Study On Graphene / Cu Reinforced Aluminum Matrix Composites

Graphene(or Cu)reinforced Al matrix composites have high conductivity and strength,so they are considered to be promising cable materials.But intermetallics are easily formed in the process of preparation and the homogeneity of materials is poor,which limits their wide application.According to the above problems,the graphene(or Cu)reinforced Al matrix composites are studied.The mixed powders were prepared by mechanical stirring,chemical method and ball milling,respectively,then sintered by SPS technology.The influence of key process parameters on the structure and properties of composites was investigated.For the Cu reinforced Al matrix composite,the mixing method,the size of Cu powder and sintering temperature have great influence on its microstructure and properties.The Al-Cu mixed powder prepared by chemical method has good uniformity.Cu particles are uniformly distributed on the surface of Al particles,and the particle size is small,about100 nm.The tensile strength and Vickers hardness of the sintered samples are 270 MPa and 300 HV respectively,which are about 2 times that of the sample prepared by ball milling.With the increase of sintering temperature,the sintering process changes from solid-phase sintering to liquid-phase sintering,and the density of the sample is increased from 1.75g/cm~3to 2.76g/cm~3.the tensile strength of the sintered sample at 530°C reaches270 MPa.The first principle calculation shows that the rigidity strengthening effect of intermetallics is obvious.In addition,with the progress of Al/Cu interface reaction,the conductivity decreases gradually.For the graphene reinforced Al matrix composite,the powder mixing method,heat reduction temperature and the type of graphene have great influence on its structure and properties.The mixing powder prepared by mechanical stirring are good uniform.The structure of sintered sample is homogeneous and its mechanical and electrical properties are better than those obtained by ball milling.The tensile strength of the composite using graphene powder as raw material is 160 MPa,and the electrical conductivity is 70.2%.The higher the thermal reduction temperature of graphene is,the better the mechanical properties and electrical conductivity of graphene reinforced Al matrix composites are.The electrical conductivity of the composites with graphene as raw material after thermal reduction treatment at 650°C reaches 70.2%IACS.