Keramische Fasern im System Silicium-Bor-Stickstoff-Kohlenstoff

DE 19530404 A UPAB: 19980819 The amorphous SiBN(C) ceramic fibres have a room temp. strength of more than 2.5 GPa, an elasticity modulus of more than 250 GPa and a creep parameter (standard BSR test, 1 h, 1400 deg. C) of 0.4-1. Also claimed is the prodn. of the above fibres by converting poly-boro-silazanes into green fibres by dry or melt spinning and then drying, making non-fusible and pyrolysing. USE - Used as reinforcing fibres in metallic or ceramic components and as a high temp. filter material (claimed), e.g. for prodn. of ceramic fibre-reinforced ceramic matrix materials for gas turbines. ADVANTAGE - The fibres remain amorphous at up to at least 1800 deg. C in inert gas, are stable in air at up to at least 1400 (esp. up to at least 1500) deg. C, have a room temp. strength of more than 2.5 (esp. 3.0-4.5) GPa, a 1400 deg. C strength of more than 1.5 (esp. 2.1-3.0) GPa, a room temp. elasticity modulus of more than 250 (esp. 350-450) GPa, a 1400 deg. C elasticity modulus of esp. 200-300 GPa and a high creep parameter (m value) of greater than 0.4.