,1060/Al-TiC/1060 and 1060/Al-SiC/1060 laminated composites were prepared by hot-roll bonding with aluminum alloy and AMCs.The interfacial bonding and the effect of reinforcement content on the microstructure and properties of the AMCs were investigated.The influence of the reinforcement content and process parameters on the microstructure and mechanical properties of laminated composties were studied.The Al and TiC in Al-TiCp composites have a certain crystallographic orientation:the TiC(111)plane is parallel to the Al(121)plane,the Al(~-311)plane is parallel to the TiC(101)plane and the Al(1~-11~-)plane is parallel to the TiC(110)plane.After first-principles calculation,it is found that the Al and C-terminated of TiC are combined in the form of a mixture of covalent and ionic bonds.The Al and Ti-terminated of TiC are combined in the form of metal bond,and the Al and C-terminated of TiC stacking interface structure is more stable.The AMCs shows typically equiaxed grains.Most of reinforcements are uniformly dispersed at the grain boundaries and a small part of reinforcement is clearly observed along the grain boundaries.Morever,the number of clusters increases with the increasing of the content of the reinforcement.The yield strength(YS)and ultimate tensile strength(UTS)of AMCs first increase with increasing of the content of the reinforcement and then decrease,while the elongation of AMCs decrease gradually.The 1060/Al-TiC/1060 and 1060/Al-SiC/1060 laminated composites with different reinforcement contents exhibite a rather inhomogeneous microstructure across the 1060layer thickness.The grains at the surface region of 1060 layer were tilted to a certain angle,and the angle decrease near the interface of 1060 layer.A through-thickness texture gradient is found in the 1060 layer.The intensity of r-cube orientation is decreased as the thicknes position moved towards the interface layer from the surface,whereas the intentisy of cube orientation is increased.The center of AMCs layers are characterized by the?-fiber and?-fiber rolling textures after the hot-roll bonding process.The volution fraction of?-fiber increases with increasing of the content of reinforcement.The YS and UTS of laminated composites first increase with increasing of the content of the reinforcement and then decrease,while the elongation of AMCs decrease gradually.For the hot-roll bonding 1060/Al-TiC/1060 laminated composites with different reductions,the degree of grain-subdivision and the number of high-angle boundaries decreased with the measured area approaching the interface of 1060 layer from the surface.The intensity of cube orientation is decreased with increasing of the rolling reduction,whereas the the intentisy of r-cube orientation is increased.The center of Al-TiC layers are characterized by the?-fiber and?-fiber rolling textures after the hot-roll bonding process,and the volution fraction of?-fiber increases with increasing of the rolling reduction.The YS and UTS of laminated composites first increase with increasing of the content of the reinforcement and then decrease,while the elongation of AMCs decrease gradually.The YS and UTS of 1060/Al-TiC/1060 laminated composites increase with increasing rolling reduction.The elongation first increased to a peak value at 43.0%,and dropped slightly with further increasing rolling reduction.For the hot-roll bonding 1060/Al-TiC/1060 laminated composites with different rolling temperature,a rather inhomogeneous microstructure across the 1060 layer thickness is observed after the hot-roll bonding process due to the shear deformation introduced by the high friction between the samples and the rollers.The rolling temperature has a great influence on the shear deformation in 1060 layers.The degree of grain-subdivision and the number of high-angle boundaries degree show a peak value at350?.The intensity of r-cube orientation first increased to a peak value at 350?,and then decreased with further increasing rolling temperature.The initial random texture in the Al-SiC layer was changed to the?-fiber and?-fiber rolling textures after the hot-roll bonding process.The YS and UTS of laminated composites first increase with increasing of the temperature and then decrease,while the elongation of AMCs increase gradually.