Abstract: A process is provided for preparing solid superconducting mixed-metal oxides whereby the superconductor can be formed into any predetermined shape by way of viscous sol precursors. The superconductors are also formed by this process into homogeneous phases.

Abstract: A silica product, method and apparatus for manufacturing a tube-shaped silica glass product using a molded green body having a hollow rod structure. A molded green body having a hollow rod structure has a uniform outer diameter and has a bore having an inner diameter increasing gradually from one end to the other. When sintered in a vertically movable sintering furnace, a tube-shaped silica glass product having a longitudinal cross section distribution less than a tolerance limit may be obtained. Optical fiber manufactured using the silica glass tube according to the present invention may have a uniform longitudinal geometrical structure, thereby exhibiting superior transmission characteristics.

Abstract: A process for producing a shaped body comprising at least one porous oxidic material and at least one metal oxide comprises the following step (i): (i) mixing the porous oxidic material or materials with at least one metal oxide sol which has a low content of alkali metal and alkaline earth metal ions and/or at least one metal oxide which has a low content of alkali metal and alkaline earth metal ions.

Abstract: A method including synthesizing polymeric precursors via organic acid modification; fabricating a fibrous material of the polymeric precursors; and fabricating a body of the fibrous material. One body has dimensions suitable as an electrode component of an electrical storage device.

Abstract: A method for producing the piezoelectric thin film is based on a sol-gel process and comprises the steps of: coating a substrate with a sol composition comprising a sol, of a metal component for constituting a piezoelectric film, and a polymer compound and then drying the coating to form a film; pre-sintering the film to form a porous thin film of gel comprising an amorphous metal oxide; pre-annealing the porous thin film of gel to convert the film to a film of a crystalline metal oxide; repeating the steps at least once to form laminated films of a crystalline metal oxide; and annealing the films thus prepared to grow crystal grains of perovskite type in the film into a larger size.

Abstract: Suspensions and powders based on indium tin oxide are prepared by a method in which indium tin oxide precursors are precipitated from solutions in one or more solvents in the presence of one or more surface-modifying components, the solvent(s) are removed from the precipitate, which is then calcined, one or more surface-modifying components and one or more solvents are added, the mixture is comminuted or dispersed to form a suspension, and the liquid components are separated from the suspension to give a powder. The powder may be converted into a moulding by a shaping process. The materials prepared by this method are especially suitable as coating materials for use in microelectronics and optoelectronics.

Abstract: A suspension adhesive comprised of a matrix material and a particulate filler material is useful for bonding, sealing, repairing, and modifying ceramic, glass, and powdered metal components in a light source. A method for making the suspension adhesive includes the selection of a filler material and a volume percentage of the filler material. Additionally, a matrix material is selected and the filler material is dispersed throughout the matrix material. The suspension adhesive is used to bond and seal components to form, for example, an arc tube for a light source.

Abstract: A composition for production of silica glass using a sol-gel process is described, comprising silica particles, a dispersing agent, and a solution containing a polymerizable monomer for formation of acrylic resin and a crosslink agent dissolved in distilled water. The polymerizable monomer is n-methylol acrylamide or n-methylol methacrylamide. A method for production of silica glass is described, including the step of adding silica particles and a dispersing agent to a premix solution of the polymerizable monomer for formation of acrylic resin and the crosslink agent dissolved in distilled water.

Abstract: A sol-gel process for producing dry porous gel monoliths, e.g., silica glass monoliths, in which the successive process steps of gelling, aging and drying all occur within a mold formed of a selected porous material, e.g., graphite. The mold is inert to the gel solution and it has sufficient strength to withstand the temperatures and pressures encountered during the process. The mold and gel thereby can remain within a sealed autoclave during these process steps, and mechanical handling of the mold and the gel are minimized. This substantially enhances the process' efficiency. Alternatively, the mold can have a non-porous inner skin to enhance ease of cleaning of the mold, and of removal of the gel.

Abstract: A method of manufacturing a ceramic matrix composite comprises forming a slurry comprising a ceramic sol, filler particles and a solvent and forming laminates of fibres (12). The laminates of fibres (12) are impregnated with the slurry and are stacked (14) on a mould (10). The stack (14) of laminates of fibres (12) is covered by a porous membrane (16), a breather fabric (18) and a vacuum bag (20). The vacuum bag (20) is evacuated and is heated to a temperature of 60° C. for 10 hours to produce a ceramic matrix composite. The ceramic matrix composite is then heated to a temperature of 1200° C. at atmospheric pressure to sinter the ceramic matrix composite.

Abstract: A low-cost, efficient method of preparing hierarchically ordered structures by combining, concurrently or sequentially, micromolding, latex templating, and cooperative self-assembly of hydrolyzed inorganic species and amphiphilic block copolymers.

Abstract: A method of manufacturing a sintered body is provided. A molding powder, a gel-forming material powder and a solvent are mixed at a temperature not higher than a dissolving point of the gel-forming material. A treatment of pulverizing agglomerates containing the molding powder, gel-forming material powder and solvent absorbed in the gel-forming material powder is carried out. The mixture is then heated to a temperature not lower than the dissolving point thereby forming a sol. The sol is then cooled to a temperature not higher than the gel point, thereby forming a molding material. The molding material is used for producing a sintering body.

Abstract: The present invention relates to a process for preparing silica-alumina carriers preferably under the form of extrudates. Further, the present invention also provides hydrogenation catalysts prepared thereof. These catalysts are used in an improved process for the reduction of the aromatic hydrocarbons content present in hydrocarbon streams.

Abstract: Disclosed is a method for fabricating a piezoelectric/electrostrictive thick film, using a seeding layer. On a substrate is formed the seeding layer which is prepared from a ceramic sol solution or a ceramic paste, both identical or similar in composition to the piezoelectric/electrostrictive film. The ceramic paste is prepared from a mixture of a ceramic oxide powder, which has a particle size of 5 &mgr;m or less and is prepared from Pb and Ti-based piezoelectric/electrostrictive elements by a non-explosive oxidation-reduction combustion reaction at 100-500° C., and a ceramic sol solution in water or an organic solvent, identical or similar in composition to the ceramic oxide powder. Then, the seeding layer is subjected to an after-treatment. A piezoelectric/electrostrictive film is directly formed on the seeding layer. Alternatively, a piezoelectric/electrostrictive film, separately formed and sintered, is attached on the seeding layer.

Abstract: A composition for production of silica glass using a sol-gel process is described, comprising silica particles, a dispersing agent, and a solution containing a polymerizable monomer for formation of acrylic resin and a crosslink agent dissolved in distilled water. The polymerizable monomer is n-methylol acrylamide or n-methylol methacrylamide. A method for production of silica glass is described, including the step of adding silica particles and a dispersing agent to a premix solution of the polymerizable monomer for formation of acrylic resin and the crosslink agent dissolved in distilled water.

Abstract: A method for producing a powder-molded body is provided, including the steps of casting a slurry containing a powder of at least one of a ceramic and a metal, and organic dispersion medium, and a gelling agent into a mold, and solidifying the slurry by gelling the slurry to obtain a molded body. The slurry is solidified by chemically bonding an organic dispersion medium having reactive functional groups and a gelling agent. The method is capable of improving gelling (solidification) efficiency and obtaining a molded body having a high density, a small firing shrinkage, and high shape precision, and which hardly experiences cracks during drying and firing.

Abstract: Disclosed is a sol-gel process for making high-density monolithic alpha-alumina articles. Cracking problems caused by shrinkage of the gel during the drying and firing stages are minimized by controlling the temperature and humidity during the drying process and by using molds formed of prescribed polymeric materials, preliminarily coated with a silicone release agent. The process of the invention provides porous alpha-alumina articles having a controlled microstructure and a controlled pore size distribution, which are beneficial features when the material is used in practical applications, e.g., as substrates for gas sensors.

Abstract: A fabrication method of graded index silica glass is disclosed. The method according to the present invention includes the steps of dispersing to form sol by mixing a starting material with a dispersion medium; molding the sol into a moisturized gel with a predetermined shape using a molding frame and separating the moisturized gel from the molding frame; drying the moisturized gel under a predetermined temperature and humidity level to remove the dispersion medium and to form a first dry gel having a predetermined moisture content distribution, hydrolyzing the moisture remained in the first dry gel and an additive solution by putting the first dry gel into the additive solution; re-drying the first dry gel, which underwent said hydrolysis, to form a second dry gel; and, thermal processing the second dry gel by supplying reaction gas thereto, removing impurities therefrom and annealing for isolation.

Abstract: A gelcasting method of making an internally graded article alternatively includes the steps of: preparing a slurry including a least two different phases suspended in a gelcasting solution, the phases characterized by having different settling characteristics; casting the slurry into a mold having a selected shape; allowing the slurry to stand for a sufficient period of time to permit desired gravitational fractionation in order to achieve a vertical compositional gradient in the molded slurry; gelling the slurry to form a solid gel while preserving the vertical compositional gradient in the molded slurry; drying the gel to form a dried green body; and sintering the dry green body to form a solid object, at least one property thereof varying along the vertical direction because of the compositional gradient in the molded slurry.

Abstract: A method for producing a powder-molded body,includes: casting a slurry containing a powder of a ceramic and/or a metal, a dispersion medium, and a gelling agent; and solidifying the slurry by gelling the slurry to obtain a molded body. The slurry is solidified by chemically bonding an organic dispersion medium having reactive functional groups and a gelling agent. The method is capable of improving gelling (solidification) efficiency and obtaining a molded body with a high density, a small firing shrinkage, and a high shape precision while scarcely causing cracks at the time of drying and firing.

Abstract: The ceramic porous membrane comprises ceramic particles and ceramic sol particles (with the exception of TiO2 sol particles). The ceramic particles and the ceramic sol particles are kneaded to obtain a kneaded product or a slurry, and the kneaded product or the slurry are sintered at a lower temperature. The ceramic sol particles have an average particle diameter of ⅕ or less of an average particle diameter of the ceramic particles, and the ceramic sol has a solid content of 1 to 30% by weight based on the weight of solid content of the ceramic particles.

Abstract: The present invention relates to a method for production of a metal oxide thin film and a method for production of an arrayed metal oxide functional device, comprising the steps of: preparing a sol containing a material and a solvent; gelating the sol to give a gel member; processing the gel member under a pressure of not less than 0.2 MPa at 100 to 400° C. in a water-vapor-containing atmosphere; and conducting a heat treatment on the water-vapor-processed gel member at 200 to 400° C.

Abstract: A composite molding compound comprising a combination of metal and ceramic powders is disclosed. The powders are combined with a binder, a liquid carrier and other processing additives in a manner to provide uniform distribution of two phases in a material format that facilitates the molding of complex parts at relatively low pressures and temperatures using conventional injection molding machines. The products formed from these molding compounds may be designed with tailored physical and mechanical properties such as thermal conductivity, thermal expansion coefficient, density, elastic modulus and wear properties.

Abstract: Processes are provided for forming composites comprising a LaMnO3 perovskite coatings (or a related perovskite) on a mat of ceramic particles (e.g., fibers, microballoons, or mixtures thereof) or LaMnO3-family sol-gel binders infused into the mat to form the connecting, rigidifying bridges.

Abstract: A process for shaping threaded metal and ceramic parts from powders and molding compositions therefor is disclosed. Parts produced by this process are formed net shape without the need for machining or other finishing operations. The process comprises forming a mixture containing metal powders, ceramic powders or mixtures thereof, a gel-forming material and an aqueous gel-forming material solvent, and molding the mixture in a mold containing internal and/or external threads under conditions of temperature and pressure to produce a self-supporting threaded article.

Abstract: A method of internal molding and decreased supercritical fluid drying times for aerogels and exergels by means of using gas porous molding features that are compatible with the prestressed fiber reinforcing system.

Abstract: A process for molding metal knife blades from powders and molding compositions therefor are disclosed. Parts produced by this process are formed near net shape without the need for machining or other finishing operations. The process comprises forming a mixture containing metal powders, a gel-forming material and an aqueous gel-forming material solvent, and molding the mixture in an injection molding machine under conditions of temperature and pressure to produce a self-supporting knife blade having a sharp edge.

Abstract: A gelcasting method of making an internally graded article alternatively includes the steps of: preparing a slurry including a least two different phases suspended in a gelcasting solution, the phases characterized by having different settling characteristics; casting the slurry into a mold having a selected shape; allowing the slurry to stand for a sufficient period of time to permit desired gravitational fractionation in order to achieve a vertical compositional gradient in the molded slurry; gelling the slurry to form a solid gel while preserving the vertical compositional gradient in the molded slurry; drying the gel to form a dried green body; and sintering the dry green body to form a solid object, at least one property thereof varying along the vertical direction because of the compositional gradient in the molded slurry.

Abstract: A method of a fabricating silica glass by sol-gel process is provided. The method includes mixing silica, a binder, a dispersing agent and a gelling agent, and forming a sol without air bubbles; injecting the sol into a mold, the injection of the sol into the mold being controlled by the pressure of an inert gas; gelating the sol injected into the mold and demolding the gel; and drying the demolded gel, and thermally-treating the dried gel. Therefore, incorporation of impurities and air bubbles during injection of a sol into a mold is minimized, and injection amount and injection rate of the sol can be controlled.

Abstract: A method of a fabricating silica glass by sol-gel process is provided. The method includes mixing silica, a binder, a dispersing agent and a gelling agent, and forming a sol without air bubbles; injecting the sol into a mold, the injection of the sol into the mold being controlled by the pressure of an inert gas; gelating the sol injected into the mold and demolding the gel; and drying the demolded gel, and thermally-treating the dried gel. Therefore, incorporation of impurities and air bubbles during injection of a sol into a mold is minimized, and injection amount and injection rate of the sol can be controlled.

Abstract: A method of net-shaping using aerogel materials is provided by first forming a sol, aging the sol to form a gel, with the gel having a fluid component and having been formed into a medium selected from the group consisting of a powder, bulk material, or granular aerobeads, derivatizing the surface of the gel to render the surface unreactive toward further condensation, removing a portion of the fluid component of the final shaped gel to form a partially dried medium, placing the medium into a cavity, wherein the volume of said medium is less that the volume of the cavity, and removing a portion of the fluid component of the medium. The removal, such as by heating at a temperature of approximately less than 50° C., applying a vacuum, or both, causes the volume of the medium to increase and to form a solid aerogel. The material can be easily removed by exposing the material to a solvent, thereby reducing the volume of the material.

Abstract: A method of producing foamed clay with optimum characteristics of porosity, mechanical resistance, high coefficients of reduced weight, and thermal and acoustic insulation, wherein a fluid mass consisting of clay is formed, into which compostions reacting therebetween are put so as to cause the homogenous foaming of the whole clay mass.

Abstract: A gelcasting method of making an internally graded article includes the steps of: preparing at least two slurries, each of the slurries including a different gelcastable powder suspended in a gelcasting solution, the slurries characterized by having comparable shrinkage upon drying and sintering thereof; casting the slurries into a mold having a selected shape, wherein relative proportions of the slurries is varied in at least one direction within the selected shape; gelling the slurries to form a solid gel while preserving the variation in relative proportions of the slurries; drying the gel to form a dried green body; and sintering the dry green body to form a solid object, at least one property thereof varying because of the variation in relative proportions of the starting slurries.

Abstract: A hydrophilic treatment by the use of a surface active agent and the like is not required for a base even the surface of which is water-repellent or thermoplastic when a viscous amorphous type titanium peroxide is used for fixing a base as a binder. In addition, a thin layer of a photocatalyst semiconductor, a dielectrical ceramics or an electrical ceraincs can be easily formed by adhering particles of a photocatalyst semiconductor, a dielectrical ceramics or an electrical ceramics to the layer of a viscous amorphous type titanium peroxide, which is a layer as a binder, in a homogeneously floating state gas. Furthermore, a layer of a titanium oxide having a photocatalyst function can be formed when a base is fixed with a viscous amorphous type titanium peroxide.

Abstract: The invention reflects discovery of a liquid phase doping technique that, unlike previous techniques, exhibits very little fluorine depletion upon subsequent heating. The invention involves the steps of providing a silica sol comprising a tetraalkylammonium hydroxide and a di-, tri-, or tetraalkylammonium fluoride, the sol having pH of about 10 to about 14, adding a gelling agent to the sol to induce gelation, casting or extruding the sol to form a gel body, and then drying, heat treating, and sintering the body. Advantageously, the fluorine-containing compound is tetramethylammonium fluoride.

Abstract: According to the present invention there is now provided a body of cemented carbide or cermets coated with at least one diamond layer. The diamond layer is smooth on all sides of the body with an Ra<1 &mgr;m. According to the present invention there is also provided a method for reactive ion etching of a diamond layer on a complex shape body where the etching is efficient at all sides of the body exposed to the plasma. The etching is made using a C— or oxygen-containing plasma with the possibility of etching of a diamond layer covered by an outer layer of preferably a Si containing material.

Abstract: A silica body useful for forming an optical fiber preform exhibits an ultimate strength of at least 20 MPa at 10 wt. % water loss. The body attains this strength, it is believed, by precipitation of silica at the contact sites of adjacent silica particles, thereby forming neck regions. The resultant network provides the strength to the gel body, such that the body is capable of being dried under more severe conditions than a gel body formed by previous sol-gel methods and is also more robust toward handling. The controlled precipitation is attained by inducing gelation and initiating drying at a pH of about 10.5 or higher, at which silica remains highly soluble. By gelling and drying at this pH level, the solubilized silica appears to precipitate in a controlled manner at the point of contact of adjacent silica particles, since such sites are the minimum free energy sites for precipitation.

Abstract: A method for making molded glass and ceramic articles including dispersing fine base articles in water, adding coarse base particles to form a bimodal dispersion of base particles, adding aqueous fluorine, agitating the dispersion of base particles and fluorine, and molding the dispersion of base particles and fluorine.

Abstract: A fibrous ceramic mat is molded from a slurry of ceramic fibers and/or ceramic microparticles and/or a metal. The mat is impregnated with a sol prior to drying. A catalyst for the sol is introduced into the mat to cause the sol to gel. The sol-gel binder forms bonds so that the mat is dimensionally stabilized. The mat is dried to produce the desired ceramic insulation that has preferably a consistent microstructure and a fully gelled sol-gel binder through its entire thickness. If we use a metal, it corrodes (i.e., oxidizes) or otherwise reacts to form a refractory binder that augments the sol and reduces the need to infuse sol incrementally to achieve strength. Using metal powder significantly reduces the cost of manufacture.

Abstract: The invention relates to a method of manufacturing an anti-oxidation system for porous ceramics on the basis of SiC or Si.sub.3 N.sub.4. By means of infiltration into the pore inner spaces of a sol containing at least one metal component, conversion of the sol to a gel (sol-gel process) and a subsequent high-temperature treatment, it is possible successfully to provide a crystalline anti-oxidation layer, which is resistant to temperatures of up to at least 1650.degree. C. even under cyclic temperature stresses, and reveals a heat expansion behavior adapted to the SiC or Si.sub.3 N.sub.4 over the entire temperature range used.

Abstract: Molding compositions for shaping parts from stainless steel powders are disclosed. The process comprises the steps of forming a mixture comprising stainless steel powder, a gel-forming material having a gel strength, measured at a temperature between 0.degree. C. and about 30.degree. C. and a gel comprising about 1.5 wt % of the gel-forming material and water, of at least about 200 g/cm2, and water, and molding the mixture at a temperature sufficient to produce a self-supporting article comprising the powder and gel. The preferred gel-forming material is an agaroid and the preferred molding process is injection molding.

Abstract: A method for making very strong gas mantles and other ceramic structures, and the resulting products, are provided. According to the method, an organic or composite structure is first pyrolyzed in the absence of oxygen to remove hydrogen, oxygen and nitrogen, leaving a porous carbon or composite structure, which is then impregnated with a metal compound-containing solution or slurry which is later fired in the presence of an oxidizing atmosphere to produce a refractory metal oxide which has about the same shape as the precursor carbon or composite structure. Due to minimal shrinkage of the mostly carbon or composite precursor, the resulting mantles and other ceramic structures have few defects in the fibers and great strength.

Abstract: A sol-gel process for producing dry porous gel monoliths, e.g., silica glass monoliths, in which the successive process steps of gelling, aging and drying all occur within a mold formed of a porous material, e.g., graphite. The mold is inert to the gel solution and it has sufficient strength to withstand the temperatures and pressures encountered during the process, yet it has sufficient porosity to facilitate the escape of liquid from the gel pores directly through the mold, itself. The mold and gel thereby can remain within a sealed autoclave during these process steps, and mechanical handling of the mold and the gel are minimized. This substantially enhances the process' efficiency. Alternatively, the mold can have a non-porous inner skin.

Abstract: Shaped ceramic articles can be obtained by screen printing the desired shapes from a dimensionally stable dispersion of a precursor of the ceramic onto a surface, drying the screen printed shapes so obtained and firing them to generate the shaped ceramic articles.

Abstract: A method for preparing a light metal or light metal alloy composite product, wherein (a) an aqueous slurry containing water, a reinforcement powder, a metal powder and an alumina sol binder is prepared; (b) a preform is prepared from the slurry; (c) the preform is sintered; and (d) the sintered preform is impregnated with a melt of a light metal or a light metal alloy to produce a light metal or a light metal alloy based composite product.

Abstract: A process for making ceramic composites includes the steps of: a) forming a polymer composition into a three-dimensional mold; b) filling said three-dimensional mold with one or more ceramic containing compositions; c) heating said filled mold to dry and sinter the ceramic; d) removing at least a portion of said three-dimensional mold thereby forming voids; and e) filling the voids with a second composition which has a piezoelectric coefficient which is substantially different from the piezoelectric coefficient of said ceramic structure. Steps a through e yield a controlled, non-random piezoelectric ceramic composite having 2-3, 3-2 or 3--3 connectivity with respect to the sintered ceramic and the second composition throughout the composite.

Abstract: A sintered metal mould formed by plastically forming a material consisting of a metal powder or ceramic powder being mixed with a binder consisting of agar powder, and sintering the material.

Abstract: The invention aims at providing highly reliable zinc oxide varistors through simple production steps. The varistor is produced by dispersing a powdery raw material comprising 1-40 molar % (in terms of Fe.sub.2 O.sub.3) iron, 0-20 molar % (in terms of Bi.sub.2 O.sub.3) bismuth, and the balance consisting of SiO.sub.2 in a solution of a water-soluble binder such as polyvinyl alcohol, and applying the formed dispersion to a molded or calcined zinc oxide varistor to form on the lateral face thereof a lateral high-resistance layer (2) containing Zn.sub.2 SiO.sub.4 as the principal ingredient and a solid solution of iron in Zn.sub.7 Sb.sub.2 O.sub.12 as the auxiliary ingredient.

Abstract: The new preparation process for making fine high specific surface ceramic powders suitable as catalysts or precursors for ceramics uses lanthanum (or other rare earth lanthanide) oxide as one of the precursors. The oxide is mixed with water to form a liquid slurry, whereby it is transformed to the hydroxide by reaction with water. The resulting hydroxide slurry, which can be milled to reduce the particle size and to speed up the reaction, is then combined, while stirring vigorously to assure homogenous mixing, with a solution of required amount of remaining metal nitrate precursors, for example strontium and cobalt nitrates. The reaction between lanthanum hydroxide and transition metal nitrates produces a colored (color depending on the transition metal) slurry consisting of metal hydroxides suspended in aqueous nitrate solution with pH>2. This perovskite precursor slurry is spray-frozen and freeze dried.

Abstract: A method for reinforcing thin panels or monoliths of aerogels, xergels, zeolites and other low density material with prestressed fibers in two of three dimensions (30, 32, 34). The utilization of internal molding and gas flow through channels (10) within the Aerogel monolith to achieve catalytic selectivity of the desired gas phase heterogeneous reaction. A method of internal molding (52) and decreased supercritical fluid drying times (72) for Aerogels by means of using gas porous molding features (60) that are compatable with the prestressed fiber reinforcing system (42).