Abstract: A method for dry process recycling of mixed (U,Pu)O2 oxide nuclear fuel waste, including a process for making fuel pellets of mixed (U,Pu)O2 oxide, including a dosage and a first mixture (1) of waste in powder form and, if required, of PuO2 and/or UO2 powders, a micronization (2) and a forced sieving (3) of said first mixture, another dosage and a second mixture (4) of the first sieved mixture, of UO2 powders and, if necessary, of the waste powder, pelletizing (6) the second mixture, and sintering (7) the resulting pellets; and a process for pre-treating the waste including pelletizing (20) and sintering (21) the powder waste to form waste pellets, and micronizing (23) the waste pellets to form the desired waste powder designed to be incorporated as waste powder, in the first (1) and/or second mixtures.

Abstract: It is directed to a silicon carbide-based porous body, wherein said body is a porous one which contains silicon carbide particles as an aggregate and metallic silicon, and has an oxygen-containing phase at the surfaces of silicon carbide particles and/or metallic silicon or in the vicinity of the surfaces thereof. The silicon carbide-based porous body contains refractory particles such as silicon carbide particles or the like and yet can be produced at a relatively low firing temperature at a low cost, has a high thermal conductivity, and is superior in oxidation resistance, acid resistance, chemical resistance to ash and particulates.

Abstract: A ceramic material suitable for use in production of paving tiles, construction tiles, flooring in offices, flooring in machinery plants and so forth is obtained by a method comprising steps of mixing defatted bran derived from rice bran with a thermosetting resin before kneading, subjecting a kneaded mixture thus obtained to a primary firing in an inert gas at a temperature in a range of 700 to 1000° C., pulverizing the kneaded mixture after the primary firing into carbonized powders, kneading the carbonized powders with which ceramic powders, a solvent, and a binder as desired are mixed into a plastic workpiece (kneaded mass), pressure-forming the plastic workpiece at pressure in a range of 10 to 100 MPa, and subjecting a formed plastic workpiece thus obtained again to firing in an inert gas atmosphere at a temperature in a range of 100 to 1400° C.

Abstract: A particulate filter for diesel engines comprises a metal shell or casing inside which is set a filtering body made of ceramic foam. The filtering body is made up of a plurality of separate elements made of ceramic foam and having a substantially plane and elongated shape, which are set about a longitudinal axis of the shell in such a way as to define, inside the shell, an inner chamber (B) set inside the array of filtering elements and at least one outer chamber (A) set outside the array. The said chambers respectively communicate with the intake pipe and with the outlet pipe, or vice versa, in such a way that, during use, the flow of the engine exhaust gases that traverses the shell passing from the intake pipe to the outlet pipe (or vice versa) is forced to traverse the aforesaid filtering elements, thus assuming a component of radial velocity with respect to the longitudinal axis of the shell.

Abstract: A pipe blanket is provided for wrapping around and insulating a pipe. The pipe blanket comprises an insulation mat having an outer surface and an inner surface adapted to lie adjacent the pipe when the pipe blanket is wrapped around the pipe. An outer cover of the pipe blanket is coupled to the outer surface of the insulation mat. The insulation mat is configured to enclose a variety of pipes having different sized diameters. The pipe blanket further includes a closure means configured for securing the insulation mat and outer cover about the pipe. The insulation mat further includes a plurality of pleats.

Abstract: The volume resistivity of a body consisting essentially of aluminum nitride is reduced by exposing the body to a soak temperature of at least about 1000° C. in an atmosphere deficient in nitrogen, such as an atmosphere consisting essentially of argon. The body can be, for example, a green body of aluminum nitride powder of a densified, or sintered body, such as a polycrystalline body. An electrostatic chuck has an electrode within a chuck body. A first portion of the chuck body, at a first side of the electrode, has a volume resistivity less than about 1×1013 ohm·cm at about 23° C. A second portion of the body, at a second side of the electrode, has a volume resistivity within one order of magnitude that of the first portion.

Abstract: A lithium-aluminosilicate glass ceramic is transformed by a suitable heat treatment into a glass ceramic comprising at least 80 vol.-% of keatite mixed crystals. This may be utilized for the preparation of optical or mechanical high-precision parts having a high temperature resistance, a good stability and compatibility with components consisting of metals having a small coefficient of thermal expansion based on nickel and iron, such as Invar®.

Abstract: An oxidation resistant carbon composite material comprises nanocrystalline silicon carbide regions distributed throughout a carbon matrix. The composite is prepared by intermixing in a solvent a silicon carbide precursor and a carbon precursor and forming a solution that is free of solids. After removing the solvent from the mixture, the remaining material is pyrolyzed and forms the characteristic nanocrystalline silicon carbide in a carbon matrix. A composite made by the subject method and a part made from the composite are also provided.

Abstract: A method for producing electroceramic materials of high sintered density from hydroxide and/or oxalate precursors is disclosed. In this method the precursor(s) are compacted to form a preform, thermally treated, recompacted and then sintered to form finished products.

Abstract: An initial resin substrate is formed by laminating resin layers, and one surface of the initial substrate is heated and pressed by a molding die to mold a projected and dented surface such that substantially no deformation occurs on the resin layer providing a surface opposed to the one surface of the initial substrate. A reversible image display medium is produced by a method comprising the steps of accommodating a dry developer into the concavities and fixing a second substrate to the first substrate using an adhesive. Alternatively a reversible image display medium may be produced by, e.g.

Abstract: The invention is a method of producing a ceramics material comprising the steps of: preparing a raw powder in which alumina particles having an average particle diameter of 0.1-1.0 &mgr;are doped with at least magnesia of 0.01-1 weight % and a solution containing yttrium of 0.1-15 weight % in yttria; molding said raw powder and calcining a molding thus created; and heating the calcined molding in an atmosphere containing a hydrogen gas to create YAG which is leached to the surface to deposit YAG on the surface and sintering the molding.

Abstract: A sintered ceramic for a scintillator having a composition represented by the general formula of Gd3-xCexAlySizGa5-y-zO12, wherein 0.001≦x≦0.05, 1≦y≦4, and 0.0015≦z≦0.03, is produced by mixing gadolinium oxide, aluminum oxide, gallium oxide, a cerium salt, a silicon compound and a fluorine compound in such proportions as to provide the above composition; calcining the resultant mixture at a temperature of 1400-1600° C.; disintegrating the resultant calcined body to ceramic powder; pressing the ceramic powder to provide a green body; and sintering the green body at a temperature of 1600-1700° C. in a non-oxidizing atmosphere at 5×104 Pa or more, and optionally further by hot isostatic pressing at a temperature of 1400-1600° C. in an argon atmosphere.

Abstract: A process for producing crack-free shaped ceramic bodies based on Si/C/N by hot pressing of crosslinked polysilazane powder and subsequent pyrolysis of the hot-pressed shaped body employs a pressing temperature higher than the temperature maximum of the TMA curve of the optimally crosslinked polymer.

Abstract: A method for manufacturing an artificial reef based on industrial waste is disclosed. Industrial wastes, including red mud, blast furnace slag, the sludges from the factories of refining raw ore, broken pieces of glass, the stone powders from the anti-pollution facilities equipped in stone- or aggregate-extracting spots, the slurries from the terminal treatment plants of water and sewage, the ashes from the incinerators for household wastes, the pulp sludges and slurries from paper mills, the coal ashes from thermoelectric power plants, and the side-products produced upon coal mining, are utilized, alone or in combination with a plasticizer and a mineralizer, in constructing artificial fishing reeves through pug-milling, molding and thermal treatment processes. The artificial fishing reef, through which the industrial wastes are converted into environment-affinitive resources, have advantages of being economically favorable and producing no pollution of the environment.

Abstract: Ceramic monoliths are described which exhibit tunable coefficients of thermal expansion from about −5 to −11×10−6° C.−1 near ambient temperatures. These two-phase ceramics, which are fabricated, for example, by reactive sintering of WO3 and ZrO2, consists of a matrix of ZrW2O8 with inclusions of ZrO2 having diameters less than 10 &mgr;m. Additives may increase the density of the monoliths to greater than 98% of the calculated density. Green body densities, pre-sintered particle size distribution, sintering atmosphere, microstructure, and mechanical properties are discussed. These ceramics may be used as substrates for thermally compensating fiber Bragg gratings.

Abstract: The application discloses a number of unique sintered quartz glass products together with new silica compositions and processes for making and using such products. Nitrided clear and opaque nitrided quartz products are disclosed having incredible physical properties resulting from the incorporation of very small, but effective, amounts (e.g., 25 ppm or more) of chemically bound nitrogen. Opaque quartz glass heat shields with remarkable resistance to transmission of infrared radiation are disclosed which can have a high bubble population density, such as 80 to 120 per mm2. These heat shields make possible remarkable improvement in the performance of tube furnaces and other reactors used in processing silicon wafers and other electronic components.

Abstract: Spherical-shape ceramics obtained by dropping starting ceramics into a low temperature medium or composite spherical-shape ceramics having a composite layer obtained by applying a hydrothermal treatment thereto.

Abstract: The present invention concerns a moulded microcrystalline spherical Al2O3- sintered body, process for its production as well as its use.

Abstract: A method for changing the dielectric properties of a polymer impregnated and pyrolyzed ceramic matrix composite (polymer impregnated and pyrolyzed ceramic matrix composite) is disclosed. The polymer impregnated and pyrolyzed ceramic matrix composite can be used in aircraft and turbine engines. polymer impregnated and pyrolyzed ceramic matrix composite comprises a ceramic matrix, a reinforcing fiber, and at least 1 additive used to change dielectric properties (dielectric constant and loss factor). The additive can be a low dielectric constant material having a dielectric constant in the range of 1 to 7.5. The low dielectric constant material can be an oxide such as silica or aluminosilicate or a non-oxide such as silicon nitride, boron nitride, or silicon carbide. The low dielectric constant material can be incorporated in the ceramic matrix as a filler.

Abstract: The present invention concerns a moulded microcrystalline spherical Al2O3- sintered body, process for its production as well as use.

Abstract: The aluminum nitride sintered body of the invention has a thermal conductivity equivalent to that of a high purity aluminum nitride sintered body and a volume resistivity of 1014 &OHgr;·cm or less, and is composed of aluminum nitride phase and yttrium aluminum oxide phase formed at grain boundaries of aluminum nitride phase, where the yttrium aluminum oxide phase is 0.5 to 10 wt % in extremes for aluminum nitride phase, and contains at least one kind of lanthanide element 0.1 to 20 atom % in extremes for yttrium element.

Abstract: An economical process for the manufacture of a polycrystalline, sintered, ceramic abrasive from a powder raw material is described, which process is characterized by the following process steps: preparation of a slip largely free from polymerizing and/or coagulating additives from the powder raw material; pressureless shallow casting of the slip in a vessel; degassing, drying and crushing of the cast sheet to obtain a fabricated material and sintering of the fabricated material to create the abrasive. This process can be used to manufacture an abrasive that permits extremely high grinding performance due to its extraordinary density and structural integrity.

Abstract: There is disclosed a silicon nitride sintered body produced by sintering a molded article which comprises a mixture of a silicon nitride powder as the main component and plural kinds of sintering additives, wherein said silicon nitride powder is set to be 0.1 to 1.0 &mgr;m in average grain size, and said plural kinds of sintering additives includes first and second sintering additives, said first sintering additive comprising oxide powders of at least one element of Group 3a element, said second sintering additive comprising oxide powders of at least one element selected from Zr (zirconium), Hf (hafnium), Nb (niobium), Ta (tantalum) and W (tungsten), said first sintering additive having the average grain size set to be 0.1 to 10 times as large as the average grain size of said silicon nitride powder and being incorporated in an amount ranging from 0.

Abstract: An indium oxide/tin oxide powder with 5-15 wt. % tin oxide is subjected to an annealing treatment at T≧1, 000° C. and is then partially reduced and subjected to hot isostatic pressing to produce a sputtering target with a density of at least 95% of the theoretical density and a thermal conductivity of at least 14 Wm−1K−1.

Abstract: The present invention provides a silicon nitride sintered body having characteristics such as excellent wear resistance, a method for manufacturing the sintered body, and a cutting insert formed thereof. The silicon nitride sintered body is formed of a polycrystalline sintered body of predominantly .beta.-Si.sub.3 N.sub.4, wherein the oxygen content is 1.2-1.5 wt. %. The method for manufacturing the silicon nitride sintered body includes the following steps: adding an organic binder to a composition containing silicon nitride as an essential component and exhibiting a theoretical oxygen content of 2.0-3.0 wt. %; heating to remove the binder; introducing an oxygen-containing gas so as to control the carbon content to 0.10-0.60 wt. %; and sintering a resultant compact in an nitrogen atmosphere to control the oxygen content to 1.2-1.5 wt. %. The cutting insert of the present invention has excellent wear resistance.

Abstract: The invention relates to the field of ceramics and concerns sintered Al.s2 O.sub.3 compositions produced from corundum powder and also methods for the use of the invented compositions as medical implants or tool material. To produce such materials, an initially unsintered precursor having a relative density of .rho..gtoreq.55% is produced from .alpha.-Al.sub.2 O.sub.3 powder having defined properties using at least two different dispersing methods, this precursor is subsequently subjected to heat treatment and sintering.

Abstract: A tunnel kiln for firing ceramic honeycomb structural body comprising a vestibule region, a carbonaceous material release region located downstream of the vestibule region and a sintering region located downstream of the carbonaceous material release region and having a multiplicity of kiln cars adapted to convey materials to be fired through the kiln. A gas distribution system is provided which includes a series of conduits each which operatively communicates with an injection site which operatively communicates with the interior of the release region for introducing a gas into the carbonaceous release region. The injection sites include a combustion burner located site, a vestibule located site, an undercar located site, a rooftop located site, and a sidewall located site or combinations thereof.

Abstract: A controlled dielectric loss, sintered aluminum nitride body having a density of greater than about 95% theoretical, a thermal conductivity of greater than about 100 W/m-K, and a dissipation factor measured at room temperature at about 1 KHz selected from:(a) less than or equal to about 0.001; and(b) greater than or equal to about 0.01.A process for producing a controlled dielectric loss, sintered aluminum nitride body, comprising heat treating an aluminum nitride body at sintering temperatures, including providing a heat treatment atmosphere which effects a selected nitrogen vacancy population in the aluminum nitride body at the sintering temperatures, and cooling the aluminum nitride body from sintering temperatures at a controlled rate and in a cooling atmosphere effective to control the selected nitrogen vacancy population.

Abstract: A number of unique processes are disclosed for manufacture of sintered high-purity quartz glass products in which a shaped silica body or preform is made from an aqueous slurry of micronized silica particles by gel casting, slip casting or electrophoretic deposition. The silica particles may comprise a major portion by weight of crystalline silica. In one embodiment of the invention the sintered quartz glass is transparent, substantially bubble-free and suitable for scientific or optical uses. In another embodiment the porous silica preform is fired in steam to increase the hydroxyl content and then nitrided in a nitrogen-hydrogen reducing atmosphere. A minute amount of chemically-combined nitrogen in the high-purity quartz glass is sufficient to provide a tremendous improvement in physical properties and an incredible increase in the resistance to devitrification.

Abstract: A method of calcining kaolin, comprising the steps of:a) producing a clay slurry comprised of water and kaolin clay of a specific particle size;b) mixing a water insoluble potassium containing glass forming compound into the clay slurry in an amount wherein the potassium content of the slurry is equal to about 1% by weight of the kaolin clay in the slurry;c) removing sufficient water from the slurry to form a material having an extrudable consistency;d) extruding the material into elongated shapes;e) heating the shapes by continuously moving them through a furnace having a zone, wherein the material is exposed to temperatures of at least 2700.degree. C. for at least 30 minutes.

Abstract: A single furnace loading cycle method for sintering at least one product comprises placing at least one product into a ventable/sealable box, and placing the box within the furnace. The box is vented inside the furnace at a first temperature range and the product is sealed inside the box in a second temperature range, wherein the second temperature range is higher than the first temperature range. The box includes a closeable top cover and a control means that comprises a first set of collapsible spacers which hold open the cover at temperatures below the first temperature range and collapse to lower the cover into sealing engagement with the box at temperatures above the first temperature range. The box further comprises a substrate to be sintered with a lower and an upper setter on opposite sides of the substrate.

Abstract: These methods relate to the preparation of a YBa.sub.2 Cu.sub.3 O.sub.7 -d catalyst for purifying an exhaust gas. The method comprises steps of mixing Y.sub.2 O.sub.3, Ba.sub.2 CO.sub.3 and CuO at a mole ratio of 1:4:6, respectively; grinding the resultant mixture to obtain fine powder having a size of at least 200 mesh; sintering the fine powder at temperature of 800.degree. C. to 900.degree. C. under an atmosphere of oxygen; annealing the fine powder to room temperature; pelletizing the powder to form pellets; grinding the pellets to obtain fine powder having a size of at least 200 mesh; re-sintering the resultant fine powder at a temperature of 800.degree. C. to 920.degree. C.; and re-annealing the fine powder to room temperature.

Abstract: A method for forming dendritic metal powders, comprising the steps of: (1) heating a powder comprising non-dendritic particles, under conditions suitable for initial stage sintering, to form a lightly sintered material; and (2) breaking the lightly sintered material to form a powder comprising dendritic particles. In one embodiment, the lightly sintered material is broken by brushing the material through a screen. Another aspect of the present invention comprises the dendritic particles that are produced by the method described above. These particles can comprise any suitable metal, such as transition metals, rare earth metals, main group metals or metalloids or an alloy of two or more such metals. The particles can also comprise a ceramic material, such as a metal oxide. These particles are characterized by a dendritic, highly anisotropic, morphology arising from the fusion of substantially non-dendritic particles, and by a low apparent density relative to the substantially non-dendritic starting material.

Abstract: A single crystal silicon sheet is formed from a polycrystalline sheet by melting a relatively small portion of the sheet at an initial location and defining a single crystallographic orientation for the silicon by placing a small silicon seed crystal in contact with the melted silicon at the initial location. The melted portion is then moved from the initial location throughout the sheet to move impurities in the sheet to the edges of the sheet and to extend the crystallographic orientation of the silicon established at the initial location to the whole sheet, inwardly of the edges. The edges containing impurities and any remaining polycrystalline structure are removed to produce a sheet of single crystal silicon. A polycrystalline sheet may be formed by spreading a slurry of a silicon powder, a binder, and solvent on a surface and allowing the solvent to evaporate to form a sheet. The sheet is moistened to cause it to expand and sheer clear of the surface.

Abstract: A process is proposed for producing non-oxidic ceramic having a thermal conductivity in a predetermined range. A shaped body of non-oxidic ceramic material is heated to remove organic constituents, and is subsequently thermally treated in an oxygen-containing atmosphere to incorporate oxygen atoms into the crystal lattice of the non-oxidic ceramic, with the temperature and/or the hold time at this temperature being selected as a function of the predetermined thermal conductivity range, and the shaped body is finally sintered in a non-oxidizing atmosphere.

Abstract: Microcrystalline bodies based on .alpha.-Al.sub.2 O.sub.3 are made by drying sub-micron powders, press compacting and shock sintering at an intermediate sinter temperature range of 1,300.degree. to 1,550.degree. C., i.e. bringing the compact up to such range in under 60 seconds, preferably under 10.