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

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.