A study on the synthesis of nanostructured WC-10 wt% Co particles from WO3, Co3O4, and graphite

The formation of the nanostructured WC-10 wt% Co powder from WO3, Co3O4, and graphite is studied. The effects of the processing parameters of high-energy ball milling, reduction in H-2 atmosphere, and carburization in Ar/CO atmosphere are investigated. The crystallite size of the as-synthesized WC is 30-40 and 40-50 nm for 900 and 1000 degrees C carburized powders, respectively. The powder is agglomerated with the size of the primary particles ranging from 50 to 700 nm. High-energy ball milling of WO3-Co3O4-C powder mixtures leads to finer particle and crystallite sizes with larger surface area. Such milled powders can be reduced to nanostructured W at 570 degrees C and carburized to form WC at temperatures as low as 900 degrees C. Crystal growth has taken place during carburization, particularly at 1000 degrees C, which results in the formation of truncated triangular prisms and nanoplates of WC at 1000 degrees C.