About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Materials and Chemistry for Molten Salt Systems
|
| Presentation Title |
Atomistic Understanding of Fluoroacidity-Dependent Cr Corrosion in Molten Fluorides from ab initio Molecular Dynamics and Metadynamics |
| Author(s) |
Minkyung Choi, Sangtae Kim |
| On-Site Speaker (Planned) |
Minkyung Choi |
| Abstract Scope |
Large differences in Cr corrosion rates between FLiNaK and FLiBe have been reported and qualitatively attributed to the availability of free F^-; the strongly fluorobasic FLiNaK stabilizes Cr(III) as [CrF6]3-, sustaining Cr attack. In contrast, near-neutral FLiBe consumes free F^- to form BeF_4^(2-), stabilizing Cr(II). However, the quantitative and molecular-level understanding of how the salt chemistry affects the corrosion behavior remains elusive. Here, we employ ab initio molecular dynamics(AIMD) and well-tempered metadynamics to quantify fluoroacidity effects on Cr dissolution. AIMD was performed to validate density, ionic structure/charges, and diffusion coefficients of FLiNaK and FLiBe against experiments, while trajectories serve as training data for machine learning interatomic potentials. Metadynamics was employed to show the free-energy landscape of Cr dissolution in these salts and quantify Cr disproportionation reactions. This approach links Cr corrosion rates mechanistically to fluoroacidity, providing transferable computational routes for screening less corrosive salt chemistries. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Environmental Effects, Computational Materials Science & Engineering, Machine Learning |