Investigation of Element Effect on High-Temperature Oxidation of HVOF NiCoCrAlX Coatings
AbstractMCrAlX (M: Ni or Co or both, X: minor elements) coatings have been used widely to protect hot components in gas turbines against oxidation and heat corrosion at high temperatures. Understanding the influence of the X-elements on oxidation behavior is important in the design of durable MCrAlX coatings. In this study, NiCoCrAlX coatings doped with Y + Ru and Ce, respectively, were deposited on an Inconel-792 substrate using high velocity oxygen fuel (HVOF). The samples were subjected to isothermal oxidation tests in laboratory air at 900, 1000, and 1100 °C and a cyclic oxidation test between 100 and 1100 °C with a 1-h dwell time at 1100 °C. It was observed that the coating with Ce showed a much higher oxidation rate than the coating with Y + Ru under both isothermal and cyclic oxidation tests. In addition, the Y + Ru-doped coating showed significantly lower β phase depletion due to interdiffusion between the coating and the substrate, resulting from the addition of Ru. Simulation results using a moving phase boundary model and an established oxidation-diffusion model showed that Ru stabilized β grains, which reduced β-depletion of the coating due to substrate interdiffusion. This paper, combining experiment and simulation results, presents a comprehensive study of the influence of Ce and Ru on oxidation behavior, including an investigation of the microstructure evolution in the coating surface and the coating-substrate interface influenced by oxidation time. View Full-Text
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Zhang, P.; Lin Peng, R.; Li, X.-H.; Johansson, S. Investigation of Element Effect on High-Temperature Oxidation of HVOF NiCoCrAlX Coatings. Coatings 2018, 8, 129.
Zhang P, Lin Peng R, Li X-H, Johansson S. Investigation of Element Effect on High-Temperature Oxidation of HVOF NiCoCrAlX Coatings. Coatings. 2018; 8(4):129.Chicago/Turabian Style
Zhang, Pimin; Lin Peng, Ru; Li, Xin-Hai; Johansson, Sten. 2018. "Investigation of Element Effect on High-Temperature Oxidation of HVOF NiCoCrAlX Coatings." Coatings 8, no. 4: 129.
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