Nanometre-scale defects in shear bands in a metallic glass
Nanometre-scale defects in shear bands in a metallic glass
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DOI：
10.1080/01418610208240056
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发表时间：
2002-09
期刊：
影响因子：
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通讯作者：
Jing Li;F. Spaepen;T. Hufnagel
中科院分区：
文献类型：
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作者：
Jing Li;F. Spaepen;T. Hufnagel
我们将剪切带的结构与金属玻璃未变形区域的结构进行了比较。利用定量高分辨率电子显微镜，我们观察到直径约为1 nm、浓度为1/100nm3的空洞状缺陷，这些缺陷是由于剪切带中的塑性变形而产生的。这些缺陷可能是由于流动停止时过量自由体积的合并造成的。通过比较含有均匀自由体积的剪切带和含有空洞的松弛剪切带的自由能，我们证明了这种合并是热力学上可能的。
Abstract We have compared the structure of shear bands with that of undeformed regions of a metallic glass. Using quantitative high-resolution electron microscopy, we observed void-like defects, approximately 1 nm in diameter and at a concentration of one in 100nm3, which are generated as a result of plastic deformation in the shear bands. These defects may result from the coalescence of excess free volume upon cessation of the flow. By comparing the free energy of the shear band containing uniformly distributed free volume with that of the relaxed shear band with voids present, we show that the coalescence is thermo-dynamically possible.