Carburization of WC-carbon nanotube composite using C2H2 gas

An untraditional way to synthesize composites of nanophase WC powders and carbon nanotubes for the first time from the reduction and carburization of tungsten oxide nanoparticles by C2H2-H-2 gas instead of CO was investigated. Pure nanophase WC powders were fabricated through the carburization of pure WO3 nano-powders by C2H2-H-2 gas with no Co in the precursors. Mixtures of alpha-W and WC were observed in the XRD patterns when the carburization temperature was below 750degreesC, above which pure WC powders with a grain size of 10-30 nm were produced. When small amount of Co source was added into the tungsten precursors, carbon nanotubes and nanorods appeared in the composite powders after the same reduction and carbonization process. The effect of the process parameters, such as temperature and gas flow, on the final tungsten carbide phase has been studied in detail.