Synthesis of tungsten carbide from bimodal tungsten powder produced by electrical explosion of wire

Abstract

In the present study, bimodal tungsten carbide WC powders are successfully prepared by a two-stage process: electrical explosion of wire (EEW) synthesis of bimodal tungsten powder followed by a carburization reaction. The conditions of the EEW synthesis have been determined, resulting in the preparation of the bimodal powder. During the carburization process, the tungsten carbide WC is formed through the transition phase W2C. The carbon content in the obtained WC powders is very close to the theoretical value. Also, it was found that a high C/W molar ratio at the carburization stage does not affect the carburization process significantly. Optimal conditions for the tungsten carbide WC synthesis have been determined: calcination at 1200 °C with 8 h dwell and C/W molar ratio to be 1.4. The yield of tungsten carbide is 99 wt% under these conditions. Thus, the carburization process of bimodal tungsten powder may provide a low-cost and high-efficiency route to prepare the WC powders for various applications.