Enhancement of Thermal Conductivity and Mechanical Properties of Cu-Reduced Graphene Oxide Composites by Interface Modification

Abstract

Copper matrix composites reinforced with reduced graphene oxide (rGO) were fabricated via charge adsorption process, thermal reduction, and hot-press sintering process. We investigated the effect of rGO on the thermal conductivity, electrical conductivity, mechanical properties, and microstructure of the composites. By controlling the reaction process, copper on the rGO surface was oxidized to form Cu2O. The presence of Cu2O at the interface enhanced interfacial bonding strength and reduced the interfacial thermal resistance, thus improving the thermal conductivity and mechanical properties. This enhancement occurred at low rGO contents. By contrast, excessive amounts led to rGO agglomeration and a degradation of the performance. At the optimum rGO content of 0.6 wt.%, the composites had a 10% increase in thermal conductivity and a 46% increase in yield strength (σ0.2), while maintaining high electrical conductivity.