Abstract As a new class of materials, High Entropy Alloys (HEAs), have been recently used for various usages such as high-temperature applications. High entropy alloys have such unique properties as high strength, high-temperature phase stability, good fracture resistance, and excellent softening resistance at high temperatures. Studies on the oxidation behavior of as-cast high entropy alloys are, however, currently limited. The oxidation behavior of Al0.5CrCoFeNi HEA was investigated at three different temperatures of 800, 900, and 1000°C, and in the air. The results showed that the oxidation kinetics of this alloy followed the parabolic rate law. However, at 1000°C, two-step oxidation kinetics was found: in the first step, it followed the almost linear oxidation rate law (n=0.97); in the second one, the predominant mechanism followed the parabolic rate law (n=0.56). Analysis of the morphology and phase composition of the oxide layers was done using the Scanning Electron Microscopy (SEM) and X-ray diffraction. At all temperatures, the results showed that the oxide layers consisting of Cr2O3/Al2O3 and spinel of Ni, Co, and Fe were formed in the Al depleted zone.

中文翻译：

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Al0.5CoCrFeNi高熵合金高温氧化行为研究

摘要 作为一类新型材料，高熵合金 (HEA) 最近已用于各种用途，例如高温应用。高熵合金具有强度高、高温相稳定性好、抗断裂性好、高温下抗软化性能优良等独特性能。然而，目前对铸态高熵合金氧化行为的研究是有限的。研究了 Al0.5CrCoFeNi HEA 在 800、900 和 1000°C 三种不同温度下以及在空气中的氧化行为。结果表明，该合金的氧化动力学符合抛物线速率规律。然而，在1000°C时，发现了两步氧化动力学：第一步，它遵循几乎线性的氧化速率规律（n=0.97）；在第二个，主要机制遵循抛物线速率定律（n=0.56）。使用扫描电子显微镜 (SEM) 和 X 射线衍射对氧化物层的形态和相组成进行分析。在所有温度下，结果表明在贫铝区形成了由 Cr2O3/Al2O3 和 Ni、Co 和 Fe 尖晶石组成的氧化层。