About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Characterization Techniques for Quantifying and Modeling Deformation
|
| Presentation Title |
Irrational Core Induced Low Mobility of Edge Pyramidal Dislocations in Magnesium |
| Author(s) |
Fei Liu, Boyu Liu, Bin Li, Zhiwei Shan |
| On-Site Speaker (Planned) |
Bin Li |
| Abstract Scope |
Lightweight magnesium faces limitations in plasticity tied to the behavior of pyramidal dislocations. Despite extensive studies, key aspects such as the motion behavior of pyramidal dislocations, remain unresolved. Using in-situ TEM, we quantitatively measure the CRSS for pyramidal dislocations. We reveal that near-screw dislocations glide smoothly under low stresses close to that of basal slip, whereas edge dislocations exhibit a jerky motion of low mobility requiring activation stresses two orders of magnitude higher. The mobility of edge dislocations can be enhanced by forming near-screw steps, well elucidating the observed step-like configurations. As temperature increases, the mobility difference between edge and near-screw dislocations narrows. Atomistic simulations indicate that the low mobility of edge dislocations is due to an irrational core structure where the theoretical half atomic plane is irrational and shifts to basal and prismatic planes, leading to the rectilinear morphology along the basal plane and necessitating a climb-like motion. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Mechanical Properties, Modeling and Simulation |