Enhancing strength and plasticity by pre-introduced indent-notches in Zr36Cu64 metallic glass: A molecular dynamics simulation study
Enhancing strength and plasticity by pre-introduced indent-notches in Zr36Cu64 metallic glass: A molecular dynamics simulation study
复制标题
通过在 Zr(36)Cu(64) 金属玻璃中预先引入凹口来提高强度和塑性：分子动力学模拟研究
DOI：
10.1016/j.jmst.2019.10.034
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发表时间：
2020-04-15
影响因子：
10.9
通讯作者：
Liu, Riping
中科院分区：
文献类型：
--
作者：
Feng, Shidong;Li, Lin;Liu, Riping
在原子尺度上用分子动力学模拟方法研究了具有预压痕的非晶合金中的形变行为。压痕可以触发在压痕影响区形成由类固体原子组成的致密堆积团簇。这些密实堆积的团簇对剪切带的形核具有很高的抵抗力。因此，剪切带更容易在凹槽影响区外形核，从而扩大了变形区，增强了强化效果和塑性变形能力。对于缺口镁合金，在确定初始屈服水平时，导致缺口影响区外剪切带形成的密集团簇与缺口根部附近的应力集中局部化变形之间存在竞争过程。当缺口深度较小时，缺口根部附近的应力集中起主导作用，导致剪切带从缺口根部开始，使人联想到缺口。随着压痕深度的增加，在压痕影响区有许多密实堆积的团簇，具有较高的抗变形能力，导致压痕影响区与基体界面形成剪切带。目前的研究成果为提高金属玻璃的室温强度和塑性提供了可行的手段。(C)2020由爱思唯尔有限公司代表《材料科学与技术杂志》编辑部出版。
The deformation behavior in Zr36Cu64 metallic glasses with pre-introduced indent-notches has been studied by molecular dynamics simulation at the atomic scale. The indent-notches can trigger the formation of densely-packed clusters composed of solid-like atoms in the indent-notch affected zone. These densely-packed clusters are highly resistant to the nucleation of shear bands. Hence, there is more tendency for the shear bands to nucleate outside the indent-notch affected zone, which enlarges the deformation region and enhances both the strengthening effect and the plastic deformation ability. For indent-notched MGs, when determining the initial yielding level, there is a competition process occurring between the densely-packed clusters leading to the shear band formation outside the indent-notch affected zone and the stress-concentration localizing deformation around the notch roots. When the indent-notch depth is small, the stress-concentration around the notch root plays a dominant role, leading to the shear bands initiating from the notch root, reminiscence of the cut-notches. As the indent-notch depth increases, there are many densely-packed clusters with high resistance to deformation in the indent-notch affected zone, leading to the shear band formation from the interface between the indent-notch affected zone and the matrix. Current research findings provide a feasible means for improving the strength and the plasticity of metallic glasses at room temperature. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.