Manipulation of relaxation processes in a metallic glass through cryogenic treatment

The relaxation spectrum of glassy solids has long been considered to probe their structural features and deformation mechanisms. Here, by systematically investigating the structural evolution, dynamical re-laxations and mechanical properties of a Zr-based metallic glass subjected to different cryogenic treatment time, we build a bridge to connect the relaxation processes and mechanical properties. It is found that the /3 -relaxation triggered by local excitations has no memory effect of the thermal history or initial free volume content of the system. However, some local denser areas with a high potential energy created by CT might contribute to /3 '-relaxation that activated at a much lower energy, which may play a crucial important role in the fundamental deformation mechanisms of metallic glasses. The relaxation behaviors and the related improved mechanical properties can be rationalized in terms of the atomic-level stress theory. These findings will advance our understanding of the intrinsic correlation between local excitations and me-chanical properties of metallic glasses, thereby may help guide to develop amorphous alloys with high mechanical performance. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

The relaxation spectrum of glassy solids has long been considered to probe their structural features and deformation mechanisms. By systematically investigating the structural evolution, dynamical relaxations, and mechanical properties of a Zr-based metallic glass, it was found that local excitations trigger β-relaxation with no memory effect of the thermal history or initial free volume content, while some local denser areas created by cryogenic treatment might contribute to β'-relaxation at a much lower energy, playing a crucial role in the fundamental deformation mechanisms of metallic glasses. These findings help advance understanding of the relationship between local excitations and mechanical properties, potentially guiding the development of high-performance amorphous alloys.