Understanding the oxidation behaviors of a Ni-Co-based superalloy at elevated temperatures through multiscale characterization

Abstract

The study explored the oxidation behaviors of a Ni-Co-based superalloy at temperatures between 900–1100 °C in air, employing a weighing method and multiscale characterization techniques. The findings indicate that the superalloy adheres to parabolic kinetics and develops a complex, four-layer oxide scale comprising a TiO2 layer, Co(Al, Cr)2O4 layer, Cr2O3 layer, and (Ti, Nb)2O5 layer. The excellent oxidation resistance is primarily attributed to the formation of the TiO2 and Co(Al, Cr)2O4 layers. These layers contribute to reducing the evaporation of Cr2O3 and the development of the (Ti, Nb)2O5 layer, which in turn helps mitigate the exfoliation of the oxide scale.