Abstract: The present invention relates to zirconium oxide powder for thermal spraying and a method for its manufacture. Furthermore, the present invention relates to thermal insulation layers, which are obtained using the zirconium oxide powder according to the invention.

Abstract: A body made of a ceramic material having a surface region extending from the surface of the body to a predetermined depth and a core region being integrally formed with the surface region. The ceramic material in the surface region includes a calcium containing crystalline phase.

Abstract: A body made of a ceramic material based on zirconia, the body having a surface region extending from the surface of the body to a predetermined depth and a core region integrally formed with the surface region. The ceramic material in the surface region includes a crystalline phase A formed by zirconia in tetragonal phase. The ceramic material in the surface region further includes a crystalline phase B, the crystal structure of which including apart from zirconium and oxygen at least one further component X in a periodic arrangement, the crystalline phase B having a lower theoretical density than crystalline phase A.

Abstract: Highly crystalline metal oxide-carbon composites, as precursors to thermally stable mesoporous metal oxides, are coated with a layer of amorphous carbon. Using a ‘one-pot’ method, highly crystalline metal oxide-carbon composites are converted to thermally stable mesoporous metal oxides, having highly crystalline mesopore walls, without causing the concomitant collapse of the mesostructure. The ‘one-pot’ method uses block copolymers with an sp or sp 2 hybridized carbon containing hydrophobic block as structure directing agents which converts to a sturdy, amorphous carbon material under appropriate heating conditions, providing an in-situ rigid support which maintains the pores of the oxides intact while crystallizing at temperatures as high as 1000 deg C. A highly crystalline metal oxide-carbon composite can be heated to produce a thermally stable mesoporous metal oxide consisting of a single polymorph.

Abstract: The tunnel kiln according to the present invention includes a tunnel kiln main body having an inner wall constituted by a furnace material, and having a debinding zone and a sintering zone wherein respectively debinding and sintering of a body to be fired containing an organic component are performed; a conveying unit for conveying the body to be fired from an inlet side to an outlet side of the tunnel kiln main body; and a lining provided so that at least an inner wall of the debinding zone of the inner wall of the tunnel kiln main body is covered therewith.

Abstract: A method for fabricating a sintered annular nuclear fuel pellet includes molding nuclear fuel powder or granule, an oxide of a fissile element (M), to fabricate an annular nuclear fuel green body. A rod-like shaped structure is inserted into the annular nuclear fuel green body and sintered in a slight oxidizing gas atmosphere such that the oxide of the fissile element has a balanced O/M ratio higher than a desired O/M ratio (oxygen/fissile element) of a final sintered annular nuclear fuel pellet, while being maintained in a cubic phase. The sintered annular nuclear fuel pellet is then reduced in a reductive gas atmosphere so as to have the desired O/M ratio in the state that the rod-like shaped structure is inserted.

Abstract: A method for determining a sintering shrinkage of a pre-sintered body. The method includes providing a green preform with at least one design feature. The green-preform is pre-sintered to form a white body. At least one change in the at least one design feature with the pre-sintering is recorded. An expected sintering shrinkage to a dense-sintered component is determined using the recorded change.

Abstract: A method of fabricating a scintillator includes forming a green part comprised of a nanometer-sized powder, sintering the green part at a first temperature for a first time period, and sintering the green part at a second temperature for a second time period.

Abstract: This invention pertains to a process of bonding a magnesium aluminate spinel article or articles and a germanate glass article or articles including the step of heating them together above the softening temperature of the glass.

Abstract: The invention relates to a method for producing a ceramic component. With the method, a ceramic base material in powdered form and a mold having the shape of the ceramic component are provided. The ceramic base material is introduced into the mold. The ceramic component is presintered at a temperature between 880° C. and 980° C. and is then removed from the mold. The surface of the ceramic component is treated with a blasting material and the ceramic component is sintered at a temperature that is higher than the presintering temperature. With the method according to the invention, ceramic components having higher surface roughness can be produced. Due to the higher surface roughness it is easier to apply a firmly adhering coating to the ceramic component.

Abstract: A seal composition includes a first alkaline earth metal oxide, a second alkaline earth metal oxide which is different from the first alkaline earth metal oxide, aluminum oxide, and silica in an amount such that molar percent of silica in the composition is at least five molar percent greater than two times a combined molar percent of the first alkaline earth metal oxide and the second alkaline earth metal oxide. The composition is substantially free of boron oxide and phosphorus oxide. The seal composition forms a glass ceramic seal which includes silica containing glass cores located in a crystalline matrix comprising barium aluminosilicate, and calcium aluminosilicate crystals located in the glass cores.

Abstract: A method for the production of a carbon or a ceramic component based on carbon, using a cellulose-containing semi-finished molded piece which is pyrolyzed. According to the invention, homogeneous large-size ceramic components may be produced, whereby a cellulose-containing, semi-finished molded piece containing fibers, chips or strands of homogeneous density distribution and homogeneous structure is used as semi-finished molded piece and is pyrolyzed in non-oxidizing gas atmospheres.

Abstract: Use of Ti and Nb cemented in TiC in prosthetic joints, such as prosthetic joint components made from sintered superhard materials.

Abstract: Lasing systems utilizing YAG and methods for producing a YAG suitable for lasing are provided. The lasing system comprises a laser activator and a laser host material is provided. The laser host material comprises a transparent polycrystalline yttrium aluminum garnet material defined by a low porosity of less than about 3 ppm.

Abstract: There is provided a plugged honeycomb structure 1 including: partition walls 2 disposed so as to form a plurality of cells 3 extending from one end face 42 to the other end face 44 in the axial direction, and plugged portions 4 disposed so as to plug the cells 3 at one of the end faces, and a production method thereof. In this honeycomb structure 1, the plugged portions 4 and partition walls surrounding the plugged portions are unitarily formed. The production method includes a forming step, a plugging step for filling a plugging material, and a firing step. The plugging material contains solid particles capable of unitarily joining with at least one kind of solid particles contained in a forming raw material in a firing step. A ratio of a dimensional change (%) upon forming the partition walls out of the partition wall-forming material to a dimensional change (%) upon forming the plugged portions out of the plugging material is controlled to be within the range of 0.7% to 1.3 in the firing step.

Abstract: Carbides as substrates in prosthetic joints, particularly in sintered polycrystalline diamond compacts and sintered cubic boron nitride compacts.

Abstract: An aluminum nitride sintered body having resistance to plasma gas and high thermal conduction and having excellent optical properties. The aluminum nitride sintered body of the present invention is characterized in that the proportion of positrons which are annihilated within a period of 180 ps (picoseconds) in the aluminum nitride crystal, as determined in the defect analysis using a positron annihilation method, is not less than 90%, and the sintered body preferably has a thermal conductivity of not less than 200 W/mK.

Abstract: In order to improve a method for the production of structural ceramics and/or functional ceramics consisting of silicon carbide ceramics, with which a porous precursor body is produced from a cellulose-containing material, the porous precursor body is converted into an open-pored carbon body by means of pyrolysis and the open-pored carbon body is converted into silicon-containing carbide ceramics, in particular, silicon carbide ceramics as a result of infiltration of silicon-containing materials, in such a manner that the structural ceramics and/or functional ceramics as well as the components produced therefrom can be produced with properties which are as reproducible as possible it is suggested that at least cellulose-containing powder be used as starting ingredient for the production of the precursor body.

Abstract: A die comprises metal-rich sections which form an inner wall and an outer wall of the die, respectively. Gradient sections are disposed adjacent to the metal-rich sections, respectively. Further, a ceramics-rich section is disposed between the gradient sections. A punch comprises an inner ceramics-rich section, a gradient section, and an outer metal-rich section. In the die, the composition ratio of metal gradually decreases from the metal-rich sections to the ceramics-rich section. Similarly, in the punch, the composition ratio of the metal gradually decreases from the metal-rich section to the ceramics-rich section.

Abstract: A capacitive vacuum measuring cell includes first and second ceramic housing bodies (1, 4) joined by an edge seal (3). A thin ceramic membrane (2) is supported between first and second housing bodies (1, 4) by the edge seal (3) at a small distance from the first housing body (1) creating a reference vacuum chamber (25) therebetween. An electrically conductive material (7) coats opposing surfaces of the first housing body (1) and the membrane (2) to form a capacitor. A measurement vacuum chamber (26) is provided between the membrane (2) and the second housing body (4). A port (5) communicates with the second housing body (4) to connect the measurement vacuum chamber (26) of the measuring cell to the medium to be measured. The membrane (2) is made from an Al2O3 slurry that is sintered in a first heating step, cooled, and then reheated to smooth the membrane.

Abstract: A dielectric ceramic composition comprising at least a main component containing a dielectric oxide of a composition expressed by {(Sr1?xCax)O}m.(Ti1?yZry)O2 and a first subcomponent containing at least one type of compound selected from oxides of V, Nb, W, Ta, and Mo and/or compounds forming these oxides after firing, wherein the symbols m, x, and y showing the molar ratio of the composition in the formula contained in the main component are in relations of 0.94<m<1.08, 0?x?1.00, and 0?y?0.20 and the ratio of the first subcomponent with respect to 100 moles of the main component, which is converted to the metal element in the oxide, is 0.01 mole?first subcomponent<2 moles. According to this dielectric ceramic composition, it is possible to obtain a superior resistance to reduction at the time of firing, obtain a superior capacity-temperature characteristic after firing, and improve the accelerated life of the insulation resistance.

Abstract: A method of producing lithium aluminosilicate (LAS) ceramics, which uses a mixing powder of lithium carbonate, aluminum oxide, and silicon oxide as a raw material powder. After being mixed by ball milling and baked dry, the raw material powder is processed with a calcinations process such that the raw material powder becomes a precursor. The precursor is then pressed into the green ceramic. Significantly, the high heat conducting metal sheets are tightly attached above and below the surfaces of the ceramic during sinter and heat-treatment processes. A solid-state sinter process is performed with the green ceramic. Next, the ceramic is treated with a proper heat-treatment process. Since the top and bottom surfaces of the ceramic are capped with the high heat conducting metal, the ceramics are uniformly heated during all the heating processes.

Abstract: A honeycomb structure body which has a number of passages partitioned with partition walls and penetrating along the axial direction. A porous honeycomb structure body which contains refractory grains as filler, one or more elements selected from the group consisting of the rare earth elements, alkaline earth elements, Al, and Si, and the crystal containing one or more kinds of these elements. The present honeycomb structure body contains refractory grains such as silicon carbide grains and the like, but it can be produced at a relatively low firing temperature at a low price, it is sufficiently porous and high in specific surface area, and it can be used as a filter for purifying automobile exhaust gas, a catalyst carrier, and the like under the high SV conditions.

Abstract: The purpose of the present invention is to provide a method for manufacturing a ceramic substrate hardly causing cracks and damages and the like attributed to pushing pressure and the like since the strength of the above-mentioned ceramic substrate is higher than that of a conventional one even in the case of manufacturing a large size ceramic substrate capable of placing a semiconductor wafer with a large diameter and the like. The present invention is to provide a method for manufacturing a ceramic substrate having a conductor formed on the surface thereof or internally thereof, including the steps of: firing a formed body containing a ceramic powder to produce a primary sintered body; and performing an annealing process to the primary sintered body at a temperature of 1400° C. to 1800° C., after the preceding step.

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: 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 of manufacturing an alumina-based ceramic includes sintering a powder compact of an iron-containing alumina powder in an atmosphere (N2, 95 N2-5 H2, H2) of a relatively low oxygen partial pressure, and annealing in an atmosphere (80 N2-20 O2, O2) higher in oxygen partial pressure than the sintering atmosphere to provide an alumina-based ceramic with a grain-boundary migration layer on a surface thereof. The resulting undulated grain boundaries on the surface layer suppress and deflect the crack propagation, thereby improving the short-crack toughness. The formation of a grain-boundary migration layer on the surface of an alumina-based ceramic brings about a great improvement in short-crack related properties, including durability and wear resistance.

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: Porous metal-containing materials are provided for a variety of uses including filters, electrodes for batteries and fuel cells, light weight structural materials, heat exchangers and catalysts. A method is provided for making the porous metal-containing materials involving vapor phase sintering of a metal oxide green form followed by reduction to form a porous metal-containing material, typically without any significant shrinkage of the sample occurring during processing. The porous metal-containing materials may have porosities of from about 40 percent to as high as 90% in some embodiments. Furthermore, the pore volume is highly interconnected, which is particularly advantageous for many applications.

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: A sintered ceramic part to be exposed to a corrosive gas, a surface of said ceramic part being machined, wherein each of grains exposed to the machined surface of the ceramic part is formed with a machined surface, and en edge of the machined surface of each of these grains is made round by material transfer. A process for producing such a sintered ceramic part includes the steps of: obtaining a machined body having a given shape by at least grinding a surface of a ceramic sintered body, and annealing the machined body.

Abstract: The invention concerns a process for manufacturing a part made of high temperature-resistant, ceramic material based on aluminum nitride and reaction sintering. The process comprises the steps of preparing a homogeneous mixture of boron nitride powder, aluminum powder and a paste-like binder, capable of solidifying by chemical reaction and by solvent loss through drying. The mixture is formed by mold casting and then pressed and heated, to a temperature not exceeding approximately 70° C., to harden the binder and to obtain a solid and manipulable unfired part. The binder is eliminated by heating to a temperature of approximately 300° C. Pores of the unfired part are impregnated by immersing the part in a bath of molten aluminum or aluminum alloy to form an impregnated preform. Thereafter, the impregnated preform is removed from the bath, cooled, and machined to the final dimensions of the part. A ceramic is obtained by reaction sintering the machined part at a temperature of 900 to 1000° C.

Abstract: A t′-phase zirconia shapes with superior properties are made by forming a zirconia powder containing a rare-earth-oxide dopant into sintered bodies. The sintered bodies are heat treated in an oxygen atmosphere at a temperature high enough to form a cubic phase. The heated body is then cooled rapidly to form a t′-phase. The t′-phase is characterized with a large grain size, is resistant to transformation, low temperature degradation, and has excellent toughness, and creep resistance. Rare earth-oxide dopants include yttria, scandia, erbia, and ceria. For yttria doped materials, the sintered body is doped with between 2.5 and 5 mole percent yttria.

Abstract: 845 A method of producing a ceramic-metal-halide (CMH) discharge lamp having a monolithic seal between a sapphire (single crystal alumina) arc tube and a polycrystalline alumina end cap. The method includes the steps of providing an arc tube of fully dense sapphire and providing an end cap made of unsintered compressed polycrystalline alumina powder. The end cap is heated until it is presintered to remove organic binder material at a low temperature relative to the sintering temperature. The presintered end cap is placed on an end portion of the arc tube to form an interface therebetween. The assembled presintered end cap and arc tube are then heated to the sintering temperature wherein the end cap is fully sintered onto the arc tube and the sapphire tube grows into the end cap. A monolithic seal is formed at the previous interface between the end cap and the arc tube as the sapphire tube grows into the polycrystalline alumina end cap.

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 method of expanding a sintered alumina substrate which includes the step, after conventional sintering, of heating the sintered alumina substrate to a temperature of about 1340 to 1380.degree. C. and holding at the temperature for a predetermined time but no less than 15 minutes, the heating step causing the sintered alumina substrate to expand.

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 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: A method of manufacturing an alumina-silicon carbide nanocomposite having particular application to improved ball bonding capillaries of a wire bonding device produces a structure with a 93-98 volume percent of .alpha.-alumina having an average diameter of 0.1-0.3 .mu.m, a 2-7 volume percent of .beta.-silicon carbide having an average diameter of 0.1-1.5 .mu.m, a bending strength of 340-550 Mpa, and a toughness of 3.3-4.1 Mpam.sup.1/2.

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 process for forming a ceramic alumina-based abrasive grain from a sol gel which contains aluminum oxide monohydrate, a dissolved metal containing sintering aid and sufficient sodium and/or calcium compound to provide in the ceramic from above about 0.05 to about 1.8 weight percent sodium plus calcium, provided that the weight percent calcium is from 0 to about 1.8 and the weight percent sodium is from 0 to about 0.4. The high sodium and calcium is permitted due to rapid heating of the sol gel after drying through a temperature range of from below about 800.degree. C. to above about 1200.degree. C., prior to sintering the dried gel at a temperature above 1200.degree. C. A grain made by the process and coated, bonded and non-woven abrasive articles comprising the grain.

Abstract: In preparing a zinc oxide base varistor in the form of a sintered body which itself has a voltage-dependent nonlinear resistance, firing is done in an atmosphere containing at least 60% of oxygen at or above the temperature at which additives form a liquid phase, and thereafter the sintered body is heat treated in an atmosphere containing at least 10% of oxygen at a temperature of 600.degree. to 1,000.degree. C. There is obtained a zinc oxide base varistor having a high energy handling capability, a high nonlinearity index .alpha., and satisfactory load life characteristics such as a humid load life.

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.