SYNTHESIS OF NANOPHASE WC POWDER BY A DISPLACEMENT REACTION PROCESS

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