About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Behavior at the Nanoscale VIII
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| Presentation Title |
From Cryogenic flow to High-Temperature instabilities: Dislocation mechanics of {110} slip in a BCC High-Entropy Alloy |
| Author(s) |
Nicolo Della Ventura, Julia Puerstl, Morgan Jones, Carolina Frey, Ravit Silverstein, Xavier Maeder, Johann Michler, Tresa Pollock, Irene Beyerlein, Daniel Gianola |
| On-Site Speaker (Planned) |
Nicolo Della Ventura |
| Abstract Scope |
Plastic deformation in RHEAs emerges from a complex interplay between dislocation dynamics, chemical disorder, and thermally activated processes. At low temperatures, plasticity is governed by sluggish screw dislocations, where strength reflects solute–dislocation interactions and high lattice friction. With increasing temperature, a strength plateau develops due to evolving dislocation mobility and the onset of phase decomposition, which alters the deformation landscape. This talk examines these mechanisms in a single-phase BCC RHEA (Hf-Mo-Nb-Ta-Ti) via in situ SEM-based micropillar compression across a wide temperature (200-1300 K) and strain-rate (0.001-100 1/s) range, activating the {110} slip system. Focus is placed on the cryogenic regime, where activation parameters are extracted, and edge–screw mobility contrast is analyzed. In this regime, strength agrees with solid solution strengthening models. At higher temperatures, phase-controlled plasticity emerges. Phase field dislocation dynamics simulations provide complementary insights, and the influence of interstitials on mechanical properties will be briefly addressed. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, High-Temperature Materials, Characterization |