High‐temperature oxidation behavior of Ni‐based superalloys with Nb and Y and the interface characteristics of oxidation scales |
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| Authors: | Fei Weng Huijun Yu Chuanzhong Chen Kai Wan |
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| Affiliation: | 1. Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials (Ministry of Education), Department of Materials Science and Engineering, Shandong University, Jinan, Shandong, China;2. Key Laboratory of High‐efficiency and Clean Mechanical Manufacture (Ministry of Education), School of Mechanical Engineering, Shandong University, Jinan, Shandong, China |
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| Abstract: | Ni‐based superalloys with niobium (Nb) or/and yttrium (Y) were prepared by vacuum melting. The oxidation kinetics of these alloys was studied by thermogravimetry at 800 °C for 100 h in static air. Morphology of oxides was studied using SEM, and the composition was analyzed by X‐ray diffraction. Energy‐dispersive X‐ray spectrometer was employed to examine the linear element distribution of the cross section of the oxidation films. Results showed that the oxidation kinetics all followed a parabolic law at different stages. The oxide films were mainly comprised of Cr2O3, NiCr2O4, Al2O3 and TiO2. All the oxide films exhibited layered structure owing to different oxidation stages. With the addition of Nb or Y, the high‐temperature oxidation resistance of the superalloy was improved significantly and the surface morphology of the oxidation film was ameliorated. The comprehensive effect of Nb and Y was remarkable in improving the high‐temperature oxidation resistance of Ni‐based alloys. Copyright © 2014 John Wiley & Sons, Ltd. |
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| Keywords: | nickel‐based superalloys niobium yttrium oxidation |
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