About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
|
| Presentation Title |
Hydrogen-Mediated Transition in Grain Boundary Migration Mechanisms in Pure Nickel: Insights from Atomistic Simulations |
| Author(s) |
Robert D. Moore, Fernando Leon Cazares, Ryan Sills, Chris San Marchi, Ian Winter |
| On-Site Speaker (Planned) |
Robert D. Moore |
| Abstract Scope |
Grain boundary (GB) migration plays a role in many key processes in structural metals, including microstructural evolution during thermomechanical processing, deformation, and grain growth. In hydrogen-containing environments, however, GBs can also serve as preferential segregation sites, potentially influencing migration behavior. While several mechanisms of hydrogen (H) embrittlement have been proposed, the atomistic processes by which H modifies GB-mediated deformation remains an open question. In this work, we investigate H segregation at GBs in pure nickel (Ni) and its effect on shear-coupled GB migration using atomistic simulations. We characterize the disconnection modes responsible for migration and reveal how H alters their energetics and activation. Broadly, these findings establish a link between atomic-scale H–GB interactions and microstructural evolution, with implications for H embrittlement and the mechanical behavior of Ni-based systems in H-rich environments. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. |