Abstract: A carbon/carbon brake disk is provided. The carbon/carbon brake disk may comprise a carbon fiber, wherein the carbon fiber is formed into a fibrous network, wherein the fibrous network comprises carbon deposited therein. The carbon fiber may undergo a FHT process, wherein micro-cracks are disposed in the carbon fiber. In various embodiments, the micro-cracks may be at least partially filled with un-heat-treated carbon via a final CVD process, wherein the final CVD process is performed at a temperature in the range of up to about 1,000° C. (1,832° F.) for a duration in the range from about 20 hours to about 100 hours. In various embodiments, the un-heat-treated carbon may be configured to prevent oxygen, moisture, and/or oxidation protection systems (OPS) chemicals from penetrating the carbon/carbon brake disk. In various embodiments, the final CVI/CVD process may be configured to increase the wear life of the carbon/carbon brake disk.

Abstract: A method of making a carbonized preform for a carbon-carbon composite brake disk may comprise: stacking a plurality of textile fabric layers, each textile fabric layer in the plurality of textile fabric layers including oxidized polyacrylonitrile (PAN) fibers, each textile fabric layer in the plurality of textile fabric layers being more uniform than a typical fabric layer formed from cross-lapping; each fabric layer being thinner than a typical fabric layer from cross-lapping, needling the plurality of textile fabric layers to form a needled non-woven board; cutting a fibrous preform from the needled non-woven board; and carbonizing the fibrous preform. The resultant non-woven carbonized preform maintains a higher fiber volume and more consistent properties throughout than what would otherwise be achieved using a typical fabric layer from cross-lapping.

Abstract: A method for making a component includes the steps of providing a preform formed of carbon fibers. A first densification is performed forming a carbon composite. A first hardening of the carbon composite is performed. The method machines the carbon composite to form a shape. The method then performs a second densification and a second hardening. The method then final machines the carbon composite to form a final shape of the component.

Abstract: A system is disclosed comprising a carbon/carbon brake disk comprising a carbon fiber having a crystal orientation (CO) between 80% and 100% and a coefficient of friction of more than 0.183 in response to a rejected takeoff condition.

Abstract: A carbon/carbon brake disk is provided. The carbon/carbon brake disk may comprise a carbon fiber, wherein the carbon fiber is formed into a fibrous network, wherein the fibrous network comprises carbon deposited therein. The carbon fiber may undergo a FHT process, wherein micro-cracks are disposed in the carbon fiber. In various embodiments, the micro-cracks may be at least partially filled with un-heat-treated carbon via a final CVD process, wherein the final CVD process is performed at a temperature in the range of up to about 1,000° C. (1,832° F.) for a duration in the range from about 20 hours to about 100 hours. In various embodiments, the un-heat-treated carbon may be configured to prevent oxygen, moisture, and/or oxidation protection systems (OPS) chemicals from penetrating the carbon/carbon brake disk. In various embodiments, the final CVI/CVD process may be configured to increase the wear life of the carbon/carbon brake disk.

Abstract: A brake stack is disclosed. In various embodiments, the brake stack includes a pressure plate; an end plate; a rotor disk disposed between the pressure plate and the end plate, the rotor disk including a rotor core comprising a carbon-carbon material and a boron-containing component; and a stator disk disposed between the pressure plate and the end plate, the stator disk including a stator core comprising the carbon-carbon material and the boron component. In various embodiments, the boron-containing component exhibits a higher heat capacity than a corresponding friction liner that comprises a ceramic matrix composite material, applied by chemical vapor infiltration, and that provides a surface optimized for aircraft brake friction and wear.

Abstract: A carbon/carbon brake disk is provided. The carbon/carbon brake disk may comprise a carbon fiber, wherein the carbon fiber is formed into a fibrous network, wherein the fibrous network comprises carbon deposited therein. The carbon fiber may undergo a FHT process, wherein micro-cracks are disposed in the carbon fiber. In various embodiments, the micro-cracks may be at least partially filled with un-heat-treated carbon via a final CVD process, wherein the final CVD process is performed at a temperature in the range of up to about 1,000° C. (1,832° F.) for a duration in the range from about 20 hours to about 100 hours. In various embodiments, the un-heat-treated carbon may be configured to prevent oxygen, moisture, and/or oxidation protection systems (OPS) chemicals from penetrating the carbon/carbon brake disk. In various embodiments, the final CVI/CVD process may be configured to increase the wear life of the carbon/carbon brake disk.

Abstract: A process for densifying an annular porous structure comprising flowing a reactant gas into an inner diameter (ID) volume and through an ID surface of the annular porous structure, flowing the reactant gas through an outer diameter (OD) surface of the annular porous structure and into an OD volume, flowing the reactant gas from the OD volume through the OD surface of the annular porous structure, and flowing the reactant gas through an ID surface of the annular porous structure and into the ID volume.

Abstract: A process for densifying an annular porous structure comprising flowing a reactant gas into an inner diameter (ID) volume and through an ID surface of the annular porous structure, flowing the reactant gas through an outer diameter (OD) surface of the annular porous structure and into an OD volume, flowing the reactant gas from the OD volume through the OD surface of the annular porous structure, and flowing the reactant gas through an ID surface of the annular porous structure and into the ID volume.

Abstract: A method of making a carbon-carbon composite part may comprise fabricating a fibrous preform comprising a fiber volume ratio of 25% or greater, heat treating the fibrous preform at a first temperature, infiltrating the fibrous preform with a first ceramic suspension, densifying the fibrous preform by chemical vapor infiltration (CVI) to form a densified fibrous preform, and heat treating the densified fibrous preform at a second temperature of 1600° C. or greater.

Abstract: A method of making carbon fiber material according to various embodiments of the present disclosure includes forming a polymer resin to have a polydispersity index (PDI) that is less than approximately 2.5. The method further includes spinning the polymer resin to create an acrylic fiber having an acrylic fiber length. The method further includes oxidizing the acrylic fiber while stretching the acrylic fiber to create an oxidized fiber that has an oxidized fiber length that is at least one of greater than or equal to approximately 100 percent (100%) of the acrylic fiber length. The method further includes carbonizing the oxidized fiber to create a carbon fiber.

Abstract: The method may include forming fibers with a silicon-based sizing, forming a fibrous preform from the fibers, forming a silicon dioxide coating around the fibers, carbonizing the fibrous preform, and densifying the fibrous preform. In various embodiments, forming the fibers with the silicon-based sizing includes utilizing a mass of the silicon-based sizing that is at least 1.0% of a mass of the fibers.

Abstract: Systems and methods for forming an oxidation protection system, on a composite structure is provided. In various embodiments, an oxidation protection system disposed on a substrate may comprise a borosilicate glass layer comprising a borosilicate glass, a base layer comprising a first pre-slurry composition comprising a first phosphate glass composition, and/or a sealing layer comprising a second pre-slurry composition comprising a second phosphate glass composition. The borosilicate glass layer, base layer, and/or sealing layer may be disposed in any suitable order relative to the composite structure.

Abstract: A method of making a carbon-carbon composite part may comprise fabricating a fibrous preform comprising a fiber volume ratio of 25% or greater, heat treating the fibrous preform at a first temperature, infiltrating the fibrous preform with a first ceramic suspension, densifying the fibrous preform by chemical vapor infiltration (CVI) to form a densified fibrous preform, and heat treating the densified fibrous preform at a second temperature of 1600° C. or greater.

Abstract: A system is disclosed comprising a carbon/carbon brake disk comprising a carbon fiber having a crystal orientation (CO) between 80% and 100% and a coefficient of friction of more than 0.183 in response to a rejected takeoff condition.

Abstract: A preform manufacturing apparatus comprising a supply of fiber strip, a moveable positive fiber strip delivery mechanism coupled between a desired lay down location and the supply of fiber strip to positively deliver and orient the supply of fiber strip to the desired lay down location, and an electronic unwinder coupled to the supply of fiber strip is described herein. The electronic unwinder is configured to interact with the moveable positive fiber strip delivery mechanism.

Abstract: A system is disclosed comprising a carbon/carbon brake disk comprising a carbon fiber having a crystal orientation (CO) between 80% and 100% and a coefficient of friction of more than 0.183 in response to a rejected takeoff condition.

Abstract: A loom system for making a fibrous preform may comprise a base, a bedplate coupled to the base, wherein the bedplate is configured to rotate about an axis of rotation, and an air entangling module coupled to the base. The air entangling module may comprise an air entangling head coupled to an outer support and an inner support, wherein the air entangling head is configured to apply a jet of air toward the bedplate at an entangling zone. The air entangling head may have freedom of motion along the outer support and the inner support, and may be configured to rest on top of a fibrous layer.

Abstract: A process for densifying an annular porous structure comprising flowing a reactant gas into an inner diameter (ID) volume and through an ID surface of the annular porous structure, flowing the reactant gas through an outer diameter (OD) surface of the annular porous structure and into an OD volume, flowing the reactant gas from the OD volume through the OD surface of the annular porous structure, and flowing the reactant gas through an ID surface of the annular porous structure and into the ID volume.

Abstract: The method may include forming fibers with a silicon-based sizing, forming a fibrous preform from the fibers, forming a silicon dioxide coating around the fibers, carbonizing the fibrous preform, and densifying the fibrous preform. In various embodiments, forming the fibers with the silicon-based sizing includes utilizing a mass of the silicon-based sizing that is at least 1.0% of a mass of the fibers.