| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Characterization Techniques for Quantifying and Modeling Deformation
|
| Presentation Title |
Avalanche Statistics and the Intermittent-to-smooth-transition in Microplasticity |
| Author(s) |
Gregory Sparks, Yinan Cui, Giacomo Po, Quentin Rizzardi, Jaime Marian, Robert Maass |
| On-Site Speaker (Planned) |
Robert Maass |
| Abstract Scope |
Plastic flow at small scales is generally observed to be intermittent, whereas the stress-strain behavior of bulk crystals is mostly smooth. Here we find that when the external deformation rate of small-scale crystals approaches the speed of the crystallographic slip velocity, an intermittent-to-smooth transition of plastic flow is observed. By defining a rate-dependent intermittency-parameter, this phenomenon can be captured with a power-law covering 5.5 orders of magnitude for Au and Nb micron-sized single crystals with experiments, and via simulations for Nb crystals. Our results indicate that the transition to smooth flow is driven by a gradual truncation of the underlying truncated power-law that describes the intermittently evolving system. This is caused by a competition of internal and external rates, which aligns with the well-known transitions from serrated to non-serrated flow in metallic glasses or materials with dynamic strain aging. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |