| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Multi-Principal Element Alloys IV: Mechanical Behavior
|
| Presentation Title |
Temperature Dependent Screw Dislocation Dynamics in MoNbTi and TaNbTi Multi-Principal Element Alloys |
| Author(s) |
Pulkit Garg, Daniel Magnuson, Kevin Hemker, Irene J. Beyerlein |
| On-Site Speaker (Planned) |
Pulkit Garg |
| Abstract Scope |
The mechanical properties of refractory multi-principal element alloys (MPEAs) with body-centered cubic crystal structure exhibit a characteristic temperature dependence. In this work, we examine screw dislocation dynamics at different temperatures in MoNbTi and TaNbTi MPEAs using a three-dimensional, atomistic informed phase-field-dislocation dynamics model combined with Langevin dynamics. The critical stress for dislocation motion is observed to sharply decrease with increasing temperature, followed by a gradual decline and then a bend in the behavior producing an athermal plateau, similar to the three-stage temperature-dependent yield strength behavior of refractory MPEAs. The mechanisms of dislocation glide are examined to identify the effect of local chemical variations on dislocation motion and to understand the role of screw dislocations on the mechanical response of refractory MPEAs in three temperature regimes. Overall, we show that screw dislocations govern the mechanical behavior of refractory MPEAs across a wide range of temperatures and not just at low temperatures. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, Mechanical Properties, Modeling and Simulation |