High temperature oxidation and corrosion properties of high entropy superalloys

The present work investigates the high temperature oxidation and corrosion behaviour of high entropy superalloys (HESA). A high content of various solutes in HESA leads to formation of complex oxides, however the Cr and Al activities of HESA are sufficient to promote protective chromia or alumina formation on the surface. By comparing the oxidation and corrosion resistances of a Ni-based superalloy-CM247LC, Al₂O₃-forming HESA can possess comparable oxidation resistance at 1100 °C, and Cr₂O₃-forming HESA can exhibit superior resistance against hot corrosion at 900 °C. This work has demonstrated the potential of HESA to maintain surface stability in oxidizing and corrosive environments.