LAUSR

A novel packed-powder diffusion coating (PPDC) technique for pure Ti and Ti alloys was developed to improve their oxidization resistance and wear resistance. The treatment led to the formation of a controllable Al3Ti intermetallic-based composite coating, of which the thickness varied from 100 µm to 1295 µm depending on the treatment temperature and time. Cyclic oxidization tests in a static air within the temperature range from 800°C to 1000°C for 24 cycles indicated that the PPDC treatment significantly increased the oxidization resistance of Ti alloys, which enabled this type of light alloy to be comparable with some Ni-based superalloys. Furthermore, the PPDC-treated Ti alloys also showed a reduced friction coefficient and increased wear resistance compared with the substrates. Hence, it is reasonable to consider that, after the PPDC treatment, the lightweight Ti alloys had strong potential to partially replace Ni-based superalloys for high-temperature applications.