Abstract:Si-Al-Y co-deposition coatings on TiAl alloy were prepared by pack cementation processes at 1050 °C for 4 h. Scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS) and X-ray diffractmeter (XRD) were employed to investigate the surface morphologies, microstructures and phase constitutions of the coatings. Friction-wear tests of the TiAl alloy substrate and the coatings were conducted in air at normal (20 °C) and high (600 °C) temperature. The results show that the coating prepared by co-deposited Si-Al-Y has a multiple layer structure: an outer layer composed of TiSi2, a middle layer composed of (Ti,X)5Si4 (X represents Nb and Cr elements) and (Ti,X)5Si3, an inner layer composed of TiAl2 and γ-TiAl, and a Al rich-interdiffusion zone. The wear resistance of Si-Al-Y coating is obviously better than that of TiAl alloy at normal and high temperature, and it has good wear resistance performance at high temperature. The wear mechanism of the coating has no significant changes at experimental temperature that is delamination abrasion and grain-abrasion. The wear mechanisms of TiAl alloy are grinding abrasion and grain-abrasion at normal temperature, and are grinding abrasion and grain-abrasion and oxidation abrasion at 600 °C