REACTIVE DEPOSITION OF TUNGSTEN AND TITANIUM CARBIDES BY INDUCTION PLASMA

A study is reported on the use of induction plasma technology for the preparation of dense free-standing deposits of tungsten carbide and ti tanium carbide from metallic powders and methane. Phase analysis by X- ray diffraction indicates that primary carburization of the particles takes place in-flight giving rise to the formation of W2C and TiC1-x. Secondary carburization occurs in the deposits resulting in the format ion of tungsten and titanium carbides. Microstructures revealed by opt ical and scanning electron microscopy show uniform small grains of the carbides. The reactive plasma spray-formed tungsten carbide shows tra nsgranular fracture, while pure tungsten deposits show intergranular f racture.