Synthesis of nanostructured WC/Co powders through an integrated mechanical and thermal activation process

摘要

In this study we describe a new process that allows for production of lowcost nanostructured WC/Co composite powders. The process is termed as the integrated mechanical and thermal activation (IMTA) process because of the integration of mechanical activation (via high-energy ball milling) and thermal activation (via thermal treatment) in the process. Using tungsten oxide (WO{sub}3), cobalt oxide (CoO) and graphite as the starting material, we have demonstrated that mechanical activation before carbothermic reduction and carburization reactions can greatly enhance the formation of WC. The product from this new process is nanostructured powder rather than coarse-grained counterparts. The high-energy milling allows the desired reaction to take place at low temperatures, thus preserving the nanostructure, while the thermal treatment is necessary to obtain the reaction between the constituents. The fundamentals associated with the IMTA process are discussed.