Synthesis of nanophase WC powder by a displacement reaction process

Nanophase WC powder has been synthesized by a novel displacement reaction process, which combines reduction and carburization of ammonium tungstate or tungsten oxide in a single operation. A critical step in the process is the heating rare, which should be slow enough to ensure a balance between reduction and carburization kinetics. The resulting WC powder has an ultrafine grain size (<10nm), which demonstrates the attractiveness of the new thermochemical processing route for preparing nanophase carbide powders at low temperatures. (C) 1997 Acta Metallurgica Inc.