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Effect of hydrothermal corrosion on the fracture strength of SiC layer in tristructural-isotropic fuel particles |
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| Authors: | Xin Xie Bing Liu Yi Guo Rongzheng Liu Xiaofeng Zhao Na Ni Fangwei Guo Ping Xiao |
| Affiliation: | 1. Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming, Shanghai Jiao Tong University, Shanghai, China;2. Key Laboratory of Advanced Reactor Engineering and Safety, Ministry of Education, Tsinghua University, Beijing, China;3. School of Materials, University of Manchester, Manchester, UK;4. Gas Turbine Research Institute, Shanghai Jiao Tong University, Shanghai, China;5. Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming, Shanghai Jiao Tong University, Shanghai, China
School of Materials, University of Manchester, Manchester, UK |
| Abstract: | The hydrothermal corrosion behavior of SiC layer in tristructural-isotropic (TRISO) fuel particles and its effect on the fracture strength were investigated. The corrosion test was performed using the static autoclave at 400°C/10.3 MPa. The SiC layer exhibited a thickness loss and the corrosion rate followed a linear law. During corrosion, carbon was formed on the SiC surface due to the loss of Si. The corrosion was found preferentially occurred at the grain boundary of SiC, leading to the grain detachment and pit formation. The rate determining step of the corrosion was SiO2 formation rather than SiO2 dissolution in the hydrothermal environment. The fracture strength of SiC shell after corrosion was evaluated using the crush test. It showed a slight decrease with an increase in corrosion time, due to the thickness reduction in SiC layer. The results of this study demonstrated that the SiC in TRISO particles has good corrosion resistance in the hydrothermal environment. |
| Keywords: | fracture strength fuel particle hydrothermal corrosion silicon carbide |