Preparation and properties of Cu/RGO composites via H2 reduction and spark plasma sintering

In this work, copper/reduced graphene oxide (Cu/RGO) mixed powders were produced by using hydrogen-reduction (H2 reduction) with graphene oxide (GO) and copper oxide powders as raw materials. The Cu/RGO composite was sintered through spark plasma sintering (SPS). The effects of RGO content and sintering conditions on the relative density, hardness and electrical conductivity of the composite were investigated. The results show that the GO and copper oxide powder can be reduced via H2 reduction when sintered at 500 °C for 8 h. Moreover, as the content of RGO increases from 0 wt% to 0.67 wt%, the hardness and electrical conductivity increases firstly and then decrease. When the content of RGO is 0.33 wt%, the hardness and electrical conductivity of the composite reach the maximum, i.e., 98.6 HV and 80.5% IACS (International Annealed Copper Standard) respectively. The hardness and electrical conductivity are maximum for the composite sintered at 600 °C for 8 h. Further increase in sintering temperature lowers the properties of the composite. The Cu/RGO composites sintered at 600 °C achieved a relative density of 95.56%, with the high hardness of 193.9 HV and electrical conductivity of 89.8% IACS. © 2022 Elsevier B.V.