State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, PR China.
WPI Advanced Institute for Materials Research, Tohoku University, Sendai, Japan.
Nat Mater. 2022 Apr;21(4):404-409. doi: 10.1038/s41563-021-01185-y. Epub 2022 Jan 31.
The similarity in atomic/molecular structure between liquids and glasses has stimulated a long-standing hypothesis that the nature of glasses may be more fluid-like, rather than the apparent solid. In principle, the nature of glasses can be characterized by the dynamic response of their rheology in a wide rate range, but this has not been realized experimentally, to the best of our knowledge. Here we report the dynamic response of shear stress to the shear strain rate of metallic glasses over a timescale of nine orders of magnitude, equivalent to hundreds of years, by broadband stress relaxation experiments. The dynamic response of the metallic glasses, together with other 'glasses', follows a universal scaling law within the framework of fluid dynamics. The universal scaling law provides comprehensive validation of the conjecture on the jamming (dynamic) phase diagram by which the dynamic behaviours of a wide variety of 'glasses' can be unified under one rubric parameterized by the thermodynamic variables of temperature, volume and stress in the trajectory space.
液体和玻璃之间原子/分子结构的相似性激发了一个长期存在的假说，即玻璃的性质可能更具有流动性，而不是明显的固体。原则上，可以通过其流变学在很宽的速率范围内的动态响应来表征玻璃的性质，但据我们所知，这在实验上尚未实现。在这里，我们通过宽带应力松弛实验报告了在相当于数百年的九个数量级时间尺度上，金属玻璃的剪切应力对剪切应变速率的动态响应。金属玻璃以及其他“玻璃”的动态响应在流体动力学框架内遵循普遍的标度定律。普遍的标度定律为关于阻塞（动态）相图的猜想提供了全面的验证，通过该相图，可以将各种“玻璃”的动态行为统一在一个纲目下，该纲目由温度、体积和轨迹空间中的应力等热力学变量参数化。
