Zirconia-toughened WC with/without VC and Cr3C2

The effects of Cr3C2 and VC on densification behavior, grain growth and mechanical properties of the WC-8 wt% ZrO2 composites were investigated, and the relationship between the mechanical properties and microstructure was studied. The addition of VC and Cr3C2 not only retarded densification of the WC–ZrO2 material, but also significantly suppressed the growth of WC-grains and ZrO2-particles. For the WC–ZrO2 composite without VC and Cr3C2, microstructure coarsening at elevated temperatures caused degradation in hardness, whereas the hardness maintained a high value of ~22 GPa for the composite with VC and Cr3C2 additives as the microstructure remained fine. The fracture toughness of the WC-based materials toughened by 8 wt% ZrO2 seemed insensitive to the coarseness of microstructure, and achieved a value of ~11 MPa m1/2 when VC and Cr3C2 were added.