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

Abstract: The invention relates to a thermochemically stable oxidic thermal insulating material presenting phase stability, which can be used advantageously as a thermal insulating layer on parts subjected to high thermal stress, such as turbine blades or such like. The thermal insulating material can be processed by plasma spraying and consists preferably of a magnetoplumbite phase whose preferred composition is MMeAl11O19, where M is La or Nd and where Me is chosen from among the alkaline earth metals, transitional metals and rare earths, preferably from magnesium, zinc, cobalt, manganese, iron, nickel and chromium.

Abstract: A light-transmitting (fluorescent) sintered body formed of specific substances different from the prior art materials, solving problems that the performance or efficiency, uses and manufacturing methods are limited which have not been solved with the prior art light-transmitting sintered body and which provides a light-emitting tube and an electric discharge lamp using a light-transmitting (fluorescent) sintered body formed of the specific substance. Provided are a light-transmitting sintered body mainly formed of a compound having a Mugnetplumbite structure or a &bgr;-alumina structure except for aluminum oxide, a light-transmitting sintered body mainly formed of a compound containing rare earth elements with an ionic valence of two, aluminum element and oxygen element as main components and an light-transmitting sintered body formed of mainly of a compound containing elements with an ionic valence of two except for rare earth elements, rare earth elements and oxygen element as main components.

Abstract: A method for making an aluminum oxide (Al2O3) component utilizes an amount of aluminum oxide in particle form. The aluminum oxide initially has less than about 100 parts per million of sodium and less than about 600 parts per million of silica. The aluminum oxide is ground with media that comprise aluminum oxide ceramic pieces that have less than about 200 parts per million of sodium to deagglomerate and reduce the particle size of the aluminum oxide. The ground aluminum oxide is placed into a slurry, and a low sodium grade binder is added to the slurry. The slurry is dried to provide an aluminum oxide powder having a sodium content that is less than about 200 parts per million. The powder may then be formed into a certain shape and thermally treated to produce an aluminum oxide component having a low sodium and low silica content.

Abstract: The invention provides a method for producing a polycrystalline transparent sintered alumina body suitable for use in a ceramic envelope for a high intensity discharge lamp, with optimized kinds and amounts of sintering aids. First, adding and mixing, to alumina of a purity of 99.9% or higher, MgO within a range from 0.002 to 0.010 wt. % and La2O3 within a range from 0.005 to 0.020 wt. %, in such a manner that a sum of MgO and La2O3 is 0.030 wt. % or less and that a ratio thereof satisfies a relation 0.2≦MgO/La2O3≦0.5. Next, firing a mixture at 900 to 1200° C. and cast molding the fired alumina. Then, after a chelating treatment, sintering the molded alumina for at least 1 hour at 1650 to 1900° C. in a reducing atmosphere under a normal pressure.

Abstract: An integrated ceramic module is formed of a first ceramic dielectric layer containing a glass as a sintering agent and having a high dielectric constant and high Q value, formed with an electronic component, and a second ceramic dielectric layer containing a glass as a sintering agent and having a low dielectric constant and a high Q value, formed with a signal transmission line.

Abstract: A microstructured or nanostructured multi-component ceramic comprises (a) a major ceramic phase comprising a ceramic oxide composite; (b) a ceramic oxide additive; and (c) a rare earth ceramic oxide additive, wherein the total of the additives (b) and (c) comprise from about 0.1 weight percent to less than 50 weight percent based on the total weight the multi-component ceramic composite. In another embodiment, a microstructured or nanostructured multi-component ceramic comprises (a) a major ceramic oxide phase comprising a ceramic oxide composite; and either (b) a ceramic oxide additive or (c) a rare earth ceramic oxide additive, wherein amount of the additive (b) or (c) comprises from about 0.1 weight percent to less than 50 weight percent based on the total weight the multi-component ceramic composite. Such ceramics are useful as bulk materials or as feedstocks for thermal spray.

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: Oxidic catalysts containing 20 to 25% by weight of aluminum and 40 to 50% by weight of zinc which are suitable for the production of unsaturated fatty alcohols containing 8 to 22 carbon atoms by hydrogenation of unsaturated fatty acids, fatty acid lower alkyl esters or unsaturated fatty acid glycerides are disclosed. A process for the production of the oxidic aluminum/zinc catalysts is also disclosed.

Abstract: Sintered alumina of Q value of greater than 25,000 and up to and greater than 45,000 at 10 GHz and at 25° C., useful in useful in dielectric resonators can be obtained by sintering alumina powders with low level of impurities at between 1500° C. and 1600° C. until a density of at least 98% of its theoretical value is obtained.

Abstract: Fused abrasive particles comprising eutectic colonies. The fused abrasive particles can be incorporated into abrasive products such as coated abrasives, bonded abrasives, non-woven abrasives, and abrasive brushes.

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: This invention relates to novel chemical compositions and manufacturing methods for producing electro-conductive, metal-ceramic materials having improved structural stability to operate at high temperatures in oxidizing atmospheres.

Abstract: There is provided a treatment container which enables to prolong a period of time taken for reaction products, such as a halide generated through reaction with corrosive halide gas, to exfoliate and fall down as particles, and decreases the frequency of periodic maintenance operation, thereby implementing increase of operating time. The treatment container constituting a chamber or a bell jar has a portion of the inner surface to be exposed to corrosive halide gas plasma and is formed with a sintered body mainly composed of a compound of yttrium and aluminum with oxygen, and the portion has a roughened surface of a mean roughness Ra of 1.5 to 10 &mgr;m.

Abstract: There are provided glass-ceramics having a high lithium ion conductivity which include in mol %: 1 P2O5 38-40% TiO2 25-45% M2O3 (where M is Al or Ga)  5-15% Li2O 10-20%

Abstract: An arc tube is formed by polycrystalline alumina so that an average crystal grain diameter of a surface is two to ten times as large as an average crystal grain diameter of an inside including a center line of a thickness and the average crystal grain diameter on the center portion of the thickness is 10 &mgr;m to 100 &mgr;m. As a result, in the arc tube, the total transmittance is 98%, and a linear ray transmittance is 5%.

Abstract: The invention relates to the utilization of doped alumina for static charge sensitive applications, and to methods for making and using the same, e.g., for varying the electrical conductivity of alumina by doping with an appropriate transition metal oxide and subsequently heating to high temperatures in a reducing environment. This treatment allows the electrical conductivity to be tailored and thus provides a cost effective means for producing components with controlled resistivity.

Abstract: The invention provides a film of an yttria-alumina complex oxide having a high peel strength with respect to a substrate. A mixture of powdery yttria and alumina materials is sprayed on a substrate to form a sprayed yttria-alumina complex oxide film. Preferably, the powdery yttria material has a 50 percent mean particle diameter in a range of 0.1 &mgr;m to 100 &mgr;m, and the powdery alumina material has a 50 percent mean particle diameter in a range of 0.1 &mgr;m to 100 &mgr;m. Preferably, the yttria-alumina complex oxide contains at least garnet phase, and may further contain perovskite phase.

Abstract: A ceramic composite containing alkali-metal-beta- or beta″-alumina and an oxygen-ion conductor is fabricated by converting alpha-alumina to alkali-metal-beta- or beta″-alumina. A ceramic composite with continuous phases of alpha-alumina and the oxygen-ion conducting ceramic, such as zirconia, is exposed to a vapor containing an alkali-metal oxide, such as an oxide of sodium or potassium. Alkali metal ions diffuse through alkali-metal-beta- or beta″-alumina converted from &agr;-alumina and oxygen ions diffuse through the oxygen-ion conducting ceramic to a reaction front where alpha-alumina is converted to alkali-metal-beta- or beta″-alumina. A stabilizer for alkali-metal-beta″-alumina is preferably introduced into the &agr;-alumina/oxygen-ion conductor composite or introduced into the vapor used to convert the alpha-alumina to an alkali-metal-beta″-alumina.

Abstract: The invention provides a method for producing a polycrystalline transparent sintered alumina body suitable for use in a ceramic envelope for a high intensity discharge lamp, with optimized kinds and amounts of sintering aids. First, adding and mixing, to alumina of a purity of 99.9% or higher, MgO within a range from 0.002 to 0.010 wt. % and La2O3 within a range from 0.005 to 0.020 wt. %, in such a manner that a sum of MgO and La2O3 is 0.030 wt. % or less and that a ratio thereof satisfies a relation 0.2≦MgO/La2O3≦0.5. Next, firing a mixture at 900 to 1200° C. and cast molding the fired alumina. Then, after a chelating treatment, sintering the molded alumina for at least 1 hour at 1650 to 1900° C. in a reducing atmosphere under a normal pressure.

Abstract: A novel multipurpose mineral composition capable of emitting a large quantity of far infrared rays, negative ions and oxygen heat is manufactured by setting up an iron railing, an iron rod and an iron plate on a brazier, placing a tinfoil on the iron plate, and layering yellow soil, kaolin, sericite, and biomineral in sequence on the tinfoil, while inserting the tinfoil between the layers, loading a pulverized elvan in the furnace, pulverizing a mixed stone including 40 wt % of germanium, 15 wt % of true marine, 30 wt % of zeolite, and 15 wt % of franklin, to the particle size under about 44 &mgr;m, and loading the pulverized mixed stone in an internal furnace which is made by winding a copper plate with a tinfoil and placed on the plurality of layers of the furnace, heating the pulverized mixed stone at about 1,000° C. for about seven days into a lump, and repulverizing the lump.

Abstract: A silicon nitride—tungsten carbide composite sintered and process for preparing the same which contains silicon nitride and tungsten carbide, and is characterized in that the total in amounts of an entirety of rare earth elements as reduced to certain corresponding oxides thereof, the elements being contained in the sintered material, and excess oxygen as reduced to silicon dioxide is 6-20 mass %; the ratio, on a mol basis, of (the amounts of rare earth elements as reduced to the certain corresponding oxides thereof)/(the amounts of the rare earth elements as reduced to the corresponding oxides thereof+the amount of excess oxygen as reduced to silicon dioxide) is 0.3-0.7; a crystalline phase is present in an intergrain region of the sintered material; and an effective firing temperature range within which a flexural strength of at least 800 MPa is obtained encompasses at least 100 degrees.

Abstract: A refractory material comprising a strontium aluminate refractory fibre and an inorganic binder comprises when fired greater than 35 wt % strontium oxide and/or Al2O3=aluminium oxide content of strontium aluminate fibre ±65 wt %, SiO2=silicon oxide content of strontium aluminate fibre ±20 wt %

Abstract: Low dielectric loss ceramic materials useful in dielectric resonators comprise alumina doped with a minor amount, preferably below 2% by weight of a metal or semi metal oxide, preferably an oxide of titanium, niobium, yttrium or zirconium. The compositions can be made by sintering the powders together below their melting point and materials with a with a Q value of greater than 35,000 at 9-10 GHz and at 25° C., can be obtained.

Abstract: Fused abrasive particles comprising eutectic material. The fused abrasive particles can be incorporated into abrasive products such as coated abrasives, bonded abrasives, non-woven abrasives, and abrasive brushes.

Abstract: A material with a low volume resistivity at room temperature composed of an aluminum nitride sintered body is provided. The sintered body contains samarium in a converted content calculated as samarium oxide of not lower than 0.04 mole percent. The sintered body contains an aluminum nitride phase and a samarium-aluminum complex oxide phase. The samarium-aluminum complex oxide phase forms intergranular layers with a low resistivity along the intergranular phase between aluminum nitride grains.

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: A thermochemically stable oxidic thermal insulating material presenting phase stability, which can be used advantageously as a thermal insulating layer on parts subjected to high thermal stress, such as turbine blades or such like. The thermal insulating material can be processed by plasma spraying and consists preferably of a magnetoplumbite phase whose preferred composition is MMeAl11O19, where M is La or Nd and where Me is chosen from among zinc, the alkaline earth metals, transition metals, and rare earths, preferably from magnesium, zinc, cobalt, manganese, iron, nickel and chromium.

Abstract: A composition providing thermal, corrosion, and oxidation protection at high temperatures is based on a synthetic aluminum phosphate, in which the molar content of aluminum is greater than phosphorous. The composition is annealed and is metastable at temperatures up to 1400° C.

Abstract: Fused abrasive particles comprising eutectic material comprising Al2O3—MgO-REO eutectic. The fused abrasive particles can be incorporated into abrasive products such as coated abrasives, bonded abrasives, non-woven abrasives, and abrasive brushes.

Abstract: Fused abrasive particles comprising eutectic material. The fused abrasive particles can be incorporated into abrasive products such as coated abrasives, bonded abrasives, non-woven abrasives, and abrasive brushes.

Abstract: Amorphous materials, 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: Al2O3-rare earth oxide-ZrO2/HfO2 ceramics (including glasses, crystalline ceramics, and glass-ceramics) and methods of making the same. Ceramics according to the present invention can be made, formed as, or converted into glass beads, articles (e.g., plates), fibers, particles, and thin coatings. The particles and fibers are useful, for example, as thermal insulation, filler, or reinforcing material in composites (e.g., ceramic, metal, or polymeric matrix composites). The thin coatings can be useful, for example, as protective coatings in applications involving wear, as well as for thermal management. Certain ceramic particles according to the present invention can be are particularly useful as abrasive particles.

Abstract: Alumina-zirconia materials 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: Fused abrasive particles comprising eutectic material. The fused abrasive particles can be incorporated into abrasive products such as coated abrasives, bonded abrasives, non-woven abrasives, and abrasive brushes.

Abstract: A ceramic membrane for a capacitive vacuum measuring cell includes a thin ceramic membrane with a thickness of <250 &mgr;m, in particular less than 120 &mgr;m. The membrane is produced from a ribbon-shaped green body of Al2O3, and is given high planarity by smoothing the membrane after sintering. The green body is sintered at a sintering temperature that is higher than the smoothing temperature applied following sintering.

Abstract: Fused, crystalline eutectic material comprising aluminum oxycarbide/nitride-Al2O3.rare earth oxide eutectics. Examples of useful articles comprising the fused eutectic material include fibers and abrasive particles.

Abstract: An article of manufacture includes a metallic nonfoam region, and a ceramic foam region joined to the metallic region. The ceramic foam region is an open-cell solid ceramic foam made of ceramic cell walls having an intracellular volume therebetween. The ceramic is preferably alumina. The intracellular volume may be empty porosity, or an intracellular metal such as an intracellular nickel-base superalloy.

Abstract: Fused, crystalline eutectic material comprising Al2O3-rare earth oxide-ZrO2 eutectic. Examples of useful articles comprising the fused eutectic material include fibers and abrasive particles.

Abstract: Al2O3—Y2O3—ZrO2/HfO2 ceramics (including glasses, crystalline ceramics, and glass-ceramics) and methods of making the same. Ceramics according to the present invention can be made, formed as, or converted into glass beads, articles (e.g., plates), fibers, particles, and thin coatings. The particles and fibers are useful, for example, as thermal insulation, filler, or reinforcing material in composites (e.g., ceramic, metal, or polymeric matrix composites). The thin coatings can be useful, for example, as protective coatings in applications involving wear, as well as for thermal management. Certain ceramic particles according to the present invention can be are particularly useful as abrasive particles.

Abstract: Methods of making amorphous material and ceramic materials. Embodiments of the invention can be used to make 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: A composite ceramic-metal material has an Al2O3 matrix interpenetrated by a network of a ductile metal phase with a higher meltin temperature than aluminum and which makes up 15 to 80 vol. % of its total volume. The Al2O3 matrix forms a coherent network that makes up 20 to 85 vol. %, and the material contains 0.1 to 20 atom % aluminide. To produce this composite material, a green body shaped by powder metallurgy and which contains a finely divided powdery mixture of Al2O3 and optionally other ceramic substances, as well as one or several metals or metal alloys different from aluminum and to which 0.1 to 20 atom % aluminum are added, in relation to the metal proportion, is sintered. The composition is selected in such a way that maximum 15 vol. % aluminide phase can be formed in the finished sintered body.

Abstract: Nanoscale corundum powders are obtained by first producing an Al2O3 precursor by adding seed crystals to an aqueous solution of an aluminium compound and adding a base and then converting the Al2O3 precursor into corundum by calcination at a high temperature. Before the calcination, the salts that are present in addition to the Al2O3 precursor are separated off. The resulting product is calcined at temperatures of 700 to 975° C. and any fines that may be present are removed. The resulting corundum powders can be sintered at temperatures of ≦1200° C. to produce compacts or components of multiple layer systems.

Abstract: Compositions for use as thermal insulation or barriers in articles that are required to function under transient elevated temperature conditions, such as are experienced during a fire. Articles in which compositions according to the invention may be used include electrical and optical cables which have fire resistant properties, electrical fittings such as terminals and cable clips, and void-filling compounds which are required to act as fire barriers. The invention provides a composition that is ductile or flexible at the elevated temperatures experienced during a fire and retains integrity so as to stay in place throughout the fire enabling it to continue to function as a thermal barrier.

Abstract: The glaze layer 2d of the spark plug 100 includes oxides of: 15 to 60 mol % of a Si component in terms of SiO2; 22 to 50 mol % of a B component in terms of B2O3; 10 to 30 mol % of a Zn component in terms of ZnO; 0.5 to 35 mol % of Ba and/or Sr components in terms of BaO or SrO; 1 mol % or less of an F component; 0.1 to 5 mol % of an Al component in terms of Al2O3; and 5 to 10 mol % in total of at least one of alkaline metal components of Na, K and Li, in terms of Na2O, K2O, and Li2, respectively, wherein Li is essential, and the amount of the Li component is 1.1 to 6 mol % in terms of Li2O.

Abstract: The present invention provides amorphous inorganic particles as a dental material comprising silica and inorganic oxide(s) other than silica and having high x-ray impermeability. The inorganic particles as a dental material comprise silica with the content in the range from 70 to 98 weight % and oxide(s) of one or more elements selected from the group consisting of Zr, Ti, La, Ba, Sr, Hf, Y, Zn, AL, and B, wherein 5 to 70 weight % of the silica is originated from an acidic silicic acid solution and 30 to 95 weight % of the silica is originated from a sol of silica. This inorganic particles as a dental material have average particle diameter in the range from 1 to 10 &mgr;m, specific surface area in the range from 50 to 350 m2/g, pore volume in the range from 0.05 to 0.5 ml/g, amorphous crystallinity as observed by x-ray diffraction, and the refractive index in the range from 1.47 to 1.60.

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 &mgr;m and a yttrium-aluminum-garnet phase having a mean crystal grain size in a range of 1.5 to 5 &mgr;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: A ceramic composite containing alkali-metal-beta- or beta″-alumina and an oxygen-ion conductor is fabricated by converting alpha-alumina to alkali-metal-beta- or beta″-alumina. A ceramic composite with continuous phases of alpha-alumina and the oxygen-ion conducting ceramic, such as zirconia, is exposed to a vapor containing an alkali-metal oxide, such as an oxide of sodium or potassium. Alkali metal ions diffuse through alkali-metal-beta- or beta″-alumina converted from &agr;-alumina and oxygen ions diffuse through the oxygen-ion conducting ceramic to a reaction front where alpha-alumina is converted to alkali-metal-beta- or beta″-alumina. A stabilizer for alkali-metal-beta″-alumina is preferably introduced into the &agr;-alumina/oxygen-ion conductor composite or introduced into the vapor used to convert the alpha-alumina to an alkali-metal-beta″-alumina.

Abstract: In order to improve a heat-cycling-durability of a structural body in which a nitrided material is provided on a substrate containing at least metallic aluminum, a heat-resistant structural body having a substrate containing at least metallic aluminum and a nitrided material formed on the substrate provided. The nitrided material is composed mainly of an aluminum nitride phase and a metallic aluminum phase. Preferably, the nitrided material contains at least one metallic element selected from Group 2A, Group 3A, Group 4A, and Group 4B in Periodic Table.

Abstract: A creep-resistant and chemical-resistant ceramic refractory composition includes a mixed oxide of the general formula R3Al5O12 where R is at least one of Dy, Ho, Y, Er, Tm, Yb, and Lu, the mixed oxide having a garnet structure and comprising in solid solution at least one dopant of a transition metal element and a rare-earth element, which effects in the composition enhanced optical emission in at least one spectral range.