摘要
A1, A1-Si and Cr-A1-Si coatings are prepared onto IC20 alloy by powder pack cementation to improve the oxidation resistance of the alloy. The isothermal oxidation behaviors of the coatings and the uncoated IC20 alloy at 1 100 ℃ are comparatively in- vestigated. For the coatings, less weight gains are obtained compared to the uncoated alloy after 100 h thermal exposure. The A1-Si coating exhibits the best oxidation resistance, while the addition of Cr accelerates the scale spallation. Phase transforma- tion from β-NiA1 to y and y＇ occurs in the coating after oxidation for extended periods. The oxidation protection and degradation mechanisms for these coatings are discussed.
A1, A1-Si and Cr-A1-Si coatings are prepared onto IC20 alloy by powder pack cementation to improve the oxidation resistance of the alloy. The isothermal oxidation behaviors of the coatings and the uncoated IC20 alloy at 1 100 ℃ are comparatively in- vestigated. For the coatings, less weight gains are obtained compared to the uncoated alloy after 100 h thermal exposure. The A1-Si coating exhibits the best oxidation resistance, while the addition of Cr accelerates the scale spallation. Phase transforma- tion from β-NiA1 to y and y＇ occurs in the coating after oxidation for extended periods. The oxidation protection and degradation mechanisms for these coatings are discussed.
基金
National Natural Science Foundation of China (50971005)
