| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Elucidating Microstructural Evolution Under Extreme Environments
|
| Presentation Title |
Advanced Statistical Techniques for 4D-STEM: Characterizing Defect Populations in Post-Irradiation Au and Cr |
| Author(s) |
Dongye Liu, Sean Mills, Dana Byrne, Benjamin Derby , Matthew Chancey, Yongqiang Wang, Andrew M. Minor |
| On-Site Speaker (Planned) |
Dongye Liu |
| Abstract Scope |
Molten-salt reactor environments present numerous challenges, where factors such as salt chemistry, temperature, irradiation-induced defects, and high operating temperatures influence degradation, the mechanical properties, and lifetime of reactor components. In metals, point defects evolve into extended defects such as stacking fault tetrahedra (SFT), dislocation loops, etc. It is challenging to quantify the nature, population, and distribution of defects. However, post-irradiation characterization techniques such as 4-dimensional scanning transmission electron microscopy (4D-STEM) with high-speed direct electron detectors together with atomic resolution STEM provide opportunities for potentially mapping point defect distributions at the nanoscale and their associated strains. In this study, we first utilize a model Au sample exposed to Helium ion radiation containing primarily SFTs to verify the approach. 4D-STEM based strain mapping was employed to measure local lattice constant variations. This technique enhances our understanding of defect populations under various thermal and radiation conditions in Cr systems, highlighting interstitial-type aggregated defects. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Nuclear Materials, |