Low friction coefficient bioinspired copper/graphene nanolaminates with high content graphene

Graphene is widely used in metal matrix composites (MMC) to improve the tribological properties of metal due to its special lamellar structure and excellent tribological properties. However, because the aggregation of graphene, it is difficult to increase the content of graphene in metal materials, which seriously hinders the further optimization of friction coefficient. In this paper, we report a bioinspired strategy to fabricate nacre-like copper/graphene nanolaminates through chemical intercalation of copper precursor into the interlayer space of expandable graphite and subsequent reduction. The regular parallel arrangement of graphene can greatly improve the agglomeration phenomenon and the aspect ratio of graphene, which harden the copper matrix by effectively restricting the motion of dislocation and also form continuous lubricating film on the surface. A low dry sliding friction coefficient 0.13 is thus obtained among copper-based composites without severely deteriorating the electrical properties, providing new prospect in sliding electrical contact applications.