Abstract The failure mechanism of ductile metals is dominated by the nucleation, growth and coalescence of voids, and it is important to capture the evolution of voids on nanoscale. More than ten atomic models, each containing about 10 million atoms, are simulated under tensile loading at strain rate 5 × 1 0 8 s − 1 . The influences of two parameters, the initial radius and the initial spacing of two voids, are also investigated in detail. The increment in void fraction increases linearly with strain at the last stage of void evolution, and the increment has little relation with initial radius and spacing of voids in this stage. The peak value of stress triaxiality increases first with the initial intervoid ligament distance until it reaches the critical point of void coalescence, and then decreases. It suggests that stress triaxiality may be an important indicator to characterize whether the void coalescence will occur. Dislocation analysis shows that the dislocation emissions from void surface is an important behavior in the initial stage of void evolution, but it has little effect on the void volume in the cases studied.

中文翻译：

---

通过原子模拟研究高应变速率拉伸载荷下单晶铜中空隙的生长和聚结

摘要 韧性金属的失效机制主要是空洞的成核、生长和聚结，在纳米尺度上捕捉空洞的演化具有重要意义。在应变速率为 5 × 1 0 8 s − 1 的拉伸载荷下模拟了十多个原子模型，每个模型包含约 1000 万个原子。还详细研究了两个参数，初始半径和两个空隙的初始间距的影响。孔隙率的增量在孔隙演化的最后阶段随应变线性增加，该阶段增量与初始半径和孔隙间距关系不大。应力三轴度的峰值随着初始空隙间韧带距离的增加先增加，直到达到空隙聚结的临界点，然后减小。这表明应力三轴性可能是表征是否会发生空隙聚结的重要指标。位错分析表明，空隙表面的位错发射是空隙演化初期的一个重要行为，但在所研究的案例中它对空隙体积的影响很小。