| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Coatings and Surface Engineering for Environmental Protection III
|
| Presentation Title |
Revealing the Long-term Growth Kinetics and Morphology of Atmospheric Corrosion Pitting in Aluminum via In-operando Microtomography |
| Author(s) |
Philip Noell, Michael Melia, Eric Schindelholz |
| On-Site Speaker (Planned) |
Philip Noell |
| Abstract Scope |
Understanding the mechanistic relationship between the environment, microstructure, and local kinetics of atmospheric corrosion damage remains a central challenge. To address this challenge, this study used laboratory-based x-ray tomography to directly observe attack in-operando over an extended period, enabling the first observations of how the growth kinetics and morphology of individual pits evolve over months of exposure. Damage evolution associated with nine pits in a 99.9% pure aluminum wire exposed to chloride salts in humid air was studied over months of exposure. Most pits grew at a nominally linear rate up until pit death. Exceptions to this were observed, with three pits exhibiting bimodal growth kinetics. This was explained by secondary droplets that formed near the pits, increasing the cathode area. A corrosion-driven drying mechanism appears to lead to pit death in both cases. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. |
| Proceedings Inclusion? |
Planned: |