| The turbine blades in aerospace are typically protected by a protective coating to improve the oxidation-resistant property of the substrate. Diffusion-aluminide coating is above 80% percent in hight temperature coating. Because diffusion-aluminide coating not only satisfieds ordinary property' demands but also has low cost and steady performance. At this paper, the aluminized coating on K4104 was prepared by pack cementation. The isothermal oxidation behavior of the coating was investigated at 1000℃ in air for 200 hours. The oxidation kinetics curve was drawed. The surface morphology and cross-sectional microstructure of the coating oxidized for different time were observed and analyzed by OM ,SEM and ED A X (with SiRion). The degradation mechanism of the coating is discussed. The resistance of high temperature oxidation on an aluminide-coated nickel-base superalloy K4104 is appraised.The results show that oxidation kinetics curve about an aluminide-coated nickel-base superalloy K4104 obeys the parabolic law. The mass gain of the aluminized coating is lower than raw material , the oxidation resistance is remarkably improved as compared to the superalloy K4104. The material has well oxidation resistance mostly because of the forming of α — Al2O3 oxide scale. α — Al2O3 oxide scale is very compact, it has steady chemical property and excellent resistance of oxidation and hot corrosion. The adhesion between the oxide scale and substrate is good. After 100 hours oxidation, some slight spallation is observed on the surface. The oxide scale becomes compact and full again in 200 hours. In 200 hours, there are part spallations. By analyzing the ED Λ X, it is still α - Al2O3 scale. Through the high temperature oxidation, the coating has changed to Ni-rich and Al-rich β -NiAl compound layer, this compound layer is significant in the oxidation resistance. β -NiAl layer is thick, As the oxidation time extending, β -phase degrades slowly.
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