NOMATEN ONLINE-SEMINAR June 24: High-Performance-Oriented Structural Design and In-situ Damage Observation Analysis of SiC based Composite Cladding
NOMATEN Online Seminar
Location: gotomeeting room - https://meet.goto.com/NCBJmeetings/nomaten-seminar
Seminar date: June 24th, 2025, 9 AM (CEST)
High-Performance-Oriented Structural Design and In-situ Damage Observation Analysis of SiC based Composite Cladding
Speaker name: Prof. Chong Wei
Speaker affiliation: School of Mechanics and Transportation Engineering, Northwestern Polytechnical University, Xi’an, China
Abstract:
The development of high-performance accident-tolerant SiC composite cladding is critical for advancing Generation IV nuclear reactor technology. However, theoretical frameworks for the structural design of fiber-braided SiCf/SiC cladding remain underdeveloped, and issues related to gas-tightness—primarily caused by high porosity—have limited the further application of SiCf/SiC cladding. In this study, an innovative multilayer gradient-braided SiCf/SiC composite cladding was proposed using parametric modeling and evaluated through a multi-scale coupled theoretical model. The results demonstrate that gradient braiding significantly enhances both the strength and toughness of the cladding. Compared to conventional uniform braiding angles, the gradient structure improves tensile strength and ultimate tensile strain by approximately 50% and 30%, respectively. The underlying strengthening mechanism was also investigated: under a constant fiber bundle volume, increasing the braiding angle reduces the matrix volume fraction. Given the high strength but low toughness of the SiC matrix, a larger braiding angle tends to decrease overall strength. However, the accompanying increase in fiber content improves toughness, resulting in higher ultimate strain. Based on the gradient structure study, a dense Mo metal liner was introduced on the inner surface of the SiCf/SiC cladding to address the issue of gas-tightness. This formed a metal–SiCf/SiC heterogeneous cladding structure. Combined with in-situ C-ring testing and finite element simulation, the damage process and mechanism were revealed. The results show that microcracks first originate from the pores at the outermost side of the SiCf/SiC layer and propagate along the boundaries of the fiber bundles. Due to the periodic distribution of pores, a “bamboo-joint”-like damage morphology appears in the SiCf/SiC layer during the C-ring loading process. The main crack forms first in the SiCf/SiC layer, while the Mo layer remains intact, indicating that the structure maintains good gas-tightness and structural integrity prior to complete failure, demonstrating the design advantage of the heterogeneous structure. This work provides both theoretical foundations and technical support for the structural optimization of fuel cladding materials in advanced nuclear energy systems.
Bio:
Prof. Chong Wei is a key supported scholar under the Northwestern Polytechnical University (NPU)’s Young Elite Scientists Sponsorship Program. He obtained his Ph.D. in Materials Science from the National Institute of Applied Sciences of Lyon (INSA Lyon), France, in 2018. From November to December 2018, he was a visiting scholar at the MATEIS Laboratory, University of Lyon. Professor Wei has over four years of international research experience, with a focus on the design, manufacturing, and performance evaluation of advanced composite materials. His work is particularly dedicated to advancing the application of these materials in biomedical engineering and nuclear engineering. Over the past five years, Prof. Wei has led nearly 12 research projects, including grants from the National Natural Science Foundation of China (NSFC)—both youth and general programs—the Shaanxi Provincial Natural Science Foundation, and the Postdoctoral Special Fund. His research findings have been published in high-impact international journals such as Acta Materialia, Composites Part B: Engineering, and the Journal of the European Ceramic Society.
