The effect of the temperature on the characteristics of the oxide films on AlCoCrFeNi high-entropy alloy (HEA) at 1073–1273 K was investigated through scanning electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction. Elemental enrichments in the outer oxide layer and internal oxide zone were studied. The oxidation resistance of AlCoCrFeNi HEA was compared with two commercial alloys [825 Ni-based alloy and 2205 duplex stainless steel (DSS)] with similar Cr content at 1273 K. These alloys are ranked as follows in descending order of oxidation resistance at 1273 K: AlCoCrFeNi HEA, 825 Ni-based alloy, and 2205 DSS. At 1273 K, both Cr and Mo were enriched in the outer oxide layer on 825 Ni-based alloy and 2205 DSS. Only Cr enrichment was observed on the AlCoCrFeNi HEA, but the Cr content in the outer oxide layer on the HEA was greater than those on the 825 Ni-based alloy and 2205 DSS. This might be the main reason why the AlCoCrFeNi HEA showed the best oxidation resistance among the three studied alloys.

中文翻译：

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AlCoCrFeNi 高熵合金在 1073–1273 K 的高温氧化行为

通过扫描电子显微镜、能量色散光谱和 X 射线衍射研究了温度对 AlCoCrFeNi 高熵合金 (HEA) 在 1073-1273 K 氧化膜特性的影响。研究了外氧化层和内氧化带中的元素富集。将 AlCoCrFeNi HEA 的抗氧化性与在 1273 K 时具有相似 Cr 含量的两种商业合金 [825 Ni 基合金和 2205 双相不锈钢 (DSS)] 进行比较。这些合金在 1273 K 时的抗氧化性按降序排列如下：AlCoCrFeNi HEA、825 Ni 基合金和 2205 DSS。在 1273 K 时，Cr 和 Mo 都富集在 825 Ni 基合金和 2205 DSS 的外氧化层中。在 AlCoCrFeNi HEA 上仅观察到 Cr 富集，但 HEA 外氧化层中的 Cr 含量高于 825 Ni 基合金和 2205 DSS 上的 Cr 含量。这可能是 AlCoCrFeNi HEA 在三种研究合金中表现出最佳抗氧化性的主要原因。