Development of Nano-sized WC Powder for Hardmetals

In order to develop the nano-sized WC powder that improved the hardness of hardmetals, carbothermal reduction of WO3 by C was examined by using the thermogravimetric analysis. At the direct carburization reaction path of $WO_3{\rightarrow}WO_{2.72}{\rightarrow}WO_2{\rightarrow}W{\rightarrow}W_2C{\rightarrow}WC$, the nano-sized grain was generated at the reaction stage $WO_{2.72}$ to $WO_2$ and W. For trial production, the intermediate products which consists of metal and carbide phases obtained by the first heating has been carburized to the final WC powder. We succeeded in the development of the WC powder of about 70nm. In addition, the nano-sized WC powder in which the vanadium of the most effective grain growth inhibitor was uniformly dispersed was developed.