Synthesis of Ni 3Al intermetallic powder in eutectic molten salts

Abstract

The powders of Ni 3Al intermetallic compounds were simply and economically synthesized by the chemical reaction in the various molten salts systems. In the relatively low temperature ranges, we studied to synthesize Ni 3Al intermetallic powders from Al and NiCl 2 in five kinds of eutectic molten salts by varying the reaction time and mole ratio of reactants. Ni 3Al intermetallic powders could be synthesized in AlCl 3–NaCl (63:37 in mol%), AlCl 3–NaCl–KCl (66:20:14 mol%), NaCl–KCl (50:50 mol%) and MgCl 2–NaCl–KCl (50:30:20 mol%) systems. However, it was impossible to separate the Ni 3Al powders from MgCl 2–NaCl–KCl (50:30:20 mol%) system. The Ni 3Al powders could not be synthesized in AlCl 3–NaCl (50:50 mol%) molten salt. The obtained powders were uniformly sub-micrometer sized. The reaction temperature at 500 °C, the reaction time for 3 h and the mole ratio of NiCl 2/Al=1.3 were the optimum conditions for synthesis of Ni 3Al intermetallic powders in AlCl 3–NaCl (63:37 mol%) molten salt.