About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
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| Symposium
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Bridging Scales: Deformation and Damage Mechanisms in Microstructurally and Compositionally Complex Metallic Alloys
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| Presentation Title |
Statistical Energy Landscapes Governing Screw Dislocation Glide and Critical Shear Stress in Refractory Complex Concentrated Alloys |
| Author(s) |
Jierui Zhao, Subhendo Chakraborty, Yang Chen, Liang Qi |
| On-Site Speaker (Planned) |
Jierui Zhao |
| Abstract Scope |
This study investigates screw dislocation migration in the refractory complex concentrated alloy WMoTaNb using atomistic simulations. Analysis of hundreds of minimum energy pathways from nudged elastic band (NEB) calculations shows that the rate determining process may involve kink nucleation, kink migration, or secondary kink nucleation. Variations in dislocation core energy reveal energetically unfavorable regions caused by atomic scale chemical fluctuations. To bridge atomistic insights with realistic dislocation lengths, we develop a physics based framework based on the statistical energy landscape obtained from the NEB calculations. The distribution of activation barriers is described using Weibull statistics, representing variability in local migration barriers due to chemical disorder. A long dislocation line is modeled as a collection of segments sampling this landscape, enabling prediction of the critical resolved shear stress from the combined effects of cutting and looping mechanisms. The model also shows that short range ordering slightly increases activation barriers but has only a minor effect on strength. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, Modeling and Simulation, Mechanical Properties |