Development of 3D-based CFC with high thermal conductivity for fusion application

Abstract

For divertor high-heat-flux components in next fusion experimental reactors such as ITER, plasma facing material with higher thermal conductivity is essentially required. In addition, it is also required the armor tile itself to have superior mechanical properties at the bonding and fatigue characteristics point of view. To meet their requirements, a new three directional CFC with highly oriented fiber contents in each direction has been basically designed by Japan Atomic Energy Research Institute and fabricated by Nippon Oil Company LTD. Major idea for improving the thermal conductivity is to use fine-pitch-base fibers with high thermal conductivity and to precise a packing density applying technologies such as HIPing process before graphitatizing. Consequently, the newly developed 3D-CFC has thermal conductivity measured as high as 540 W·m −1 ·k −1 at room temperature. To improve poor compatibility of CTE between 3D-CFC and heat sink made of copper alloy, we also designed and fabricated a 1D/3D functional CFC with high thermal conductivity (-600 W·m −1 ·k −1 ) and with relatively large coefficient of thermal expansion (˜5 × 10 −6 k −1 ) based on the full 3D CFC.