Abstract
The TaC/VC inhibitor was added in nanophase WC/Co powders by either a mechanical or chemical doping method. The microstructure and mechanical properties have been investigated for the WC/Co hard alloys which were sintered with these powders. After sintering, most of the WCs maintained their original round morphology and fine microstructure. In the mechanically doped alloy, exaggerated and abnormal local grain growth was observed which was supposed to be caused by the non-uniform distribution of the TaC/VC dopant. However, such an abnormal grain growth problem does not appear in the alloy when the inhibitors were chemically doped into the powders. Due to relatively fine and homogeneous microstructure, the nanophase WC/Co doped by the chemical method showed a higher hardness and better transverse rupture strength than that doped by the mechanical method.
