Abstract Energetic electron beams (e-beams) are used in the welding, 3D printing and imaging of various materials. It is commonly accepted that the e-beam irradiation inside transmission electron microscope has a negligible effect on the intrinsic mechanical properties of small-volume metallic materials during in situ investigation. However, as small-volume Al is usually covered by a thin layer of native oxide, we show here that high-energy (200 keV) e-beam irradiation can dramatically alter the deformation behavior. E-beam irradiation can drastically rejuvenate the amorphous structure of the oxide layer, producing a defective interface/surface, and promoting the transition of the deformation mode from internal dislocation multiplication to interface-dominated dislocation nucleation mediated plasticity, as indicated by the enhanced strain rate sensitivity and reduced activation volume. Moreover, the amorphous oxide layer undergoes viscous flow under the e-beam irradiation, such that nanoscale single-crystal Al confined by a 29% volume fraction of native oxide shell exhibits more than 60% uniform elongation.

中文翻译：

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电子束辐照下小体积Al-4Cu合金的变形

摘要 高能电子束（e-beams）用于各种材料的焊接、3D打印和成像。人们普遍认为，在原位研究过程中，透射电子显微镜内的电子束辐照对小体积金属材料的内在机械性能的影响可以忽略不计。然而，由于小体积铝通常被一层薄薄的天然氧化物覆盖，我们在这里展示了高能 (200 keV) 电子束辐射可以显着改变变形行为。电子束辐照可以极大地恢复氧化层的非晶结构，产生有缺陷的界面/表面，并促进变形模式从内部位错倍增向界面主导的位错形核介导的塑性转变，如应变率敏感性增强和活化体积减少所示。此外，无定形氧化物层在电子束照射下经历粘性流动，使得由 29% 体积分数的天然氧化物壳限制的纳米级单晶 Al 表现出超过 60% 的均匀伸长率。