About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Interstitial–Metal Interactions: The Outsized Role of Small Atoms
|
| Presentation Title |
Coupled Effects of Hydrogen, Grain Boundaries, and Free Surfaces on Dislocation Activity in Polycrystalline Nickel |
| Author(s) |
Matthew Melfi, S. Mohadeseh Taheri-Mousavi |
| On-Site Speaker (Planned) |
Matthew Melfi |
| Abstract Scope |
Hydrogen-induced ductility loss remains a major limitation to the durability of structural alloys, arising from interactions between H and microstructural defects such as grain boundaries and free surfaces that alter local deformation mechanisms. Here, large-scale atomistic simulations are employed to investigate hydrogen-assisted deformation in polycrystalline nickel containing a broad range of grain boundary misorientation angles, with and without free surfaces. To elucidate the influence of crack-like free surfaces on plasticity, deformation mechanisms in samples containing both grain boundaries and free surfaces are compared with fully periodic polycrystalline systems. The evolution of dislocation activity, nucleation behavior, and local von Mises stress is quantified as a function of grain boundary misorientation. The results show that free surfaces significantly modify the stress state and deformation response of grain boundaries, particularly for misorientation angles between 25° and 45°. These findings provide new atomistic insight into hydrogen-induced strain partitioning and localization, supporting the development. |
| Proceedings Inclusion? |
Planned: |