Advanced SiC fibers and SiC/SiC composites toward industrialization

In order to establish the industrialization basis of advanced SiC fibers and SiC/SiC composites to be used in nuclear fusion reactors, R and D of Tyranno-SA grade fibers (Cef-NITETM) and NITE-SiC/SiC with sufficient quality control has been carried out. The important elements in this effort are fiber structure control and matrix density and homogeneity control. From the continuous heat treatments of pre-crystallized SiC fibers, the improved uniformity of grain size for radial position in 7-10 μm diameter SiC fibers has been confirmed with the fiber strength over 2.0 GPa. In order to establish stable mass production of NITE-SiC/SiC (Cera-NITETM), with sufficient quality control, efforts on production of mid-products, such as green sheets, prepreg sheets and preforms, have been extensively carried out. The important elements were to improve the homogeneity and density of preform so that the following sintering process has been modified for improving structure control.