Publication - Mechanical Properties of SiC-based Nuclear-Fuel Cladding

Our EMAM group members, Dr Guanjie Yuan and Dr Qiance Zhang, have recently had a paper of theirs published in Materials & Design.

You can find their paper at this link.

Abstract:
"Continuous SiC fibre reinforced SiC matrix composites (SiC_f-SiC_m CMC) with monolithic SiC coatings are promising candidate accident-tolerant fuel cladding materials for light-water-reactors. Thick monolithic SiC coatings can increase failure strength and improve hermeticity, but may also suppress toughening mechanisms in the cladding system.
Here, 2D fibre braided SiC_f-SiC_m cladding with thick inner and outer SiC coatings were examined, with outer-coating-thickness ranging from ∼240 to ∼440 μm.
C-ring compression tests were performed up to 1200°C in Ar, combined with in-situ synchrotron X-ray micro-computed tomography and digital-volume-correlation (DVC) to quantify 3D strain distributions.
All specimens exhibited brittle fracture initiated in the outer coating, consistent with localized tensile hoop strain measured by DVC. No obvious crack-deflection toughening at the coating/CMC interfaces was observed before failure. Within the limited six-specimen dataset, apparent nominal hoop strength and DVC-derived localized hoop strain showed a positive association with outer-coating-thickness. Because coating-thickness and testing temperature were not varied independently, this association is an indicative trend rather than a design allowable or general thickness–strength law. Newman–Raju calculations semi-quantitatively rationalized the thickness-associated trend in terms of surface-flaw stress intensity.
These results highlight the designing need to balance coating thickness, CMC-layer fraction and interfacial strength."

CRediT Authorship of Group Members:
Guanjie Yuan: Writing – original draft, Investigation, Formal analysis.
Qiance Zhang: Writing – review & editing.
Dong Liu: Writing – review & editing, Resources, Methodology, Funding acquisition, Conceptualization.

Acknowledgements:
"This research was funded in whole, or in part, by the UKRI [ST/W001683/1, EP/T000368/1]. For the purpose of Open Access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. The authors also acknowledge the use of the X-ray synchrotron micro-tomography beamline (8.3.2) at the Lawrence Berkeley National Laboratory's Advanced Light Source, which is supported by the Office of Science of the U.S. Department of Energy under contract no. DE-AC02-05CH11231. Thanks are also due to Dr. Dula Parkinson for help with these synchrotron tomography experiments."