Effects of water vapor and nitrogen on oxidation of TNM alloy at 650 ℃

摘要

The effect of water vapor on the oxidation behavior of a TiAl alloy, TNM, was investigated at 650 degrees C. The oxidation mass gains were four times higher in wet Ar and twice as high in wet air than in the corresponding dry atmospheres. No external Al2O3 formed during oxidation in different atmospheres after 500 h. TEM revealed that multi-layered oxide scales were formed by oxidation in different atmospheres. An amorphous Al-rich oxide layer that was stabilized by the formation of a Ti(Al)N layer provided better protection against oxidation of the TNM alloy in air than in a water vapor-containing atmosphere.