The influence of pre-oxidation on oxidation resistance of Ti-6Al-4V alloy at 600 ℃ in air was examined. The surface morphology

phase constituent and structure in oxidized layer were analyzed by means of XRD and SEM. The results showed that the formation of sound Al

2

O

3

and TiO

2

films on the surface of pre-oxidized Ti alloy not only changed the oxidation mechanism from the diffusion of O

2

towards interior to the diffusion of Ti towards exterior during oxidation at high temperature

but also decreased greatly the oxidation rate of the alloy

improving the adherence and the peeling off resistance of oxidized film.