| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Materials and Chemistry for Molten Salt Systems
|
| Presentation Title |
Atomistic Insights into Orientation-Assisted Corrosion of NiCr Alloys in Molten FLiNaK salt using ReaxFF Molecular Dynamics |
| Author(s) |
Hamdy Arkoub, Daniel Flynn, Miaomiao Jin |
| On-Site Speaker (Planned) |
Hamdy Arkoub |
| Abstract Scope |
The corrosion behavior at the NiCr-FLiNaK interface is driven by complex Cr-F- chemical interactions, highlighting the need to understand these dynamics to optimize NiCr alloy behavior in molten salt environments. In this work, we employ reactive force field (ReaxFF) molecular dynamics to investigate the impact of crystallographic orientation and temperature on the corrosion behavior of NiCr alloys exposed to FLiNaK salt. Specifically, the (100), (110), and (111) orientations of Ni0.75Cr0.25 slabs are evaluated at various temperatures ranging from 600 to 800 oC and/or an external electric field. It is found that the corrosion behavior of NiCr surfaces began with the enrichment of fluoride ions on the surface, and then the dissolution of surface atoms (mostly Cr) to form an effect similar to pitting corrosion. The simulations also reveal orientation-dependent differences in the corrosion mechanism, with the (110) orientation exhibiting the highest susceptibility to attack, as evidenced by the corrosion morphology of the surface and Cr dissolution. Increasing temperature is shown to amplify the corrosion effects by accelerating dissolution and reaction rates at the metal-salt interface. Furthermore, the activation energy is calculated to estimate the metal atoms dissolution from different slab orientations by fitting the results into the Arrhenius relation. Atomic-scale analyses, including charge transfer, radial distribution functions, and diffusion characteristics, provide insights into the underlying mechanisms driving initial corrosion behaviors. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Nuclear Materials, Computational Materials Science & Engineering, Modeling and Simulation |