Preparation and characterization of Cu/(WC-TiC-Co)/graphene nano-composites as a suitable material for heat sink by powder metallurgy method

Abstract Cu/WC-TiC-Co/GNs nano-composites were successfully prepared by the powder metallurgy technique. The predetermined weight percent value of WC-TiC-Co powder was mixed with 0.25, 0.5, 0.75, and 1 wt% of graphene nano-sheets for 3 h. by 1:2 powder to ball ratio. The mixed powders were coated with 90 wt% copper by the electro-less deposition technique. The composites were compacted at 900 MPa then sintered twice in a hydrogen atmosphere furnace once at 1000 °C and another at 1100 °C for 140 min. Sintering at 1000 °C proved to present the more suitable temperature. Both SEM and EDAX were used to investigate the microstructure and constituents of the sintered nano-composites. The relative density, hardness, electrical and thermal conductivity were studied. The microstructure refers to a good adhesion and homogeneous distribution of WC-TiC-Co and GNs in the copper metal matrix. The results showed that the relative density was increased up to 0.25 wt% GNs then decreased. In spite of the decreasing of the density after 0.25 wt% GNs, the hardness increased up to 1 wt% GNs. Because of the large surface area and the nano-size thickness of GNs, electrical and thermal conductivities got increased by its increasing up to 1 wt%.