Long range stress fields and cavitation along a shear band in a metallic glass: The local origin of fracture
Long range stress fields and cavitation along a shear band in a metallic glass: The local origin of fracture
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DOI：
10.1016/j.actamat.2015.06.062
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发表时间：
2015-10-01
期刊：
影响因子：
9.4
通讯作者：
Volkert, C. A.
中科院分区：
文献类型：
--
作者：
Maass, R.;Birckigt, P.;Volkert, C. A.
研究了锆基非晶合金沿着单一剪切带的纳米力学性能。压痕硬度和模量的空间映射揭示了复杂的长程软化模式，这是内部应力场沿着剪切带的指示。这些内应力达到被测金属玻璃的屈服强度量级的值。观察到沿剪切带沿着方向的应力松弛随时间变化的现象，并发现了微米尺度的剪切带空穴，空穴和内应力都归因于剪切带的非平面性，在剪切带扩展过程中，剪切带产生了相对于剪切方向的离轴应力分量.空腔是剪切带裂纹过渡的签名，这是由应力场已知的发展提前混合模式I和II裂纹尖端。(C)2015 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Nanomechanical properties along a single shear band in a Zr-based metallic glass were studied. Spatial mapping of both indentation hardness and modulus reveal complex long-range softening patterns that are indicative of internal stress fields along the shear band. These internal stresses reach values of the order of the yield strength of the tested metallic glass. Time dependent stress relaxation along the shear band is observed, and shear-band cavitation at the micron scale is found. Both the cavitation and the internal stresses are attributed to the non-planar shear plane that during shear-band propagation leads to the development of off-axis stress components relative to the shear direction. The cavities are a signature of a shear-band-to-crack transition, which is supported by stress fields known to develop ahead of mixed mode I and II crack tips. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.