Synthesis of intermetallic NiAl and Ni3Al fine powders through organometallic precursors

Abstract

Fine powders of intermetallic NiAl and Ni3Al were synthesized through organometallic precursors, which were coprecipitated from aqueous solutions of NiCl2 and AlCl3 by the addition of ammonium benzoate and hydradinium monochloride as precipitants. Ni3Al and NiAl were synthesized by a two-step heat treatment of the precursors. The initial step was the thermal decomposition of organic groups to form homogeneous mixtures of Ni3C, amorphous Al2O3, and free C below 1000 °C. The other step was the reaction above 1300 °C to form the intermetallics. Single phase powders of NiAl and Ni3Al with the particle size less than 3 μm were obtained above 1300 and 1400 °C, respectively.