Abstract: A method of forming a ceramic matrix composite structure. The method comprises forming at least one prepregged composite material comprising a ceramic fiber preform and a pre-ceramic matrix slurry. The at least one prepregged composite material is placed over at least one surface of a tool using an advanced fiber placement apparatus to form an at least partially uncured composite material structure. The at least partially uncured composite material structure is exposed at least to elevated temperatures to convert the at least partially uncured composite material structure into a ceramic matrix composite structure. A system for forming a ceramic matrix composite structure, an advanced fiber placement apparatus, and a ceramic matrix composite structure are also described.

Abstract: A method of forming a ceramic matrix composite structure. The method comprises forming at least one prepregged composite material comprising a ceramic fiber preform and a pre-ceramic matrix slurry. The at least one prepregged composite material is placed over at least one surface of a tool using an advanced fiber placement apparatus to form an at least partially uncured composite material structure. The at least partially uncured composite material structure is exposed at least to elevated temperatures to convert the at least partially uncured composite material structure into a ceramic matrix composite structure. A system for forming a ceramic matrix composite structure, an advanced fiber placement apparatus, and a ceramic matrix composite structure are also described.

Abstract: A method of forming a ceramic matrix composite structure. The method comprises forming at least one prepregged composite material comprising a ceramic fiber preform and a pre-ceramic matrix slurry. The at least one prepregged composite material is placed over at least one surface of a tool using an advanced fiber placement apparatus to form an at least partially uncured composite material structure. The at least partially uncured composite material structure is exposed at least to elevated temperatures to convert the at least partially uncured composite material structure into a ceramic matrix composite structure. A system for forming a ceramic matrix composite structure, an advanced fiber placement apparatus, and a ceramic matrix composite structure are also described.

Abstract: A method of making multipart assemblies by producing single parts from ceramic composite materials that are machined and bonded together to form the multipart assembly. The method is used to make turbine engine vanes.

Abstract: A precursor formulation of a silicon carbide material that includes a ceramic material and a boron-11 compound. The ceramic material may include silicon and carbon and, optionally, oxygen, nitrogen, titanium, zirconium, aluminum, or mixtures thereof. The boron-11 compound may be a boron-11 isotope of boron oxide, boron hydride, boron hydroxide, boron carbide, boron nitride, boron trichloride, boron trifluoride, boron metal, or mixtures thereof. A material for use in a nuclear reactor component is also disclosed, as are such components, as well as a method of producing the material.

Abstract: Aspects of the invention relate to a construction system and method for components in high temperature environments, such as the hot gas path components of a turbine engine. Such a component can include a skeleton and a coating. The skeleton can be formed by a plurality of interconnected frame members, which can give the component its general shape. The frame members can be made of ceramic matrix composite. A coating can be provided around at least a portion of the skeleton. Preferably, the coating is a refractory material, such as refractory ceramic. Examples of turbine engine components that can be constructed according to aspects of the invention are airfoils with or without platforms, blade rings, combustor tiles and heat shields. A component according to aspects of the invention can be made using low cost fabrication and construction methods.

Abstract: A ceramic matrix composite (CMC) material (10) with increased interlaminar strength is obtained without a corresponding debit in other mechanical properties. This is achieved by infusing a diffusion barrier layer (20) into an existing porous matrix CMC to coat the exposed first matrix phase (19) and fibers (12), and then densifying the matrix with repeated infiltration cycles of a second matrix phase (22). The diffusion barrier prevents undesirable sintering between the matrix phases and between the second matrix phase and the fibers during subsequent final firing and use of the resulting component (30) in a high temperature environment.

Abstract: A precursor formulation of a silicon carbide material that includes a ceramic material and a boron-11 compound. The ceramic material may include silicon and carbon and, optionally, oxygen, nitrogen, titanium, zirconium, aluminum, or mixtures thereof. The boron-11 compound may be a boron-11 isotope of boron oxide, boron hydride, boron hydroxide, boron carbide, boron nitride, boron trichloride, boron trifluoride, boron metal, or mixtures thereof. A material for use in a nuclear reactor component is also disclosed, as are such components, as well as a method of producing the material.

Abstract: A ceramic matrix composite (CMC) material (10) with increased interlaminar strength is obtained without a corresponding debit in other mechanical properties. This is achieved by infusing a diffusion barrier layer (20) into an existing porous matrix CMC to coat the exposed first matrix phase (19) and fibers (12), and then densifying the matrix with repeated infiltration cycles of a second matrix phase (22). The diffusion barrier prevents undesirable sintering between the matrix phases and between the second matrix phase and the fibers during subsequent final firing and use of the resulting component (30) in a high temperature environment.

Abstract: A precursor formulation of a silicon carbide material that includes a ceramic material and a boron-11 compound. The ceramic material may include silicon and carbon and, optionally, oxygen, nitrogen, titanium, zirconium, aluminum, or mixtures thereof. The boron-11 compound may be a boron-11 isotope of boron oxide, boron hydride, boron hydroxide, boron carbide, boron nitride, boron trichloride, boron trifluoride, boron metal, or mixtures thereof. A material for use in a nuclear reactor component is also disclosed, as are such components, as well as a method of producing the material.

Abstract: A precursor formulation of a silicon carbide material that includes a ceramic material and a boron-11 compound. The ceramic material may include silicon and carbon and, optionally, oxygen, nitrogen, titanium, zirconium, aluminum, or mixtures thereof. The boron-11 compound may be a boron-11 isotope of boron oxide, boron hydride, boron hydroxide, boron carbide, boron nitride, boron trichloride, boron trifluoride, boron metal, or mixtures thereof. A material for use in a nuclear reactor component is also disclosed, as are such components, as well as a method of producing the material.

Abstract: Aspects of the invention relate to a construction system and method for components in high temperature environments, such as the hot gas path components of a turbine engine. Such a component can include a skeleton and a coating. The skeleton can be formed by a plurality of interconnected frame members, which can give the component its general shape. The frame members can be made of ceramic matrix composite. A coating can be provided around at least a portion of the skeleton. Preferably, the coating is a refractory material, such as refractory ceramic. Examples of turbine engine components that can be constructed according to aspects of the invention are airfoils with or without platforms, blade rings, combustor tiles and heat shields. A component according to aspects of the invention can be made using low cost fabrication and construction methods.

Abstract: A method for changing the dielectric properties of a polymer impregnated and pyrolyzed ceramic matrix composite (polymer impregnated and pyrolyzed ceramic matrix composite) is disclosed. The polymer impregnated and pyrolyzed ceramic matrix composite can be used in aircraft and turbine engines. polymer impregnated and pyrolyzed ceramic matrix composite comprises a ceramic matrix, a reinforcing fiber, and at least 1 additive used to change dielectric properties (dielectric constant and loss factor). The additive can be a low dielectric constant material having a dielectric constant in the range of 1 to 7.5. The low dielectric constant material can be an oxide such as silica or aluminosilicate or a non-oxide such as silicon nitride, boron nitride, or silicon carbide. The low dielectric constant material can be incorporated in the ceramic matrix as a filler.

Abstract: Small diameter silicon carbide-containing fibers are provided in a bundle such as a fiber tow that can be formed into a structure where the radii of curvature is not limited to 10-20 inches. An aspect of this invention is directed to impregnating the bundles of fibers with the slurry composition to substantially coat the outside surface of an individual fiber within the bundle and to form a complex shaped preform with a mass of continuous fibers.

Abstract: A method for producing a sized, coated ceramic fiber decreases mechanical damage to the fiber during weaving, and the sizing can be removed after weaving by heating at a low temperature.

Abstract: Small diameter silicon carbide-containing fibers are provided in a bundle such as a fiber tow that can be formed into a structure where the radii of curvature is not limited to 10-20 inches. An aspect of this invention is directed to impregnating the bundles of fibers with the slurry composition to substantially coat the outside surface of an individual fiber within the bundle and to form a complex shaped preform with a mass of continuous fibers.

Abstract: A method for making an environmentally stable, fiber reinforced ceramic matrix composite member includes use as a bonding agent of a ceramic precursor which transforms upon heating to a ceramic phase. The ceramic phase bonds together discontinuous material comprising ceramic particles, and reinforcing fibers at a relatively low processing temperature.

Abstract: A method for making an environmentally stable, fiber reinforced ceramic matrix composite member includes use as a bonding agent of a ceramic precursor which transforms upon heating to a ceramic phase. The ceramic phase bonds together discontinuous material comprising ceramic particles, and reinforcing fibers at a relatively low processing temperature.

Abstract: A method of making a consolidated, reinforced composite member from a matrix mixture including a consolidation shrinkable discontinuous ceramic material, for example ceramic particles, and a selected amount of a particulate inorganic filler which will exhibit net expansion relative to the discontinuous material, the mixture being interspersed about reinforcing fibers. Subsequent consolidation of a preform of such materials can be conducted substantially at ambient pressure, without application of additional pressure, to provide an improved reinforced composite article.

Abstract: An oxide barrier coating for a reinforcing fiber is provided with a preselected microstructure and thickness through control of the concentration of metal salt in heat decomposable form as a precursor of metal oxide. In one form, the salt is a metal oxyhalide salt such as zirconium oxyhalide or hafnium oxyhalide. Fibers, such as ones of alumina, aluminasilicate or silicon carbide, having the coating of the invention are especially useful as reinforcing fibers for reinforced ceramic matrix composites.