论文标题
在有限温度下机械退火的二进制玻璃中延迟的屈服过渡
A delayed yielding transition in mechanically annealed binary glasses at finite temperature
论文作者
论文摘要
使用分子动力学模拟研究了应变振幅，玻璃稳定性和热波动对剪切带形成和屈服过渡的影响。首先将模型二进制混合物逐渐冷却在玻璃过渡温度以下，然后定期变形以进入广泛的势能状态。我们发现，对于大约一千个剪切周期内的高度退火玻璃，临界应变振幅变得更大。此外，在固定应变振幅下继续加载后，机械退火至较低能量状态的玻璃杯中的屈服过渡会延迟。还证明，具有较大非植物位移的一小群原子的成核与屈服过渡相关的急剧变化。这些结果对于具有可调机械和物理性能的无定形合金的热和机械加工很重要。
The influence of strain amplitude, glass stability and thermal fluctuations on shear band formation and yielding transition is studied using molecular dynamics simulations. The model binary mixture is first gradually cooled below the glass transition temperature and then periodically deformed to access a broad range of potential energy states. We find that the critical strain amplitude becomes larger for highly annealed glasses within about one thousand shear cycles. Moreover, upon continued loading at a fixed strain amplitude, the yielding transition is delayed in glasses mechanically annealed to lower energy states. It is also demonstrated that nucleation of a small cluster of atoms with large nonaffine displacements precedes a sharp energy change associated with the yielding transition. These results are important for thermal and mechanical processing of amorphous alloys with tunable mechanical and physical properties.
