Oxidation Behavior Of Sic/sic Composites For Helium Cooled Solid Breeder Blanket

摘要

In order to evaluate the oxidation behavior and mechanism of SiC/SiC composites with conventional pyrolitic graphite interface (PyC-SiC/SiC) and advanced multilayer interface (ML-SiC/SiC) in a HCSB blanket environment, a thermal gravimetric analysis (TGA) in He + O_2 environment at 1000℃ and 1200℃ was performed. The PyC-SiC/SiC at 1200℃ and the ML-SiC/SiC at 1000℃ and l200℃ showed relatively smaller weight change during oxidation because SiO_2 formed on the SiC-matrix and SiC-fiber sealed the specimen surface before the PyC interface recession by gasification of graphite due to relatively high SiO_2 formation rate. While the PyC-SiC/SiC at 1000℃ showed significant weight loss because the specimen surface was not sealed by SiO_2 and significant PyC interface recession occurred due to relatively slow SiO_2 formation.