A study of combustion synthesis of Ti-Al intermetallic compounds

The mechanisms involved in the combustion synthesis of Ti-Al intermetallics have been studied by quenching partially transformed pellets to suppress the reaction prior to its completion. The reaction steps leading to the formation of TiAl₃, TiAl or Ti₃Al were found to be similar in all three compositions used for the study. In each case the initial product detected by X-ray diffraction was TiAl₃, while substantial dissolution of Ti into molten Al was found. At the same time the molten Al-Ti liquid adsorbed oxygen, and on quenching the partially transformed pellet, a glass was formed from the liquid. If the combustion synthesis process was completed, the oxygen-rich liquid decomposed, yielding a mixture of oxides and intermetallic compounds.