The effects of shear deformation at 1173 K on the mechanical properties and deformation mechanism of pure tungsten are investigated by molecular dynamics (MD). The results show that the shear deformation of pure tungsten is dominated by dislocation multiplication and slip band deformation. The shear angle has a significant effect on the mechanical properties of pure tungsten. The yield strength is 4.21 Gpa at a shear angle of 11∘, and it increases significantly to 11.84 Gpa while the shear angle increasing to 27∘. In the plastic deformation stage, the stress–strain curve shows obvious oscillation due to the interaction of dislocations in the single-crystal tungsten and the effect of strain strengthening. In addition, the evolution of dislocation and twining in the compression system against shear angle indicates the variation of deformation behavior. When the shear angle is 11∘, the lengths of dislocation 1/2〈111〉 and 〈100〉 increase to a peak rapidly, which illustrates dislocation strengthening. However, when the shear angle is more than 11∘, the decrease of dislocation length and the appearance of twins along 〈111〉 direction demonstrate the twining accompanied with dislocation tangling, resulting in the additional increase of strength.

中文翻译：

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剪切变形在纯钨中的作用：力学性能和微观机理

通过分子动力学（MD）研究了1173 K剪切变形对纯钨力学性能和变形机制的影响。结果表明，纯钨的剪切变形以位错倍增和滑带变形为主。剪切角对纯钨的力学性能有显着影响。剪切角为 11 时，屈服强度为 4.21 Gpa∘, 并显着增加到 11.84 Gpa, 而剪切角增加到 27∘. 在塑性变形阶段，由于单晶钨中位错的相互作用和应变强化的作用，应力-应变曲线表现出明显的振荡。此外，压缩系统中位错和缠绕对剪切角的演变表明变形行为的变化。当剪切角为 11∘, 位错长度 1/2〈111〉和〈100〉迅速增加至峰值，说明位错强化。但是，当剪切角大于 11∘, 位错长度的减少和双胞胎的出现〈111〉方向表现出伴随位错缠结的缠绕，导致强度的额外增加。