SILICON-CARBIDE FIBERS AND COMPOSITES FROM GRAPHITE PRECURSORS FOR FUSION ENERGY APPLICATIONS

A high purity beta-SiC is projected to exhibit neutron stability in a fusion reactor environment because of its microstructure and physical dimension stability. A pure beta-SiC fiber could therefore be expected to be an excellent candidate as a reinforcement to produce beta-SiC/beta-SiC composites. Graphite fibers can be converted to pure beta-SiC utilizing several different siliconizing reactions, however, fiber cracking and low strengths are typical. A reaction window has been demonstrated that has produced pure beta-SiC fiber with strengths in the 1-2 GPa range. Fiber and composite properties are discussed in comparison with other commercially available SiC fibers and composites.