About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
|
Environmental Degradation of Multiple Principal Component Materials
|
Presentation Title |
Simulations of Chloride on Hydroxylated Passive Oxide Surfaces Related to Localized Corrosion Initialization |
Author(s) |
Aditya Sundar, Ganlin Chen, Liang Qi |
On-Site Speaker (Planned) |
Liang Qi |
Abstract Scope |
To understand the chloride (Cl)-induced initiation mechanism of localized corrosion of metallic alloys with passive oxide layers, we apply density functional theory (DFT) calculations and atomistic simulations to investigate the interactions between Cl and hydroxylated oxide surfaces under aqueous electrochemical conditions. Hydroxylated alumina and chromia surfaces thermodynamically stable in aqueous environments are constructed based on DFT calculations and atomistic simulations for both the single-crystal and bicrystal configurations. AIMD simulations suggest a Cl anion can only be stabilized on these surfaces by substituting a surface hydroxyl (OH) group. This substitution is thermodynamically favorable at sites on surface terminations of grain boundaries (GBs) but not favorable at sites on single-crystal surfaces. The adsorbed Cl may increase the thermodynamic driving force for cation dissolution from passive oxide surfaces, which can initiate localized corrosion. We also investigate whether alloying elements, such as Mo, can affect the related chloride adsorption and the following cation dissolutions. |
Proceedings Inclusion? |
Planned: |
Keywords |
Environmental Effects, Modeling and Simulation, Other |