材料期刊网

NiCoCrAlY-ZrO2•Y2O3 coatings were deposited on the substrates by using a technology of combining electron, atom and ion beams (three beams). Isothermal oxidation for these samples was performed at 1100℃ for 100–300 h. The results show that a thermally grown oxide (TGO) layer was formed between NiCoCrAlY layer and ZrO2•Y2O3 layers according to the cross-section morphologies of the samples after high temperature isothermal oxidation. The TGO contains α-Al2O3 and Y4Al2O9 etc. oxides. The intensity ratio of α-Al2O3/Y4Al2O9 was monotonously decreased with increasing oxidation time based on XRD (X-ray diffraction) analysis. The Y4Al2O9 phase plays the most important role in high temperature oxidation resistance at 1100℃. The related mechanism was also discussed.