| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Composite Materials for Nuclear Applications III
|
| Presentation Title |
On the Reduced Damage Tolerance of Fine-Grained Nuclear Graphite at ElevatedTtemperatures Using In Situ 4D Tomographic Imaging |
| Author(s) |
Ming Jiang, Houzheng Wu, Robert O. Ritchie, Martin Kuball, Dong (Lilly) Liu |
| On-Site Speaker (Planned) |
Dong (Lilly) Liu |
| Abstract Scope |
This study focused on investigating the flexural strength and fracture toughness of two fine-grained graphite (SNG623 and T220) using real-time X-ray micro-tomography imaging at room temperature, 750°C and 1100°C. Specifically, nonlinear-elastic fracture mechanics-based JR(a) R-curves at these temperatures were presented with evolution of damage and failure micro-mechanisms, local strain distributions and J-integral fracture analysis. Compared to the coarser-grained Gilsocarbon nuclear graphites used in the current UK advanced gas-cooled reactors, these modern fine-grained graphites display deficient fracture resistance in the form of far less stable crack growth prior to catastrophic fracture and reduced failure strain at 1100°C. Moreover, their elevation in strength and toughness at high temperatures is remarkably lower to that of Gilsocarbon graphite. Based on in situ high-temperature Raman spectroscopy mapping, one of the major causes of this behaviour was attributed to the smaller magnitude of ‘frozen-in’ residual stress relaxed at elevated temperatures compared with Gilsocarbon graphite. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Ceramics, Composites, Nuclear Materials |