Microstructure, electrical conductivity and hardness of multilayer graphene/Copper nanocomposites synthesized by flake powder metallurgy

In this study, the influence of multilayer graphene content on the green and sintered properties of the multilayer graphene/Copper nanocomposites was investigated. Flake powder metallurgy, as a new production method, was employed to prepare the multilayer graphene reinforced copper matrix nanocomposites. Results showed that the increase in agglomeration content inhibited particle-particle contact during the sintering process and therefore sintered density decreased with increasing the multilayer graphene content. The green density of 8.46 g/cm3 was found for the monolithic Cu sample, which was 16.4% higher than that of the 5 wt% MLG/Copper nanocomposites. The high conductivity value (78.5 IACs) was obtained with 0.5 wt% the multilayer graphene reinforced nanocomposites. The electrical conductivity of sintered 5 wt% the multilayer graphene/Copper nanocomposites was 61.48 IACs. When the amount of the multilayer graphene particles as higher than 3 wt%, the decreasing rate in hardness significantly increased. The decreasing rate in the hardness of the multilayer graphene/Copper nanocomposites can be attributed to decrease in density and the non-homogeneous distribution of multilayer graphene particulates in Cu matrix.