During the operation of a fusion reactor, a certain type of transients could induce rapid cooldown of the reactor with relatively high or increasing system pressure. This induces a high tensile stress at the inner surface of the blanket, which is called the thermal shock. Test Blanket Module (TBM) has been designed to account for the performance of DEMO-relevant blanket. But, the TBM uses helium as coolant and tritium as purge gas, and FM steel, SiC f / SiC composites as a structural material. The SiC f / SiC composites with a SiC sub-layer/ PyC interlayers were therefore fabricated in order to improve the oxidation resistance. In the refractory field SiC f / SiC composites need to investigate residual stress and thermal shock behavior when high chemical stability and corrosion resistance are necessary. In this study, SiC f / SiC composite were fabricated by NITE process and the chemical vapor infiltration (CVI) method. SiC f / SiC composites have been examined and the detail analyses of the microstructure and the mechanical strength were conducted. Various pyrolytic carbons ( PyC ) with SiC interlayer coatings were applied to the composites for improvement of the mechanical properties at the interface.
