Abstract

In this work, an electron microscopic study of the surface of a high-entropy alloy (HEA) of the Al–Co–Cr–Fe–Ni system obtained by wire-arc additive manufacturing and modified with a pulsed electron beam is performed. It is shown that the alloy is a polycrystalline aggregate with a grain size of (4–15) µm and has a non-equiatomic composition with a high content of Al and Ni. It is established that the boundary volumes of the alloy (volumes located along the grain boundaries) are enriched with chromium and iron atoms, the grain volume is enriched with Ni and Al atoms, and Co is distributed in the alloy quasi-uniformly. It is shown that irradiation with a pulsed electron beam leads to fragmentation of the surface layer of the samples by microcracks; it is accompanied by homogenization of the surface layer and the formation of a submicro-nanocrystalline (100–200 nm) structure. There is no change found in the elemental composition of the HEA-sample surface layer after irradiation in vacuum with a pulsed electron beam (200 µs, (10–30) J/cm², 3 pulses).

中文翻译：

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脉冲电子束辐照对 Al-Co-Cr-Fe-Ni 系非等原子高熵合金表面结构的影响

摘要

在这项工作中，对通过线弧增材制造获得并用脉冲电子束改性的 Al-Co-Cr-Fe-Ni 系统的高熵合金 (HEA) 的表面进行了电子显微镜研究。结果表明，该合金是一种多晶聚集体，晶粒尺寸为 (4-15) µm，具有非等原子组成，Al 和 Ni 含量高。确定合金的边界体积（沿晶界的体积）富含铬和铁原子，晶粒体积富含 Ni 和 Al 原子，Co 准均匀地分布在合金中。结果表明，脉冲电子束照射导致样品表面层因微裂纹而破碎；它伴随着表面层的均匀化和亚微纳米晶体（100-200 nm）结构的形成。在真空中用脉冲电子束 (200 µs, (10–30) J/cm) 照射后，HEA 样品表面层的元素组成没有变化^2、3个脉冲）。