| 摘要 |
The invention relates to fibre-reinforced porous shaped bodies of silicon carbide and also a process for their production, where the fibres provided for the reinforcement are first pyrolysed at temperatures between 500 DEG C and 1500 DEG C, preferably between 600 DEG C and 1200 DEG C, in vacuo or in an inert gas atmosphere, e.g. argon, the fibres thus treated are sheathed using a silicate ester or finely divided silicon dioxide and are subsequently subjected to heat treatment at from 900 DEG C to 1300 DEG C, during which the silicon dioxide located on the fibre surface is converted into a silicon carbide layer, the fibres thus coated are then mixed with binder, silicon and silicon carbide powder of a different particle size and are uniformly mixed, and where the mixture thus obtained is placed in a mould provided for this purpose and cured at from about 130 DEG C to 180 DEG C and the cured shaped body is pyrolysed at from 800 DEG C to 1200 DEG C. <IMAGE> |
