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| Abstract No.: |
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Scheduled at:
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Thursday, May 12, 2016, Yellow River Hall 12:00 PM
Power Generation III
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| Title: |
Influence of Ce and Ru on the behavior of of HVOF NiCoCrAlX coatings in high temperature oxidation
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| Authors: |
Pimin Zhang* / Linköping University, Sweden
Ru Lin Peng / Linkoping University, Sweden
Xin-hai Li/ Siemens Industrial Turbomachinery AB, Sweden
Sten Johansson/ Linkoping University, Sweden
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| Abstract: |
MCrAlX (M: Ni or Co or both, X: minor elements) have been widely used to protect hot components in gas turbines against oxidation and corrosion at high temperatures. The elemental function is important in the design of durable MCrAlX coatings. In this study, three Ni-based MCrAlX coatings with different composition were deposited on Inconel 792 substrate by HVOF. Samples were subjected to oxidation test in air at 900, 1000, 1100 ºC and thermal cyclic fatigue (TCF) test between 100 ºC and 1100 ºC with 1 hour dwell time at 1100 ºC. It was observed that under isothermal exposure, the oxidation rate, characterized by the rate of beta depletion, was similar for all coatings. For TCF testing, however, the coating with Ce as reactive element shows a much higher oxidation rate than the coating with Y reactive element. Besides, ²-depletion due to interdiffusion between coating and substrate was significantly lower when Ru was present. This paper presents a detailed study of the influence of Ce and Ru on oxidation behavior including investigation of the evolution of microstructure and elemental distribution influenced by oxidation time at coating surface and coating-substrate interface. Also simulation using a developed oxidation-diffusion model was undertaken. In addition, the influence of different elements on the formation of transient Alumina was also discussed.
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