Effect of reduced graphene oxide nanoplatelets content on the mechanical and electrical properties of copper matrix composite

The homogeneous distribution of graphene nanoplatelets within a metal matrix is of utmost importance in producing high-performance metal matrix composites with superior mechanical and physical properties. In this study, graphene-reinforced copper matrix composite powder with a uniform distribution of graphene was prepared by a simple wet chemical mixing of Cu powder particles with graphene oxide (GO) nanoplatelets. The bulk composite samples containing 0.25–1 wt % reduced graphene oxide (rGO) were fabricated by the hot rolling process. The morphological changes and chemical interactions during the synthesis of the powders were inspected by scanning electron microscopy (SEM), Fourier transformation infrared spectroscopy (FT-IR), and Raman spectroscopy. The effect of rGO concentration on the hardness, compressive strength, and electrical conductivity of Cu/rGO composite were also examined. The results reveal that GO is partially reduced and covered the Cu particles surface upon wet chemical mixing, giving rise to the uniform distribution of reinforcing nanoplatelets rather than agglomerating into clusters. As the rGO content in the composite increases, the hardness of Cu/rGO composites increases while the compressive strength and electrical resistivity initially rise and later decline. The mechanical and electrical test results show that with an addition of only 0.75 wt% rGO nanoplatelets, the Cu/rGO composite exhibits 132%, 365%, and 11% increase in the hardness, compressive yield strength, and electrical conductivity over unreinforced Cu, respectively.