High heat-resistant SiC-polycrystalline fibre and its fibre-bonded ceramic

Here we describe a type of SiC polycrystalline fibre (SA fibre) obtained by sintering an amorphous Si-Al-C-O fibre precursor at 1900°C in Ar atmosphere. Furthermore, we also explain a sintered SiC fibre-bonded ceramic (SA-Tyrannohex), which was synthesized by hot-pressing piled sheets of the amorphous Si-Al-C-O fibre precursor prepared from an organosilicon polymer. The former SA fibre with high strength showed no reduction in strength on heating to 2000°C in inert atmosphere. This fibre also showed excellent creep resistance in air, high thermal conductivity and good weave-ability. The latter SA-Tyrannohex consisted of highly ordered, close-packed structures of very fine hexagonal columnar fibres with a thin interfacial carbon layer. The interior of the fibre element was composed of sintered SiC crystal. This material with high strength showed fibrous fracture behaviour, high thermal conductivity and excellent high-temperature strength up to 1700°C.