Abstract:The effects of sputtered NiCrAlY coating on hot corrosion resistance of Ti₃Al intermetallics in the presence of(Na, K)₂SO₄ salts film at 950℃ in air were studied. It was shown that Ti3Al suffered from severe corrosion , forming a poor adhesive scale with an outer TiO₂-enriched and inner Al₂O₃ enriched layer. The electrochemical mechanism was responsible for the corrosion process. The sputtered NiCrAlY coating can greatly improve corrosion resistance of Ti₃Al by the the formation of a good adhesive Al₂O₃ enriched scale. But a-three-layer diffusion zone formed between coating and substrate alloy.

Key words: intermetallic compounds; Ti₃Al NiCrAlY coating; hot corrosion