On dipping of γ-TiAl in low-concentration phosphoric acid solution and consecutive oxidation resistance at 800 °C

The oxidation behaviour of γ-TiAl previously treated in low-concentration phosphoric acid solution has been investigated at 800 °C in air. The chemical treatment promotes, instead of the usual TiO2/Al2O3 mixed phase, the fast formation of a TiP2O7 pyrophosphate layer with a subsequent large reduction in the oxidation rate.