DIRECT CURRENT ARC-PLASMA SYNTHESIS OF TUNGSTEN CARBIDES.

Article abstract of DOI:10.1007/BF02402828

Chemical reactions which occur in a thermal plasma between fine powders of tungsten and graphite and between powdered tungsten and methane have been studied. When using a commercial d. c. torch and a standard reactor design, the conversion to tungsten carbide is relatively poor. With a specially designed reactor operating in a transferred-arc mode, nearly complete conversion to carbide results when operating at the same power level and with methane as a reactant. Crystal structures and particle morphologies have been studied with electron microscopy and X-ray diffraction. Several initial stages of the particle-particle and particle-gas reactions have been determined. A number of interesting composite particles corresponding to intermediate reaction steps has been observed.