About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
|
Dynamic Behavior of Materials IX
|
Presentation Title |
Effect of Surfaces on Dislocation Mobility in the Transonic Regime |
Author(s) |
Ta Duong, Michael J. Demkowicz |
On-Site Speaker (Planned) |
Ta Duong |
Abstract Scope |
We use molecular dynamics to investigate the effect of free surfaces on the mobility of dislocations in single crystal copper (Cu). Dislocation velocities up to 4000 m/s are modeled. In the subsonic regime, dislocation velocity matches the applied strain rate. However, above the lowest transverse sound speed (c2~1600m/s), the dislocation velocity alternates periodically between c2 and a higher value (~2700m/s). The time spent at each velocity is such that the average velocity again matches the applied strain rate. We rationalize this behavior based on dislocation interactions with the nearby free surfaces in the model. These findings shed new light on the mechanisms of plastic deformation under high strain rate loading. |
Proceedings Inclusion? |
Planned: |
Keywords |
Modeling and Simulation, Mechanical Properties, Computational Materials Science & Engineering |