Strengthening mechanisms of the nanolayered polycrystalline metallic multilayers assisted by twins
Strengthening mechanisms of the nanolayered polycrystalline metallic multilayers assisted by twins
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孪晶辅助纳米层多晶金属多层膜的强化机制
DOI：
10.1016/j.ijplas.2015.05.014
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发表时间：
2015-09
影响因子：
9.8
通讯作者：
Liu, Yu
中科院分区：
文献类型：
--
作者：
Zhu, Yaxin;Li, Zhenhuan;Huang, Minsheng;Liu, Yu
为了研究纳米层状多晶金属多层膜中生长孪晶对其强度的帮助，通过分子动力学方法对纳米孪晶Cu//Ag和Cu//Ni多层膜进行了一系列单轴拉伸建模，特别关注孪晶片层厚度及其空间分布对强化机制的影响。结果表明，通过在纳米孪晶多层膜中引入纳米孪晶片层，可以显着提高纳米孪晶多层膜的强度，并表现出很强的孪晶厚度效应。通过对原子细节的检验，发现存在一个临界孪晶层厚度，高于该厚度，金属多层膜的变形机制为发夹状部分位错滑移为主，低于该临界厚度，则为项链状多重锯齿状位错滑移为主。对不同变形机制的形成和转变进行了详细讨论和理论分析，并定量描述了不同变形机制对多层膜强度的影响。此外，还讨论了两种具有非均匀孪晶片层分布的纳米孪晶Cu//Ag多层膜的强度和变形机制。结果表明，在非均匀孪晶多层膜中，项链状位错机制和发夹状位错机制可以共存，并且在较厚的孪生片层中意外地观察到项链状多重锯齿状扩展位错。尽管两种机制之间存在协同相互作用，但具有不均匀纳米孪晶片层厚度的多层膜的强度可以通过混合规则很好地预测。
To study the assistance of growth twin in nano-layered polycrystalline metallic multilayers to their strength, a series of uniaxial tensile modeling of nano-twinned Cu//Ag and Cu//Ni multilayers is performed via molecular dynamics method, with especial attentions to the influence of the twin lamella thickness and its spatial distribution on the strengthening mechanism. The results indicate that the strengths of nano-twinned multilayers can be enhanced significantly by introducing nano-twin lamellae into them and show strong twin thickness effect. By checking the atomic details, it is found there exists a critical twin lamella thickness above which the deformation mechanism of metallic multilayers is the hairpin-like partial dislocation gliding dominated and below which it becomes the necklace-like multiple jogged dislocation gliding dominated, however. The formation and transition of different deformation mechanisms are discussed in detail and analyzed theoretically, and the effect of the distinct deformation mechanisms on the strength of multilayers is also depicted quantitatively. In addition, the strengths and deformation mechanisms of two type nano-twinned Cu//Ag multilayers with non-uniform twin lamellae distribution are also discussed. The results show that the necklace-like dislocation mechanism and the hairpin-like dislocation mechanism can coexist in those non-uniform twinned multilayers and the necklace-like multi-jogged extended dislocations are unexpectedly observed in thicker twin lamellae. Although there are synergetic interactions between two mechanisms, the strengths of multilayers with non-uniform nano-twin lamella thickness can be well predicted by the rule of mixture.
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影响因子：
9.4
作者：
Yuntian Zhu;Xiaolei Wu;X. Liao;J. Narayan;L. Kecskes;S. Mathaudhu
通讯作者：
Yuntian Zhu;Xiaolei Wu;X. Liao;J. Narayan;L. Kecskes;S. Mathaudhu
揭示 25 nm Cu/Au 多层膜中可调谐孪晶/解孪晶行为
影响因子：
4
作者：
Yan, J. W.;Zhang, G. P.
通讯作者：
Zhang, G. P.
影响因子：
6
作者：
Shen, YF;Lu, L;Lu, K
通讯作者：
Lu, K
影响因子：
9.8
作者：
Liu, Y.;Chen, Y.;Zhang, X.
通讯作者：
Zhang, X.
影响因子：
9.4
作者：
Youxing Chen;Yue Liu;Cheng Sun;Kai Yu;M. Song;H. Wang;Xinghang Zhang
通讯作者：
Youxing Chen;Yue Liu;Cheng Sun;Kai Yu;M. Song;H. Wang;Xinghang Zhang