A process for production of titanium aluminide: Reaction mechanism

A new combustion synthesis process for production of TiAl from TiO 2 , Al, Ca and KClO 4 has been developed. In a closed reaction vessel, this process gets started at about 505°C with the reaction between Ca and KClO 4 yielding CaO and KCl. Subsequent two-stage reaction between TiO 2 and Al leads to formation of titanium aluminides and α-Al 2 O 3 . Then the reaction between α-Al 2 O 3 and CaO results in formation of CaAl 4 O 7 (grossite). The overall reaction scheme can be represented as 6TiO 2 + 22Al + 4KClO 4 + 4Ca = 6TiAl + 4CaAl 4 O 7 + 4KCl. The temperature reached in the process (1950°C) is high enough for the melting of TiAl and CaAl 4 O 7 and evaporation of KCl.