Extraordinary plasticity of ductile bulk metallic glasses
Extraordinary plasticity of ductile bulk metallic glasses
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DOI：
10.1103/physrevlett.96.245502
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发表时间：
2006-06-23
影响因子：
8.6
通讯作者：
Sakurai, Toshio
中科院分区：
文献类型：
--
作者：
Chen, Mingwei;Inoue, Akihisa;Sakurai, Toshio
剪切带通常引发应变软化，并导致金属玻璃的低延展性。在这封信中，我们报告高分辨率电子显微镜观察剪切带的韧性金属玻璃。发现由局部剪切引起的应变软化被有效地防止由剪切带内的塑性流动原位产生的纳米化，导致大的塑性和应变硬化。这些原子尺度的观测结果不仅很好地解释了最近在一些大块金属玻璃中观察到的非凡塑性，而且还揭示了一种新的变形机制，可以有效地提高整体金属玻璃的延展性。
Shear bands generally initiate strain softening and result in low ductility of metallic glasses. In this Letter, we report high-resolution electron microscope observations of shear bands in a ductile metallic glass. Strain softening caused by localized shearing was found to be effectively prevented by nanocrystallization that is in situ produced by plastic flow within the shear bands, leading to large plasticity and strain hardening. These atomic-scale observations not only well explain the extraordinary plasticity that was recently observed in some bulk metallic glasses, but also reveal a novel deformation mechanism that can effectively improve the ductility of monolithic metallic glasses.