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| Main Authors: | , , |
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| Format: | Preprint |
| Published: |
2025
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2509.06512 |
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| _version_ | 1866912576248479744 |
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| author | Jian, Wu-Rong Wang, Yifan Cai, Wei |
| author_facet | Jian, Wu-Rong Wang, Yifan Cai, Wei |
| contents | Dislocation jogs have strong effects on dislocation motion that governs the strain-hardening behavior of crystalline solids, but how to properly account for their effect in mesoscale models remains poorly understood. We develop a mobility model for jogged edge dislocations in FCC nickel, based on systematic molecular dynamics (MD) simulations across a range of jog configurations, stresses, and temperatures. At low stresses, jogged edge dislocations exhibit non-linear, thermally activated dragging and a higher Peierls barrier compared to straight dislocations. Surprisingly, stress-velocity curves for a given jog configuration across varying temperatures intersect at an invariant point ($τ_{\rm c}$, $v_{\rm c}$), where $τ_{\rm c}$ delineates thermally-activated and phonon-drag regimes and is close to the Peierls stress ($τ_{\rm p}$). Motivated by this observation, we propose a simple three-section expression for jogged dislocation mobility, featuring minimal and physically interpretable parameters. This mobility law offers a realistic description of jog effects for dislocation dynamics (DD) simulations, improving their physical fidelity for crystal plasticity predictions. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2509_06512 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Non-linear jog-dragging effect on the mobility law of edge dislocations in face-centered cubic nickel Jian, Wu-Rong Wang, Yifan Cai, Wei Materials Science Dislocation jogs have strong effects on dislocation motion that governs the strain-hardening behavior of crystalline solids, but how to properly account for their effect in mesoscale models remains poorly understood. We develop a mobility model for jogged edge dislocations in FCC nickel, based on systematic molecular dynamics (MD) simulations across a range of jog configurations, stresses, and temperatures. At low stresses, jogged edge dislocations exhibit non-linear, thermally activated dragging and a higher Peierls barrier compared to straight dislocations. Surprisingly, stress-velocity curves for a given jog configuration across varying temperatures intersect at an invariant point ($τ_{\rm c}$, $v_{\rm c}$), where $τ_{\rm c}$ delineates thermally-activated and phonon-drag regimes and is close to the Peierls stress ($τ_{\rm p}$). Motivated by this observation, we propose a simple three-section expression for jogged dislocation mobility, featuring minimal and physically interpretable parameters. This mobility law offers a realistic description of jog effects for dislocation dynamics (DD) simulations, improving their physical fidelity for crystal plasticity predictions. |
| title | Non-linear jog-dragging effect on the mobility law of edge dislocations in face-centered cubic nickel |
| topic | Materials Science |
| url | https://arxiv.org/abs/2509.06512 |