Synthesis of nickel borides in molten salts at elevated temperatures and thermodynamic characterization of the system Ni–B

Abstract This article focuses on the synthesis of nickel borides in different molten-salt systems (eutectic NaCl/KCl and borax) at elevated temperatures. The differences in the thermodynamic stability of different nickel borides and the formation of NiB in an eutectic halite-sylvine mixture at T = 950 °C with different nickel-containing starting materials (NiO, Ni) has been elucidated. The results are compared to theoretical data calculated by the Calphad method. The results of the analysis shows that NiB2, if it exists, may only form a metastable phase.