Influence of Competition between Intragranular Dislocation Nucleation and Intergranular Slip Transfer on Mechanical Properties of Ultrafine-Grained Metals
Influence of Competition between Intragranular Dislocation Nucleation and Intergranular Slip Transfer on Mechanical Properties of Ultrafine-Grained Metals
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DOI：
10.2320/matertrans.mh201313
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发表时间：
2013-09
影响因子：
1.2
通讯作者：
T. Tsuru;Y. Aoyagi;Y. Kaji;T. Shimokawa
中科院分区：
文献类型：
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作者：
T. Tsuru;Y. Aoyagi;Y. Kaji;T. Shimokawa
对含Frank源的铝多晶薄膜进行了剪切变形实验的大规模原子模拟，以阐明超细晶金属的晶间和晶内塑性变形过程与力学性能之间的关系。为了研究晶界对流动应力的影响，制备了两种多晶模型，分别由多个晶界分别再现易滑移和硬滑移。两种模型的第一次塑性变形都是以位错在晶界内的退缩运动进行的，而随后的塑性变形则受到位错在晶界传递的滑移阻力的强烈影响。考虑了晶内位错形核和晶间滑移的竞争对材料强度的影响。该纳米结构材料的强度依赖于与晶粒度和位错源长度相关的局部缺陷结构。[DOI：10.2320/MATERTRA.MH201313]
Huge-scale atomistic simulations of shear deformation tests to the aluminum polycrystalline thin film containing the FrankRead source are performed to elucidate the relationship between the interand intragranular plastic deformation processes and the mechanical properties of ultrafine-grained metals. Two-types of polycrystalline models, which consist of several grain boundaries reproducing easy and hard slip transfer, respectively, are prepared to investigate the effect of grain boundary on flow stress. While the first plastic deformation occurs by the dislocation bow-out motion within the grain region for both models, the subsequent plastic deformation is strongly influenced by the resistance of the slip transfer by dislocation transmission through grain boundaries. The influence of the competition between the intragranular dislocation nucleation and intergranular slip transfer on the material strength is considered. The nanostructured material’s strength depending on local defect structures associated with grain size and dislocation source length is assessed quantitatively. [doi:10.2320/matertrans.MH201313]