Patent classifications
C04B41/5001
Method for producing ceramic sintered body, and method and device for producing ceramic molded body
The present invention is a sintering method of a ceramic for sintering characterized by forming a layer containing a carbon powder on a surface of an article consisting of a ceramic for sintering, and then irradiating with laser a surface of the carbon powder-containing layer of a lamination obtained.
SLURRY INFILTRATION HEAT TREATMENT METHOD
A method of producing a melt infiltrated ceramic matrix composite (CMC) article that includes the steps of: forming a ceramic fiber preform; optionally, rigidizing the ceramic fiber preform with a fiber interphase coating via a Chemical Vapor Infiltration (CVI) process, infiltrating a ceramic slurry into the porous body or preform, conducting one or more secondary operations, and finally, melt infiltrating the preform with molten silicon or a silicon alloy to form the CMC article. The infiltration of a ceramic slurry into a ceramic fiber preform to form a green body is performed along with the use of convection and/or conduction as heat transfer mechanisms, such that the ceramic slurry does not require the incorporation of a pre-gelation material in order for the slurry to remain within the green body during subsequent processing steps.
High temperature oxidation protection for composites
The present disclosure provides a method for coating a composite structure, comprising forming a first slurry by combining a first pre-slurry composition with a first carrier fluid, applying the first slurry on a surface of the composite structure, and heating the composite structure to a temperature sufficient to form a base layer on the composite structure. The first pre-slurry composition may comprise a first phosphate glass composition and a low coefficient of thermal expansion material, wherein the low coefficient of thermal expansion material is a material with a coefficient of thermal expansion of less than 10×10.sup.−6° C.
High temperature oxidation protection for composites
The present disclosure provides a method for coating a composite structure, comprising forming a first slurry by combining a first pre-slurry composition with a first carrier fluid, applying the first slurry on a surface of the composite structure, and heating the composite structure to a temperature sufficient to form a base layer on the composite structure. The first pre-slurry composition may comprise a first phosphate glass composition and a low coefficient of thermal expansion material, wherein the low coefficient of thermal expansion material is a material with a coefficient of thermal expansion of less than 10×10.sup.−6° C.
Method to process a ceramic matrix composite (CMC) with a protective ceramic coating
A method of producing a ceramic matrix composite including a protective ceramic coating thereon comprises applying a surface slurry onto an outer surface of an impregnated fiber preform. The surface slurry includes particulate ceramic solids dispersed in a flowable preceramic polymer comprising silicon, and the impregnated fiber preform comprises a framework of ceramic fibers loaded with particulate matter. The flowable preceramic polymer is cured, thereby forming on the outer surface a composite layer comprising a cured preceramic polymer with the particulate ceramic solids dispersed therein. The cured preceramic polymer is then pyrolyzed to form a porous ceramic layer comprising silicon carbide, and the impregnated fiber preform and the porous ceramic layer are infiltrated with a molten material comprising silicon. After infiltration, the molten material is cooled to form a ceramic matrix composite body with a protective ceramic coating thereon.
Method to process a ceramic matrix composite (CMC) with a protective ceramic coating
A method of producing a ceramic matrix composite including a protective ceramic coating thereon comprises applying a surface slurry onto an outer surface of an impregnated fiber preform. The surface slurry includes particulate ceramic solids dispersed in a flowable preceramic polymer comprising silicon, and the impregnated fiber preform comprises a framework of ceramic fibers loaded with particulate matter. The flowable preceramic polymer is cured, thereby forming on the outer surface a composite layer comprising a cured preceramic polymer with the particulate ceramic solids dispersed therein. The cured preceramic polymer is then pyrolyzed to form a porous ceramic layer comprising silicon carbide, and the impregnated fiber preform and the porous ceramic layer are infiltrated with a molten material comprising silicon. After infiltration, the molten material is cooled to form a ceramic matrix composite body with a protective ceramic coating thereon.
CERAMIC MEMBER MANUFACTURING METHOD, CERAMIC GREEN BODY, AND CERAMIC MEMBER MANUFACTURING SYSTEM
A method for manufacturing a ceramic member includes a mark process for forming a mark indicating information about a ceramic green body on the ceramic green body by using a mark material capable of being erased by a predetermined heat treatment; and a heat treatment process for erasing the mark by applying the ceramic green body to the predetermined heat treatment.
CERAMIC MEMBER MANUFACTURING METHOD, CERAMIC GREEN BODY, AND CERAMIC MEMBER MANUFACTURING SYSTEM
A method for manufacturing a ceramic member includes a mark process for forming a mark indicating information about a ceramic green body on the ceramic green body by using a mark material capable of being erased by a predetermined heat treatment; and a heat treatment process for erasing the mark by applying the ceramic green body to the predetermined heat treatment.
Laser induced graphitization of boron carbide in air
The localized formation of graphene and diamond like structures on the surface of boron carbide is obtained due to exposure to high intensity laser illumination. The graphitization involves water vapor interacting with the laser illuminated surface of boron carbide and leaving behind excess carbon. The process can be done on the micrometer scale, allowing for a wide range of electronic applications. Raman is a powerful and convenient technique to routinely characterize and distinguish the composition of Boron Carbide (B.sub.4C), particularly since a wide variation in C content is possible in B.sub.4C. Graphitization of 1-3 μm icosahedral B.sub.4C powder is observed at ambient conditions under illumination by a 473 nm (2.62 eV) laser during micro-Raman measurements. The graphitization, with ˜12 nm grain size, is dependent on the illumination intensity. The process is attributed to the oxidation of B.sub.4C to B.sub.2O.sub.3 by water vapor in air, and subsequent evaporation, leaving behind excess carbon. The effectiveness of this process sheds light on amorphization pathways of B.sub.4C, a critical component of resilient mechanical composites, and also enables a means to thermally produce graphitic contacts on single crystal B.sub.4C for nanoelectronics.
Laser induced graphitization of boron carbide in air
The localized formation of graphene and diamond like structures on the surface of boron carbide is obtained due to exposure to high intensity laser illumination. The graphitization involves water vapor interacting with the laser illuminated surface of boron carbide and leaving behind excess carbon. The process can be done on the micrometer scale, allowing for a wide range of electronic applications. Raman is a powerful and convenient technique to routinely characterize and distinguish the composition of Boron Carbide (B.sub.4C), particularly since a wide variation in C content is possible in B.sub.4C. Graphitization of 1-3 μm icosahedral B.sub.4C powder is observed at ambient conditions under illumination by a 473 nm (2.62 eV) laser during micro-Raman measurements. The graphitization, with ˜12 nm grain size, is dependent on the illumination intensity. The process is attributed to the oxidation of B.sub.4C to B.sub.2O.sub.3 by water vapor in air, and subsequent evaporation, leaving behind excess carbon. The effectiveness of this process sheds light on amorphization pathways of B.sub.4C, a critical component of resilient mechanical composites, and also enables a means to thermally produce graphitic contacts on single crystal B.sub.4C for nanoelectronics.