论文标题
在施加的应力下冷却恢复无定形合金并增强其延展性
Cooling under applied stress rejuvenates amorphous alloys and enhances their ductility
论文作者
论文摘要
使用分子动力学模拟研究了在二元玻璃冷却过程中施加的拉伸应力对势能状态和机械性能的影响。我们研究了三维二元混合物，该混合物首先在玻璃过渡温度附近退火，然后在张力下迅速冷却到玻璃相中。已经发现，在较大的施加应力值下，液体玻璃在较高应变下冻结，其势能得到增强。对于固定的冷却速率，在玻璃过渡点以上的初始温度上升时，在冷却过程中可以施加的最大拉伸应力会降低。我们还表明，复兴玻璃的无定形结构的特征是较小类型原子之间的接触次数增加。此外，拉伸测试的结果表明，在较大的施加应力和较高的初始温度下制备的玻璃中，弹性模量和应力过冲的峰值被降低，从而表明延展性增强。这些发现可能对开发加工和制造方法有用，以改善散装金属玻璃的可塑性。
The effect of tensile stress applied during cooling of binary glasses on the potential energy states and mechanical properties is investigated using molecular dynamics simulations. We study the three-dimensional binary mixture that was first annealed near the glass transition temperature and then rapidly cooled under tension into the glass phase. It is found that at larger values of the applied stress, the liquid glass former freezes under higher strain and its potential energy is enhanced. For a fixed cooling rate, the maximum tensile stress that can be applied during cooling is reduced upon increasing initial temperature above the glass transition point. We also show that the amorphous structure of rejuvenated glasses is characterized by an increase in the number of contacts between smaller type atoms. Furthermore, the results of tensile tests demonstrate that the elastic modulus and the peak value of the stress overshoot are reduced in glasses prepared at larger applied stresses and higher initial temperatures, thus indicating enhanced ductility. These findings might be useful for the development of processing and fabrication methods to improve plasticity of bulk metallic glasses.
