Effect of Graphene on the Microstructure and Mechanical Properties of WC-Based Cemented Carbide

Abstract

WC-based cemented carbides were prepared by spark plasma sintering (SPS) of WC-Co-Cr3C2-VC alloy powder by adding different contents of graphene. The phase composition, microstructure, mechanical properties, and magnetic properties of cemented carbide were investigated by means of XRD, SEM, Vickers hardness and fracture toughness tests, and magnetic properties tests. The results showed that the mechanical properties of the specimens show a trend of first increasing and then decreasing with the increase in graphene content. After adding 0.6 wt.% graphene, graphene is uniformly distributed on the substrate in the form of flakes, WC grain size decreases, the hardness of the specimen increases to 2009 HV, the relative density increases to 94.3%, the fracture toughness is 11.72 MPa·m1/2, and the coercivity of the sample is 437.55 Oe. Therefore, cemented carbide with a graphene content of 0.6 wt.% has excellent comprehensive performance (Vickers hardness and fracture toughness).