About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
|
Materials Corrosion Behavior in Advanced Nuclear Reactor Environments
|
Presentation Title |
Charged Point Defect Transport through Passivating Oxide Films Simulated with Cluster Dynamics Models |
Author(s) |
Aaron Kohnert, Edward F Holby, Blas P Uberuaga |
On-Site Speaker (Planned) |
Aaron Kohnert |
Abstract Scope |
Mass flux through passivating oxide scales is mediated by point defects leading to net growth of the oxide layer. Extra point defects created by irradiation may lead to changes in the mass flux, and subsequently to differences in long term corrosion behavior in nuclear reactors. In this work, we develop a reaction diffusion model to simulate the differences in mass transport between thermal and radiation environments, applied specifically to the growth of hematite (Fe2O3) outer layers on magnetite (Fe3O4) scales. Importantly, the model uses the cluster dynamics formalism to include dynamic charge state rebalancing for point defects, consistent with radiation induced Fermi level changes. Building on DFT calculations of point defect properties, the model reproduces many physical properties of hematite including high temperature oxygen deficiency and self-diffusion kinetics. It predicts substantial effects on oxidation kinetics under select irradiation conditions, including non-parabolic growth behaviors which can emerge for thicker hematite scales. |
Proceedings Inclusion? |
Planned: |