Microstructure formation of metallic nanoglasses: Insights from molecular dynamics simulations
Microstructure formation of metallic nanoglasses: Insights from molecular dynamics simulations
复制标题
金属纳米玻璃的微观结构形成：来自分子动力学模拟的见解
DOI：
10.1016/j.actamat.2017.12.014
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发表时间：
2018-02-15
期刊：
影响因子：
9.4
通讯作者：
Albe, Karsten
中科院分区：
文献类型：
--
作者：
Adjaoud, Omar;Albe, Karsten
通过分子动力学模拟纳米金属玻璃球的固结过程，研究了Pd 80 Si 20和Cu 64 Zr 36纳米玻璃的微观结构形成.我们的研究结果表明，在冷压缩过程中，大多数的玻璃球变形均匀的塑性流动，并在一些玻璃球应变局部化发生在剪切带，贯穿整个玻璃球。此外，当静水压力超过4GPa时，孔隙度关闭。所得的纳米玻璃由玻璃-玻璃界面连接的玻璃质区域组成。结果表明，这些接口的宽度是显着大于估计在以前的原子模型的基础上的平面接口。此外，结构变化不仅发生在界面，而且在玻璃化区域。此外，热力学分析表明，表面偏析是有利的，在初级玻璃球，但并不总是在纳米玻璃。本研究揭示了金属纳米玻璃微结构的形成过程，并可用于解释实验结果。(C)2017 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
We investigate the microstructure formation of Pd80Si20 and Cu64Zr36 nanoglasses by molecular dynamics simulations of the consolidation process of nanometer-sized metallic glassy spheres. Our results reveal that during cold compaction most of the glassy spheres deform by homogeneous plastic flow and in some glassy spheres strain localization occurs in a shear band which traverses the whole glassy sphere. Moreover, the porosity is closed if hydrostatic pressures exceed 4 GPa. The resulting nanoglasses are composed of glassy regions connected by glass-glass interfaces. The results reveal that the width of these interfaces is significantly larger than estimated in previous atomistic models based on planar interfaces. Moreover, structural changes occur not only in the interfaces but also in the glassy regions. In addition, thermodynamics analysis show that surface segregation is favorable in the primary glassy spheres but not always in the nanoglass. The present findings shed light on the process of the microstructure formation of metallic nanoglasses and can serve to interpret the experimental results. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.