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 |
Kink Dynamics and Cross-Kink Effects in Screw Dislocation Migration of Refractory Complex Concentrated Alloys |
| Author(s) |
Jierui Zhao, Subhendo Chakraborty, Liang Qi |
| On-Site Speaker (Planned) |
Jierui Zhao |
| Abstract Scope |
This study investigates fundamental mechanisms of screw dislocation migration in typical refractory complex concentrated alloys (RCCA), such as WMoNbTa, by atomistic simulations. Under low-temperature conditions, analysis of hundreds of minimum energy pathways obtained by nudged elastic band (NEB) methods reveals that rate-determining events during dislocation migrations may include kink nucleation, kink migration, or secondary kink nucleation. By examining dislocation core energy difference, we identify “energy-unfavorable regions” for local dislocation segments raised from local chemical fluctuations. The combined influences of the core energy differences due to these “energy-unfavorable regions” and dislocation line tensions lead to different migration behaviors. In addition, other mechanisms such as cross-kinks, which also act as “energy-unfavorable regions”, should be considered at higher temperatures. We apply molecular dynamics simulations to generate cross-kinks and investigate how local chemical environments influence their development. Finally, we develop a multiscale model describing how these mechanisms govern the critical shear stress. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, Modeling and Simulation, Mechanical Properties |