Preparation of ultra-fine grain WC-10Co-VC alloy by spark plasma sintering

This work successfully prepared ultra-high hardness WC-10Co-VC cemented carbides by spark plasma sintering (SPS) with self-synthesized ultra-fine VC powder used as a grain growth inhibitor. The effects of VC content on the densification degree, grain size and mechanical properties were investigated. The results showed that adding VC decreased the relative density and inhibited grain growth. In addition, with the increase of VC content, both hardness and toughness increased first and then decreased. When the content of VC was 3%, the hardness reached the maximum value of 2 235 HV₃₀ due to solid solution and fine grain strengthening. The small-sized grains not only increased the crack deflection frequency but also prolonged the crack propagation path, which increased the energy consumption of crack propagation, thereby improving the fracture toughness.