Claims
- 1. A silicon oxycarbonitride ceramic having the formula SiN.sub.z C.sub.x O.sub.y where x is greater than zero up to 2.0, y is 0.5 up to 3.0, and z is greater than zero and up to 1.5.
- 2. The ceramic of claim 1 wherein x is 0.1 to 1.0, y is 0.7 to 1.8, and z is 0.2 to 1.0.
- 3. A reinforced ceramic composite consisting essentially of
- (a) a silicon oxycarbonitride matrix having the nominal formula SiN.sub.z C.sub.x O.sub.y where x is greater than zero up to 2.0, y is 0.5 up to 3.0 and z is greater than zero and up to 1.5;
- (b) reinforcing fibers embedded in said matrix of (a) having a diameter of 1 to 200 .mu.m and selected from the group consisting of boron, silicon carbide, graphite, silica, quartz, S-glass, E-glass, alumina, aluminosilicate, aluminoborosilicate, boron nitride, silicon nitride, silicon oxynitride, boron carbide, titanium boride, titanium carbide, zirconium oxide, and zirconia toughened alumina.
- 4. The reinforced ceramic composite of claim 3 wherein said reinforcing fibers are coated to reduce interfacial bonding.
- 5. A composite of claim 3 wherein said silicon oxycarbonitride matrix is prepared by pyrolysis in an ammonia-containing atmosphere of the reaction product of a polymer prepared from (a) a cyclosiloxane monomer having the formula ##STR5## where n is an integer from 3 to about 30, R is hydrogen, and R' is an alkene of from 2 to about 20 carbon atoms in which one vinyl carbon atom is directly bonded to silicon or (b) two or more different cyclosiloxane monomers having the formula of (a) where for at least one monomer R is hydrogen and R' is an alkyl group having from 1 to about 20 carbon atoms and for the other monomers R is an alkene from about 2 to about 20 carbon atoms in which one vinyl carbon is directly bonded to silicon and R' is an alkyl group of from 1 to about 20 carbon atoms, or (c) cyclosiloxane monomers having the formula of (a) where R and R' are independently selected from hydrogen, an alkene of from 2 to about 20 carbon atoms in which one vinyl carbon atom is directly bonded to silicon, or an alkyl group of from 1 to about 20 carbon atoms and at least one of said monomers contains each of said hydrogen, alkene, and alkyl moleties, said polymerization reaction taking place in the presence of an effective amount of hydrosilylation catalyst.
- 6. The composite of claim 5 wherein said polymer is pyrolyzed in an atmosphere containing greater than zero up to 100% ammonia to a temperature in the range of about 800.degree. C. to about 1400.degree. C.
- 7. The composite of claim 6 wherein said polymer is pyrolyzed in an atmosphere comprising ammonia and hydrogen or ammonia, hydrogen, and nitrogen.
- 8. The composite of claim 5 wherein said polymer contains the moieties ##STR6## where R.degree. is the unreacted residue of an alkene having 2 to 20 carbon atoms
- R" is H, an alkyl group having 1 to 20 carbon atoms, or an alkene having 2 to 20 carbon atoms.
Parent Case Info
This application is a division of application Ser. No. 07/890,418, filed May 29, 1992, now U.S. Pat. No. 5,322,825.
US Referenced Citations (8)
Foreign Referenced Citations (5)
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Entry |
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P. J. Heimann et al., "Polymeric Routes to Silicon Carbide and Silicon Oxycarbide CMC", Ceramic Eng. & Sc. Proceedings, vol. 12, No. 7/8 8/91 p. 1292-1303. |
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Divisions (1)
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Number |
Date |
Country |
Parent |
890413 |
May 1992 |
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