| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Advances in Multiphysics Modeling and Multi-modal Imaging of Functional Materials
|
| Presentation Title |
Chemo-Mechanical Origin of Accelerated Oxidation Near the Surface Flaws |
| Author(s) |
Ruyue Fang, Yang Yang, Dingchuan Xue, Yanzhou Ji, Long-qing Chen, Sulin Zhang |
| On-Site Speaker (Planned) |
Ruyue Fang |
| Abstract Scope |
Oxidation in metals such as aluminum typically exhibits a self-limiting behavior due to the formation of a protective oxide layer. However, our investigation into the oxidation of nanoscale Zircaloy-4 thin foils at elevated temperatures identifies a complex dualistic mechanism involving both self-amplification and self-limiting processes. Using in-situ environmental transmission electron microscopy (E-TEM), we observed accelerated oxidation around surface flaws in comparison to other free edges. Phase-field modeling revealed that this disparate oxidation rate is due to the heterogeneous stress distribution in the presence of surface flaws, modulating oxygen transport and chemical reaction. Oxidation-induced stress near the surface flaws initiates cracking and the fractured surfaces act as conduits for oxygen diffusion, thereby intensifying further oxidation in a self-amplifying manner. The resultant oxidation leads to the crack development emanating from both the surface flaws within the oxidized domain and the free surfaces in the metal domain. |