Atomistic processes of diffusion-induced unusual compression fracture in metallic nanocrystals
Atomistic processes of diffusion-induced unusual compression fracture in metallic nanocrystals
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DOI：
10.1080/21663831.2022.2108349
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发表时间：
2022-08
影响因子：
8.3
通讯作者：
Sixue Zheng;Xiang Wang;Susheng Tan;Guofeng Wang;S. Mao
中科院分区：
文献类型：
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作者：
Sixue Zheng;Xiang Wang;Susheng Tan;Guofeng Wang;S. Mao
局部增厚，导致个别的位移或扩散机制，经常观察到在纳米级金属在压缩。然而，还没有完全理解耦合的位移-扩散机制如何介导金属陶瓷的压缩变形。在这里，通过进行原位原子尺度的压缩测试，我们发现，而不是当地增厚通常报告到目前为止，异常变薄事件连续发生在银纳米晶体，预先存在的位错和晶体滑移作为刺激激活表面原子扩散。低于临界宽度，在银纳米晶体中发生拉伸断裂样失效。这项工作揭示了原子尺度的扩散介导的压缩变形的金属陶瓷。图形摘要影响声明原位原子尺度的压缩试验表明，表面原子扩散介导连续减薄事件和最终压缩断裂的银纳米晶体。
Local thickening, resulting from displacive or diffusive mechanisms individually, is frequently observed in nanoscale metals during compression. However, it is not fully understood how a coupled displacive-diffusive mechanism would mediate the compressive deformation of metallic nanocrystal. Here, by conducting in situ atomic-scale compression tests, we find that, instead of local thickening commonly reported thus far, abnormal thinning events consecutively occur in silver nanocrystals, where preexisting dislocations and crystal slip serve as stimuli to activate surface atom diffusion. Below a critical width, tensile-fracture-like failure occurs in the silver nanocrystals. This work sheds light on atomic-scale diffusion-mediated compressive deformation of metallic nanocrystal. GRAPHICAL ABSTRACT IMPACT STATEMENT In situ atomic-scale compression tests reveal that surface atom diffusion mediates consecutive thinning events and ultimate compression fracture in silver nanocrystals.