Low‐temperature preparation of titanium diboride fine powder via magnesiothermic reduction in molten salt

Phase pure titanium diboride (TiB 2 ) powder of 100‐200 nm was synthesized from TiO 2 and B 2 O 3 using a molten‐salt‐assisted magnesiothermic reduction technique. The effects of salt type, Mg amount, reaction temperature, and TiO 2 raw materials on the synthesis process were examined and the relevant reaction mechanisms discussed. Among the three chloride salts (NaCl, KC l, and MgCl 2 ), MgCl 2 showed the best accelerating‐effect. To synthesize phase pure TiB 2 , 20 mol% excessive Mg had to be used to compensate for the evaporation loss of Mg. Particle shape and size of raw material TiO 2 showed little effect on the formation of TiB 2 and its shape and size, suggesting that relatively cheaper and coarser TiO 2 raw materials could be used for low‐temperature synthesis of TiB 2 fine particles. The “dissolution‐precipitation” mechanism governed the overall molten salt synthesis process.