Claims
- 1. A method for forming structural carbon-carbon composites, which comprises:
- pretreating an organic fibrous precursor by exposure for about three hours to an oxidizing atmosphere maintained at a temperature range of 260.degree.-315.degree. C.;
- impregnating the fibrous precursor with a matrix-forming resinous binder admixed with a solvent material;
- composing an assemblage of the resinous binder impregnated fibrous precursor cut to form a composite layup of predetermined configuration;
- subjecting the composite layup to a curing temperature and molding pressure cycle of about 165.degree. C. over a rise time of about one hour and a holding time of about one hour at a pressure range of 15-80 psi to form a cured laminate;
- pyrolyzing the cured laminate in a pyrolization furnace by gradually raising the furnace temperature to about 815.degree. C. over a heating cycle of 72-336 hours to form a pyrolyzed laminate; and
- heat treating the pyrolyzed laminate over a heating cycle of about 14 hours to a temperature of about 2000.degree. C. and maintaining such temperature for about two additional hours followed by a gradual cooling of heat treated laminate to ambient temperature.
- 2. The method as recited in claim 1, wherein the organic fibrous precursor is selected from the group consisting of polyacrylonitrile, and phenolic.
- 3. The method as recited in claim 1, wherein the resinous binder is selected from the group consisting of polyphenylene resin, phenolic resin and furan resin.
- 4. The method as recited in claim 1, wherein the solvent material is selected from the group consisting of isopropyl alcohol and methyl ethyl ketone.
- 5. A method for forming structural carbon-carbon composites, which comprises:
- pretreating woven cloth of organic fibrous material by exposure for about three hours to an oxidizing atmosphere maintained at a temperature range of 260.degree.-315.degree. C.;
- impregnating the fibrous material with a matrix-forming resinous binder admixed with a solvent material;
- composing one upon another a plurality of plies of the resinous binder impregnated fibrous material cut to form a composite layup of predetermined configuration;
- subjecting the composite layup to a curing temperature and molding pressure cycle of about 165.degree. C. over a rise time of about one hour and a holding time of about one hour at a pressure range of 15-80 psi to form a cured laminate;
- pyrolyzing the cured laminate in a pyrolization furnace by gradually raising the furnace temperature to about 815.degree. C. over a heating cycle of 72-336 hours to form a pyrolyzed laminate; and
- heat treating the pyrolyzed laminate over a heating cycle of about 14 hours to a temperature of about 2000.degree. C. and maintaining such temperature for about two additional hours followed by a gradual cooling of the heat treated laminate to ambient temperature.
- 6. The method as recited in claim 5, wherein the organic fibrous material is preferably pitch fibers woven into cloth.
- 7. A method for forming structural carbon-carbon composites, which comprises:
- pretreating organic fibrous material by exposure for about three hours to an oxidizing atmosphere maintained at a temperature of 260.degree.-315.degree. C.;
- composing a layered mat of the fibrous material shaped to form a composite layup of predetermined configuration;
- impregnating the composite layup with a matrix-forming resinous binder admixed with a solvent material;
- subjecting the composite layup to a curing temperature and molding pressure cycle of about 180.degree. C. over a rise time range of 40-140 minutes at a pressure range of 200-1000 psi to form a cured laminate;
- pyrolyzing the cured laminate in a pyrolization furnace by gradually raising the furnace temperature to about 815.degree. C. over a healing cycle of 72-382 hours to form a pyrolyzed laminate; and
- heat treating the pyrolyzed laminate over a heating cycle of about 14 hours to a temperature of about 2000.degree. C. and maintaining such temperature for about two additional hours followed by a gradual cooling of the heat treated laminate to ambient temperature.
- 8. The method as recited in claim 7, wherein the layered mat consists of organic fibrous material chopped in one-half inch lengths and fluffed in a blender at high speed.
- 9. A method for forming structural carbon-carbon composites, which comprises:
- pretreating elongated bodies of unidirectional organic fibrous material by exposure for about three hours to an oxidizing atmosphere maintained at a temperature range of 260.degree.-315.degree. C.; impregnating the fibrous material with a matrix-forming resinous binder admixed with a solvent material;
- composing one upon another a plurality of plies of the resinous binder impregnated, parallel oriented fibrous material cut to form a composite layup of predetermined configuration;
- subjecting the composite layup to a curing temperature and molding pressure cycle of about 165.degree. C. over a rise time of about one hour and a holding time of about one hour at a pressure range of 15-80 psi to form a cured laminate;
- pyrolyzing the cured laminate in a pyrolization furnace by gradually raising the furnace temperature to about 815.degree. C. over a heating cycle of 72 hours to form a pyrolyzed laminate; and
- heat treating the pyrolyzed laminate over a heating cycle of about 14 hours to a temperature of about 2000.degree. C. and maintaining such temperature for about two additional hours followed by a gradual cooling of the heat treated laminate to ambient temperature.
- 10. The method as recited in claim 9, wherein the elongated bodies of unidirectional organic fibrous material are wound under tension around a drum.
- 11. The method as recited in claim 9, wherein the elongated bodies of unidirectional organic fibrous material are wound under tension in successive layers onto a two bladed wheel.
- 12. The method as recited in claim 9, wherein the elongated bodies of unidirectional organic fibrous material are impregnated in a vacuum chamber with the matrix-forming resinous binder.
RIGHTS OF THE GOVERNMENT
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
US Referenced Citations (7)