Effect of VC addition on microstructural evolution of WC-Co alloy: mechanism of grain growth inhibition

Specimens of WC-30Co and WC-1VC-30Co (wt-%) were heat treated at 1500°C for up to 64 h. During the early stage of heat treatment, it was observed that the addition of VC has effectively retarded the coarsening of WC grains. After the prolonged heat treatment, however, the abnormally grown, very large WC grains appeared in the WC-1VC-30Co specimen. The role of VC has been interpreted in terms of grain coarsening which is suggested to occur by a two-dimensional nucleation mechanism.