Abstract: Disclosed is a proppant core, having low density and high strength and a process for its production. The proppant core is especially useful in crude oil and natural gas extraction. The proppant properties are achieved by virtue of the raw material mixture consisting of melt phase former and at least one further component and containing less than 35% Al2O3. The process includes mixing the raw material components, homogenizing, granulating and then thermally treating the cores.

Abstract: ESD safe ceramic component is provided which includes a sintered composition which is formed of a base material and a resistivity modifier. The base material includes a primary component and a secondary component, the primary component including Al2O3 and the secondary component including tetragonal-ZrO2.

Abstract: An injectable heat generating biocompatible ceramic compositions based on hydraulic calcium aluminate, which can be used for therapeutic treatment in vivo, such as tumour treatment, pain control, vascular treatment, drug activation etc, when curing in situ, and which form a biocompatible solid material that can be left in the body for prolonged periods of time without causing negative health effects, and can also be used to restore the mechanical properties of the skeleton after cancerous diseases as well as in a medical implant, an orthopaedic implant, and a dental implant as a dental filling material.

Abstract: The invention presents yttria elements containing high-density chrome based refractory composites, which consist of: (A) Fused polymeric compound as aggregate, containing: 40 to 50 wt % of particles in size from 1 to 4 mm and 15 to 25 wt % of particles in size below 1 mm; (B) A matrix consisting of fused polymeric compounds with particle sizes below 66 ?m, active sintered Al2O3, active industrial Cr2O3 and Y2O3, (C) Binders accounting for 2.5 to 3.5 wt %. Since Y2O3 has resistance to the slag corrosion and penetration with its compatibility with slag, it has been introduced to activate the major component Cr2O3 crystal lattice in favor with Al2O3 so that it helps to reduce the sintering temperature, increase the rate of finished products as well as reduce the manufacturing cost.

Abstract: A sintered body for thermistor device comprising: at least one element selected from elements of group 3 in a periodic table proviso that La is excluded; at least one element selected from elements of group 2 in a periodic table; Mn; Al; and oxygen, and being substantially free from any transition metal other than Mn and the at least one element selected from elements of group 3 in the periodic table.

Abstract: A ceramic body, as well as a method of making the ceramic body, wherein in one aspect a hot-pressing method is used to produce the ceramic body. In another aspect, a sintering to full density method is used to produce the ceramic body. The hot-pressed ceramic body contains between about 15 volume percent and about 35 volume percent of a boron carbide phase and at least about 50 volume percent of alumina, and the substrate has a fracture toughness (KIC, 18.5 Kg Load E&C) greater than or equal to about 4.5 MPa·m0.5. The sintered to full density ceramic body contains between about 15 volume percent and about 50 volume percent of a boron carbide irregular-shaped phase and at least about 50 volume percent alumina.

Abstract: A method of preparing spherical pellets from a slurry comprising a ceramic powder, a solvent, and any desired additives, by means of a drop-generating orifice to which said slurry is fed is described, wherein the drops are released from said orifice by means of a relative flow of a liquid medium which is a poor solvent for the solvent of the slurry, formed into spherical bodies in said liquid medium by means of the action of surface tension, and thereafter treated for consolidation. More specifically, the present invention relates to the preparation of pellets of a catalyst or catalyst support material, suitable for use in high temperature conditions.

Abstract: A substrate holding structure having excellent corrosion resistance and airtightness, excellent dimensional accuracy and sufficient durability when mechanical or thermal stress is applied thereto is obtained. A holder (1) serving as the substrate holding structure includes a ceramic base (2) for holding a substrate, a protective cylinder (7) joined to the ceramic base (2) and a joining layer (8) positioned therebetween for joining the ceramic base (2) and the protective cylinder (7) to each other. The joining layer (8) contains at least 2 mass % and not more than 70 mass % of a rare earth oxide, at least 10 mass % and not more than 78 mass % of aluminum oxide, and at least 2 mass % and not more than 50 mass % of aluminum nitride. The rare earth oxide or the aluminum oxide has the largest proportional content among the aforementioned three types of components in the joining layer (8).

Abstract: The present invention pertains to a quasi-crystalline boehmite containing additive in a homogeneously dispersed state. Suitable additives are compounds containing elements selected from the group of alkaline earth metals, alkaline metals, rare earth metals, transition metals, actinides, silicon, gallium, boron, titanium, and phosphorus. Said QCBs according to the invention may be prepared in several ways. In general, a quasi-crystalline boehmite precursor and an additive are converted to a quasi-crystalline boehmite containing the additive in a homogeneously dispersed state.

Abstract: This invention relates to refractory mixes produced by mixing a refractory material with an organic binder and heating to a temperature of typically from about 50° C. to about 100° C. to form a stable composite granulate. The refractor mixes comprise a major amount of a refractory material and a minor amount of a binder composition comprising (a) condensed tannin and (b) furfuryl alcohol. The refractory mixes are used to prepare shaped (e.g. bricks) and unshaped (e.g. blast furnace tap holes, troughs, and tundish liners) refractory products. The invention also relates to a process for preparing the refractory products using the refractory mixes.

Abstract: The present invention provides sliding members respectively having sliding surfaces opposed to each other for creating dynamic pressure in a fluid, in which the sliding surfaces are formed of ceramics containing crystal grains of Al2O3, crystal grains of TiC contained in the crystal grains of Al2O3, and crystal grains of TiC existing independently of the crystal grains of Al2O3, and having a TiC content of 5 to 20 mass % in the total amount of Al2O3 and TiC, and the respective volume resistivity values R1 and R2 of the ceramics forming the sliding surfaces are within a range simultaneously satisfying equations (1) to (3) to prevent spark discharges from being induced between the sliding surfaces, and a fluid dynamic pressure bearing and a motor to which the configuration is applied: 106 ?·cm<R1?1012 ?·cm??(1) 106 ?·cm<R2?1012 ?·cm??(2) |R1?R2|?105 ?·cm??(3)

Abstract: A chemical mechanical polishing slurry contains an alumina powder including ?-alumina particles and at least one other alumina particles having a crystal structure different from that of ?-alumina, and resin particles.

Abstract: This invention concerns a non-basic refractory batch as well as its use.

Abstract: The invention relates to a method for the production of a sintered, microcrystalline ?-Al2O3-based shaped body, which are used, for example, as abrasive bodies, wherein an ?-Al2O3 powder is used as starting material, said powder having an average particle diameter of <2 ?m, and processed with at least one binder and a solvent with the purpose of obtaining an extrudable material that is subsequently extruded. The extrudate is then further processed into a shaped body that is sintered at a temperature range of between 1300° C. and 1750° C.

Abstract: A ceramic includes alumina in an amount between about 90 and about 99% by weight, a zirconium containing compound in an amount between about 0 and about 1% by weight, and an oxide mixture in an amount between about 1 and about 10% by weight. The oxide mixture includes a glass former and a network modifier, wherein the molar ratio of the glass former to the network modifier ranges between about 0.8:1 and 1.2:1. The ceramic insulator is particularly adapted for use as an insulator in a spark plug to provide improved dielectric strength and shunt resistance of greater than one 1000 megaohms at 1000 degrees Fahrenheit, so as to reduce the shunting of the spark plug and thereby improve the quality of the spark generated by the spark plug.

Abstract: An alumina sintered body having communicating pores of 400–1100 ? in average pore diameter and 4–16% in porosity and being obtainable by mixing first alumina particles 1 having a particle diameter of 0.2–0.7 ?m and a sphericity of 0.7–1.0 as an aggregate and second alumina particles having a particle diameter of 0.01–0.1 ?m as a pore forming material to embed a plurality of the second alumina particles 2 in the spaces between the first alumina particles 1, and sintering the mixture at a temperature of 1200–1400° C. The alumina sintered body can be used for a part for various gas permeable industrial materials inclusive of protective film for gas sensors, and the like.

Abstract: A crucible comprising Al2O3 and at least one selected from rare earth oxides inclusive of Y2O3 as main components and characterized by firing at 500–1,800° C., the distribution of the rare earth oxide at a higher proportion in a fine particle portion having a particle size of up to 0.5 mm than in a coarse particle portion having a particle size in excess of 0.5 mm, and the substantial absence of the reaction product of the rare earth oxide with Al2O3 is suitable for the melting of a rare earth alloy.

Abstract: A porous catalyst layer containing mixed conducting oxide having substantially a perovskite structure and containing a first element selected from Co and Fe, and a second element selected from In, Sn and Y arranged in the B site in the perovskite structure is contiguous to a second surface (1a) of a selective oxygen-permeable dense continuous layer (1) containing mixed conducting oxide. A porous intermediate catalyst layer (3) containing mixed conducting oxide and at least one of Co, Fe, Mn and Pd is contiguous to a first layer (1b) of the dense continuous layer (1). A porous reactive catalyst layer (4) provided with a metal catalyst selected from at least one of Ni, Co, Ru, Rh, Pt, Pd, Ir and Re and a support is continguous to the porous intermediate catalyst layer (3) in a manner to sandwich between the dense continuous layer (1) and the porous reactive catalyst layer (4).

Abstract: Glass-ceramics and methods of making the same. Embodiments of the invention include abrasive particles. The abrasive particles can be incorporated into a variety of abrasive articles, including bonded abrasives, coated abrasives, nonwoven abrasives, and abrasive brushes.

Abstract: The present invention provides a raw material composition for preparing a sintered body of aluminum titanate, the composition comprising (i) 100 parts by weight of a mixture comprising 40 to 50 mol % of TiO2 and 60 to 50 mol % of Al2O3, (ii) 1 to 10 parts by weight of an alkali feldspar represented by the formula: (NaxK1?x)AlSi3O8 (0?x?1), and (iii) 1 to 10 parts by weight of at least one Mg-containing component selected from the group consisting of a Mg-containing oxide with spinel structure, MgCO3 and MgO, and a process for preparing a sintered body of aluminum titanate comprising sintering a formed product prepared from the raw material composition at 1300 to 1700° C. According to the present invention, a sintered body of aluminum titanate having high mechanical strength and ability to be stably used at high temperatures, as well as its inherent properties of low coefficient of thermal expansion and high corrosion resistance, can be obtained.

Abstract: The disclosed invention relates to novel crystalline compositions which may be obtained by doping the alpha (?) form of AlPO4 ceramics, which find use as piezoelectric materials, stable supports for catalysts, biotechnology uses, and the like.

Abstract: Disclosed herein is a method to produce ceramic materials utilizing the sol-gel process. The methods enable the preparation of intimate homogeneous dispersions of materials while offering the ability to control the size of one component within another. The method also enables the preparation of materials that will densify at reduced temperature.

Abstract: A material (100) formed of a sintered aggregation of ceria particles (106), mullite particles (108) and an alumina matrix material (110). Differential thermal expansion of the ceria and mullite particles generates thermal stress sufficient to create micro-cracking of the ceria particles. The ratio of ceria to mullite may be selected to achieve a desired coefficient of thermal expansion for matching the thermal growth of a mating CMC material (102). The micro cracks provide the material with a desired degree of strain tolerance useful in high temperature applications such as a solid core gas turbine vane (20).

Abstract: The invention relates to an improvement in tourmaline known as a functional ore. In particular, the invention provides a composite having a novel formation in which a far infrared radiation emitting property and others among tourmaline's properties are effectively exploited, a novel process for producing the composite, and composite materials to be used therefore.

Abstract: The thermistor portion of a thermistor device consists of a mixed sintered body of aY(Cr0.5Mn0.5)O3.bAl2O3 made of the perovskite-type compound Y(Cr0.5Mn0.5)O3 and Al2O3, or a mixed sintered body of aY(Cr0.5Mn0.5)O3.b(Al2O3+Y2O3) made of Y(Cr0.5Mn0.5)O3, Al2O3 and Y2O3. The mole fractions a and b have the relationships 0.05?a<1.0, 0<b?0.95 and a+b=1. This is required to obtain a thermistor device that has stable characteristics and exhibits a small change in its resistance value, even in a heat history from room temperature to 1000° C. or the like, and also has a resistance value of 50? to 100 k? in the temperature range from room temperature to 1000° C. The precursor compounds triethoxy yttrium, diethoxy manganese and tris (2,4-pentadiono) chromium are mixed in a mixed solvent of ethanol and isopropyl alcohol, and refluxing is performed to obtain a composite metal alkoxide solution.

Abstract: A process for producing roundish alumina particles includes the steps of granulating a composition containing at least one pulverized product of electrofused alumina and sintered alumina having a mean particle size of 5 to 35 ?m and at least one species selected from the group consisting of a halogen compound, a boron compound and an alumina hydrate to obtain a granulated product, heating the granulated product at 1,000 to 1,600° C., and crushing the heated product.

Abstract: A chemically bonded ceramic material based on calcium aluminate hydrate with additives of primarily calcium titanate, but also chemically similar compounds. The material is a biocompatible material for implants, particularly for orthopaedic and dental applications. The material possesses the properties required for an orthopaedic biocement. It cures through reaction with water and develops its strength within a short period of time, has good workability prior to curing, is shape stable, has a low heat generation during curing, and is friendly to adjacent tissues.

Abstract: There is provided a ceramic member for semiconductor manufacturing equipment which is formed of an alumina-based sinter containing an yttrium-aluminum-garnet at the amount of 3 to 50 wt %, silicon oxide at the amount of not more than 0.2 wt %, preferably 0.1 wt %, and the balance substantially alumina, wherein the sinter has dielectric loss of not more than 4×10?4 particularly 2.5×10?4 or less in the frequency range of 10 MHz to 5 GHz. Such a member may be formed of a ceramic sinter including an aluminum phase having mean crystal grain size in a range of 2 to 10 ?m and a yttrium-aluminum-garnet phase having a mean crystal grain size in a range of 1.5 to 5 ?m, wherein the ratio of the mean crystal grain size of the alumina phase to that of the yttrium-aluminum-garnet phase is larger than 1 and smaller than 7.

Abstract: Particles particularly useful for thermal spraying a wear resistant coating on to a substrate comprise an essentially single phase crystalline structure comprising from 45 to 99% by weight of chromia and 55 to 1% by weight of alpha alumina.

Abstract: The present invention provides a process for preparing an aluminum-titanate-based sintered body comprising the step of firing, at 1250 to 1700° C., a formed product prepared from a raw material mixture containing 100 parts by weight of a mixture of TiO2 and Al2O3 in a weight ratio of TiO2:Al2O3=40:60 to 60:40, and 1 to 15 parts by weight of an alkali feldspar represented by the formula:(NaxK1-x)AlSi3O8 wherein 0?x?1. According to the process of the present invention, it is possible to obtain an aluminum-titanate-based sintered body in which inherent properties of an aluminum titanate, i.e., a low coefficient of thermal expansion and high corrosion resistance are maintained, the mechanical strength thereof is improved, and which can be stably used even under high temperature conditions.

Abstract: A ZrO2—Al2O3 composite ceramic material having high mechanical strength and toughness as well as excellent wear resistance and hardness is provided. This ceramic material includes a first phase of ZrO2 grains containing 10 to 12 mol % of CeO2 as a stabilizer and having an average grain size of 0.1 ?m to 1 ?m, and a second phase of Al2O3 grains having an average grain size of 0.1 to 0.5 ?m.

Abstract: The use of a three-component water-soluble polymer comprising 5–90% by weight of a component a), preferably of the maleic acid, fumaric acid or itaconic acid type, 5–90% by weight of a component b) essentially from the group consisting of 2-acrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid and vinylphosphonic acid, and 5–90% by weight of a component c) comprising acrylic acid, methacrylic acid, acrylamide or methacrylamide, as fluidizer for refractory compositions comprising alumina cement is described. The copolymer, which has a preferred molecular weight Mw of <50,000, can also be combined with further quality-improving additives such as silica, lime or soda and further customary additives for refractory compositions.

Abstract: The invention relates to uses of glasses and glass-ceramics in dental and orthodontic applications.

Abstract: High-surface-area alumina honeycombs are subjected to a water vapor pre-treatment to obtain protection from cracking damage on subsequent exposure to aqueous media e.g., aqueous solutions for depositing catalysts on the honeycombs.

Abstract: Sintered, translucent ceramic microbeads, preferably alumina, titania, zirconia, yttria, zirconium phosphate, or yttrium aluminum garnet (YAG) are doped with one or more optically active species. The beads may be added to substances such as explosives in order to create a distinctive optical signature that identifies a manufacturer, lot number, etc. in the event of the need for forensic analysis. Because the beads have a generally spherical surface, the radius of curvature provides an additional distinguishing characteristic by which a particular sample may be identified. The beads could also be formulated into paints if needed to create distinctive optical signatures for camouflage, decoys, or other countermeasures and could also be applied as a dust to track the movement of personnel, vehicles, etc.

Abstract: A process for producing roundish alumina particles includes heating at 1,000 to 1,600° C. a composition containing at least one of electrofused alumina and sintered alumina having a mean particle size greater than 35 ?m, and at least one species selected from the group consisting of a halogen compound, a boron compound and an alumina hydrate; and crushing the composition.

Abstract: When a sintered body of ceramic is shot-blasted at normal temperatures to plastically deform the crystal structure of the shot-blasted surface to apply residual stress and is heat-treated to recrystallize fine cracks, dislocated cells in the grain boundary are formed, crystals are finely divided, and the fracture toughness is significantly improved. When the sintered body of ceramic is a thin product, an effective toughening can be attained by shot blasting both the front and back sides. After heat treatment, mechanical strength is significantly improved by removing a part of the modified surface layer by an abrasion treatment.

Abstract: A mixture, in particular for the production of fireproof molded bodies, including a fireproof metal oxidic main component, and an elastifying component containing a mineral emery. If needed, a binder component such as lignin sulphonate is added. A method is provided for the production of the mixture.

Abstract: The present invention provides a semiconductive zirconia sintering material comprising more than 2% by weight of aluminum oxide and sintered zirconia material derived therefrom as well as a method of producing the sintered material. The sintered semiconductive zirconia materials of the present invention have a better physical and mechanical properties than conventional sintered semiconductive zirconia materials.

Abstract: A dry refractory composition having superior resistance to crack propagation. The dry refractory composition includes at least matrix materials and metal fibers. The composition also may include dense refractory aggregate. The dry refractory composition is particularly suitable for use in metal containment applications.

Abstract: The invention provides a ceramic capacitor including a ceramic dielectric body at least two spaced-part electrodes in contact with the body wherein at least 80 weight percent of the body consists of alumina, the body further including at least 0.5 BaTiO3 w/w %, at least 0.5 w/w % MgO, <0.05 w/w % SiO2, at least 4.5 w/w % ZrO2 and at least 0.07 w/w % HfO2.

Abstract: Composites of ceramic materials, notably alumina or metal oxides in general, with single-wall carbon nanotubes are consolidated by electric field-assisted sintering to achieve a fully dense material that has an unusually high fracture toughness compared to the ceramic alone, and also when compared to composites that contain multi-wall rather than single-wall carbon nanotubes, and when compared to composites that are sintered by methods that do not include exposure to an electric field.

Abstract: A method of manufacturing aluminum-substituted hematite represented by ?-(Fe1-xAlx)2O3 where x=0.01 to 0.15, by mixing an iron compound and an aluminum compound such that an atomic ratio of Fe to Al falls within the range of 99:1 to 85:15, adding citric acid and ethylene glycol to the mixture of the iron compound and aluminum compound to produce a gel, and pyrolyzing the gel, followed by calcining the pyrolyzed product.

Abstract: The invention is directed at a mullite-aluminum titanate porous diesel particulate filter constituting a porous ceramic body containing, expressed in terms of weight percent of the total body, of 60-90%, preferably 70-80%, most preferably 70% iron-aluminum titanate solid solution having a stoichiometry of Al2(1?x)Fe2xTiO5, where x is 0-0.1, and 10-40%, preferably 20-30%, most preferably 30% mullite (3Al2O3.2SiO2), and consists essentially, expressed in terms of weigh percent on the oxide basis, of 3 to 15% SiO2, 55 to 65% Al2O3, 22 to 40% TiO2, and 0 to 10% Fe2O3, and being useful for filtration of diesel exhaust. The inventive diesel particulate filter exhibits high interconnected open porosity and large median pore size, in combination with high permeability when fired to a temperature of between 1650° to 1700° C., along with high thermal shock resistance and good filtration capability.

Abstract: The present invention provides aluminum oxide crystalline materials including dopants and oxygen vacancy defects and methods of making such crystalline materials. The crystalline materials of the present invention have particular utility in optical data storage applications.

Abstract: A refractory repair batch material includes a refractory, in particular a basic resistor component in granule form and a binder system. The binder system contains at least one hard bitumen component in granule form, at least one ignitable metal powder and at least one combustible mineral oil.

Abstract: The invention relates to the field of technical ceramics and specifically relates to a method of synthesis for aluminum oxides of different crystalline structure and to the products obtained by the method. The aim of the invention is to provide a method of producing redispersible nanoparticulate corundum and nanoporous Al2O3 sintered products, the method using precursors and being viable on a commercial scale. To this aim, inter alia, a method of producing redispersible nanoparticulate corundum of an average particle size of D50<100 nm is used which method includes the addition of crystal nuclei. According to the method, organic or chlorine-free inorganic precursors are dissolved or processed to a sol and hydrolyzed. The substance is then dried and calcinated at temperatures of between 350 and 650° C. and is then further heated by increasing the temperature to ?950° C.

Abstract: A raw material with a high content of aluminum oxide has the following composition, in weight-percent, based on dry weight: 1 Al2O3  50-80% MgO   2-15% SiO2   1-15% CaO 0.5-20% Fe2O3 0.5-2% Na2O 0.5-2% Al (metallic) 0.1-2% AlN 0.1-1% K2O 0.1-1.5% F 0.1-2% Cl 0.1-0.

Abstract: A method of making cermet inert anodes for the electrolytic production of metals such as aluminum is disclosed. The method includes the step of spray drying a slurry comprising ceramic phase particles and metal phase particles. The resultant spray dried powder, which comprises agglomerates of both the ceramic phase and metal phase particles, may then be consolidated by techniques such as pressing and sintering to produce a cermet inert anode material. The ceramic phase may comprise oxides of Ni, Fe and at least one additional metal selected from Zn, Co, Al, Li, Cu, Ti, V, Cr, Zr, Nb, Ta, W, Mo, Hf and rare earths. The metal phase may comprise Cu, Ag, Pd, Pt, Au, Rh, Ru, Ir and/or Os. The consolidated cermet inert anode material exhibits improved properties such as reduced porosity. The cermet inert anodes may be used in electrolytic reduction cells for the production of commercial purity aluminum as well as other metals.

Abstract: An economical and environment-friendly process for the synthesis of anionic clays with carbonate and/or hydroxide anions as the charge-balancing interlayer species is disclosed. The process involves reacting a slurry comprising an aluminum source and a magnesium source, the aluminum source comprising two types of aluminum-containing compounds, preferably aluminum trihydrate and/or thermally treated calcined aluminum trihydrate. There is no necessity to wash or filter the product. It can be spray dried directly to form microspheres or can be extruded to form shaped bodies. The product can be combined with other ingredients in the manufacture of catalysts, absorbents, pharmaceuticals, cosmetics, detergents, and other commodity products.