CYCLIC OXIDATION OF ALUMINIZED Ti-14Al-24Nb ALLOY.

Article abstract of DOI:10.1007/BF01115749

Titanium aluminides are considered as replacements for superalloys in applications in gas turbine engines because of their outstanding properties. Ti//3Al has a superior creep strength up to 815 degree C, but has poor oxidation resistance above 650 degree C. Two approaches can be followed to improve the oxidation resistance of Ti//3Al above 650 degree C. One is alloying and the other obtaining a protective surface coating. Niobium was found to improve the oxidation resistance, when added as an alloying element. Recent investigations showed that a TiAl//3 surface layer considerably improves the oxidation resistance of titanium. In the present work, a TiAl//3 layer was obtained on a Ti-14Al-24Nb (wt percent) alloy using a pack aluminizing process. The cyclic oxidation behaviour of aluminized and uncoated samples was evaluated.