论文标题
驱动力引起的Ni晶界热行为的过渡
Driving force induced transition in thermal behavior of grain boundary migration in Ni
论文作者
论文摘要
晶界（GB）迁移表现出有趣的抗热行为（或非阿拉尼乌斯行为），温度和驱动力起着至关重要的作用。通过对镍双晶的原子模拟，我们研究了GB迁移率随温度和驱动力的变化而变化。我们的结果表明，GB迁移率最初随温度而增加，随后在达到过渡温度（TTRAN）后降低，尤其是Trans与与GB迁移相关的激活能（Q）表现出线性关系。通过调节驱动力，我们发现驱动力可以有效地降低Q，从而导致Trans向较低的温度转移。此外，发现较高的驱动力在较低的温度下激活更多的迁移模式，可能导致GB迁移热行为过渡。我们的工作支持现有的基于经典热激活和断开成核的GB迁移的理论模型。此外，我们通过纳入驱动力的影响来完善现有模型。修改的模型不仅可以描述驱动力对GB迁移热行为的影响，还可以说明GB迁移中观察到的“抗驾驶力”现象。我们的研究有可能在更复杂的约束和环境下研究现实的GB迁移，提供有价值的见解。
Grain boundary (GB) migration exhibits intriguing anti-thermal behavior (or non-Arrhenius behavior), with the temperature and driving force playing crucial roles. Through atomistic simulations on nickel bicrystals, we investigate the change in GB mobility with variations in both temperature and driving force. Our results reveal that the GB mobility initially increases with temperature and subsequently decreases after reaching the transition temperature (Ttrans), and, notably, Ttrans exhibits a linear relationship with the activation energy (Q) associated with GB migration. By modulating the driving force, we found that the driving force could effectively lower Q, resulting in the shift of Ttrans towards lower temperatures. Additionally, higher driving forces were found to activate more migration modes at lower temperatures, potentially leading to a transition in the thermal behavior of GB migration. Our work supports the existing theoretical models for GB migration based on both classical thermal activation and disconnection nucleation. Furthermore, we refined the existing model by incorporating the influence of the driving force. The modified model can not only describe the effect of driving force on the thermal behavior of GB migration but also accounts for the observed "anti-driving force" phenomenon in GB migration. Our research has the potential to offer valuable insights for investigating realistic GB migration under more intricate constraints and environments.
