Evaluation of thermal conductivity of unidirectional SiC composite enhanced with carbon fibers

The authors have proposed a new divertor concept using SiC composite with directional high thermal conductivity enhanced with fiber as substrate of the divertor structure in fusion reactor. In this study, unidirectional SiC composite with pitch-based carbon fibers (UD-C_f/SiC) was fabricated as the model material. The thermal conductivity (or thermal diffusivity) in directions parallel (0°), inclined (45°), and transverse (90°) to the C_f orientation was measured by the laser flash method. The results were compared with monolithic SiC (mono-SiC) in order to evaluate the enhancement of thermal conductivity by an introduction of C_f. Although the thermal conductivity of the UD-C_f/SiC in directions of 45° and 90° was relatively lower than that of the mono-SiC, that of the UD-C_f/SiC in direction of 0° was ten times as large as that of the mono-SiC.