Lattice dislocation induced misfit dislocation evolution in semi-coherent {111} bimetal interfaces
Lattice dislocation induced misfit dislocation evolution in semi-coherent {111} bimetal interfaces
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DOI：
10.1557/s43578-021-00184-8
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发表时间：
2021-04
影响因子：
2.7
通讯作者：
A. Selimov;Shuozhi Xu;Youping Chen;D. McDowell
中科院分区：
文献类型：
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作者：
A. Selimov;Shuozhi Xu;Youping Chen;D. McDowell
半共格界面介导的位错塑性研究可以帮助设计某些异质结构材料，如纳米层压材料。在复杂的应力场下，位错堆积引起的界面错配模式的演变可以影响局部位错/界面相互作用，包括多个进入位错的影响。这项工作利用并行原子连续体建模框架，以探测半共格Ni/Cu和Cu/Ag界面的失配结构的演变，通过纳米压痕产生的位错堆积冲击。连续微旋转度量计算在压痕过程的各个阶段，并用于可视化的界面失配位错图案的演变。接近位错的应力状态导致界面处失配位错结构的混合收缩和膨胀。对于Ni/Cu，每单位界面面积的错配节点的数量较低，与错配节点附近的原子的较大局部变形相一致。降低的失配节点间距Cu/Ag交替分布与塑性变形在更大比例的原子在界面处的重组。界面滑动促进失配位错运动被发现，以促进变形扩展到体晶格上的失配节点为中心。这些领域的渗透深度被发现是更大的Ni/Cu比Cu/Ag。半共格界面介导的位错塑性研究可以帮助设计某些异质结构材料，如纳米层压材料。在复杂的应力场下，位错堆积引起的界面错配模式的演变可以影响局部位错/界面相互作用，包括多个进入位错的影响。这项工作利用并行原子连续体建模框架，以探测半共格Ni/Cu和Cu/Ag界面的失配结构的演变，通过纳米压痕产生的位错堆积冲击。连续微旋转度量计算在压痕过程的各个阶段，并用于可视化的界面失配位错图案的演变。接近位错的应力状态导致界面处失配位错结构的混合收缩和膨胀。对于Ni/Cu，每单位界面面积的错配节点的数量较低，与错配节点附近的原子的较大局部变形相一致。降低的失配节点间距Cu/Ag交替分布与塑性变形在更大比例的原子在界面处的重组。界面滑动促进失配位错运动被发现，以促进变形扩展到体晶格上的失配节点为中心。这些领域的渗透深度被发现是更大的Ni/Cu比Cu/Ag。
The study of dislocation plasticity mediated by semi-coherent interfaces can aid in the design of certain heterostructured materials, such as nanolaminates. The evolution of interface misfit patterns under complex stress fields arising from dislocation pileups can influence local dislocation/interface interactions, including effects of multiple incoming dislocations. This work utilizes the Concurrent Atomistic-Continuum modeling framework to probe the evolution of misfit structures at semi-coherent Ni/Cu and Cu/Ag interfaces impinged by dislocation pileups generated via nanoindentation. A continuum microrotation metric is computed at various stages of the indentation process and used to visualize the evolution of the interface misfit dislocation pattern. The stress state from approaching dislocations induces mixed contraction and expansion of misfit dislocation structures at the interface. A lower number of misfit nodes per unit interface area coincides with greater localized deformation with regard to atoms near misfit nodes for Ni/Cu. The decreased misfit node spacing for Cu/Ag alternatively distributes the restructuring associated with plastic deformation over a larger percentage of atoms at the interface. Interface sliding facilitated by misfit dislocation motion is found to facilitate deformation extending into the bulk lattices centered on misfit nodes. The depth of penetration of those fields is found to be greater for Ni/Cu than for Cu/Ag. The study of dislocation plasticity mediated by semi-coherent interfaces can aid in the design of certain heterostructured materials, such as nanolaminates. The evolution of interface misfit patterns under complex stress fields arising from dislocation pileups can influence local dislocation/interface interactions, including effects of multiple incoming dislocations. This work utilizes the Concurrent Atomistic-Continuum modeling framework to probe the evolution of misfit structures at semi-coherent Ni/Cu and Cu/Ag interfaces impinged by dislocation pileups generated via nanoindentation. A continuum microrotation metric is computed at various stages of the indentation process and used to visualize the evolution of the interface misfit dislocation pattern. The stress state from approaching dislocations induces mixed contraction and expansion of misfit dislocation structures at the interface. A lower number of misfit nodes per unit interface area coincides with greater localized deformation with regard to atoms near misfit nodes for Ni/Cu. The decreased misfit node spacing for Cu/Ag alternatively distributes the restructuring associated with plastic deformation over a larger percentage of atoms at the interface. Interface sliding facilitated by misfit dislocation motion is found to facilitate deformation extending into the bulk lattices centered on misfit nodes. The depth of penetration of those fields is found to be greater for Ni/Cu than for Cu/Ag.