Enhanced thermal insulation and corrosion resistance in Ni-Fe cermet through incorporation of high-entropy spinel oxides

The influence of high-entropy spinel oxide (HESO) content on the microstructure, electrical conductivity, and high-temperature corrosion resistance of HESO/NiFe cermets were investigated. The results found that the addition of 10–30 wt% HESO enhanced sintering densification and thermal insulation, although it also resulted in reduced electrical conductivity. Isothermal oxidation tests conducted at 900 °C for 10 hours revealed that cermets containing 30–50 wt% HESO exhibited significantly lower weight gains (0.954–1.167 mg cm⁻²) and oxidation rate constants (0.1057–0.1525 mg² cm⁻⁴ h⁻¹). Furthermore, static corrosion tests in AlF₃-KF-Al₂O₃ molten salt demonstrated that HESO effectively mitigated the erosion of the metallic phase by the fluoride molten salt. This study holds significant potential by providing new insights for the design of inert anodes for aluminum electrolysis and exploring the practical applications of high-entropy oxide materials.