About this Abstract |
| Meeting |
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Symposium
|
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Presentation Title |
Carbide Precipitate Dissolution in Advanced RAFM Steels Studied Using In-Situ TEM Ion Irradiation |
| Author(s) |
Ethan Polselli, T.M. Kelsy Green, Hangyu Li, Kai Sun, Weicheng Zhong, Ying Yang, Kevin G. Field |
| On-Site Speaker (Planned) |
Ethan Polselli |
| Abstract Scope |
Castable Nanostructured Alloys (CNAs) are advanced steels developed for fusion energy systems, featuring improved strength due to carefully designed processing, which creates a high density (>10<sup>22</sup> m<sup>-3</sup>) of small (<15 nm) and dispersed TiC precipitates. Conventional ex-situ ion irradiation demonstrates near-complete dissolution of these precipitates at high doses; however, experiments are limited to discrete damage levels, providing limited insight into the dynamic evolution of precipitates leading to dissolution. In contrast, in-situ transmission electron microscopy (TEM) with ion beam irradiation allows for direct study of precipitate dissolution under irradiation in real-time. This work seeks to validate the study of precipitate stability under irradiation utilizing in-situ TEM ion irradiation analysis. We demonstrate the dissolution of TiC precipitates in CNA alloys using dark-field TEM near the [100] zone axis using the ḡ = 002 condition between 15 and 50 displacements per atom (DPA). The dissolution of precipitates is further confirmed and cross-referenced with conventional ex-situ ion beam irradiation using scanning transmission electron microscopy with energy dispersive X-ray spectroscopy chemical analysis. Post-irradiation examination of in-situ samples is compared with ex-situ irradiation conditions at 300, 400, and 500°C at a damage of 15 DPA. In-situ irradiation has demonstrated precipitate stability at damage levels approaching 50 DPA, exceeding what is observed using ex-situ techniques. Differences in precipitate stability between experimental techniques will be discussed as a result of enhanced surface defect sink effects by irradiating a thin film specimen. |
| Proceedings Inclusion? |
Undecided |