Influence of different ageing temperatures on aluminide coating of GH220 Alloy

Influence of ageing temperatures and times on aluminide coating structure is investigated in this paper. The results show that aged aluminide coating consist mainly of the outer and the inner layers. The outer layer includes Al2O3 oxide zone, β-NiAl zone and denuded zone. The inner layer includes rich C zone and needlelike phase zone. It has been concentrated on discussion of exhaustion mechanizm and: of reasons, of needlelike phase formation in aluminide coating.