Abstract: The high temperature oxidized behavior of Ti-50Al, Ti-50Al-15Cr, Ti-45Al-15Cr and Ti-67Al-8Cr(at.%) alloy at 900~1000℃ was studied. The results showed that Ti-50Al-15Cr, Ti-45Al 15Cr and Ti-67Al-8Cr have good oxidation resistance. The weight gain at 950℃ for Ti 50Al 15Cr and Ti 67Al 8Cr is more than that at 1000℃, which is due to a decrease in titanium activity in Ti-Al-Cr alloys when Cr is added into Ti-Al alloys. Oxides formed on the surface of Ti-50Al-15Cr, Ti-45Al-15Cr and Ti-67Al-8Cr after oxidation consist of α Al₂O₃ and tiny TiO₂. The formation of Al₂O₃ is attributed to the role of Cr. Effect of Cr can be described by ‘gettering effect’.

Key words: T i-A l-Cr, h igh temperature oxidat ion, effect of Cr, T iA l