METHOD TO PRODUCE A TRANSITION METAL CARBIDE FROM A PARTIALLY REDUCED TRANSITION METAL COMPOUND

摘要

A transition metal carbide (for example, WC) is prepared by the following steps. A carbon-precursor mixture is formed by mixing a precursor comprised of (i) a transition metal oxide (for example, WOx) and (ii) a material selected from the group consisting of: a transition metal (for example, W); a transition metal carbide (for example, WC) and a substoichiometric carbide (W2C), in the presence of a source of carbon (for example, carbon black) in an amount sufficient to form a reduced mixture comprised of the transition meta l carbide and substoichiometric transition metal carbide, wherein the amount o f the transition metal oxide and transition metal is essentially zero in said reduced mixture. The carbon-precursor mixture is heated in a reducing atmosphere (for example, 5 percent hydrogen in argon) to a reducing temperature and for a time sufficient to produce the reduced mixture. The reduced mixture is milled in the presence of a source of carbon in an amount sufficient to carburize the substoichiometric transition metal carbide to fo rm the transition metal upon heating in a reducing atmosphere. Finally, the milled reduced mixture is heated in a reducing atmosphere to a carburizing temperature that is greater than the reducing temperature for a time sufficient to carburize the substoichiometric transition metal carbide to fo rm the transition metal carbide of this invention (for example, WC).