Patent classifications
C04B35/634
METHOD OF FABRIC PROCESSING FOR IMPROVED CMC INFILTRATION
A method of preparing a woven fabric material for use in a ceramic matrix composite includes securing a woven fabric tape in tension across a roller, the roller having an outer surface with a plurality of spiked protrusions extending radially therefrom, each of the plurality of spiked protrusions having a diameter between 10 microns and 500 microns. The method further includes passing the woven fabric along the roller, such that the roller rotates with the passing of the woven fabric tape, thereby impinging the spiked protrusions into the woven fabric tape, and separating filaments within tows of the woven fabric tape by penetration of at least one of the spiked protrusions into the woven fabric tape, such that filaments within various tows of the woven fabric tape are pushed apart to form a separated woven fabric tape with a greater number of tows per unit area than the woven fabric tape.
SUPERHARD MATERIAL-CONTAINING OBJECTS AND METHODS OF PRODUCTION THEREOF
A superhard material-containing object is configured to have a controlled and repeatable three-dimensional geometry and/or shape. The object further includes a desired three-dimensional spatial variation in microstructure, grain size and/or composition. The superhard material is selected from the group consisting of diamond, boron-doped diamond and cubic boron nitride. A process for production of a superhard material-containing object from a powder of a superhard material, a binder and an optional additive, includes the steps of: (a) producing a feedstock of the superhard material and a polymer binder; (b) extruding one or more filaments from a granulated superhard material-binder feedstock; (c) preparing a printed superhard material-containing object using the one or more filaments; (d) subjecting the printed object to debinding to prepare a debindered object; and (e) sintering the debindered printed object to produce the superhard material-containing object.
METHOD OF PREPARATION OF CERAMIC SLURRY FOR USE IN 3D PRINTING AND METHOD OF PREPARATION OF CERAMIC PRODUCT
A method of preparation of a ceramic slurry for use in 3D printing includes steps of: (A) providing a plasticizer and a disperser and mixing the plasticizer and the disperser evenly; (B) mixing the mixture obtained in step (A) with an adhesive, wherein the adhesive is polyvinyl alcohol; and (C) adding a Yttria-stabilized zirconia powder to the mixture obtained in step (B) to produce, by sufficient blending and deaerating, the ceramic slurry for use in 3D printing. A method of preparation of a ceramic product includes steps of: (A) preparing a ceramic slurry with the method; (B) performing 3D printing with the ceramic slurry to form a primary green body; (C) placing the primary green body in a freezer to undergo a refrigeration process, thereby causing crystallization of polyvinyl alcohol; and (D) thawing the frozen primary green body to form a plastic green body with gel structure.
GRAIN-GRADE ZIRCONIA TOUGHENED ALUMINA CERAMIC SUBSTRATE AND METHOD FOR PREPARING THE SAME
A grain-grade zirconia toughened alumina ceramic substrate and a method for preparing the same. The ceramic substrate is prepared from alumina power (main phase) and zirconia powder (secondary phase) in a binary azeotrope of anhydrous ethanol and butanone in the presence of magnesia-alumina spinel powder (as sintering aid), phosphate ester (as dispersant), polyvinyl butyral (as binder) and dibutyl phthalate (as plasticizer). In a mixture of the alumina power and the zirconia powder, a volume percentage of the alumina power is 82.44-96.7%, and a volume percentage of the zirconia powder is 3.30-17.56%. The magnesia-alumina spinel powder is 0.1-4.0% by weight of the mixture of the alumina power and the zirconia powder. A particle size ratio of the alumina powder to the zirconia powder is 2.415-4.444.
PASTE FOR CERAMIC 3D SHAPING AND METHOD FOR MANUFACTURING THREE-DIMENSIONAL SHAPED OBJECT
A paste for ceramic 3D shaping according to the present invention is a paste for ceramic 3D shaping containing a curable resin and inorganic particles, in which the inorganic particles contain ceramic particles and glass particles.
Fully ceramic microencapsulated fuels containing tristructural-isotropic particles with a coating layer having higher shrinkage than matrix
The present invention relates to a method for preparing a fully ceramic capsulated nuclear fuel material containing three-layer-structured isotropic nuclear fuel particles coated with a ceramic having a composition which has a higher shrinkage than a matrix in order to prevent cracking of ceramic nuclear fuel, wherein the three-layer-structured nuclear fuel particles before coating is included in the range of between 5 and 40 fractions by volume based on after sintering. More specifically, the present invention provides a composition for preparing a fully ceramic capsulated nuclear fuel containing three-layer-structured isotropic particles coated with the substance which includes, as a main ingredient, a silicon carbine derived from a precursor of the silicon carbide wherein a condition of ΔL.sub.c>ΔL.sub.m at normal pressure sintering is created, where the sintering shrinkage of the coating layer of the three-layer-structured isotropic nuclear fuel particles is ΔL.sub.c and the sintering shrinkage of the silicon carbide matrix is ΔL.sub.m; material produced therefrom; and a method for manufacturing the material. The residual porosity of the fully ceramic capsulated nuclear fuel material is 4% or less.
LOCALIZED PARTICLE ADDITIONS TO REDUCE DEFECTS IN CERAMIC MATRIX COMPOSITES CAUSED BY COMPLEX GEOMETRY PREFORMING
A method of forming a ceramic matrix composite component includes forming a fiber preform, the fiber preform including a plurality of ceramic fiber plies, a non-reduced fiber region having an areal weight, and a reduced fiber region characterized by a reduced areal weight less than the areal weight of the non-reduced fiber region by at least 5 percent. The method further includes selectively applying ceramic particles to the reduced fiber region in such manner as to avoid applying the ceramic particles to the non-reduced fiber region, and subsequently densifying the preform.
Method for manufacturing an elastic ceramic matrix composite
Disclosed are: damage-resistant ECMCs that need to work and remain elastic between minus 120° C. and positive 300° C.; ECMCs that need to be able to contain a flame of 1900° C. for more than 90 minutes; and composite structures, especially highly stressed structures. One of the characteristic problems of ceramic matrices is their fragility. Indeed, when a fracture starts, it propagates easily in the matrix. Disclosed are elastic ceramic matrix composites (ECMCs), for which: the ceramic matrix is split into solid “ceramic microdomains” (CMDs); the CMDs are connected to one another by a dense network of “elastic microelements” (EMEs); and the bonds between the EMEs and the CMDs are strong chemical bonds, preferably covalent.
Method for manufacturing an elastic ceramic matrix composite
Disclosed are: damage-resistant ECMCs that need to work and remain elastic between minus 120° C. and positive 300° C.; ECMCs that need to be able to contain a flame of 1900° C. for more than 90 minutes; and composite structures, especially highly stressed structures. One of the characteristic problems of ceramic matrices is their fragility. Indeed, when a fracture starts, it propagates easily in the matrix. Disclosed are elastic ceramic matrix composites (ECMCs), for which: the ceramic matrix is split into solid “ceramic microdomains” (CMDs); the CMDs are connected to one another by a dense network of “elastic microelements” (EMEs); and the bonds between the EMEs and the CMDs are strong chemical bonds, preferably covalent.
COMPOSITIONS AND METHODS FOR THREE-DIMENSIONAL PRINTING
The present disclosure provides mixtures, systems, and methods for printing a three-dimensional (3D) object. In some aspects, the present disclosure provides a mixture for printing a 3D object, comprising a plurality of granulated particles. In some aspects, the present disclosure provides a mixture for printing a 3D object, comprising a plurality of precursor compounds configured to react to form a plurality of particles.