With a view to developing a more energy-efficient and environment-friendly process route for the production of W-C based cutting tools, a single step process for the synthesis of tungsten carbides containing Ni from oxide precursors was investigated in the present work. A fluidized bed reactor was employed, wherein the mixed oxides were subjected to simultaneous reduction and carburization using H_2-CH_4-Ar gas mixtures in the temperature range 1073-1273 K. The carbon potential in the gas phase could be accurately controlled by suitably adjusting the H_2/CH_4 ratio. The impact of gas flow rates and temperature on the reaction product was examined. The carbide product obtained was characterized by SEM and X-ray diffraction. The results showed that the product consisted of Ni-W-C alloys, which were in consistency with the phase diagram at the temperature of reaction. The particle size of the carbides is in the range of 10~(-8) m, which was dependent on the process temperature, higher temperature yielding larger grains. The results indicate that the gas-solid reaction route combining reduction and carburization is an efficient method that can be commercially applied for the production of a variety of cemented carbides.
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