About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Thermo-Mechanical Processing of Refractory Alloys
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| Presentation Title |
Dislocation mechanisms governing the continuous and discontinuous dynamic recrystallization behavior in refractory multi-principal element alloys |
| Author(s) |
Pulkit Garg, Nathan E Peterson, Amy J. Clarke, Irene J. Beyerlein |
| On-Site Speaker (Planned) |
Pulkit Garg |
| Abstract Scope |
Dynamic recrystallization (DRX) drives microstructural evolution during thermomechanical processing of refractory multi-principal alloys (RMPEAs). In body-centered cubic RMPEAs, DRX typically occurs through subgrain rotation and misorientation buildup, as observed in MoNbTi. However, recent experimental studies report discontinuous DRX characterized by grain boundary bulging and necklace structures in HfMoTaTiZr near half its melting temperature. To investigate dislocation mechanisms underlying these contrasting DRX behaviors, we employ phase-field dislocation dynamics simulations. In both alloys, screw dislocations glide via kink-pair mechanism involving two edge-character kinks that introduce higher line energy and greater lattice distortions than screw segments. HfMoTaTiZr shows a higher kink-pair density on the slip plane and increased cross-slip activity, resulting in greater lattice distortion and stored local strain energy. These features promote localized grain nucleation consistent with discontinuous DRX observed in HfMoTaTiZr. Our findings mechanistically distinguish between continuous and discontinuous DRX modes, highlighting the role of dislocation behavior on processing–microstructure relationships. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, Mechanical Properties, High-Temperature Materials |