Magnesiothermal synthesis of W-WB powders in ionic melts

Abstract

Conditions for synthesis of W-W2B and W-WB powders by simultaneous reduction of the metal oxide- and boron-containing compounds with magnesium in molten salts of the NaF-NaCl system (1: 1) have been considered. It is shown that synthesis involves successive redox reactions yielding tungsten powders with variable concentrations of boride phases. The powder fineness characteristics have been determined in experiments. The volume particle size distribution of the powders has been calculated. It is found that the specific surface area decreases from 1.18 × 106 to 0.63 × 106 as the concentration of the boride phase in the powders rises to ∼40%.