Compatibility of SiC/SiC composite materials with molten lithium metal and Li16-Pb84 eutectic alloy

Abstract

SiC/SiC composite material is one of the candidates of plasma facing and structural materials for a fusion reactor. In an inertial fusion reactor and a magnetic confinement fusion reactor, interactions of solid and liquid breeder materials as well as coolant materials with various structural materials are considered to be very important. Therefore corrosion tests of SiC/SiC composite materials with molten lithium and Li16-Pb84 alloy were performed. SiC/SiC specimens of five kinds, different in fiber/matrix interface, manufacturers and manufacturing methods, were used. In the case of lithium, the corrosion temperature was 500 K, and it was 573 K in the case of Li16-Pb84 alloy. Duration for the compatibility tests were about 2.5 Ms (29 days). During the heating of corrosion test argon gas was made to flow over the liquid metal. The SiC/SiC composite sample, which had a free silicon component within its matrix, was corroded by molten lithium and came to each plane fabrics of fiber. The monolithic specimen t hat contained a silicon phase was also entirely broken by lithium. While, the attack by Li16-Pb84 alloy was not observed.