Atomic-scale mechanisms of tension-compression asymmetry in a metallic glass
Atomic-scale mechanisms of tension-compression asymmetry in a metallic glass
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金属玻璃中拉压不对称的原子尺度机制
DOI：
10.1016/j.actamat.2012.11.054
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发表时间：
2013-04-01
期刊：
影响因子：
9.4
通讯作者：
Jiang, J. Z.
中科院分区：
文献类型：
--
作者：
Chen, L. Y.;Li, B. Z.;Jiang, J. Z.
材料在塑性方面表现出拉-压不对称。这种现象通常用连续介质力学来解释，忽略了应力引起的结构变化。本文用原位加载和高能X射线散射法研究了一种以%为单位的Zr46.5Cu45Al7Ti1.5金属玻璃在拉压应力下的结构变化。给出了金属玻璃的应力诱导结构变化与塑性的异常拉-压不对称性之间的关系。另一个有趣的现象是，金属玻璃在晶化方面也表现出拉压不对称。讨论了应力诱导的结构变化对金属玻璃晶化行为的影响。所得结果揭示了金属玻璃在拉应力和压应力作用下的结构演化，为研究非晶态固体结构中的拉-压不对称性提供了新的视角。(C)2012 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Materials exhibit a tension-compression asymmetry in terms of plasticity. This phenomenon is usually interpreted by continuum mechanics, which neglects the stress-induced structure change. Here we investigated the structure change of a metallic glass of Zr46.5CU45 Al7Ti1.5 (in at.%) under both tensile and compressive stresses by in situ loading and high-energy X-ray scattering. A relationship between the stress-induced structure change and the extraordinary tension-compression asymmetry of plasticity in the metallic glass is presented. Another interesting phenomenon is that the metallic glass also exhibits tension-compression asymmetry in terms of crystallization. The influence of the stress-induced structure change on the crystallization behavior of metallic glasses is discussed. The results obtained here reveal the structure evolution of a metallic glass under both tensile and compressive stresses, and might provide a new perspective on the tension-compression asymmetry in the structure of amorphous solids. (c) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.