Patent classifications
C04B2235/5212
Methods of forming ceramic matrix composites using sacrificial fibers and non-wetting coating
Methods for preparing ceramic matrix composites using melt infiltration are provided as well as the resulting ceramic matrix composites. The methods and products include the incorporation of a non-wetting coating to one or more sacrificial fibers. The one or more sacrificial fibers are removed, such as decomposed during pyrolysis, resulting in the formation of a plurality of functional features, in the form of regular and elongate channels along the ceramic matrix composite. During the removing of the one or more sacrificial fibers, the non-wetting coating remains on an interior surface of the plurality of functional features to block infiltration of an infiltrant to the plurality of functional features and deposition thereon. Alternatively, the sacrificial fibers may be removed subsequent to melt infiltration.
FIBER-REINFORCED BRITTLE MATRIX COMPOSITE
There is provided a fiber-reinforced brittle matrix composite. The fiber-reinforced brittle matrix composite comprises a brittle matrix material (for example, a cementitious or ceramics material) and a coated fiber embedded in the brittle matrix material, wherein the coated fiber comprises a fiber (for example, polyethylene fiber, glass fiber, silicon carbide fiber, alumina fiber, mullite fiber) and a coating material (for example, carbon nanofibers, carbon nanotubes), which is non-covalently disposed on the fiber. A method for producing the fiber-reinforced brittle matrix composite is also provided. The method comprises providing a fiber, disposing a coating material on the fiber to form a coated fiber, wherein the coating material is non-covalently disposed on the fiber, and embedding the coated fiber in a brittle matrix material to obtain the fiber-reinforced brittle matrix composite.
HIGH TEMPERATURE FIBER AND METHOD OF MAKING
Disclosed is a method of making high temperature fiber including incorporating an inorganic atom into a polymer precursor fiber to form a modified polymer precursor fiber and converting the modified polymer precursor fiber to a high temperature fiber having a bonded inorganic atom.
CMC component cooling cavities
A component for a gas turbine engine including a core and an outer enclosure. The core includes an exterior surface extending along a length between a first end and a second end and at least partially defines a cooling cavity on the exterior surface extending from the first end along at least a portion of the length. The cooling cavity is fluidly coupled to an air supply at the first end. The outer enclosure includes an outer surface. The outer enclosure is positioned outside the core and extends from the first end of the core along at least a portion of the length of the core and at least partially defines the cooling cavity.
Zircon-based sintered concrete
A sintered concrete having the following mean chemical composition, as mass percentages on the basis of the oxides and for a total of 100%; ZrO.sub.2: 55 to 70%, SiO.sub.2: 25 to 40%, P.sub.2O.sub.5: 0.2 to 9.0%, Al.sub.2O.sub.3: 0.5 to 7.0%, CaO: >0.2%, CaO+MgO+B.sub.2O.sub.3+Fe.sub.2O.sub.3: 0.2 to 10.0%, MgO+B.sub.2O.sub.3+Fe.sub.2O.sub.3; 7.5%, B.sub.2O.sub.3+MgO: 4.5%, ZrO.sub.2+SiO.sub.2+P.sub.2O.sub.5+Al.sub.2O.sub.3+CaO+MgO+B.sub.2O.sub.3+Fe.sub.2O.sub.3: 95.0%, and containing more than 70% of zircon, as a mass percentage on the basis of the mass of the crystalline phases.
Preceramic resin formulations, impregnated fibers comprising the preceramic resin formulations, and related methods
A preceramic resin formulation comprising a polycarbosilane preceramic polymer, an organically modified silicon dioxide preceramic polymer, and, optionally, at least one filler. The preceramic resin formulation is formulated to exhibit a viscosity of from about 1,000 cP at about 25 C. to about 5,000 cP at a temperature of about 25 C. The at least one filler comprises first particles having an average mean diameter of less than about 1.0 m and second particles having an average mean diameter of from about 1.5 m to about 5 m. Impregnated fibers comprising the preceramic resin formulation are also disclosed, as is a composite material comprising a reaction product of the polycarbosilane preceramic polymer, organically modified silicon dioxide preceramic polymer, and the at least one filler. Methods of forming a ceramic matrix composite are also disclosed.
Catalyst manufacturing method
A method for producing a catalyst or catalyst precursor is described including: applying a slurry of a particulate catalyst compound in a carrier fluid to an additive layer manufactured support structure to form a slurry-impregnated support, and drying and optionally calcining the slurry-impregnated support to form a catalyst or catalyst precursor. The mean particle size (D50) of the particulate catalyst compound in the slurry is in the range 1-50 m and the support structure has a porosity 0.02 ml/g.
Honeycomb filter
Disclosed is a honeycomb filter for collecting fine particles that includes a wall portion formed from a base material containing ceria-zirconia composite oxide and an inorganic binder. In a pore diameter distribution in which a pore diameter and a log differential pore volume measured through mercury porosimetry are respectively represented by a horizontal axis and a vertical axis, the wall portion has a peak in a range in which the pore diameter is greater than or equal to 0.01 m and less than 1 m and a peak in a range in which the pore diameter is greater than or equal to 1 m and less than or equal to 50 m.
Ceramic Matrix Composite Articles and Methods for Manufacturing the Same
CMC articles and methods for forming CMC articles are provided. In one example aspect, a method for forming a CMC article includes forming a CMC preform defining a first section and a second section. The first section has one or more plies that include sacrificial fibers. The second section of the CMC preform does not include sacrificial fibers. The first and second sections can be laid up to form the CMC prior to thermally processing, e.g., consolidation, firing, and infiltration. When the CMC preform is fired or burned out, the sacrificial fibers are removed or decomposed resulting in formation of channels within the first section of the pyrolyzed CMC preform. The channels are used as gas transport paths during chemical vapor infiltration to facilitate infiltration of a gaseous infiltrant into the fired CMC preform. The channels are then backfilled with a liquid infiltrant during a melt infiltration process.
DOPED SILICON CARBIDE CERAMIC MATRIX COMPOSITE
A method for forming ceramic matrix composite (CMC) component includes forming a fiber preform, positioning the fiber preform into a chemical vapor infiltration reactor chamber, and densifying the fiber preform. Densification includes infiltrating the fiber preform with a first gas comprising precursors of silicon carbide and infiltrating the fiber preform with a second gas comprising a first rare earth element, wherein the steps of infiltrating the fiber preform with the first gas and infiltrating the fiber preform with the second gas are conducted simultaneously to produce a first rare earth-doped silicon carbide matrix in a first region of the component.