About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Interstitial–Metal Interactions: The Outsized Role of Small Atoms
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| Presentation Title |
Time-scale Competition of Hydrogen–Defect Interactions: A Phase–Field Crystal Study |
| Author(s) |
Daniel Lessa Coelho, Nikolas Provatas |
| On-Site Speaker (Planned) |
Daniel Lessa Coelho |
| Abstract Scope |
Hydrogen embrittlement (HE) triggers a profound loss of ductility in structural metals; however, a unified framework bridging atomic-scale interstitial interactions with mesoscale mechanics remains elusive. We address this by extending the Vapor-forming Structural Phase-Field Crystal (VXPFC) model to a binary metal–hydrogen system, capturing diffusion-deformation coupling at diffusive time scales. We demonstrate that three-particle interactions are essential to capture the elastic response of Cottrell atmospheres alongside concurrent hydrogen absorption and grain boundary segregation. By quantifying the energy of hydrogen trapping, we identify a critical threshold where the time scale of hydrogen diffusion competes with dislocation glide. This defines a transition from a hydrogen-dragged regime to a decoupled regime, providing a rigorous mechanistic basis for the dual hardening and softening effects observed in hydrogen-exposed metals. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Environmental Effects, Mechanical Properties, Computational Materials Science & Engineering |