Patent classifications
C04B2235/5276
Systems and methods for thermally processing CMC components
Systems and methods for thermally processing composite components are provided. In one exemplary aspect, a system includes a thermal system, a mover device, and a control system. The system also includes a plurality of vessels in which one or more components may be placed. The vessels are similarly shaped and configured. A vessel containing the one or more components therein may be mounted into a chamber defined by the thermal system during thermal processing. The thermal system and vessels include features that allow components to be thermally processed, e.g., compacted, burnt-out, and densified via a melt-infiltration process, a polymer impregnation and pyrolyzing process, or a chemical vapor infiltration process. utilizing the same thermal system and common vessel design. The control system may control the thermal system and mover device to automate thermal processing of the composite components.
UNCALCINED GEOPOLYMER-BASED REFRACTORY MATERIAL AND METHOD FOR ITS PREPARATION
An uncalcined geopolymer-based refractory material is provided, comprising a matrix of a geopolymer obtainable by polymerization of a mixture consisting of mineral powder, fly ash, and metakaolin; and SiC whiskers embedded in the geopolymer matrix. The material has excellent mechanical properties and high resistance to high temperatures and exhibits a ductile fracture mechanism instead of a brittle fracture mechanism.
Preparation method of alumina ceramic valve core ceramic chip and product thereof
A preparation method of an alumina ceramic valve core ceramic chip and a product thereof. The alumina ceramic valve core ceramic chip is obtained by the steps of mixing alumina, a sintering aid and a toughening agent according to a raw material ratio, ball-milling, drying, cold isostatic pressing, sintering and the like. The alumina ceramic valve core ceramic chip is prepared by adopting nano alumina and zirconium oxide as the sintering aid, so that the material has excellent bending strength, fracture toughness, hardness and low wear rate, the bending strength can reach 357.8-360.06 MPa, the fracture toughness is 4.32-4.56 MPa.sup.1/2, the Vickers hardness is 1592.7-1614.8 MPa, the wear rate is 0.04-0.09%, and the alumina ceramic valve core ceramic chip is an ideal material for preparing a faucet valve core.
Method of making whisker reinforced high fracture toughness ceramic threaded fasteners
A high temperature fastener including a bolt and a nut, where the bolt and the nut are constructed of an aluminum oxide ceramic material reinforced with silicon-carbide crystal whiskers or silicon nitride.
Short-Fiber-Reinforced Oriented MAX-Phase Ceramic-Based Composite and Preparation Method Therefor
The present invention relates to the field of MAX-phase ceramic-based composites, specifically to a short-fiber-reinforced oriented MAX-phase ceramic-based composite and a preparation method therefor. By using a new process with a fiber, a nano lamellar MAX-phase ceramic powder, other additives, etc., for preparing a fiber-reinforced MAX-phase ceramic-based composite, a novel ternary composite is prepared, wherein a matrix is composed of a highly oriented lamellar MAX-phase ceramic, the fiber is distributed parallel to the lamellar MAX-phase ceramic in an axial direction, and a granulate ceramic phase enhancement phase is dispersed in the matrix. Thus, the problems of a MAX-phase ceramic-based composite matrix material prepared by an existing method, such as coarse grains, multiple internal defects and a low strength, and a poor fracture toughness; and a reaction sintering temperature being too high such that fibers are chemically and physically damaged in a substrate, resulting in performance degradation, are solved. Fibers prepared by the method are suitable for large-scale industrial preparation and have properties that are far superior to those of any existing known fiber MAX-phase composite.
Low-shrinkage, high-strength, and large ceramic plate and manufacturing method thereof
Disclosed are a low-shrinkage, high-strength, and large ceramic plate and a manufacturing method thereof. The method comprises the following steps: (1) preparing a ceramic raw material powder; (2) subjecting an acicular wollastonite to surface coating with a silane coupling agent and to pre-dispersion with a fumed silica to obtain a pre-treated acicular wollastonite; and (3) thoroughly mixing the ceramic raw material powder and the pre-treated acicular wollastonite and granulating the resulting mixture, the amount of the pre-treated acicular wollastonite added being 10 wt % to 30 wt % of the ceramic raw material powder, and subjecting the resulting granules to dry pressing and sintering to obtain the large ceramic plate. The acicular wollastonite is incorporated into the manufacturing of the large ceramic plate to take full advantage of the reinforcing effect and low sintering shrinkage characteristics of the acicular wollastonite. The invention reduces sintering shrinkage and increases product strength.
INDUCTION MELT INFILTRATION PROCESSING OF CERAMIC MATRIX COMPOSITE COMPONENTS
A system and method of melt infiltrating components is provided. In one example aspect, an inductive heating system includes a heating source that inductively heats a susceptor. The susceptor defines a working chamber in which components can be received. During melt infiltration, the system can heat the susceptor and thus the components and melt infiltrants disposed within the working chamber at a first heating rate. The first heating rate can be faster than 50° C./minute. The system can then heat the components and melt infiltrants at a second heating rate. The first heating rate is faster than the second heating rate. Thereafter, the system can heat the components and infiltrants at a third heating rate. The third heating rate can be a constant rate at or above the melting point of the melt infiltrants. The infiltrants can melt and thus infiltrate into the component to densify the component.
SHEAR BINDER AGGLOMERATES ENABLING HIGH POROSITY IN CERAMIC HONEYCOMB BODIES
A ceramic precursor mixtures for extrusion and firing into porous ceramics. The ceramic precursor mixtures include ceramic beads and green inorganic shear binder agglomerates. The green inorganic shear binder agglomerates can include inorganic filler particles and a polymeric binder. The green inorganic shear binder agglomerates can deform under an applied shear stress during mixing and/or extrusion such that they are smeared into a plurality of interbead gaps between adjacent ceramic beads or pore former particles. During firing, the smeared green inorganic shear binder agglomerates can sinter and react to form ribbons extending between, and interconnecting adjacent ceramic beads.
Three-dimensional printed objects with optimized particles for sintering and controlled porosity
A three-dimensional printed structure can include a photocurable resin, a sinterable material, and a plurality of elongated particles. The elongated particles are distributed within the printed structure. The elongated particles are shaped and distributed to promote porosity control (e.g., improved densification) within the structure.
METHOD OF DENSIFYING A CERAMIC MATRIX COMPOSITE USING A FILLED TACKIFIER
A method of producing an enhanced ceramic matrix composite includes applying a tackifier compound to a fiber preform. The tackifier compound includes inorganic filler particles. The method further includes modifying the tackifier compound such that the inorganic filler particles remain interspersed throughout the fiber preform, and occupy pores of fiber preform.