Boronation reaction between molybdenum or tungsten powder and boron carbide in aluminium melt

Molybdenum or tungsten borides are excellent high-temperature ceramics or electrocatalysis materials. In this paper, Mo or W borides were prepared by boronizing Mo or W powder in Al melt with B 4 C as boron source. By thermodynamic calculation, the feasibility of preparing various borides and the stability of borides in Al melt were evaluated. Through high temperature reaction at 1523 K and the following acidic leaching, single phase MoAlB, W 2 B 5 , WB, and W 2 B 5 powders were successfully synthesized. Owing to the decarburizing function of Al melt, C contents of various boride products were below 1 wt%. In addition, the phase transition processes of various products in the synthesis stage were revealed.