Ti-Al-Si coatings exhibit excellent metallurgical bonding with the substrate. Ti-Al-Si coatings exhibit higher microhardness compared with Ti-Al coating and the substrate. Ti-Al-Si coatings exhibit excellent oxidation resistance compared with the substrate. The synergistic effect of Al and Si on oxidation resistance of the coatings is better than the single effect of Al. The mechanism of Si on improving high temperature oxidation resistance of Ti-Al-Si system coatings includes refining the oxide grains and promoting the formation of Al2O3.