J. Korean Ceram. Soc. > Volume 52(6); 2015 > Article
 Journal of the Korean Ceramic Society 2015;52(6): 441. doi: https://doi.org/10.4191/kcers.2015.52.6.441
 High-Temperature Fracture Strength of a CVD-SiC Coating Layer for TRISO Nuclear Fuel Particles by a Micro-Tensile Test Hyun Min Lee, Kwi-Il Park, Ji-Yeon Park1, Weon-Ju Kim1, Do Kyung Kim Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST)1Nuclear Materials Research Division, Korea Atomic Energy Research Institute (KAERI) ABSTRACT Silicon carbide (SiC) coatings for tri-isotropic (TRISO) nuclear fuel particles were fabricated using a chemical vapor deposition (CVD) process onto graphite. A micro-tensile-testing system was developed for the mechanical characterization of SiC coatings at high temperatures. The fracture strength of the SiC coatings was characterized by the developed micro-tensile test in the range of $25^{circ}C$ to $1000^{circ}C$. Two types of CVD-SiC films were prepared for the micro-tensile test. SiC-A exhibited a large grain size (0.4 ~ 0.6 m) and the [111] preferred orientation, while SiC-B had a small grain size (0.2 ~ 0.3 mm) and the [220] preferred orientation. Free silicon (Si) was co-deposited onto SiC-B, and stacking faults also existed in the SiC-B structure. The fracture strengths of the CVD-SiC coatings, as measured by the high-temperature micro-tensile test, decreased with the testing temperature. The high-temperature fracture strengths of CVD-SiC coatings were related to the microstructure and defects of the CVD-SiC coatings. Key words: SiC coating layer, TRISO, Micro-tensile-test, High temperature fracture strength, Weibull statistics
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