Oxidation resistance of intermetallic compounds Al3Ti and TiAl

Article abstract of DOI:10.1007/BF01105677

The oxidation kinetics and morphological features of Al₃Ti and TiAl were investigated. The oxidation resistance of Al₃Ti is much better than that of TiAl, for example, by a factor of about 30 at 1000°C for 48 h. The big difference in the oxidation resistance is related to the characteristics of the external oxide scales of a protective Al₂O₃ or a mat of crystalline TiO₂ formed on Al₃Ti or TiAl, respectively. Sufficient aluminium transport from Al₃Ti assists the formation of the Al₂O₃ scale which acts as a protective film against oxidation. The poor aluminium content of TiAl produces Ti₃Al phase at the interface of TiAl and oxide scales and increases the diffusivity of titanium in the Al₂O₃ scale. The external crystalline TiO₂ scale produced by the diffusion of titanium through the Al₂O₃ scale enhances oxidation of TiAl.