New Type of Sintered SiC Fiber and Its Composite Material

摘要

High-temperature stability of SiC-based ceramics has been well-known, and therefore its composite materials have been investigated for the application to thermostructural materials. However, well-known SiC-based fibers and matrix-materials stained with salt are easily oxidized at high temperatures in air. This would be serious problem when these materials are used near the ocean or in a combustion gas containing alkali elements. We have developed a new type of sintered SiC fiber with prominent alkali resistance. This fiber also shows high-strength, high-modulus, excellent high-temperature stability and superior creep resistance. Moreover, this fiber indicated very high thermal conductivity about 20-fold larger than ordinary SiC based fibers. Furthermore, we also have developed a new type of sintered SiC fiber-bonded ceramics using an intermediate fiber for preparing above mentioned fiber. This composite material maintained initial strength up to 1600℃, and what is more, showed very high fracture energy and thermal conductivity.