Effects of the graphene content on mechanical properties and corrosion resistance of aluminum matrix composite

Graphene with excellent mechanical and physical properties has shown its great application potential in aluminum matrix composites. In this paper, graphene oxide nanosheets with negative charges were fabricated by the Hummers' method and they are absorbed on the treated aluminum powders with positive charges by electrostatic self-assembly. Then, graphene reinforced aluminum matrix composites (Gr/Al) were prepared by powder metallurgy. The effects of the Gr content on mechanical performance and corrosion resistance were investigated. The results show that Gr is distributed at the boundary and bonds well with aluminum in Gr/Al composite. Mechanical properties of the composite initially increase then decrease with the increase of Gr content. When the Gr content reaches 0.3 wt%, the ultimate tensile strength reaches 110 MPa and the wear coefficient is 0.39. However, the corrosion resistance decreases with increasing the Gr content and the corrosion mechanism is also investigated in details.