Time-resolved atomic-scale observations of deformation and fracture of nanoporous gold under tension
Time-resolved atomic-scale observations of deformation and fracture of nanoporous gold under tension
复制标题
纳米多孔金在张力下变形和断裂的时间分辨原子尺度观测
DOI：
10.1016/j.actamat.2018.11.022
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发表时间：
2019-02-15
期刊：
影响因子：
9.4
通讯作者：
Chen, Mingwei
中科院分区：
文献类型：
--
作者：
Liu, Pan;Wei, Xiao;Chen, Mingwei
几十年来，人们已经知道，电偶腐蚀过程中选择性浸出产生的纳米孔会导致材料在张力下的延展性和强度急剧下降。然而，纳米孔诱导脆性的基本原子机制仍然知之甚少。在这里，我们报告了利用最先进的像差校正透射电子显微镜和快速直接电子检测相机对合金纳米孔金的变形和破坏的现场观察。我们的时间分辨原子观察表明，纳米孔金的脆性破坏源于单个金韧带的塑性不稳定，这是位错塑性和应力驱动的表面扩散相互作用的结果。(C) 2018材料学报Elsevier Ltd.出版。版权所有。
It has been known for decades that nanopores produced by selective leaching during galvanic corrosion can lead to dramatic loss of materials ductility and strength under tension. However, the underlying atomic mechanisms of the nanopore induced embrittlement remain to be poorly known. Here we report in situ observations of the deformation and failure of dealloyed nanoporous gold by utilizing the state-of-the art aberration-corrected transmission electron microscopy and fast direct electron detection camera. Our time-resolved atomic observations reveal that the brittle failure of the nanoporous gold originates from plastic instability of individual gold ligaments by the interplay between dislocation plasticity and stress-driving surface diffusion. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.