Fabrication of Ti-Al intermetallics by a two-stage aluminothermic reduction process using Na2TiF6

A novel two-stage method, based on aluminothermic reduction of Na2TiF6, has been proposed to prepare Ti-Al intermetallic alloys in this paper. The entire process of the two-stage aluminothermic reduction was introduced in detail. The result of thermal analysis demonstrated that the aluminothermic reduction reaction was an exothermic process and occurred at approximately 660 °C. Besides Ti-containing cryolite, pure Ti3Al, TiAl and TiAl3 intermetallics could be prepared after the first stage reduction. Further, in secondary reduction, Ti-containing cryolite contained Ti4+, TiOS and Ti-Al intermetallics could be purified completely. As a result, pure cryolite and Al-Ti alloy were obtained. A concept of continuous and cyclic route was proposed. The two-stage aluminothermic reduction process provided a high productivity and pollution-free metallurgical way for preparing Ti-Al intermetallic alloys.