Temperature-dependence of various mechanical properties of Si-Ti-C-O fiber-bonded ceramic is investigated. The material was produced by hot-pressing the laminae of oxidized satin-woven Si-Ti-C-O fibers, and then showed very high fiber-volume fraction (around 0.85) and very little porosity, compared with ordinary ceramic matrix composites. The in-plain tensile, compressive and inter-laminar shear strengths of the material at room temperature were maintained up to 1400°C, whereas the Young's modulus and the compressive strength of out-plain direction (transverse direction) decreased at 1400°C. The behavior toward the tensile and inter-laminar shear strengths were in good agreement with the changes in fiber pull-out length and delaminating position, respectively. A buckling of the fibers parallel to the stress axis and a large deformation of the specimen were observed in the fracture surface after compression tests of in- and out-plain directions at 1500°C, respectively. From the differences in the mechanical properties and fracture morphologies, it was concluded that the change in the fracture strength at the high temperature was caused by softening of the amorphous SiO2 phase.
