论文标题
金属眼镜中热循环恢复活力的原子建模
Atomistic Modelling of Thermal-Cycling Rejuvenation in Metallic Glasses
论文作者
论文摘要
在环境温度和低温温度之间循环金属玻璃可以引起更高能量的状态玻璃形成在更快的冷却速度上的特征。这种复兴，因为它发生在小宏观菌株上，并且远低于热诱导的结构变化的温度，例如在改善可塑性方面很重要。分子动力学模拟阐明了热循环可以诱导松弛（达到较低能量）的机制以及恢复活力。热循环超过数十个循环，驱动局部原子重排逐渐消除了初始玻璃结构。这主要来自每个热周期中的加热阶段，与金属玻璃中的内在结构异质性有关。尽管特别是MD模拟中的时间尺度比物理实验中的时间尺度短，但本模拟会重现许多物理上观察到的效果，这表明它们可能有助于优化热循环，以调整金属玻璃和玻璃的性质。
Cycling of a metallic glass between ambient and cryogenic temperatures can induce higher-energy states characteristic of glass formation on faster cooling. This rejuvenation, unexpected because it occurs at small macroscopic strains and well below the temperatures of thermally induced structural change, is important, for example, in improving plasticity. Molecular-dynamics simulations elucidate the mechanisms by which thermal cycling can induce relaxation (reaching lower energy) as well as rejuvenation. Thermal cycling, over tens of cycles, drives local atomic rearrangements progressively erasing the initial glass structure. This arises mainly from the heating stage in each thermal cycle, linked to the intrinsic structural heterogeneity in metallic glasses. Although, in particular, the timescales in MD simulations are shorter than in physical experiments, the present simulations reproduce many physically observed effects, suggesting that they may be useful in optimizing thermal cycling for tuning the properties of metallic glasses and glasses in general.
