The influences of the oxidation conditions

microstructure and composition on the oxidation resistance of Ti-Al alloys were investigated.The results reveal that Ti-48 Al-2 Cr-2 Nb alloy exhibits a desirable oxidation resistance and a kind of four-layered structure exists in the oxide films at 700 and 800℃.With the isothermal oxidation test for 100 hat 800℃

the mass increment of Ti-48 Al-2 Cr-2 Nb alloy samples with three kinds of microstructures is increased from the sample with a duplex structure to the one with a nearly lamellar structure

and then to the sample with full lamellar structure.The mass increment of Ti-Al alloys with three compositions is increased from Ti-45 Al-8 Nb-0.2 W-0.1 B-0.1 Yalloy to Ti-46.5 Al-2.5 V-1 Cr alloy

and then to Ti-48 Al-2 Cr-2 Nb alloy.The Ti-45 Al-8 Nb-0.2 W-0.1 B-0.1 Yalloy sample with duplex structure shows a low oxidation mass increment of 4.8 g/m

2

after the isothermal oxidation test for 100 hat 800 ℃.