About this Abstract |
| Meeting |
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Symposium
|
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Presentation Title |
Temperature and Dose Effects on Dislocation Loops in Self-Ion Irradiated High-Purity Iron and Fe-Cr Alloys |
| Author(s) |
Yao Li, Zehui Qi, Arunodaya Bhattacharya, Steven Zinkle |
| On-Site Speaker (Planned) |
Yao Li |
| Abstract Scope |
Body-centered cubic (BCC) Fe-based alloys are promising candidate materials for advanced nuclear reactors. Prevailing perspectives suggest that the formation of <001> loops becomes increasingly favorable over ½<111> loops at irradiation temperatures >~300°C in pure iron but can be mitigated by the addition of Cr content. However, the temperature effects on loop type have been primarily examined via in-situ ion irradiation on TEM thin foils with only limited studies on bulk samples, raising concerns about the potential influence of TEM thin foil artifacts on observed results. We conducted 6.7-8 MeV Fe ion irradiations on ultra-high purity BCC Fe and Fe-Cr specimens over a wide temperature range (Tirr = 250–500 °C) on bulk samples, employing varied doses and dose rates. The use of relatively high ion energies was purposely chosen to provide a broader midrange “safe analysis zone” that was separated from near-surface and implanted ion regions. Post-irradiation Burgers vector analysis on dislocation segments and loops revealed that <001> loop fraction does not show a monotonic positive correlation with irradiation temperature in our bulk Fe and Fe-Cr. Strain field can play a critical role in <001> loop formation and the loop’s spatial distribution is dependent on Cr concentration. Combined with previous and current theoretical as well as experimental findings, we compare our experimental observations on temperature effects underlying <001> loop formation with previously proposed mechanistic models. |
| Proceedings Inclusion? |
Undecided |