Structural rejuvenation in a bulk metallic glass induced by severe plastic deformation
Structural rejuvenation in a bulk metallic glass induced by severe plastic deformation
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DOI：
10.1016/j.actamat.2009.09.021
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发表时间：
2010-01-01
期刊：
影响因子：
9.4
通讯作者：
Egami, T.
中科院分区：
文献类型：
--
作者：
Dmowski, W.;Yokoyama, Y.;Egami, T.
利用高能X射线衍射技术研究了高压扭转（HPT）技术产生剧烈塑性变形的大块金属玻璃样品的原子结构。我们得到了原子对分布函数（PDF），并确定了由于变形的PDF的变化。PDF中观察到的变化清楚地显示了结构无序，这表明通过重变形进行结构更新。然而，这些变化不能简单地解释为产生了过量的自由体积，它们表明变形导致了更广泛的原子重排。此外，我们认为，所观察到的结构变化很可能是由于变形局部加热的结果，可能不会直接提供应变局部化的原子机制的知识。(C)2009 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Using high-energy X-ray diffraction we examined the atomic structure in bulk metallic glass samples which underwent severe plastic deformation by the high-pressure torsion (HPT) technique. We obtained the atomic pair distribution function (PDF) and determined the changes in the PDFs due to deformation. The observed changes in the PDF clearly show structural disordering, which suggests structural rejuvenation by heavy deformation. However, the changes cannot be explained simply in terms of creating excess free volume, and they indicate that much more extensive atomic rearrangements take place as a consequence of deformation. Also, we suggest that the observed structural change may well be an outcome of local heating due to deformation and may not directly provide the knowledge of the atomistic mechanism of strain localization. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.