Ceramic fibers for matrix composites in high-temperature engine applications
High-temperature engine applications have been limited by the performance of metal alloys and carbide fiber composites at elevated temperatures. Random inorganic networks composed of silicon, boron, nitrogen, and carbon represent a novel class of ceramics with outstanding durability at elevated temperatures. SiBN(3)C was synthesized by pyrolysis of a preceramic N-methylpolyborosilazane made from the single-source precursor Cl(3)Si-NH-BCl(2). The polymer can be processed to a green fiber by melt-spinning, which then undergoes an intermediate curing step and successive pyrolysis. The ceramic fibers, which are presently produced on a semitechnical scale, combine several desired properties relevant for an application in fiber-reinforced ceramic composites: thermal stability, mechanical strength, high-temperature creep resistivity, low density, and stability against oxidation or molten silicon.
Baldus
P
Bayer AG, ZF-MFA, Gebaude Q18, D-51368 Leverkusen, Germany. Max-Planck-Institut fur Festkorperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany. Fraunhofer Institut fur Silicatforschung, Neunerplatz 2, D-97082 Wurz.
Jansen
M
Sporn
D