Abstract: Methods of forming ceramic matrix composite structures include joining at least two lamina together to form a flexible ceramic matrix composite structure. Ceramic matrix composite structures include at least one region of reduced inter-laminar bonding at a selected location between lamina thereof. Thermal protection systems include at least one seal comprising a ceramic matrix composite material and have at least one region of reduced inter-laminar bonding at a selected location between lamina used to form the seal. Methods of forming thermal protection systems include providing one or more such seals between adjacent panels of a thermal protection system.

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: Methods of forming ceramic matrix composite structures include joining at least two lamina together to form a flexible ceramic matrix composite structure. Ceramic matrix composite structures include at least one region of reduced inter-laminar bonding at a selected location between lamina thereof. Thermal protection systems include at least one seal comprising a ceramic matrix composite material and have at least one region of reduced inter-laminar bonding at a selected location between lamina used to form the seal. Methods of forming thermal protection systems include providing one or more such seals between adjacent panels of a thermal protection system.

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 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: Methods of forming ceramic matrix composite structures include joining at least two lamina together to form a flexible ceramic matrix composite structure. Ceramic matrix composite structures include at least one region of reduced inter-laminar bonding at a selected location between lamina thereof. Thermal protection systems include at least one seal comprising a ceramic matrix composite material and have at least one region of reduced inter-laminar bonding at a selected location between lamina used to form the seal. Methods of forming thermal protection systems include providing one or more such seals between adjacent panels of a thermal protection system.

Abstract: Radomes include an outer wall having a first average thickness and an inner wall having a second average thickness that is different from the first average thickness. At least a major portion of the inner wall is separated from at least a major portion of the outer wall by a space therebetween. The outer wall may comprise a layer of ceramic matrix composite (CMC) material. Aircraft and spacecraft include such radomes. Methods of forming radomes include forming an outer wall having a first average thickness, forming an inner wall having a different second average thickness, and coupling together the inner wall and the outer wall in such a manner as to provide a space between at least a major portion of the outer wall and at least a major portion of the inner wall.

Abstract: Radomes include an outer wall having a first average thickness and an inner wall having a second average thickness that is different from the first average thickness. At least a major portion of the inner wall is separated from at least a major portion of the outer wall by a space therebetween. The outer wall may comprise a layer of ceramic matrix composite (CMC) material. Aircraft and spacecraft include such radomes. Methods of forming radomes include forming an outer wall having a first average thickness, forming an inner wall having a different second average thickness, and coupling together the inner wall and the outer wall in such a manner as to provide a space between at least a major portion of the outer wall and at least a major portion of the inner wall.

Abstract: A precursor of a ceramic adhesive suitable for use in a vacuum, thermal, and microgravity environment. The precursor of the ceramic adhesive includes a silicon-based, preceramic polymer and at least one ceramic powder selected from the group consisting of aluminum oxide, aluminum nitride, boron carbide, boron oxide, boron nitride, hafnium boride, hafnium carbide, hafnium oxide, lithium aluminate, molybdenum silicide, niobium carbide, niobium nitride, silicon boride, silicon carbide, silicon oxide, silicon nitride, tin oxide, tantalum boride, tantalum carbide, tantalum oxide, tantalum nitride, titanium boride, titanium carbide, titanium oxide, titanium nitride, yttrium oxide, zirconium boride, zirconium carbide, zirconium oxide, and zirconium silicate. Methods of forming the ceramic adhesive and of repairing a substrate in a vacuum and microgravity environment are also disclosed, as is a substrate repaired with the ceramic adhesive.

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 of a ceramic adhesive suitable for use in a vacuum, thermal, and microgravity environment. The precursor of the ceramic adhesive includes a silicon-based, preceramic polymer and at least one ceramic powder selected from the group consisting of aluminum oxide, aluminum nitride, boron carbide, boron oxide, boron nitride, hafnium boride, hafnium carbide, hafnium oxide, lithium aluminate, molybdenum silicide, niobium carbide, niobium nitride, silicon boride, silicon carbide, silicon oxide, silicon nitride, tin oxide, tantalum boride, tantalum carbide, tantalum oxide, tantalum nitride, titanium boride, titanium carbide, titanium oxide, titanium nitride, yttrium oxide, zirconium boride, zirconium carbide, zirconium oxide, and zirconium silicate. Methods of forming the ceramic adhesive and of repairing a substrate in a vacuum and microgravity environment are also disclosed, as is a substrate repaired with the ceramic adhesive.

Abstract: A precursor of a ceramic adhesive suitable for use in a vacuum, thermal, and microgravity environment. The precursor of the ceramic adhesive includes a silicon-based, preceramic polymer and at least one ceramic powder selected from the group consisting of aluminum oxide, aluminum nitride, boron carbide, boron oxide, boron nitride, hafnium boride, hafnium carbide, hafnium oxide, lithium aluminate, molybdenum silicide, niobium carbide, niobium nitride, silicon boride, silicon carbide, silicon oxide, silicon nitride, tin oxide, tantalum boride, tantalum carbide, tantalum oxide, tantalum nitride, titanium boride, titanium carbide, titanium oxide, titanium nitride, yttrium oxide, zirconium diboride, zirconium carbide, zirconium oxide, and zirconium silicate. Methods of forming the ceramic adhesive and of repairing a substrate in a vacuum and microgravity environment are also disclosed, as is a substrate repaired with the ceramic adhesive.

Abstract: A method and system for assembly and attachment of high temperature materials used as thermal protection systems (TPS) for applications such as re-entry or hypersonic vehicles are disclosed. The attachment system comprises a fastener that passes through an aperture of and a fitting attached to a ceramic matrix composite (CMC) TPS panel. The flexure fitting allows thermal growth in the panel while providing a structurally stiff interface to support the panel through structural and acoustic loading. The flexure fitting is detachably attached to the substructure, or fuel tank of a vehicle. The fastened connection is accessed through an aperture via an access cover plate conformal to the surface of the CMC TPS panel. It is by way of the access cover that the fastened connection is externally serviced.

Abstract: A method for producing ceramic matrix composites wherein the method has the steps of impregnating crystalline silicon carbide fibers coated with an interfacial coating with a ceramic matrix precursor; forming the impregnated fibers into the desired shape; curing the shape; and heating the cured shape to a temperature in the range of greater than 1450° C. to 1800° C. to convert the ceramic matrix precursor into a crystal containing ceramic. A densification step may be optionally carried out until the desired porosity/density of the ceramic matrix composite is achieved.