Direct electrochemical reduction of mixed TiO2 and NiO powders to TiNi alloy has been successfully demonstrated in molten CaCl2 at 900℃ by constant voltage electrolysis. The electrolysis en- ergy consumption was as low as 23.4 kWh/kg-TiNi, although the current efficiency was 20.5% in the pre- liminary experiments. During the process, NiO was first reduced to Ni at high speed, accompanied by TiO2 being perovskitized to CaTiO3?x which was gradually reduced to Ni3Ti and TiNi, assisted by the depolarization of the preformed Ni. The cell voltage for preparation of the TiNi alloy was lower than that for Ti. Adjusting the cell voltage not only affected the reduction speed, but also offered a convenient ac- cess to the preparation of the nickel/perovskite composite.
ZHU YongMA MengWANG DihuaJIANG KaiHU XiaohongJIN XianboGeorge Z. CHEN
