Nanobubble Fragmentation and Bubble-Free-Channel Shear Localization in Helium-Irradiated Submicron-Sized Copper
Nanobubble Fragmentation and Bubble-Free-Channel Shear Localization in Helium-Irradiated Submicron-Sized Copper
复制标题
氦辐照亚微米铜中的纳米气泡破碎和无气泡通道剪切定位
DOI：
10.1103/physrevlett.117.215501
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发表时间：
2016
影响因子：
8.6
通讯作者：
Shan Zhi-Wei
中科院分区：
文献类型：
--
作者：
Ding Ming-Shuai;Tian Lin;Han Wei-Zhong;Li Ju;Ma Evan;Shan Zhi-Wei
氦气泡是金属及合金中典型的辐射组织之一，对其变形行为有重要影响。然而，到目前为止，关于应变下氦气泡的动态演化的研究还很少。在这里，通过在透射电子显微镜内进行现场微观机械测试，我们发现氦气泡不仅可以与相邻的气泡合并，还可以在拉伸下分裂成几个纳米级的气泡。沿滑移线对齐分裂可以产生无气泡的通道，该通道看起来更柔软，促进了剪切局部化，并在剪切模式下加速了破坏。详细的分析表明，气泡的意外破碎是位错切割和内表面扩散共同作用的结果，这是氦辐照铜的另一种微观损伤机制，即气泡合并。
Helium bubbles are one of the typical radiation microstructures in metals and alloys, significantly influencing their deformation behavior. However, the dynamic evolution of helium bubbles under straining is less explored so far. Here, by usingin situmicromechanical testing inside a transmission electron microscope, we discover that the helium bubble not only can coalesce with adjacent bubbles, but also can split into several nanoscale bubbles under tension. Alignment of the splittings along a slip line can create a bubble-free channel, which appears softer, promotes shear localization, and accelerates the failure in the shearing-off mode. Detailed analyses unveil that the unexpected bubble fragmentation is mediated by the combination of dislocation cutting and internal surface diffusion, which is an alternative microdamage mechanism of helium irradiated copper besides the bubble coalescence.