| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Chemistry and Physics of Interfaces
|
| Presentation Title |
Disconnection Mobility and Grain Boundary Doping |
| Author(s) |
Spencer L. Thomas, Jason R. Trelewicz |
| On-Site Speaker (Planned) |
Spencer L. Thomas |
| Abstract Scope |
The Disconnection Mechanism is a powerful model to describe grain boundary (GB) behaviors including GB migration, sliding, and GB-bulk defect exchange. While disconnection nucleation is well-studied, disconnection migration is comparatively underexamined. This work illustrates the role of disconnection mobility in shear-coupled migration of the Σ5(310) symmetric-tilt GB in nickel. Some energetically favorable disconnection modes are restricted by low disconnection mobility. If low-mobility disconnections form, disconnection pile-up results in GB roughening, creating nucleation sites for subsequent disconnections. Roughening reduces the critical nucleation length scale, which augments the effects of GB migration driving forces, potentially influencing GB mobility measurements. We show that certain dopants (e.g., tungsten) impede disconnection migration, potentially influencing mode selection and/or reducing GB mobility by orders of magnitude in ways that cannot be predicted from nucleation barriers. The availability of disconnections in real microstructures due to dislocation absorption and initial crystallization further demands investigations of disconnection migration. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Other, Mechanical Properties, Computational Materials Science & Engineering |