About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
|
Symposium
|
Bulk Metallic Glasses XVII
|
Presentation Title |
Stress Breaks Universal Aging Behavior in a Metallic Glass |
Author(s) |
Amlan Das, Peter M Derlet, Chaoyang Liu, Eric Dufresne, Robert Maass |
On-Site Speaker (Planned) |
Robert Maass |
Abstract Scope |
Using thermal and thermo-mechanical processing of metallic glasses to change their structural state has a long history. Annealing below the glass transition temperature is known to relax the structure, leading to an increase in structural relaxation times with time (age). This aging process is ubiquitous and has been captured with an empirical but universal time-waiting time-temperature superposition principle. Here we focus on the structural dynamics occurring in response to a mechanical stress within the elastic regime. This is done via in-situ x-ray photon correlation spectroscopy (XPCS) of a prototypical Zr-based metallic glass. We find that stress breaks the universal thermally-activated aging response: relaxation times increase with stress, but significant structural intermittency is seen that leads to distinct non-monotonous structural dynamics. These features are ascribed to microplastic processes, leading to the conclusion that structural evolution under the bias of stress is fundamentally different than conventional thermally-activated relaxation. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |