Fabrication and High-Temperature Flexural Strength of a Sintered SiC Fiber Reinforced SiC Composite
Michiyuki SUZUKI, Yoshiyuki INOUE, Mitsuhiko SATO, Toshihiro ISHIKAWA and Koichi GODA
Abstract:A sintered SiC polycrystalline fiber, which has been developed by UBE Industries, Ltd., possesses high modulus, excellent thermal stability and oxidation resistance. A SiC matrix composite reinforced by the sintered SiC fiber was fabricated by polymer impregnation and pyrolysis (PIP) method. The composite consisted of 26 vol% 3-D sintered SiC fabric and polymer-derived SiC matrix. Carbon coating was applied by chemical vapor deposition on the 3-D sintered SiC fabric prior to the matrix densification. Three point flexural tests of the sintered SiC fiber reinforced SiC composite up to 1400 in Ar were carried out, and the results were compared with a SiC matrix composite reinforced by an amorphous Si-Zr-C-O fiber. The flexural strength of the sintered SiC fiber reinforced SiC composite at 1400 retained 84% of the strength at room temperature, while that of the amorphous Si-Zr-C-O fiber reinforced SiC composite retained only 56%. In addition, the sintered SiC fiber reinforced SiC composite showed higher stiffness than that of the amorphous Si-Zr-C-O fiber reinforced SiC composite. The higher retention ratio of the strength at 1400 and higher stiffness of the sintered SiC fiber reinforced SiC composite were attributed to excellent heat resistance and high tensile modulus of the sintered SiC fiber. Key Words:Sintered SiC fiber, SiC matrix composite, Flexural strength, Stiffness, Heat resistance, Fiber pull-out, Interfacial sliding