About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Hume-Rothery Symposium: Interface Structure and Properties: Impact on Microstructure Evolution
|
| Presentation Title |
Critical assessment of grain boundaries in hydrogen trapping and diffusion in metals |
| Author(s) |
Jun Song |
| On-Site Speaker (Planned) |
Jun Song |
| Abstract Scope |
Grain boundaries (GBs) are known to influence hydrogen trapping and diffusion, crucial to hydrogen embrittlement (HE) in metals. Employing an approach combining polyhedral tessellation and first-principles calculations, we revealed the chemomechanical origin of hydrogen adsorption at GBs and developed a general predictive model of hydrogen trapping and segregation energetics. Meanwhile, we elucidated the dual role of GBs in hydrogen diffusion, demonstrating a transition between slow and fast diffusion along GBs with an abrupt change in diffusivity. Low-angle GBs are shown to comprise isolated high-barrier regions to impede hydrogen diffusion, with diffusivity well prescribed by the classical trapping model, while high-angle GBs provide interconnected low-barrier channels to facilitate hydrogen transport. Based on the Frank-Bilby model, such slow-fast diffusion transition is identified to result from dislocation core overlapping and accurately predicted. Our study provides critical, predictive assessment of hydrogen-GB interactions, and key mechanistic insights to guide GB engineering for effective HE mitigation. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Modeling and Simulation, Thin Films and Interfaces, Other |