Preparation of Monophasic Tungsten boride powder from Tungsten and boron carbide

Tungsten borides are special compounds with potential applications in superhard materials, anti-friction materials, and catalytic materials. In this study, a new synthetic method for tungsten boride is proposed using tungsten (W) and boron carbide (B 4 C) as raw materials. First, the boronization reaction between W and B 4 C was carried out at a high temperature; then, the boronization products were reacted with calcium to generate CaC 2 for decarburization. After acidic leaching of the CaC 2 and Ca, pure tungsten boride could be prepared. By investigating the reaction between different ratios of W and B 4 C, it was found that only pure W 2 B and WB were synthesized in the current method, and W 2 B 5 could react rapidly with Ca to form WB and CaB 6 . However, in the absence of a decarburization treatment after the boronization process, carbon-containing WB (C content = 1.2 wt%) and W 2 B 5 (C content = 3.4 wt%) could also be prepared. In addition, it was concluded that the prepared tungsten boride roughly maintained the morphology and particle size of raw W, and ultra-fine tungsten boride could be synthesized with ultra-fine W powder at a low boronization reaction temperature.