Formation process and oxidation behavior of MCrAlY plus AlSiY composite coatings on a Ni-based superalloy

An AlSiY coating and two MCrAlY + AlSiY composite coatings with different thickness of MCrAlY inter layer were prepared by arc ion plating (AIP) and vacuum annealing. The isothermal oxidation behavior of coatings at 1100 degrees C for 300 h was also investigated to characterize the microstructure evolution of coatings during annealing. The composite coatings exhibited a better high-temperature oxidation resistance at 1100 degrees C. The reason is that the addition of MCrAlY layer can greatly contribute to prevent the diffusion of refractory elements to the outer layer. The inhibition of Al inward diffusion can be much stronger, as the Si content increases in the outer layer during annealing. (c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

In this study, an AlSiY coating and two MCrAlY + AlSiY composite coatings with different thickness of MCrAlY inter layer were prepared using arc ion plating (AIP) and vacuum annealing. The isothermal oxidation behavior of the coatings at 1100 degrees C for 300 h was investigated. The composite coatings showed better high-temperature oxidation resistance due to the addition of MCrAlY layer, which effectively prevented the diffusion of refractory elements to the outer layer. The inhibition of Al inward diffusion was stronger as the Si content increased in the outer layer during annealing.