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

Abstract

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 H2 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 °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 °C and carburized to form WC at temperatures as low as 900 °C. Crystal growth has taken place during carburization, particularly at 1000 °C, which results in the formation of truncated triangular prisms and nanoplates of WC at 1000 °C.