| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Refractory Metals 2024
|
| Presentation Title |
Effects of Strain Path and Surface Pinning on Recrystallization in Deformed High-purity Niobium |
| Author(s) |
Zackery L. Thune, Thomas R Bieler |
| On-Site Speaker (Planned) |
Zackery L. Thune |
| Abstract Scope |
The consistent production of high-purity niobium superconducting radiofrequency (SRF) cavities is critical for the improvement of accelerator performance. To produce these cavities the high-purity niobium is deformed into the half-cell geometry, welded, polished to remove the damaged surface layer, and post-purified by heat-treatment at 800°C for 3 hours. Significant improvement in cavity performance has been observed when annealing between 900 and 1000°C. Recent work has shown that the strain path plays a significant role on the extent of recrystallization observed using electron backscatter diffraction (EBSD) analysis of the geometrically necessary dislocation (GND) density that quantifies the extent of recrystallization. Observations of the same surface before and after vacuum heat-treatment and a cross-section measurement indicates that the surface microstructure is pinned, such that the extent of recrystallization depends on how and where the measurement is made. Electropolishing to remove the surface pinned layer may account for improved cavity performance. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Other, Other |