| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phonons, Electrons and Dislons: Exploring the Relationships Between Plastic Deformation and Heat
|
| Presentation Title |
Do Moving Dislocations Induce Lattice Instabilities? |
| Author(s) |
Benat Gurrutxaga-Lerm |
| On-Site Speaker (Planned) |
Benat Gurrutxaga-Lerm |
| Abstract Scope |
'Phonon radiation' is caused by the breaking and rebuilding of bonds as dislocations glides. In this talk, I will discuss how phonon radiation is associated with fundamental lattice instabilities triggered by the moving dislocation in the lattice. Complementary models based on lattice dynamics and molecular dynamics(MD) will be used to explain them. Lattice dynamics offer mathematical understanding, showing the existence of breakdown velocities at which moving dislocations trigger lattice resonances; MD simulations offer a way of understanding how the lattice responds to them.
In particular, two phenomena are observed at resonance: significant local heating, and a kinematic generation mechanism, which results in a new pair of dislocations being generated. A repetition of this process in cascade ultimately results in an avalanche of further dislocations. These instabilities offer a physical rationale for local plastic softening of the sort relevant in phenomena such as adiabatic shear banding. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, Modeling and Simulation, |