Study On Microstructure And Properties Of The Aluminum Matrix Composites Reinforced With The Graphene

0.25wt%~1wt% graphene reinforced 7075 aluminum matrix composites and1060 aluminum matrix composites were prepared by Rotational Friction Extrusion(RFE).On the basis of the optimal process parameters,the effect of graphene contents on macro morphology and microstructure of composite were investigated.Some phases of the composite were analyzed by XRD,SEM and EMPA.What's more,the mechanical properties and the electrical properties were tested.At last,the strengthening mechanism of the composites was studied.The main results show that as following:The aluminum matrix composites reinforced with the graphene can be well formed with the optimum process parameters.The 1060 Al composites can get good shape and length of 140 mm with the parameter of n=555rpm and v=0.36mm/s,the 7075 Al composites which have well shape and length of 150 mm can be fabricated with the parameter of n=315rpm and v=0.28mm/s.The content of graphene is great influences on the shape of the composites.graphene is dispersed uniformly in the aluminum matrix and makes grains finer.The composites can get good shape with the content of 0.25wt% graphene,but the shape becomes worse with increasing of the graphene contents.Through the test of XRD,SEM and EMPA,the organization of composites is finer equiaxed grain and the graphene is equally distributed in the composites.The interface reaction don't occurre between aluminum and graphene in the RFE process,so it has not the reaction product which is Al4C3.The addition of the graphene significantly improves the micro-hardness,tensile strength and conductivity.With the increasing of graphene contents,the hardness,tensile strength and conductivity of the composites are increased.The hardness of the1wt%1060Al composite is 43.3HV,which is increased nearly 72.5% comparing with aluminum.The hardness of the 1wt%7075Al composite is 132.3HV,which is 1.26 times of aluminum by RFE.The tensile strength of the 0.6wt%1060Al composite is 113.4MPa,which is 1.37 times of aluminum.The tensile strength of 0.6wt%7075Al composite is474.4MPa and about 22.3% higher than the aluminum by RFE.The conductivity of the0.25wt%1060Al composite is 80%IACS,which is increased nearly 3.6% comparing with aluminum.The conductivity of the 0.25wt%7075Al composite is 40.3%IACS,anincrease of 5.2% compared to the aluminum by RFE.