Atomistic modeling of plastic deformation in B2-FeAl/Al nanolayered composites
Atomistic modeling of plastic deformation in B2-FeAl/Al nanolayered composites
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DOI：
10.1007/s10853-021-06377-0
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发表时间：
2021-08
影响因子：
4.5
通讯作者：
S. Dong;Xiang-Yang Liu;Caizhi Zhou
中科院分区：
文献类型：
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作者：
S. Dong;Xiang-Yang Liu;Caizhi Zhou
本文研究了B2-FeAl/Al金属间复合材料作为金属间界面纳米层复合材料的模型材料体系的变形响应。采用原子模拟方法研究了B2-FeAl/Al纳米层复合材料的变形机理和界面错配位错结构。结果表明，界面错配位错网络中包含两组位错，并与界面初始位错成核有关。研究了层厚对B2-FeAl/Al多层材料单轴变形响应的影响。我们观察到，在压缩载荷下，FeAl层的比例越小，总流动应力越低。在拉伸载荷作用下，研究了空洞的形成机制，表明界面结构和FeAl层中的位错活动对触发应变局部化起重要作用，导致空洞在界面处开始成核。研究还发现，“弱”Fe/Cu界面下的变形行为与“强”FeAl/Al界面下的变形行为有很大不同。纳米层复合材料的原子模型研究为“强”金属间界面材料系统的力学响应提供了基础。在Fe/Cu模拟中，在整个塑性变形过程中没有出现空洞形核，这是由于Fe/Cu多层材料的位错密度更高，滑移系统激活更多，位错痕迹分布相对均匀。
In this work, the deformation response of the B2-FeAl/Al intermetallic composites, as a model material system for nanolayered composites comprised of intermetallic interfaces, has been explored. We use atomistic simulations to study the deformation mechanisms and the interface misfit dislocation structure of B2-FeAl/Al nanolayered composites. It is shown that two sets of dislocations are contained in the interface misfit dislocation network and are correlated with the initial dislocation nucleation from the interfaces. The effects of layer thickness on the uniaxial deformation response of the B2-FeAl/Al multilayers are investigated. We observed that under compressive loading the smaller proportion of the FeAl layers leads to the lower overall flow stress. Under tensile loading, the void formation mechanism is investigated, suggesting the interface structure and the dislocation activities in the FeAl layers playing a significant role to trigger the strain localization which leads to void nucleation commencing at the interface. It is also found that the deformation behavior in the “weak” Fe/Cu interface behaves substantially different than that of the “strong” FeAl/Al interface. The atomistic modeling study of the nanolayered composites here underpinned the mechanical response of “strong” intermetallic interface material systems. There is no void nucleation during the entire plastic deformations in the Fe/Cu simulations, which is attributed to much higher dislocation density, more slip systems activated, and relative uniformly distributed dislocation traces in the Fe phase of the Fe/Cu multilayers.