About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Magnesium Technology 2027
|
| Presentation Title |
Atomistic Understanding of Low-Temperature Prismatic Slip and Solute Softening in Magnesium |
| Author(s) |
Masoud Rahbar Niazi, Orcun Koray Celebi |
| On-Site Speaker (Planned) |
Orcun Koray Celebi |
| Abstract Scope |
In-plane formability of Mg alloys can be enhanced through the activation of prismatic slip. Experiments have shown that below 150 K, prismatic screw dislocations exhibit jerky glide and that dilute Zn additions soften prismatic slip. Despite extensive investigations, the mechanism governing low-temperature prismatic slip remains unresolved. Using atomistic simulations with machine-learning interatomic potentials, we show that basal-dissociation-induced locking develops locally rather than uniformly along the dislocation line. Consequently, dislocation bow-out occurs without the energetically costly basal dislocation constriction required by the conventional Friedel mechanism. The proposed mechanism predicts a CRSS consistent with the experimentally observed value (~100 MPa), resolving the order-of-magnitude discrepancy with the ~1000 MPa predicted by the Friedel constriction–bow-out model. Furthermore, a single solute atom strongly pins the bowed-out dislocation arms, suppressing basal-segment propagation and providing a mechanistic explanation for the anomalous solute-induced softening observed experimentally. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Magnesium, Mechanical Properties, Computational Materials Science & Engineering |