Development of Boron Carbide-Carbon Fiber Composite Ceramics as Plasma Facing Materials in Nuclear Fusion Reactor (Part 1)

Fabrication and Characteristics of the Materials

Abstract

New materials for plasma facing component such as divertor and the first wall armors in thermonuclear fusion were studied. The materials were fabricated by hot-pressing aggregates of unidimensionally oriented carbon fibers (CF) impregnated with boron carbide (B₄C) powder. The relation between density, thermal properties and sintering temperature of B₄C simple materials, bonding state between B₄C and CF interface by sintering, and the effect of CF volume and sintering temperature on microstructure, thermal and mechanical properties of B₄C/CF composite ceramics, were investigated in this study. As a result; Sintered body with high density over 95 percent was obtained, when sintered at 2100°C regardless of the CF content. Sintered body with thermal conductivity more than 150W/m·K was obtained when the sintering temperature was 2100°C and it contained more than 65 percent CF, and bending strength of the sintered body was over 500MPa and 20 to 30MPa for directions perpendicular and parallel to CF, respectively.