Abstract: A vibrating plate-bonded body includes a supporting substrate composed of silicon, a vibrating plate composed of a highly rigid ceramics and having a thickness of 100 ?m or smaller, and a bonding layer between the supporting substrate and vibrating plate, contacting a bonding surface of the vibrating plate and composed of ?-Si. The arithmetic average roughness Ra of the bonding surface of the vibrating plate is 0.01 nm or more and 10.0 nm or less, and the pit density of the bonding surface of the vibrating plate is 10 counts or more per 100 ?m2.

Abstract: The present invention relates to injectable dermal filler compositions in the form of a gel, comprising hyaluronic acid (HA), carboxymethyl cellulose (CMC) and, optionally, microparticles such as calcium hydroxyapatite (CaHAP) microparticles. The injectable dermal filler compositions have improved rheological properties while at the same time have low extrusion forces. The present invention further relates to a method for preparing such injectable dermal filler compositions and their use for cosmetic and therapeutic purposes.

Abstract: For the purpose of producing an alumina composite in which the integrity between alumina and an inorganic material is further improved, a dispersion liquid preparation step, a solidification step and a burning step are performed, wherein the dispersion liquid preparation step comprises preparing a dispersion liquid in which an inorganic material such as a carbon material is homogeneously dispersed in an alumina raw material solution having an organic additive dissolved therein, the solidification step comprises drying the dispersion liquid to produce a solid raw material, and burning step comprises burning the solid raw material in a non-acidic atmosphere while contacting hydrogen chloride with the solid raw material. In this manner, an alumina composite can be produced, in which at least a portion of an inorganic material such as a carbon material is embedded in the inside of each of ?-alumina single crystal particles the constitute alumina particles.

Abstract: Low scatter water clear zinc sulfide with reduced metal contamination is prepared by coating a chuck which holds zinc sulfide and machining the zinc sulfide with uncoated particles. An inert foil is cleaned with an acid cleaning method and also cleaning the zinc sulfide. The zinc sulfide is wrapped in the inert foil and then treated by a HIP process to provide a low scatter water-clear zinc sulfide. The low scatter water-clear zinc sulfide may be used in articles such as windows and domes.

Abstract: A metal-oxide sintered body for a temperature sensor that can be installed in a combustion engine and components connected to the engine in order to sense temperature uses metal oxide. The metal-oxide sintered body has particles with large resistance values and particles with small resistance values mixed therein. The particles with the small resistance values may serve as a main resistance component in the temperature range of 0° C. to 500° C., and the particles with the large resistance values may contribute to the total resistance in proportion to the mixing ratio in the temperature range of 500° C. to 900° C. Thus, the metal-oxide sintered body enables a single sensor to measure all resistances, and can be used in an exhaust device or the like of a motor vehicle that requires temperature measurement over a wide range of temperatures.

Abstract: One object is to provide a deposition technique for forming an oxide semiconductor film. By forming an oxide semiconductor film using a sputtering target including a sintered body of a metal oxide whose concentration of hydrogen contained is low, for example, lower than 1×1016 atoms/cm3, the oxide semiconductor film contains a small amount of impurities such as a compound containing hydrogen typified by H2O or a hydrogen atom. In addition, this oxide semiconductor film is used as an active layer of a transistor.

Abstract: Polycrystalline alumina and methods for manufacturing polycrystalline alumina exhibiting improved transmission in the infrared region. In one embodiment, polycrystalline alumina articles are formed by providing a powder of substantially alpha phase alumina having a grain size of up to about 1 ?m, dispersing the powder in a liquid to form a slurry comprising powdered solids and liquid, removing excess of the liquid from the slurry to form a body, heating the body to provide a densified body, hot isostatically pressing the densified body under conditions to provide an article having a density of at least about 99.9% of theoretical density, and optionally annealing the article, wherein one or more of the annealing or heating are performed in an inert, dry gas.

Abstract: The present invention relates to extrudable ceramic masses and other masses which set as a result of baking or sintering, which masses comprise specific additives based on water-soluble cellulose ethers, an extrusion process, the extrudates and their use.

Abstract: The present invention uses a high-gain observer which contains the discrete-time arithmetic expressions derived from a mathematical model of an injection and pressure application mechanism in an electric-motor driven injection molding machine consisting of state equations and outputs an estimate of injection pressure, which is one of the state variables of the above state equations, by using a screw position signal and a servomotor current demand signal or actual motor current signal as inputs. The high-gain observer obtains the exact injection pressure estimate with very small time-lag without using a pressure detector. Thus the estimate of injection pressure fed by the high-gain observer can be adopted as a feedback signal of actual injection pressure for controlling injection pressure.

Abstract: Fused silica ceramics plays demanding role in high velocity missile/aircraft'radome development. Slip casting is the most common and commercially viable process utilized for radome production. Unfortunately slip casting cannot afford high density due to its poor green packing density which in turn results in poor rain erosion resistance. Present invention discloses process for preparing high density fused silica bodies by adding boron oxide (B2O3) with the commercially available high purity fused silica as sintering aid cum de-vitrification inhibitor. Various concentrations of B2O3 were added to high purity fused silica. Thus formed compositions were made into slip-castable slurries in aqueous medium without any addition of dispersing agents. The reheological properties like mild shear thinning and low thixotropic behaviour of the slurries were established. These slurries were then slip-casted in plaster of parries mold. The green and sintered properties of the casted samples were studied.

Abstract: An electronic component 100 which includes: a dielectric body (a ceramic substrate) 110 containing a dielectric ceramic composition containing Al2TeO5 as a main component; and terminals 120 each provided on a pair of opposed side surfaces of the dielectric body 110 is provided.

Abstract: A method for forming a transparent ceramic preform in one embodiment includes forming a suspension of oxide particles in a solvent, wherein the suspension includes a dispersant, with the proviso that the suspension does not include a gelling agent; and uniformly curing the suspension for forming a preform of gelled suspension. A method according to another embodiment includes creating a mixture of inorganic particles, a solvent and a dispersant, the inorganic particles having a mean diameter of less than about 2000 nm; agitating the mixture; adding the mixture to a mold; and curing the mixture in the mold for gelling the mixture, with the proviso that no gelling agent is added to the mixture.

Abstract: Methods of forming a shaped article having a matrix that contains sintered fly ash are disclosed that include forming a fly ash dough that includes fly ash and water. In one form a superplasticiser is added in the dough. A green article is formed in a desired shape from the fly ash dough that is subsequently fired so that the shaped article is hardened by sintering its fly ash matrix. In one form, the green article is cured under conditions of moderate heating and high humidity. A building element having a matrix of sintered fly ash is also disclosed.

Abstract: A method of making an expanded polytetrafluoroethylene (ePTFE) membrane including the steps of: providing an unsintered or partially sintered ePTFE membrane; matting the unsintered or partially sintered ePTFE membrane; and immediately thereafter, sintering the matted ePTFE membrane. A method for making ePTFE tubes includes the steps of: providing an unsintered or partially sintered ePTFE membrane; wrapping the ePTFE membrane around a mandrel or form tool to form an ePTFE tube; matting the ePTFE tube; immediately thereafter, sintering the matted ePTFE tube; and removing the sintered ePTFE tube from the mandrel or form tool.

Abstract: A porous ceramic substrate is disclosed that is fabricated from biosoluble ceramic fibers. Porosity and permeability of the substrate is provided by intertangled biosoluble fibers, that can be formed into a honeycomb form substrate through an extrusion process. The fibrous structure is formed from mixing biosoluble fibers with additives that include a bonding agent, and a fluid to provide an extrudable mixture. The structure is sintered at a temperature that exceeds the glass formation temperature of the bonding agent, but less than the maximum operational limits of the biosoluble fiber, to form a structure that has sufficient strength and porosity to provide for filtration and/or as a catalytic host.

Abstract: The transparent polycrystalline optoceramic has single grains with a symmetric cubic crystal structure and at least one optically active center. The optoceramic has the following formula: A2+xByDzE7, wherein ?1.15?x?0, 0?y?3, 0?z?1.6, and 3x+4y+5z=8, and wherein A is at least one trivalent rare earth cation, B is at least one tetravalent cation, D is at least one pentavalent cation, and E is at least one divalent anion. The method of making the optoceramic includes preparing a powder mixture from starting materials, pre-sintering, sintering and then compressing to form the optoceramic. Scintillator media made from the optoceramic are also described.

Abstract: The transparent polycrystalline optoceramic has single grains with a symmetric cubic crystal structure and at least one optically active center. The optoceramic has the following formula: A2+xByDzE7, wherein 0?x?1.1, 0?y?3, 0?z?1.6, and 3x+4y+5z=8, and wherein A is at least one trivalent rare earth cation, B is at least one tetravalent cation, D is at least one pentavalent cation, and E is at least one divalent anion. The method of making the optoceramic includes preparing a powder mixture from starting materials, pre-sintering, sintering and then compressing to form the optoceramic. Scintillator media made from the optoceramic are also described.

Abstract: A method of sintering a ZrB2—SiC composite body at ambient pressures, including blending a first predetermined amount of ZrB2 powder with a second predetermined amount of SiC powder, wherein both powders are characterized by the presence of surface oxide impurities. Next the blended powders are mixed to yield a substantially homogeneous powder mixture and a portion of the substantially homogeneous powder mixture is formed into a green body. The body is fired to a first temperature, wherein substantially all surface oxide impurities are reduced and/or volatilized to substantially eliminate oxides from the green body, and the body is heated to a second temperature and sintered to yield a composite body of at least about 99 percent theoretical density and characterized by SiC whisker-like inclusions distributed substantially evenly in a ZrB2 matrix.

Abstract: A porous ceramic substrate is disclosed that is fabricated from biosoluble ceramic fibers. Porosity and permeability of the substrate is provided by intertangled biosoluble fibers, that can be formed into a honeycomb form substrate through an extrusion process. The fibrous structure is formed from mixing biosoluble fibers with additives that include a bonding agent, and a fluid to provide an extrudable mixture. The structure is sintered at a temperature that exceeds the glass formation temperature of the bonding agent, but less than the maximum operational limits of the biosoluble fiber, to form a structure that has sufficient strength and porosity to provide for filtration and/or as a catalytic host.

Abstract: There is disclosed a pre-sintering process for reducing non-uniformities in the density of a sintered material comprising (a) providing a mixture of (i) a first sinterable material containing a contaminant the presence of which during sintering of the first sinterable material results in a higher vapor pressure than would occur during sintering of pure first sinterable material and (ii) a second material having a higher affinity for the contaminant than does the first sinterable material; and (b) heating the mixture at a temperature and for a time sufficient to allow the second material to at least partly mitigate the propensity of the contaminant to raise the vapor pressure during the sintering of the first sinterable material. Other embodiments are also disclosed.

Abstract: An insulating target material for obtaining a conductive complex oxide film represented by a general formula ABO3, the insulating target material including an oxide of an element A, an oxide of an element B, and at least one of an Si compound and a Ge compound.

Abstract: The invention relates to an endoprosthesis component which is formed from a ceramic material and in which the ceramic material is partially coated with a titanium alloy. An uncoated surface portion of the endoprosthesis component is designed to interact as slide surface with another endoprosthesis component. A coated surface portion of the endoprosthesis component is designed to establish a connection to a bone. According to the invention, the part of the ceramic material forming an interface to the coating has a roughness Ra of between 2.5 ?m and 7 ?m. This creates a firm connection between the coating and the ceramic material. The invention further relates to a method for producing such an endoprosthesis component. The invention relates finally to a method for producing a ceramic component that can serve as a basis for an endoprosthesis component according to the invention. To achieve the desired roughness of the surface, the ceramic component is presintered at a temperature of between 880° C. and 980° C.

Abstract: The present invention relates to a process for the production of sintered three-dimensional strips of shaped bodies and for the production of the shaped bodies from a pulverulent, inorganic material, to sintered three-dimensional shaped bodies and to the use of the sintered, three-dimensional shaped bodies as shot pellets, munitions, angling weights, for balancing tires, as oscillating weight in clocks, for radiation screening, as a balancing weight in drive motors and engines, for the production of sports equipment or as a catalyst support.

Abstract: A method for manufacturing a diamond composite, includes: a) mixing diamonds with additives, the mixture comprising at least 50 wt % and less than 95 wt % of diamonds and more than 5 wt % additives; b) forming a work piece from the mixture using a pressure of at least 100 Mpa; c) heating the formed work piece to at least 300° C. for removing possible water and wholly or partially removing additives; d) heating the work piece and controlling the heating temperature and heating time so that a certain desired amount of graphite is created by graphitization of diamonds, wherein the amount of graphite created by graphitization is 3-50 wt % of the amount of diamond; e) infiltrating silicon or silicon alloy into the work piece.

Abstract: A spacer assembly has first and second spacers that are set up integrally on first and second surfaces, respectively, of a substrate. Each spacer is tapered toward its extended end. In forming the spacer assembly, first and second molding dies having through holes coated with a parting agent that contains an organic component are prepared, and these molding dies are located on the first and second surfaces of the substrate so as to be intimately in contact with them, individually. Thereafter, a spacer forming material is filled into the through holes of the molding dies and cured, whereupon the first and second spacers are formed integrally on the substrate surfaces.

Abstract: A transparent aluminum oxynitride product is produced by a first heat treating step wherein a combination of Al2O3 and AlN at a temperature within the solid-liquid phase and a second step of sintering the heat treated combination at a temperature at least 50° C. less than the heat treating temperature. The method introduces a small fraction of liquid that aids in pore elimination and densification. In a single step, the material is shifted from the liquid/solid region into a solid AlON solution region, wherein the liquid is fully reacted with the solid AlON phase, with further sintering occurring. The procedure is sufficient to eliminate voids and other imperfections which often result in a reduction in optical clarity.

Abstract: A SiAlON-based ceramic particularly suited for use as a cutting tool in the high speed chip forming machining of metals composed of a SiAlON matrix including a) a phase of alpha′ SiAlON represented by the general formula of Mx (Si,Al)12(O,N)16, wherein 0<x<2 and M is at least two cationic elements, a first cationic element being 0.2 to 4 weight percent Mg and optionally between 0.5 and 15 weight percent of one or more of Ca, Sr, and Ba calculated as oxide, based on the SiAlON matrix, and a second cationic element being one or more of Y, Sc, La and the rare earth (RE) elements; b) a phase consisting of beta′ SiAlON represented by the general formula Si6−zAl2OzN8−z wherein 0<z<4.2; and c) a component containing glass, and at least one additional intergranular crystal phase that is detectable using X-ray diffraction techniques is provided.

Abstract: A spacer assembly has first and second spacers that are set up integrally on first and second surfaces, respectively, of a substrate. Each spacer is tapered toward its extended end. In forming the spacer assembly, first and second molding dies having through holes coated with a parting agent that contains an organic component are prepared, and these molding dies are located on the first and second surfaces of the substrate so as to be intimately in contact with them, individually. Thereafter, a spacer forming material is filled into the through holes of the molding dies and cured, whereupon the first and second spacers are formed integrally on the substrate surfaces.

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: The invention relates to a method for producing high-density, translucent, scintillator ceramics by means of a pressure-less sintering carried out at an elevated temperature. According to the method, particles of a MOS composition are prepared using a specific wet milling method whereby being reduced, in particular, to a particle size of less than 10 &mgr;m. The particles are compacted to form compacted bodies with green densities of up to 50% and higher. The sintering is carried out under specific sintering parameters.

Abstract: A particulate silicone based material and method for forming a heat resistant composite is provided. The particulate silicone based material is heated to a temperature between about 200° F. and about 400° F. The particulate silicone based material is cooled until a solid composite is formed. The solid composite is resistant to melting and thermal decomposition when heated to temperatures of at least 3000° F. The particulate silicone based material may be formed by mixing liquid silicone resin with a catalyst and powdered silicone molding compound.

Abstract: A permanent, biocompatible material for soft tissue augmentation. The biocompatible material comprises a matrix of smooth, round, finely divided, substantially spherical particles of a biocompatible ceramic material, close to or in contact with each other, which provide a scaffold or lattice for autogenous, three dimensional, randomly oriented, non-scar soft tissue growth at the augmentation site. The augmentation material can be homogeneously suspended in a biocompatible, resorbable lubricious gel carrier comprising a polysaccharide. This serves to improve the delivery of the augmentation material by injection to the tissue site where augmentation is desired. The augmentation material is especially suitable for urethral sphincter augmentation, for treatment of incontinence, for filling soft tissue voids, for creating soft tissue blebs, for the treatment of unilateral vocal cord paralysis, and for mammary implants. It can be injected intradermally, subcutaneously or can be implanted.

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: Method of making a ceramic core for casting an industrial gas turbine engine airfoil having a large airfoil pitch by forming a precursor core (chill) of smaller dimensions than the final desired ceramic core, firing the chill, applying a thin ceramic skin to the fired chill to form a coated core of final dimensions, and then firing the coated core. Firing of the thin ceramic skin reduces airfoil pitch shrinkage resulting from the latter firing operation to reduce overall core dimensional tolerance variations.

Abstract: A method of manufacturing large thin wall ceramics board includes pulverizing and uniformly mixing, in dry content conversion, plasticity clay in an amount of 30-40% by weight, wollastonite having an aspect ratio of more than 10 in an amount of 20-50% by weight, and feldspar and talc in an amount of 10 50% by weight to form a mixture. The mixture is added with a solution having a 16-21% weight of the weight of this mixture. The solution has 10% by weight of a paraffin emulsion. The clay-like composition is extruded with a vacuum kneading machine to form a cylindrical shape. The extruded clay-like composition is made into dough board compact of desired thickness after being partially cut parallel to the cylinder. The dough board compact is heated to approximately 80 degrees Celsius with far infrared radiation.

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: Method of making a ceramic core for casting an industrial gas turbine engine airfoil having a large airfoil pitch by forming a precursor core (chill) of smaller dimensions than the final desired ceramic core, firing the chill, applying a thin ceramic skin to the fired chill to form a coated core of final dimensions, and then firing the coated core. Firing of the thin ceramic skin reduces airfoil pitch shrinkage resulting from the latter firing operation to reduce overall core dimensional tolerance variations.

Abstract: In a method of manufacturing piezoelectric ceramics by molding pre-fired or calcined powders of ingredients of a piezoelectric ceramic material and sintering the powder mold at a high pressure, the powder mold is pre-sintered at an atmospheric pressure before sintering at high pressure (HIP). Preferably, after the sintering HIP step, a thermal treatment is performed at a temperature of from 500 to 1000.degree. C. under an oxidizing atmosphere. For a Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 --PbTiO.sub.3 based piezoelectric ceramic, the composition is preferably set to (Pb.sub.1-x Ba.sub.x)[(Zn.sub.1/3 Nb.sub.2/3).sub.1-y Ti.sub.y ]O.sub.3, where 0.001<x<0.055 and 0.05<y<0.20.

Abstract: A solar-cell watch dial to be disposed on or above a solar cell housed in a watch, the solar-cell watch dial including an alumina of the formula Al.sub.2 O.sub.3 whose purity is at least 99.90% and exhibiting a light transmission ranging from 40 to 60%. The invention also includes a process for producing a solar-cell watch dial, which includes the steps of: mixing together an alumina of the formula Al.sub.2 O.sub.3 whose purity is at least 99.90%, an organic binder and water to thereby obtain an Al.sub.2 O.sub.3 mixture (A); drying and granulating the Al.sub.2 O.sub.3 mixture to thereby obtain a granular material (B); molding the granular material into a plate dial precursor (C); firing the dial precursor at 700 to 1500.degree. C. in atmospheric environment to thereby obtain a preliminary firing product (D); and firing the preliminary firing product at 1500 to 1800.degree. C. under a pressure of 1.times.10.sup.-2 to 1.times.10.sup.-5 torr for 1 to 10 hr to thereby obtain a solar-cell watch dial (E).

Abstract: A process for manufacturing a ceramic metal composite body in the case of which a dimensionally stable and porous sacrificial body is produced from ceramic initial products and is filled at a filling temperature with a softened metal, particularly under an increased pressure. The filled sacrificial body is heated to a reaction temperature and the metal to be filled in, BMe, is reacted with a metal of the ceramics. KMe, forming the ceramic metal composite body which has a ceramic phase having KMe.sub.m B.sub.x and/or KMe.sub.n C.sub.y and/or KMe.sub.o CN and BMe.sub.p O.sub.3 and has a metallic phase having an intermetallic compound which is formed of KMe and BMe, the filling temperature being lower than the reaction temperature and higher than or equal to the softening temperature of the metal.

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 making a ceramic arc tube for a metal halide lamp comprises the steps of forming as an integral unit a hollow body having one open end and a substantially closed end. The substantially closed end includes an outwardly extending capillary tube having an electrode receiving aperture therein that communicates with the hollow body. An end cap is then formed for closing the open end. The end cap comprises an annular portion and an extending capillary tube, The end cap is fitted into the open end of the hollow body to form a pre-assembly. The pre-assembly is then fired to seal the end cap to the hollow body to form an assembly and the assembly is subsequently fired to sinter the same.

Abstract: Process for making graded porosity ceramics. A process for making graded porosity ceramics is described which includes the steps of placing a chosen amount of ceramic powder into a mold, compacting the ceramic powder into a green body, applying at least one sintering aid precursor to at least one chosen surface of the green body, allowing the at least one sintering aid precursor to penetrate the at least one surface within a chosen volume of the green body, heating the green body, whereby the sintering precursor generates a sintering aid, and hot pressing and sintering the heated body at a temperature whereby the green body is transformed into the sintered ceramic object.

Abstract: A process for the production of dense polycrystalline silicon carbide shaped articles; includes (a) heating a powder compact containing silicon carbide and alumina or a precursor thereof to an intermediate temperature, and maintaining the said intermediate temperature for an extended dwell, and then (b) heating the product of step (a) to a higher temperature for sufficient time to produce a dense polycrystalline silicon carbide product.

Abstract: A process for the production of dense polycrystalline silicon carbide shaped articles, includes the steps: (a) heating a powder compact containing silicon carbide and alumina or a precursor thereof together with a secondary sintering assist, to an intermediate temperature for an extended dwell, and then (b) heating the product of step (a) to a higher temperature for sufficient time to produce a dense polycrystalline silicon carbide product. The secondary sintering assist includes one or more rare earths or their precursors, for example scandia, yttria or dysprosia.

Abstract: The invention is directed to a method of firing ceramics and a furnace for manufacturing ceramics. Ceramic forms are first fired in a cylindrical heat resistant container in a furnace core tube by using a lateral tubular furnace to increase their mechanical strength. Then, the container is rotated while the ceramic forms are fired further in a predetermined temperature region, which includes a maximum temperature. In this manner the ceramic forms are heated in a uniform state, both thermally and atmospherically, while receiving moderate impact by rotation, and defective appearance and fluctuations in the characteristics of the ceramics are suppressed. In particular, the container is rotated within a temperature region which is higher than the temperature used to start increasing the mechanical strength of the ceramic forms. Further, the ceramic forms can be packed into the container at a higher rate during the rotation portion of the process than during the first firing.

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.