Isothermal and cyclic oxidation behaviour of Ni-25Cr-10Al-0.5Y coating deposited by AIP and magnetron sputtering at 1323 K
(1. School of Materials Science and Engineering, Chongqing University of Technology, Chongqing 401320, China;
2. Yantai Research Institute, Harbin Engineering University, Yantai 264000, China;
3. School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China;
4. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China;
5. Zhongfa Aviation Institute of Beihang University, Hangzhou 310023, China;
6. Southwest Institute of Technology and Engineering, Chongqing 400039, China;
7. Shi-Changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
8. Shenyang National Laboratory for Materials Science, Northeastern University, Shenyang 110819, China)
2. Yantai Research Institute, Harbin Engineering University, Yantai 264000, China;
3. School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China;
4. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China;
5. Zhongfa Aviation Institute of Beihang University, Hangzhou 310023, China;
6. Southwest Institute of Technology and Engineering, Chongqing 400039, China;
7. Shi-Changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
8. Shenyang National Laboratory for Materials Science, Northeastern University, Shenyang 110819, China)
Abstract: Two kinds of NiCrAlY coatings (Ni-25Cr-10Al-0.5Y) were prepared on K417 superalloy using ion plating (AIP) and magnetron sputtering (MS), respectively. The isothermal and cyclic oxidation behaviors of the two NiCrAlY coatings were evaluated at 1323 K in stair air. The results revealed that the nanocrystalline NiCrAlY coating exhibited better isothermal and cyclic oxidation resistance compared to the conventional NiCrAlY at 1323 K. The mass gain and parabolic rate constant Kp of the nanocrystalline NiCrAlY coating were 45.2% and 44.7% lower than those of the conventional NiCrAlY coating, respectively. During cyclic oxidation, the tendency for spallation of the oxide scale was evidently decreased by nanocrystallization due to the formation of a continuous, compact, adherent, and slow-growing exclusive α-Al2O3 scale. The mechanism responsible for the improvement of the nanocrystalline NiCrAlY coating was discussed.
Key words: MCrAlY; nanocrystalline; thermal grown oxide; high-temperature oxidation; spallation