About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Computational Thermodynamics and Kinetics
|
Presentation Title |
Accelerating Off-lattice Kinetic Monte Carlo Simulations to Predict Hydrogen Vacancy-cluster Interactions in α–Fe |
Author(s) |
Conor John Williams, Enrique Galindo-Nava |
On-Site Speaker (Planned) |
Conor John Williams |
Abstract Scope |
We present an enhanced off-lattice kinetic Monte Carlo (KMC) model, incorporating a new method for tolerant classification of atomistic local-environments, capable of simulating vacancy-hydrogen complexes at atomic resolution and hydrogen embrittlement timescales. Our classification method is invariant under Euclidean-transformations and permutation of identical atoms and equivalence is controlled by a single tolerance parameter. We apply our model to study the trapping/detrapping of hydrogen from up to five-vacancy clusters and simultaneously the effect hydrogen has on the diffusivity of these clusters. We predict the diffusion pathways of clusters/complexes without a priori assumptions of their mechanisms. We detail the hydrogen-induced changes in the clusters' diffusion mechanisms and find evidence that, in contrast to mono-vacancies, the introduction of hydrogen to larger clusters can increase their diffusivity. Finally, we compute the trapping atmosphere of meta-stable states surrounding non-point traps, opening new avenues to better understand and predict hydrogen embrittlement in complex alloys. |
Proceedings Inclusion? |
Planned: |
Keywords |
Computational Materials Science & Engineering, Modeling and Simulation, Other |