| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Composite Materials for Nuclear Applications
|
| Presentation Title |
Experimental Characterisation of the Variation of Local Residual Stresses in TRISO Coatings |
| Author(s) |
Alexander Leide, Steven Knol, Arjan Vreeling, Dave Goddard, Dong Liu |
| On-Site Speaker (Planned) |
Alexander Leide |
| Abstract Scope |
Multi-layer components inherently experience internal stresses due to differences in the properties of their constituent materials, such as thermal expansion coefficient or elastic constants. TRISO coatings (SiC and pyrolytic carbon) processed by chemical vapour deposition will experience thermal stresses during cooling, causing residual stresses and potentially micro-cracking or layer debonding.
During operation in a reactor, stresses in TRISO coatings evolve due to dimensional changes caused by neutron irradiation (shrinkage, swelling, creep) and gas pressure build-up. These operational stresses and dimensional changes are affected by the initial stress state and layer structure of the particles, resulting in different failure criteria than predicted.
Local spatially varying residual stresses have been characterised using Raman spectroscopy, ring-core FIB-DIC, nanoindentation, and X-ray diffraction in particles with different coating layers. The stresses are correlated to processing conditions and local microstructure, and they are used to assist the understanding of the dimensional changes in neutron irradiated particles. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Nuclear Materials, Ceramics, Characterization |