A study on the resistance to tellurium diffusion of MCrAlY coating prepared by arc ion plating on a Ni-16Mo-7Cr alloy.

In this study, MCrAlY coatings were prepared by arc ion plating (AIP) on a Ni-16Mo-7Cr alloy to investigate its role of inhibiting tellurium (Te) diffusion into the alloy. The results show that the depth of Te diffusion in the MCrAlY coating is significantly lower than that in alloy. The ultrafine grain structure of the coating and its higher Cr content promote the formation of a dense Cr 3 Te 4 layer on the surface of coating during the Te diffusion, which contributes to prevent inward diffusion of Te and thus improve the resistance to intergranular cracking of the alloy induced by Te. • Effect of MCrAlY coating on the resistance to Te diffusion in Te vapor was investigated. • MCrAlY coating can significantly decrease the diffusion depth of Te into the coating. • A reaction layer composed of Cr 3 Te 4 forms on the surface of coating. • A dense of Cr 3 Te 4 layer can impede the Te diffusion on the grain boundary of the coating. [ABSTRACT FROM AUTHOR]