New sight on the oxide film growth mechanism in a single crystal Ni-based superalloy with a ground surface signature

Abstract

The oxide film characteristics and growth mechanism of a single crystal Ni-based superalloy were studied under the ground surface signature. In the transient oxidation, oxygen atoms invaded the substrate along with the γ ´ phases, resulting in the Ni-Al spinels and alumina with nanosize formed simultaneously. Moreover, the outer layer of NiAl2O4 obeyed a liner law (with n ≈ 1) and was controlled by the outward diffusion of Ni and Al cations (with Q= 1.13 eV), whereas the inner Al2O3 layer followed a parabolic law(with n ≈ 0.5) and was determined by the inward diffusion of oxygen (with Q= 1.43 eV).