Preparation of ultrafine tungsten carbide powder by CVD method from WCl₆–C₂H₂–H₂ mixtures

The synthesis of ultrafine tungsten carbide powder from WCl₆–C₂H₂-H₂ mixtures was investigated. Under most experimental conditions, a mixture of α–WC and β–W₂C was produced. The specific surface area and morphology of the product prepared under various reaction conditions were determined. The product particle size increased with temperature up to 1373 K and then decreased, went through a minimum with increasing WCl₆ partial pressure, and decreased with increasing H₂ flow rate. The specific surface area of the product showed the opposite trend in all cases.