Abstract: A silicon based coating composition for a wide range of surfaces, which composition is formed from a mixture of constituents comprising appropriate portions of silazane, siloxane, and silane, and optionally organic solvent and additives, and the composition results in a coating having a thickness between 0.1 and 1.5 mil, a hardness of 2-9H and a standard coefficient of friction between about 0.03 to about 0.04.

Abstract: Ceramic matrix composite materials and processes for making said composite materials are disclosed.

Abstract: In one aspect, the present invention provides undoped and doped siloxanes, germoxanes, and silagermoxanes that are substantially free from carbon and other undesired contaminants. In a second aspect, the present invention provides methods for making such undoped and doped siloxanes, germoxanes, and silagermoxanes. In still another aspect, the present invention provides compositions comprising undoped and/or doped siloxanes, germoxanes, and silagermoxanes and a solvent, and methods for forming undoped and doped dielectric films from such compositions. Undoped and/or doped siloxane compositions as described advantageously provide undoped and/or doped dielectric precursor inks that may be employed in forming substantially carbon-free undoped and/or doped dielectric films.

Abstract: The invention pertains to a nuclear fuel assembly grid or a portion or a part of the grid, such as a grid strap and/or an integral flow mixer that is at least partially constructed of a composition containing one or more ternary compounds of the general formula I: Mn+1AXn??(I) wherein, M is a transition metal, A is an element selected from the group A elements in the Chemical Periodic Table, X is carbon or nitrogen, and n is an integer from 1 to 3.

Abstract: A spherical crystalline silicon carbide powder as well as its manufacturing methods are proposed; the new power's mean grain size is 0.5-5 micrometers, its specific volume of interior pores having a mean diameter of 0.003 through 0.1 micrometer is 0.000007 cc/g through 0.01 cc/g, and its specific surface area is 0.5 m2/g through 8.0 m2/g.

Abstract: The invention relates to a refractory ceramic batch and to a refractory ceramic brick produced therefrom.

Abstract: A method for the production of tungsten carbide based cemented carbide or cermet tools or components using the powder injection molding method includes mixing of hard constituent powder and a metallic binder powder with an organic binder system, consisting of 30-60 wt-% olefinic polymers and 40-70 wt-% nonpolar waxes, acting as a carrier for the powder. A metallic binder powder that is granulated with a nonpolar wax is used.

Abstract: Provided are a drill blank, a method for manufacturing a blank, a drill, and a method for manufacturing a drill which allow a step of brazing to be easy and allow the brazing to be precise. A drill includes a drill blank brazed thereto in an elongated columnar-shape and made of cemented carbide. In the drill blank, both dA and dB are equal to or smaller than 2 mm, dA?dB>dC, a ratio of the length to dA is equal to or larger than 3, and dB/dA=0.96 to 1 and dC/dA=0.9 to 0.995 in a longitudinal direction, where dA indicates the diameter of one end of both ends, dB indicates the diameter of the other end thereof, and dC indicates the minimum diameter of a central portion. Brazing of the drill blank is easy and precision in brazing is enhanced.

Abstract: A method for manufacturing a silicon carbide powder according to the embodiment includes forming a mixture by mixing a silicon (Si) source containing silicon with a solid carbon (C) source or a C source containing an organic carbon compound; heating the mixture; cooling the mixture; and supplying hydrogen gas into the mixture.

Abstract: A dense composite material of the present invention contains 37% to 60% by mass of silicon carbide grains, also contains titanium silicide, titanium silicon carbide, and titanium carbide, each in an amount smaller than the mass percent of the silicon carbide grains, and has an open porosity of 1% or less. Such a dense composite material is, for example, characterized in that it has an average coefficient of linear thermal expansion at 40° C. to 570° C. of 7.2 to 8.2 ppm/K, a thermal conductivity of 75 W/mK or more, and a 4-point bending strength of 200 MPa or more.

Abstract: The invention relates to a bearing comprising a sintered ceramic body traversed by a hole. According to the invention, the body includes a top surface and a bottom surface each of which includes a functional element communicating with said hole.

Abstract: A method for producing monolithic Zirconium Carbide (ZrC) is described. The method includes raising a pressure applied to a ZrC powder until a final pressure of greater than 40 MPa is reached; and raising a temperature of the ZrC powder until a final temperature of less than 2200° C. is reached.

Abstract: There is disclosed a method of making a metallic or ceramic component, such as a cutting or forming tool, from at least two distinct powder precursors. In one embodiment, the method comprising forming a first mixture comprised of a plurality of coated particles, such as Tough-Coated Hard Powder (TCHP) composite particles created by encapsulating extremely hard core particles with very tough binder and structural materials, and at least one support powder, such as a carbide, typically WC—Co. The mixture is formed into a green body and sintered to form a functionally graded or multicomponent article. Non-limiting examples of the articles made from the disclosed methods are also disclosed and include drills, mills, cutting tools, forming tools, wires dies and mechanical components.

Abstract: A process for the fabrication of a SiC-based article that includes preparing an aqueous suspension with SiC powder, a titanium source, a carbon source and boron carbide powder, spray drying the mixture to obtain a powder, preparing a green body from the powder, applying heat treatment to the green body in a pyrolysis/thermolysis step, pressureless sintering the green body, optimally followed by HIPing for further densification.

Abstract: The invention relates to a method for producing a polysilane-polycarbosilane copolymer solution. Said method comprises the preparation of a polysilane, obtained by the disproportionation of a methylchlorodisilane or a mixture of methylchlorodisilanes of formula Si2MenC16-n with a Lewis base as the catalyst, a subsequent thermal cross-linking of the polysilane to form an infusible polysilane-polycarbosilane copolymer that is soluble in inert solvents, in addition to the production of said solution by the dissolution of the polysilane-polycarbosilane copolymer in an inert solvent. The invention also relates to a method for producing oxygen-depleted ceramic fibers and other molded bodies with a composition similar to that of SiC. Said method comprises the spinning of the solution to obtain green fibers according to the dry spinning method and the pyrolysis of the dried green fibers in an inert gas atmosphere or a reductive atmosphere.

Abstract: A tough ultra-high temperature ceramic (UHTC) composite comprises grains of UHTC matrix material, such as HfB2, ZrB2 or other metal boride, carbide, nitride, etc., surrounded by a uniform distribution of acicular high aspect ratio reinforcement ceramic rods or whiskers, such as of SiC, is formed from uniformly mixing a powder of the UHTC material and a pre-ceramic polymer selected to form the desired reinforcement species, then thermally consolidating the mixture by hot pressing. The acicular reinforcement rods may make up from 5 to 30 vol % of the resulting microstructure.

Abstract: Embodiments of the present invention disclosed herein include a sintering aid composition that has a material useful for sintering, an amine, and optionally a carboxylic acid.

Abstract: The present invention relates to a novel electrical devices fabricated from polycrystalline silicon carbide (SiC) and methods for forming the same. The present invention provides a method for fabricating polycrystalline silicon carbide (SiC) products infiltrated with SiC-containing preceramic precursor resins to substantially mask the deleterious effects of trace contaminants, typically nitrogen and aluminum, while reducing operative porosity and enhancing manufacturing ease.

Abstract: A method of forming a sintered silicon carbide body includes mixing silicon carbide powder having an oxygen content of less than about 3 wt % and having a surface area in a range of between about 8 m2/g and about 15 m2/g, with boron carbide powder and carbon sintering aid to form a green silicon carbide body. Alternatively, a method of producing a sintered silicon carbide body includes mixing the silicon carbide powder with titanium carbide powder having an average particle diameter in a range of between about 5 nm and about 100 nm and with carbon sintering aid to form a green silicon carbide body. In another alternative, a method of forming a sintered silicon carbide body includes mixing silicon carbide powder with boron carbide powder, the titanium carbide powder, and carbon sintering aid to form a green silicon carbide body. After sintering, the silicon carbide bodies have a density at least 98% of the theoretical density of silicon carbide.

Abstract: The present invention relates to a novel electrical devices fabricated from polycrystalline silicon carbide (SiC) and methods for forming the same. The present invention provides a method for fabricating polycrystalline silicon carbide (SiC) products infiltrated with SiC-containing preceramic precursor resins to substantially mask the deleterious effects of trace contaminants, typically nitrogen and aluminum, while reducing operative porosity and enhancing manufacturing ease.

Abstract: Embodiments of the present invention disclosed herein include a sintering aid composition that has a material useful for sintering, an amine, and optionally a carboxylic acid.

Abstract: Disclosed is a highly-pure fine titanium carbide powder having a maximum particle size of 100 nm or less and containing metals except titanium in an amount of 0.05 wt % or less and free carbon in an amount of 0.5 wt % or less. The powder has a NaCl-type crystal structure, and a composition represented by TiCxOyNz, wherein X, Y and Z satisfy the relations: 0.5?X?1.0; 0?Y?0.3; 0?Z?0.2; and 0.5?X+Y+Z?1.0.) The powder is produced by: dissolving an organic substance serving as a carbon source in a solvent to prepare a liquid, wherein the organic substance contains at least one OH or COOH group which is a functional group coordinatable to titanium of titanium alkoxide, and no element except C, H, N and O; mixing titanium alkoxide with the liquid to satisfy the following relation: 0.7???1.

Abstract: A method for preparing ordered mesoporous silicon carbide (OMSiC) nanocomposites uses an evaporation-induced self-assembly of a precursor composition that preferably includes a phenolic resin, pre-hydrolyzed tetraethyl orthosilicate, a surfactant, and butanol. The precursor mixture is dried, cross-linked and heated to form ordered mesoporous silicon carbide material having discrete domains of ordered, mesoscale pores.

Abstract: The present invention relates to an optical part holding member made of ceramic and a production method thereof, and provides an optical part holding member made of ceramic such that a sintered body after processes of degreasing and sintering has small dimensional changes over dimensions of a mold, and a production method thereof. An example includes a lens holder to hold an optical part, made of a silicon nitride ceramic base composite material produced through a process in which silicon and nitrogen are reacted to be nitrided and contains silicon carbide and an iron compound.

Abstract: Methods are disclosed for producing architectural preforms and high-temperature composite structures containing high-strength ceramic fibers with reduced preforming stresses within each fiber, with an in-situ grown coating on each fiber surface, with reduced boron within the bulk of each fiber, and with improved tensile creep and rupture resistance properties tier each fiber. The methods include the steps of preparing an original sample of a preform formed from a pre-selected high-strength silicon carbide ceramic fiber type, placing the original sample in a processing furnace under a pre-selected preforming stress state and thermally treating the sample in the processing furnace at a pre-selected processing temperature and hold time in a processing gas having a pre-selected composition, pressure, and flow rate.

Abstract: A precursor tape casting method is one in which chemical precursors are converted into a final chemical phase from green tapes to products. Because chemical precursors are employed rather than the final powder materials, sintering is not required to form the material. Lower annealing temperatures instead of high temperature sintering allow the formation of grains of about 1 to about 100 nanometers in the final material. In addition, when the final material is a magnetic/insulator composite, improved magnetic properties may be obtained.

Abstract: Provided are a silicon carbide-based porous article comprising silicon carbide particles as an aggregate, metallic silicon and an aggregate derived from organometallic compound particles to form pores through volume shrinkage due to decomposition/conversion by heat treatment; and a method for producing the silicon carbide-based porous article, comprising, adding organometallic compound particles to form pores through volume shrinkage due to decomposition/conversion by heat treatment to a raw-material mixture containing silicon carbide particles and metallic silicon, then forming into an intended shape, calcinating and/or firing the resultant green body, forming pores through volume shrinkage due to decomposition/conversion of the organometallic compound particles, and the decomposed/converted substance of the organometallic compound particles being present as an aggregate in the porous article.

Abstract: An aspect of the present invention is to provide an economical production technology for obtaining a dense boron carbide ceramic product without impairment to excellent mechanical properties, which boron carbide ceramics are inherently equipped with, by conducting heating under normal pressure without application of pressure and without needing addition of a large amount of a sintering additive to a raw material or needing any special additive or treatment. The present invention provides a production process in which, upon heating a boron carbide green body under normal pressure without application of pressure after pressing a boron carbide powder material to obtain the boron carbide green body, the boron carbide green body is heated with one of a powder, green body or sintered body, which contains at least one of aluminum and silicon, being disposed in a furnace.

Abstract: Methods are disclosed for producing architectural preforms and high-temperature composite structures containing high-strength ceramic fibers with reduced preforming stresses within each fiber, with an in-situ grown coating on each fiber surface, with reduced boron within the bulk of each fiber, and with improved tensile creep and rupture resistance properties for each fiber. The methods include the steps of preparing an original sample of a preform formed from a pre-selected high-strength silicon carbide ceramic fiber type, placing the original sample in a processing furnace under a pre-selected preforming stress state and thermally treating the sample in the processing furnace at a pre-selected processing temperature and hold time in a processing gas having a pre-selected composition, pressure, and flow rate.

Abstract: A Si—C—O composite powder is obtained by curing a reactive silane or siloxane having crosslinkable groups through heat curing or catalytic reaction into a crosslinked product and sintering the crosslinked product in an inert gas stream at a temperature of 700-1,400° C. into an inorganic state. It exhibits satisfactory cycle performance when used as the negative electrode material for non-aqueous electrolyte secondary cells.

Abstract: The invention provides a method of forming a dense, shaped article, such as a crucible, formed of a refractory material, the method comprising the steps of placing a refractory material having a melting point of at least about 2900° C. in a mold configured to form the powder into an approximation of the desired shape. The mold containing the powder is treated at a temperature and pressure sufficient to form a shape-sustaining molded powder that conforms to the shape of the mold, wherein the treating step involves sintering or isostatic pressing. The shape-sustaining molded powder can be machined into the final desired shap and then sintered at a temperature and for a time sufficient to produce a dense, shaped article having a density of greater than about 90% and very low open porosity. Preferred refractory materials include tantalum carbide and niobium carbide.

Abstract: The present invention relates to a to novel electrical devices fabricated from polycrystalline silicon carbide (SiC) and methods for forming the same. The present invention provides a method for fabricating polycrystalline silicon carbide (SiC) products infiltrated with SiC-containing preceramic precursor resins to substantially mask the deleterious effects of trace contaminants, typically nitrogen and aluminum, while reducing operative porosity and enhancing manufacturing ease.

Abstract: A silicon carbide-silicon carbide fiber composite consists of silicon carbide particles and silicon carbide fibers. The composite has excellent oxidation resistance and finds a wide range of application as heat resistant material. The silicon carbide conversion method is simple and consistent enough to ensure production of silicon carbide-silicon carbide fiber composites with minimized variation in quality.

Abstract: A method for manufacturing a honeycomb structure having a low pressure loss and a high strength includes preparing a material composition containing a silicon carbide powder, a binder and an additive; molding the material composition to manufacture a pillar-shaped honeycomb body molded having cells disposed in parallel with one another and in a longitudinal direction; carrying out a degreasing treatment on the honeycomb molded; and carrying out a firing treatment on the honeycomb degreased body to manufacture a honeycomb fired body. The silicon carbide powder of the material composition contains a silicon carbide coarse powder and a silicon carbide fine powder having an average particle diameter (D50) smaller than that of the silicon carbide coarse powder, and the additive contains a metal oxide power. An amount of the metal oxide powder in the material composition is in the range of about 0.8 to about 4.0% by weight.

Abstract: A method of producing a sintered silicon carbide using a reaction sintering method, comprising: (1) dissolving and dispersing a silicon carbide powder in a solvent to produce a mixed powder slurry, (2) flowing the resulted mixed powder into a mold and drying it to obtain a green body, (3) temporarily sintering the green body in one of a vacuum atmosphere or inert gas atmosphere at 1200 to 1900° C. to obtain a temporarily sintered first body, (4) impregnating the resulted temporarily sintered first body with a phenol resin as a carbon source, (5) temporarily sintering the resulted carbon source-impregnated temporarily sintered first body in one of a vacuum atmosphere or inert gas atmosphere at 900 to 1400° C.

Abstract: There are provided in accordance with embodiments of the invention metal-containing inorganic block copolymers, structures formed by self-assembly of such copolymers, and metal-containing ceramics which may be formed from such copolymers and/or structure. Methods for making such copolymers, structures and ceramics are also provided. Other embodiments are also disclosed.

Abstract: A process for fabricating ceramic composites employs a thermoplastic photo-curable pre-ceramic polymer in which the component is shape by a variety of standard composite fabrication techniques, such as filament winding, tape winding, and woven cloth winding. The process includes steps of passing ceramic fiber monofilament, tow, mat, or woven cloth through a solution of said thermoplastic photo-curable pre-ceramic polymer, applying ceramic fiber monofilament, tow, mat, or woven cloth to a moving flat substrate, using a compaction roller to press the thermoplastic pre-ceramic polymer coated ceramic fiber onto flat substrate using photo-light of the ultraviolet, visible, or infrared light spectrum to induce cross-linking (curing) of the photo-curable pre-ceramic polymer thereby rendering a thermoset polymer and either partially or completely pyrolyzing the now cured pre-ceramic polymer matrix coated ceramic fiber material.

Abstract: A preformed of SiC fiber, which is coated with one or more of C, BN and SiC, is impregnated with a slurry, which suspends fine SiC powder and a sintering additive therein. The impregnated preform is hot-pressed at 1600-1800° C. with a pressure of 10 MPa or more. The sintering additive may be one or more of Al2O3, Y2O3, SiO2 and CaO. The slurry may futher contain a silicone polymer selected from polycarbosilane, polyvinylsilane and polymethylsilane. Reaction of SiC fiber with a matrix is inhibited by the coating, so as to manufacture a SiC fiber-reinforced SiC-matrix composite remarkably improved in mechanical properties.

Abstract: The present invention relates to a method of making a sintered body comprising one or more hard constituents in a binder phase by injection molding or extrusion. According to the invention, the granulating agent during drying is an ethylene oxide polymer and the binder system is not miscible with that compound. The extraction step is performed in an alcohol based solvent at a temperature of 50-78° C., preferably 60-78° C.

Abstract: A method of producing a silicon carbide sintered body jig using a reaction sintering method, comprising: (a)dispersing a silicon carbide powder and an organic substance as a carbon source in a solvent, to produce a mixed slurry powder, (b) pouring the resulted slurry powder into a mold and drying this to obtain a green body, (c) temporarily-sintering the resulted green body under a vacuum atmosphere at 1800° C., to obtain a temporarily-sintered body, (d) temporarily-molding said temporarily-sintered body, to obtain a temporarily-molded body, (e) impregnating a melted metal silicon into the resulted temporarily-molded body by a capillary phenomenon and reacting free carbon in said temporarily-molded body with silicon sucked into said temporarily-molded body by a capillary phenomenon, to obtain a silicon carbide sintered body, and (f) subjecting the resulted silicon carbide sintered body to precise processing, to obtain a silicon carbide sintered body jig.

Abstract: The present invention provides a sintered silicon carbide jig production method capable of simply increasing the purity of a sintered silicon carbide jig. A method of producing a sintered silicon carbide jig comprising a process in which a second sintered body is heated at a temperature rising rate of 3 to 5° C./min up to heating treatment temperature selected in the range of 2200 to 2300° C. under an argon atmosphere, kept at the same heating treatment temperature for 3 hours, and cooled at a temperature lowering rate of 2 to 3° C./min down to 1000° C.

Abstract: Composite materials containing silicon, titanium, carbon, and nitrogen, formed by spark plasma sintering of ceramic starting materials to a high relative density, demonstrate unusually high electrical conductivity as well as high-performance mechanical and chemical properties including hardness, fracture toughness, and corrosion resistance. This combination of electrical, mechanical, and chemical properties makes these composites useful as electrical conductors in applications where high-performance materials are needed due to exposure to extreme conditions such as high temperatures, mechanical stresses, and corrosive environments.

Abstract: A mixed polymer liquid is prepared by mixing a polycarbosilane-dissolved organic solvent with poly(methylsilane) and moderated to viscosity of 5–20 Pa·s by heat-treatment to promote partial cross-linking reaction. The mixed-polymer is then melt-spun to fiber at 250–350° C. The fiber is cured by treatment at 100–200° C. in an oxidizing atmosphere, and baked at 1000° C. or higher. Due to thermosetting action of poly(methylsilane), the mixed polymer liquid is continuously melt-spun without breakage, and SiC fiber produced in this way is useful for reinforcement of SiC composite excellent in toughness, strength and heat-resistance.

Abstract: A silicon carbide fiber having a boron nitride layer in a fiber surface and having the following properties of a to c, a. the existent ratio of boron slopingly increases towards the surface of the fiber, b. the existent ratio of boron in the region of from the fiber surface to a depth of 500 nm is 0.5 to 1.5% by weight, c. the existent ratio of boron in a fiber central portion which is a region of a depth of at least 3 ?m below the fiber surface is 0 to 0.2% by weight, and a process for the production thereof.

Abstract: There are provided a high-strength zirconia-containing inorganic fiber having excellent alkali resistance, oxidation resistance, catalyst function and/or catalyst-carrying function and a process for the production thereof. The zirconia-containing inorganic fiber is a fiber which is formed of a composite oxide phase comprising a first phase mainly formed of a silica component or silicon carbide and a second phase formed of zirconia, and it is characterized in that the ratio of Zr slopingly increases toward the surface layer of the fiber.

Abstract: A ceramic composite material, for example, a ceramic molded body or a layer obtained by pyrolysis of a starting mixture, containing at least one polymer precursor material and at least one filler, which has an average particle size of less than 200 nm. Such a composite material may be used, for example, for producing fibers, filters, catalyst support materials, ceramic sheathed-element glow plugs, metal-containing reactive composite materials, porous protective shells for sensors, ceramic or partially ceramic coatings or microstructured ceramic components.

Abstract: A method for reaction forming refractory metal carbides. The method involves the fabrication of a glassy carbon preform by casting an organic, resin-based liquid mixture into a mold and subsequently heat treating it in two steps, which cures and pyrolizes the resin resulting in a porous carbon preform. By varying the amounts of the constituents in the organic, resin-based liquid mixture, control over the density of the carbon preform is obtained. Control of the density and microstructure of the carbon preform allows for determination of the microstructure and properties of the refractory metal carbide material produced. The glassy carbon preform is placed on a bed of refractory metal or refractory metal—silicon alloy. The pieces are heated above the melting point of the metal or alloy. The molten metal wicks inside the porous carbon preform and reacts, forming the refractory metal carbide or refractory metal carbide plus a minor secondary phase.

Abstract: A multilayer ceramic composite is described which contains at least one supporting zone having oxidation-sensitive reinforcing fibers as well as a matrix. The matrix optionally contains oxidation-sensitive components. The composite further contains at least one surface layer, as well as at least one additional protective layer disposed between the supporting zone and surface layer, and whose matrix is composed substantially of at least one component of the matrix of the supporting zone or cover layer. The protective layer further contains additives that form self-healing layers.

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.

Abstract: The present invention relates to a method for producing silicon oxycarbide fibers by pyrolysis of preceramic precursors.