Thermal and mechanical properties of copper-graphite and copper-reduced graphene oxide composites

Graphene and its derivatives have a high value of thermal conductivity and good mechanical properties. Rare studies focused on the anisotropic thermal conductivity, while anisotropic thermal conductivity and hardness of reduced graphene oxide/metal are still far behind the expected values. In this work, different mesh sizes of graphite and graphene oxide were used for making copper-graphite and copper-reduced graphene oxide composites with the powder metallurgy technique. Raman, XRD, XPS and SEM were performed to evaluate the disorder, phase analysis, surface morphology and microstructure evolution of the composites as well as synthesized graphene oxide. Anisotropic thermal conductivity and Vickers hardness of the composites were characterized to check the effects of different mesh size on copper-graphite and copper-reduced graphene oxide composite. Results show that anisotropic thermal conductivity in-plane and through-plane ratio (1.68) and hardness (71.2 HV) which is 80% and 61% greater than pure copper were attained at only 1 wt% graphene oxide mesh size 3500 μm copper-reduced graphene oxide composite. Moreover, graphite and graphene oxide mesh size (3500 μm) gave good results compared with mesh sizes 500 μm and 1000 μm. The good anisotropic thermal conductivity and high hardness suggest that it may be ideal materials as heat sinks in thermal packaging.