Preparation And Properties Of Graphene Reinforced Aluminum Matrix Composites By Powder Metallurgy

Graphene has excellent mechanical and electrical properties,if can be added to the aluminum alloy and effectively apply its performance,can greatly improve the mechanical properties and conducting performanceof the aluminum matrix,which is of far-reaching significance for thegreat promotion of thedevelopment of power,automobile and even the aerospace.So far,there are few literatures on the graphene reinforced aluminum matrix composites,so it is necessary to study the effect of graphene on the aluminum matrix composites.This paper use the powder metallurgy technology to prepare the graphene/aluminum composite and aluminum alloy composite materials,using the method of orthogonal test to determine the optimal sintering process of composite materials and the amount of graphene,further study the aluminum alloy composite with the best preparation process of different graphene content,to study the mechanical properties such as tensile properties,and the conductivity change by the graphene content,to analyze the effect mechanism,we also studied the influence on aluminum alloy composite material after destressing annealing process.The results of this study are as follows:With the increase of the content of graphene,the bending strength and hardness of graphene/pure Al composites increase first and then decrease,and the conductivity always decreased with the increase of the content of graphene.The aluminum alloy composite has the best performance when the content of graphene is 0.4wt%and the sintering process is to retain its heat for a 4 hours at 585℃.With the increase of the content of graphene,the density and bending strength of aluminum alloy composites increase first and then decrease,it reach the maximum when the graphene content is 0.4%,Si and Mg can improve the wettability between aluminum matrix and graphene,improve the bonding effect of interface,so then improve the density of the matrix.With the increase of the content of graphene,the tensile strength,hardness,conductivity and elongation of aluminum alloy composites increase first and then decrease.The tensile strength of the composites is 282.52MPa when the content of graphene is 0.4%,which Improve 38.92%comparing with aluminum matrix.The elongation rate of 0.2%composites is 1.79%,which is the maximum.Increasing the content of graphene,the number of the tearing edges and dimples on fracture morphology is growing,tearing edges become smaller and dimples become more and more deep,the plasticity of composites gradually increase;The dimples of the 0.2%graphene composite material’s fracture surface are the deepest,the plastic of the composites are the best at this time.When the graphene’s content continues to increase,the dimple fracture morphology become bigger,the tearing edges become bigger too,when the graphene’s content reaches 0.6%,it even show a brittle fracture characteristics with a certain degree.In addition to the elongation rate,the properties of aluminum alloy composites are improved after annealing,but the influence law of graphene on properties is the same.