Creating defects on graphene basal-plane toward interface optimization of graphene/CuCr composites

Abstract

In-situ formation of appropriate interfacial carbides by matrix-alloying with carbide-forming elements offers an efficient approach to improve the interfacial bonding of graphene/CuX composites. However, the carbide formation commonly occurs at graphene edge/matrix interface, which is not enough to achieve the sufficient interfacial bonding because the vast majority of graphene/matrix interface is basal-plane/matrix interface rather than edge/matrix interface. To alleviate this limitation, we reported a new design of creating defects on graphene basal-plane (CDGB) to optimize the interface and mechanical properties of graphene/CuCr composites. Plasma treatment was employed to create the structural defects (∼7 nm nanopores) on graphene basal-plane. When incorporating the plasma-treated graphene into the CuCr matrix, the Cr7C3 carbides were found to be in-situ formed at both basal-plane/matrix and edge/matrix interfaces. Ex-situ and in-situ tensile tests both demonstrated that the plasma-treated graphene led to the composite that showed a larger strength enhancement and a higher load transfer capability than untreated counterpart, which was ascribed to the largely improved interfacial bonding contributed by the Cr7C3 formed at basal-plane/matrix interface. This study suggests that the CDBG via plasma treatment affords a feasible solution for the interface optimization of graphene/CuX composites with enhanced mechanical properties.