Enhanced high-temperature oxidation resistance of low-cost Fe–Cr–Ni medium entropy alloy by Ce-adulterated

Abstract

Medium-entropy alloys (MEAs) and high-entropy alloys (HEAs) are good candidates for high-temperature applications, taking advantage of their exceptional thermal stability. However, most of them contain high-priced Co elements, which limited further promotion and application. Therefore, it is imperative to elaborate HEAs/MEAs with superb oxidation resistance and relatively low cost. An economically Fe–Cr–Ni MEA, which exhibits an outstanding high-temperature oxidation resistance, was developed by Ce-adulterated. The Ce-containing Fe–Cr–Ni MEA possessed a lower oxidation rate and a higher oxidative activation energy (461.4 kJ mol−1, 14% increment compared with the reference MEA). The splendid high-temperature oxidation resistance primarily benefited from the protective oxide scales formed on the surface of MEA, which were denser, slow-growing, and well adherently. This research sheds light on exploiting low-cost MEAs with excellent resistance to oxidation for high-temperature applications.

Keywords

• Medium-entropy alloys
• High-temperature oxidation
• Rare earth element
• Oxide scales