Influence of Size and Number of Nanocrystals on Shear Band Formation in Amorphous Alloys
Influence of Size and Number of Nanocrystals on Shear Band Formation in Amorphous Alloys
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DOI：
10.2320/matertrans.48.1001
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发表时间：
2007-05
影响因子：
1.2
通讯作者：
Junyoung Park;Y. Shibutani;M. Wakeda;S. Ogata
中科院分区：
文献类型：
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作者：
Junyoung Park;Y. Shibutani;M. Wakeda;S. Ogata
在本研究中，采用分子动力学模拟方法，对嵌入纳米晶体结构的二元（铜和锆）非晶金属进行单轴拉伸，揭示剪切带结构形成的机理。选择纳米晶体的数量和尺寸作为研究参数。纳米晶的数量影响应力应变曲线和剪切带的形成，而纳米晶的尺寸对结果影响不显著。根据目前发表的实验报告，在拉伸下，在剪切带或晶体和非晶态材料之间的界面处发现了聚结空洞。模拟结果表明，压缩加载下的剪切带数量远大于拉伸加载下的剪切带数量。我们还发现，即使在压缩载荷下，剪切带也从具有足够自由体积的区域开始。
In this study, binary (copper and zirconium) amorphous metals with embedded nanosized crystal structures are subjected to uniaxial tension using molecular dynamics simulations to reveal the mechanism of shear band structure formation. The number and the size of the nanocrystals are chosen as the study parameters. The number of nanocrystals affects the stress-strain curve and shear band formation while the size of the nanocrystals does not significantly affect the results. As reported in the experimental work published so far, under tension coalescent voids are found in the shear bands or at the interface between crystalline and amorphous materials. The simulation results show that the number of shear bands under compressive loading is much larger than that under tensile loading. We also found that, even under compressive loading, the shear bands started from regions with enough free volume.