About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
| Presentation Title |
Atomistic Modeling of Hydrogen Segregation in Polycrystalline Structural Alloys |
| Author(s) |
Matthew Melfi, Amirreza Dana, Ismaila Dabo, S. Mohadeseh Taheri-Mousavi |
| On-Site Speaker (Planned) |
Matthew Melfi |
| Abstract Scope |
Hydrogen (H)-induced ductility loss in structural alloys is a major challenge resulting from complex interactions between H-atoms and microstructural defects. These interactions alter local deformation mechanisms, particularly by changing strain partitioning near grain boundaries (GBs). Experimental characterization at this scale remains limited due to technical difficulties for nanoscale H-tracking. To overcome these challenges, atomistic modeling frameworks combining molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) methods was developed to simulate H-segregation and associated deformation mechanisms at polycrystalline scale. Density functional theory calculations were performed to validate the interatomic potential. Larger samples with 27 randomly oriented grains were used to investigate H-GB interactions across varying H-concentrations. Analyzing segregation behavior demonstrated a strong dependence of H trapping on GB characteristics and mainly GB energy, and followed Sieverts’ law which reveals the interconnection among influential parameters. These results support predictive modeling and alloy design strategies to mitigate hydrogen-induced embrittlement via GB engineering. |
| Proceedings Inclusion? |
Planned: |