Stability of shear banding process in bulk metallic glasses and composites
Stability of shear banding process in bulk metallic glasses and composites
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DOI：
10.1557/jmr.2017.243
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发表时间：
2017-07
影响因子：
2.7
通讯作者：
Yusheng Qin;Xiaoliang Han;K. Song;Li Wang;Yun Cheng;Zequn Zhang;Q. Xue;Nianzhen Sun;J. Wang-J.-Wa
中科院分区：
文献类型：
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作者：
Yusheng Qin;Xiaoliang Han;K. Song;Li Wang;Yun Cheng;Zequn Zhang;Q. Xue;Nianzhen Sun;J. Wang-J.-Wa
大块金属玻璃在变形过程中剪切带的传播对决定其宏观塑性起着关键作用。本文研究了Cu_（46）Zr_（46）Al_（8）BMG及其原位和非原位制备的BMG复合材料在塑性变形过程中剪切带的扩展。与脆性BMG相比，这两种类型的韧性BMG复合材料表现出更稳定的剪切带行为所揭示的更大的幂律标度指数从统计分析的锯齿记录在压缩曲线。原位生成的BMG复合材料具有较高的截止弹性能密度（δ c），这与剪切带数目的增加有关。而非原位制备的BMG复合材料的δ c值几乎相等或稍大，这是因为其变形主要由主导剪切带而不是多剪切带控制。这样的观察意味着，在变形过程中的BMG的剪切带的稳定性增强，不仅通过诱导多个剪切带，但也通过阻碍运动的主导剪切带在其驱动路径。
The shear-band propagation in bulk metallic glasses (BMGs) during deformation plays a key role in determining their macroscopic ductility. In this work, the shear band propagation during plastic deformation was investigated in the Cu_46Zr_46Al_8 BMG and its in situ or ex situ prepared BMG composites. Compared with the brittle BMG, both types of ductile BMG composites show a more stable shear banding behavior as revealed by a larger power-law scaling exponent obtained from statistical analysis of serrations recorded in compressive curves. A higher cut-off elastic energy density (δ_c) linked with the multiplication of shear bands is observed for the in situ prepared BMG composites. However, the ex situ fabricated BMG composites show an almost equivalent or slightly larger δ_c since the dominant shear band but not multiple shear bands mainly governs their deformation. Such observations imply that the shear banding stability of BMGs during deformation is enhanced not only by inducing multiple shear bands but also by obstructing the movement of the dominant shear band at its driven path.