Journal of Materials Science, Vol.36, No.7, 1665-1670, 2001
Cryogenic properties of Si-Ti-C-O fibre-bonded ceramic using satin weave
Mechanical and thermophysical characteristics of Si-Ti-C-O fibre-bonded ceramic produced by hot-pressing the laminated material of oxidized satin-woven Si-Ti-C-O fibre have been investigated at room and cryogenic temperatures. The fibre element (diameter: 8 mum, fibre volume fraction: 85 +/- 1%) constructing the Si-Ti-C-O fibre-bonded ceramic showed a close-packed structure of the oxidized Si-Ti-C-O fibre mainly composed of fine SiC crystals, amorphous SiO2-based phase and turbostratic carbon. The Si-Ti-C-O fibre-bonded ceramic with lightweight (density: 2.45 x 10(3)kg/m(3)) and low porosity (<1 vol%) showed a markedly higher fracture energy (notched, cross-plied specimen: approximately 10kJ/m(2)) and lower thermal conductivity (1/10 the value of stainless steel). The reason why the fibre- bonded ceramic showed such a low thermal conductivity in spite of very high thermal conductivity of a pure SiC and carbon could be attributed to the complicated microstructure of Si-Ti-C-O fibre-bonded ceramics.