Abstract (CoCrFeNi)93.5Mn6.5 nanocrystalline high-entropy alloy (nc-HEA) with an average grain size of 25 nm was prepared by inert gas condensation (IGC) using a laser evaporation source. An unprecedented increment in hardness was found from 484 HV to 791 HV after annealing at 600 °C for 1 h. More surprisingly, the original high hardness is maintained even after annealing at 1100 °C, which demonstrates superb thermal stability of the nc-HEA. The underlying strengthening mechanism is attributed to the unique microstructure of the nc-HEA and its evolution during annealing. This study provides a new preparation technique (laser-IGC) for high-performance nc-HEAs with great potential for applications.

中文翻译：

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惰性气体冷凝制备的纳米晶 CoCrFeNiMn 高熵合金的超高硬度和优异的热稳定性

摘要 使用激光蒸发源通过惰性气体冷凝（IGC）制备平均晶粒尺寸为25 nm的（CoCrFeNi）93.5Mn6.5纳米晶高熵合金（nc-HEA）。在 600 °C 下退火 1 小时后，硬度从 484 HV 增加到 791 HV，这是前所未有的。更令人惊讶的是，即使在 1100 °C 退火后仍保持原始高硬度，这表明 nc-HEA 具有极好的热稳定性。潜在的强化机制归因于 nc-HEA 的独特微观结构及其在退火过程中的演变。该研究为具有巨大应用潜力的高性能 nc-HEAs 提供了一种新的制备技术（laser-IGC）。