Oxidation behaviour and related microstructural changes of two β0–phase containing TiAl alloys between 600 °C and 900 °C

A comparative study on the isothermal oxidation behaviour of the two β0–containing titanium aluminide alloys GE 4822 and TNM-B1 in the HIPed condition has been conducted at temperatures between 600 °C and 900 °C for up to 1000 h in air. The two alloys exhibit clear differences in their oxidation behaviour, however, both suffer from undesirable embrittlement due to oxidation after exposure for 100 h even at 600 °C. Phase transformations in the subsurface zone were shown to have a strong impact on the mechanical properties at room temperature.