Abstract: A refractory composition for forming a working lining in a metallurgical vessel contains a coarse-grain refractory particle fraction and a fine-grain refractory particle fraction, or at least 0.25% additive calcium oxide, or at least 0.25% titanium dioxide. The coarse-grain refractory particles can include alumina particles, magnesia particles, magnesium aluminate spinel particles, zirconia particles, or doloma particles, or a combination of any of these particles. The fine-grain refractory particles can be comprised of any low-magnesia refractory oxide. The refractory composition can be applied to a metallurgical vessel by spraying, gunning, shotcreting, vibrating, casting, troweling, or positioning preformed refractory shapes, or a combination of any of these techniques.

Abstract: A structure for manufacturing castings, containing an inorganic fiber, a layered clay mineral, and an inorganic particle other than the layered clay mineral and having an organic content of 5 mass % or lower or having a mass loss of 5 mass % or lower when heated at 1000° C. for 30 minutes. The inorganic particle preferably contains one or more selected from obsidian, graphite, and mullite. The inorganic fiber preferably contains carbon fiber. The inorganic fiber preferably has an average length of 0.5 to 15 mm. The layered clay mineral preferably contains one or more selected from bentonite and montmorillonite.

Abstract: Disclosed is a ceramic composition comprising a plurality of at least semi-coherent particles with an average diameter ranging from 1 nm to 50 nm included within a matrix, wherein the matrix comprises one metal carbonate salt, metal oxide or metalloid oxide, the particles and the matrix share at least one metal element and the metal element is 10% to 80% of the total content of said matrix, and the composition has a lattice mismatch of less than 5%. Disclosed are also an article and methods for making the ceramic composition of the present invention.

Abstract: A wellbore isolation device capable of being set from the top including one or more components capable of degrading when exposed to a wellbore environment. A method and system for providing zonal isolation in a wellbore that includes a downhole degradable top-setting wellbore isolation device.

Abstract: An abrasive article including a body including abrasive particles contained within a bond material, a first major surface, a second major surface, and a side surface extending between the first major surface and second major surface, and a coating overlying at least a portion of one of the first major surface or the second major surface. In an embodiment, the coating comprises at least one element selected from the group of chromium, nickel, carbon, nitrogen, tungsten, sulfur, molybdenum, iron, zinc, silicon, titanium, aluminum, zirconium, magnesium, zinc, boron, cobalt, calcium, or any combination thereof. In another embodiment, the coating comprises a cermet, a ceramic, or a combination thereof.

Abstract: A refractory object can include at least approximately 10 wt % Al2O3 and at least approximately 1 wt % SiO2. In an embodiment, the refractory object can include an additive. In a particular embodiment, the additive can include TiO2, Y2O3, SrO, BaO, CaO, Ta2O5, Fe2O3, ZnO, or MgO. The refractory object can include at least approximately 3 wt % of the additive. In an additional embodiment, the refractory object can include no greater than approximately 8 wt % of the additive. In a further embodiment, the creep rate of the refractory object can be at least approximately 1×10?6 h?1. In another embodiment, the creep rate of the refractory object can be no greater than approximately 5×10?5 h?1. In an illustrative embodiment, the refractory object can include a glass overflow trough or a forming block.

Abstract: A fused grain is essentially composed of a matrix of a magnesium aluminum oxide of spinel structure MgAl2O4 and/or of the MgO—MgAl2O4 eutectic, the matrix including inclusions essentially composed of magnesium oxide, the grain exhibiting the following overall chemical composition, as percentages by weight, expressed in the form of oxides: more than 20.0% and less than 50.0% of Al2O3, Al2O3 and MgO together represent more than 95.0% of the weight of the grain, wherein the cumulative content of CaO and ZrO2 is less than 4000 ppm by weight.

Abstract: The present invention discloses crystallized silicate-synthetic powder comprising a cordierite (2MgO.2Al2O3.5SiO2) crystalline phase, a mullite (3Al2O3.2SiO2) crystalline phase and a corundum (Al2O3) crystalline phase, and discloses a high-heat resistant porcelain body containing the above crystallized silicate-synthetic powder and formed by mixing the crystallized silicate-synthetic powder and kaolin mineral.

Abstract: A cermet catalyst material, including a spinel matrix defining a spinel grain and a plurality metal particles embedded in and on the surface of the spinel grain. When the spinel grain is in a first oxidizing atmosphere and at a temperature above about 800 degrees Celsius the metal particles are absorbed into the spinel matrix in the form of metal cations. When the grain is in an second, less oxidizing atmosphere and at a temperature below about 1100 degrees Celsius the metal cations emerge from the spinel matrix to yield a plurality of metal particles adhering to the spinel grain or residing in intragranular pores.

Abstract: Disclosed are phosphors of formula (I) (Ln1?a?bGdaSmb)wMgxSry(Al1?cBc)zO(3/2w+x+y+3/2z) (I), where Ln=Y, La and/or Lu; a, c=0.0 to 1.0; 0<b<0.2 and a+b<1.0; w=1.0 to 3.0; x, y=1.0 to 2.0 and z>0.0 to 12.0, and to a process for the preparation of these phosphors and to the use thereof as conversion phosphors for conversion of the near-UV emission from an LED.

Abstract: This disclosure involves a new spinel and glass micro-composite material and process for making such. The composite has excellent transmission in the 0.5-5.0 ?m wavelength region suitable for various visible and mid IR applications utilizing windows, domes and other geometric shapes. The composite can be made at a temperature about 40% lower than the glass melting temperature and about 50% lower than the spinel sintering temperature. The composite material has high modulus and fracture toughness which are important for impact resistance in armor and other practical applications.

Abstract: A magnesium aluminate-based sintered body and a member for a semiconductor manufacturing apparatus. The magnesium aluminate-based sintered body contains magnesium aluminate as a main crystal phase. The magnesium aluminate-based sintered body also contains Zn and K such that a sum of zinc content in terms of ZnO and potassium content in terms of K2O is in a range of 30 ppm to 500 ppm relative to the total mass of oxides calculated from the contents of all constituents. The member for a semiconductor manufacturing apparatus includes the magnesium aluminate-based sintered body.

Abstract: A non-conductive ceramic material contains a base ceramic material and at least one other ceramic material having a lower coefficient of thermal expansion than that of the base material so that the coefficient of thermal expansion of the non-conductive ceramic material is identical to that of a metallic material to which it will be matched. Methods of making and using same are disclosed.

Abstract: A cordierite sintered body and a member for semiconductor manufacturing apparatus are disclosed. The cordierite sintered body includes a crystal phase and an amorphous phase. The crystal phase includes a main crystal phase that essentially consists of cordierite crystal grains; and a sub crystal phase that includes sub crystal grains containing alumina, mullite or sapphirine. The amorphous phase contains calcium and is located at grain boundaries of the cordierite crystal grains and the sub crystal grains. A crystal phase proportion of the main crystal phase to the crystal phase (or total of the main crystal phase and the sub crystal phase) is 95% to 97.5% by mass or less. A crystal phase proportion of the sub crystal phase to the crystal phase is 2.5% to 5% by mass or less. The sintered body contains calcium by 0.4% to 0.6% by mass or less in terms of CaO.

Abstract: A transparent, polycrystalline ceramic is described. The ceramic comprises crystallites of the formula AxCuByDvEzFw, whereby A and C are selected from the group consisting of Li+, Na+, Be2+, Mg2+, Ca2+, Sr2+, Ba2+, Al3+, Ga3+, In3+, C4+, Si4+, Ge4+, Sn2+/4+, Sc3+, Ti4+, Zn2+, Zr4+, Mo6+, Ru4+, Pd2+, Ag2+, Cd2+, Hf4+, W4+/6+, Re4+, Os4+, Ir4+, Pt2+/4+, Hg2+ and mixtures thereof, B and D are selected from the group consisting of Li+, Na+, K+, Mg2+, Al3+, Ga3+, In3+, Si4+, Ge4+, Sn4+, Sc3+, Ti4+, Zn2+, Y3+, Zr4+, Nb3+, Ru3+, Rh3+, La3+, Lu3+, Gd3+ and mixtures thereof, E and F are selected mainly from the group consisting of the divalent anions of S, Se and O and mixtures thereof, x, u, y, v, z and w satisfy the following formulae 0.125<(x+u)/(y+v)?0.55 z+w=4 and at least 95% by weight of the crystallites display symmetric, cubic crystal structures of the spinel type, with the proviso that when A=C=Mg2+ and B=D=Al3+, E and F cannot both be O.

Abstract: To provide a light-transmitting window material made of a spinel sintered body, wherein the largest diameter of pores contained in the light-transmitting window material is not more than 100 ?m, and the number of pores having a largest diameter of not less than 10 ?m is not more than 2.0 per 1 cm3 of the light-transmitting window material, and wherein light scattering factors are further reduced, and a method for producing a spinel light-transmitting window material including the steps of preparing a spinel molded body; a primary sintering step of sintering the spinel molded body at normal pressure or less or in a vacuum at a temperature in the range of 1500 to 1900° C.; and a secondary sintering step of sintering the spinel molded body under pressure at a temperature in the range of 1500 to 2000° C., wherein the relative density of the spinel molded body after the primary sintering step is 95 to 96% and the relative density of the spinel molded body after the secondary sintering step is 99.8% or more.

Abstract: The invention provides a fused cast refractory product having the following mean chemical composition by weight, as a percentage by weight based on the oxides: 25%<MgO<30%; 70%<Al2O3<75%; other species: <1%. The invention is applicable to a regenerator associated with a soda-lime glass fusion furnace operating under reducing conditions.

Abstract: A composite ceramic body which includes three phases consisting of a MgO phase, a YAP (YAlO3) phase and a spinel (MgAl2O4) phase. This composite ceramic body has a plasma resistance greater than that of alumina and approximately equal to that of MgO. Mechanical properties, such as hardness and bending strength, of the composite ceramic body, are approximately equal or superior to those of Al2O3. A raw material cost and a manufacturing cost thereof are lower than those of a rare-earth oxide. Further, electric conductive particles may be added thereto to lower an electrical resistivity. The composite ceramic body is suitably usable as component parts for a semiconductor manufacturing equipment.

Abstract: A method is provide for preparing potassium metal which comprises embedding a polycrystalline alkali metal ??-Al2O3 molding in an oxidic powder containing potassium and aluminum of a molar K2O:Al2O3 ratio within the range of 1:(x?1) to 1:(x+1), the weight of oxidic powder amounting to at least two times the weight of the molding; heating the embedded molding at a rate of at least 100° C. per hour to at least 1100° C.; and further heating to at least 1300° C., this temperature being maintained for at least one hour prior to cooling.

Abstract: A material mixture for producing a fireproof material, including spinel and zirconium oxide and a coarse-grained fraction with a weight fraction of greater than 50% and a fine-grained fraction, wherein the coarse-grained fraction includes coarse grains with dimensions larger than 20 ?m and the fine-grained fraction includes fine grains with dimensions smaller than 20 ?m.

Abstract: A molten and cast refractory material having a chemical composition, in weight percent on the basis of oxides, of: —Al2O3: the remainder up to 100%; —MgO: 28% to 50%; —CuO: 0.05% to 1.0%; —B2O3: ?1.0%; —SiO2: <0.5%; —Na2O+K2O: <0.3%; —CaO: <1.0%; —Fe2O3+TiO2: <0.55%; —and other oxide species: <0.5%.

Abstract: Disclosed are ceramic articles comprising ceramic honeycomb bodies and an aqueous composition, for example in the form of a cold-set plug, as well as processes for preparing ceramic articles and processes for making an aqueous composition for use with ceramic articles, for example as a cold-set plug composition.

Abstract: Provided herein are methods and apparatus to remove unwanted elements in commercial powders, and particularly in commercial powders that include one or more of a crystalline ceramic oxide. The methods involve treating powders in reduced pressure atmosphere, such as a vacuum, with or without heating, for a period of time sufficient to remove impurities. Impurities and contaminants, including anionic species, are removed from the powders without any undesirable changes in the physical characteristics of the starting material, such as particle size and particle size distribution, surface area, and volume, for example. The resulting purified powder starting material can be consolidated without the need for any sintering aids such as LiF to produce nearly colorless, extremely transparent polycrystalline articles that approach identical properties and performance of single crystal spinels.

Abstract: This binder for monolithic refractories includes a solid solution obtained by dissolving Ca components in ?-SrAl2O4 or ?-SrAl2O4, wherein when the Ca components are dissolved in the ?-SrAl2O4, a crystallite diameter of the solid solution is from 40 nm to 75 nm, and when the Ca components are dissolved in the ?-SrAl2O4, a crystallite diameter of the solid solution is from 35 nm to 70 nm.

Abstract: The invention relates to a material for the formation of protective layers resistant to high temperatures on chromium oxide forming substrates, to a manufacturing method and to a use of these materials. It is suitable for a use as a chromium evaporation layer for metallic alloys containing chromium in the high temperature range. It is the object of the invention to provide a material for applications as a protective layer for chromium oxide forming alloys of high temperature resistance which is thermally and mechanically permanently stable and ensures a high electrical conductivity at the operating temperature of the fuel cell. In accordance with the invention, the material is formed from a spinel phase and an oxidic secondary phase which is preferably formed with an oxidic compound containing manganese.

Abstract: The invention relates to a sintered product containing: in mass percent based on oxides, more than 99.5% of a material having a cubic crystallographic structure for more than 95% of the mass thereof, known as a material with a cubic structure, and having a refractive index of less than 2.75 in the wavelength range between 0.2 ?m and 5 ?m; and more than 50 ppma of dopants which must contain titanium oxide TiO2 and at least one additional dopant selected from ZrO2, CaO, and MgO, in which said at least one additional dopant is different from the oxide(s) forming the material with a cubic structure, but can be MgO when the material with a cubic structure is spinel MgAl2O4.

Abstract: An in-situ method for nanomixing magnesium aluminate spinel nanoparticles with a uniformly distributed controlled concentration of nanoparticles of an inorganic sintering aid, such as LiF, to produce ready-to-sinter spinel powder. The spinel-sintering aid nanomixture is formed by induced precipitation of the sintering aid nanoparticles from a dispersion of the spinel nanoparticles in an aqueous solution of the sintering aid, followed by separation, drying and deagglomeration of the spinel-sintering aid nanomixed product.

Abstract: Preparation for producing refractory materials, characterized in that it comprises one or more particulate, refractory components and one or more binders, where—the particulate, refractory component has a mean particle diameter of >0.3 m and—the binder is selected from among—from 0.05 to 50% by weight of a very finely particulate binder having a mean particle diameter of from 10 nm to 0.3 m selected from the group consisting of aluminum oxide, titanium dioxide, zirconium dioxide and/or mixed oxides of the abovementioned oxides, —from 0 to 20% by weight of an inorganic binder, from 0 to 20% by weight of a hydraulically setting binder, —from 0 to 15% by weight of an organic, silicon-free binder—and the preparation additionally contains from 0 to 35% by weight of water, where—the proportion of the particulate, refractory component is equal to 100 and the percentages of the further materials in the preparation are based on the particulate component.

Abstract: There is provided a sintered body that does not readily deform during use and that allows a high flexibility for the design of surface layers, a method for manufacturing the sintered body, and an optical component including the sintered body. The method for manufacturing a sintered body includes a sintered body having a predetermined shape, the sintered body having a ceramic base material, the method for manufacturing a sintered body comprising a step for preparing a ceramic preform, a step for using a predetermined mold having an upper die and a lower die to hot-press the ceramic preform to form a pressure-sintered body, and a step for cooling the pressure-sintered body while applying a pressure load of approximately 5% or more and 100% or less (and preferably approximately 20% or more and 40% or less) of the pressure load applied during the step for forming the pressure-sintered body.

Abstract: Methods of making and compositions of dense sintered ceramic nano- and micro-composite materials that are highly stable in a variety of conditions and exhibit superior toughness and strength. Liquid feed flame spray pyrolysis techniques form a plurality of nanoparticles (e.g., powder), each having a core region including a first metal oxide composition comprising Ce and/or Zr or other metals and a shell region including a second metal oxide composition comprising Al or other metals. In certain aspects, the core region comprises a partially stabilized tetragonal ZrO2 and the shell region comprises an ?-Al2O3 phase. The average actual density of the ceramic after sintering is greater than 50% and up to or exceeding 90% of a theoretical density of the ceramic.

Abstract: A method for producing an orthodontic bracket is comprised of sintering a molded body of highly-pure alumina fine powder at a temperature of 1,200° C. to 1,300° C. to obtain a sintered body composed of crystals having a relative density of 96% to 99.5% and an average crystal grain size of at most 1 ?m, and thereafter subjecting the sintered body to an HIP treatment at a temperature of 1,200° C. to 1,350° C., under a pressure of at least 50 MPa. Such an orthodontic bracket has high strength and high translucency, can be processed into a complicated shape, similar to that of a metal bracket, and maintains excellent translucency.

Abstract: A transmitting optical element of polycrystalline material that includes crystallites of magnesium spinel MgAl2O4 or lutetium-aluminum garnet Lu3Al5O12, wherein the polycrystalline material includes an average total concentration of foreign element contamination caused by Y, Sc, Co, Ni, Zr, Mo, Sn and/or Nb of less than 50 ppm, preferably of less than 20 ppm, and more preferably of less than 15 ppm.

Abstract: Polycrystalline monolithic magnesium aluminate spinels are disclosed. The polycrystalline monolithic magnesium aluminate spinels have small grain sizes and may be deposited on substrates as thick one-piece deposits. The polycrystalline monolithic magnesium aluminate spinels may be prepared and deposited by chemical vapor deposition. Articles made with the polycrystalline monolithic magnesium aluminate spinels also are disclosed.

Abstract: A solid polycrystalline potassium ion conductor having a ??-Al2O3 structure, its production, and the preparation of potassium metal using this potassium ion conductor.

Abstract: A low-cost spinel sintered body having small polarization and high heat-conductivity is provided. Also, a useful light-transmitting window and light-transmitting lens for light-emitting device is provided. For such purpose, the spinel sintered body of the present invention has a contrast ratio of 300 or more in the case of white light, where the contrast ratio is defined as the quotient obtained by dividing an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being parallel to each other, by an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being orthogonal to each other.

Abstract: A fusion-cast refractory product based on zirconium dioxide is provided. The zirconium dioxide crystals are stabilized by magnesium oxide and surrounded by at least one magnesium oxide-containing crystalline phase. The content of magnesium oxide-containing crystalline phases, relative to the total mass of the product, amounts to 1 to 8 wt. %. In an example, the stabilized zirconium dioxide crystals are surrounded by at least one of the following magnesium oxide-containing crystalline phases: forsterite, enstatite, cordierite or spinel.

Abstract: The invention relates to a baked refractory ceramic product. According to the invention, both shaped and unshaped products come within this generic term. Shaped products are those which have a defined shape, so that they can be ready-made at the manufacturer's premises. The shaped products include: bricks, nozzles, tubes, stoppers, plates, etc. The products categorized as unshaped products include those which are usually produced at the user's premises from a suitable material. These include bottoms of furnace assemblies which are cast from a material, but also repair materials, etc.

Abstract: A refractory brick having durability equal to alumina-magnesia castable materials, which is especially suitable for a ladle for steel making is provided. A refractory brick prepared by using an alumina raw material and a magnesia raw material containing 90% by mass or more of a fine powder of not more than 0.5 mm, press molding and then heat treating at 100° C. or higher and not higher than 1,150° C., the refractory brick containing Al2O3 and MgO in a total sum of 90% by mass or more, from 4 to 16% by mass of MgO, from 0.5 to 5% by mass of SiO2, and Na2O and K2O in a total sum of from 0.3 to 2% by mass, with the remainder being inevitable impurities and Al2O3.

Abstract: A spark plug includes an insulator formed of a ceramic material. The ceramic material comprises Al2O3 in an amount of 98.00 wt % to 99.50 wt %; Group 2 oxides in an amount of 0.16 wt % to 0.70 wt %; SiO2 in an amount of 0.25 wt % to 0.75 wt %, Group 4 oxides in an amount of 0.01 wt % to 0.16 wt %, Group 1 oxides in an amount less than 0.0060 wt %, and P2O5 in an amount of less than 0.0040 wt %. The Al2O3 is formed of particles having a D50 median particle size by volume of 1.2 ?m to 1.8 ?m. The ceramic material is pressed, sintered, and formed to a predetermined shape. The sintered ceramic material includes a glass phase comprising the Al2O3, Group 2 oxides, and SiO2. The sintered ceramic material also includes secondary crystals of calcium hexa-aluminate (CaAl12O19) spinel (MgAl2O4), anorthite (CaAl2Si2O8), and mullite (Al6Si2O13).

Abstract: A laminate includes base material layers and interlayer constraining layers disposed therebetween. The base material layers are formed of a sintered body of a first powder including a glass material and a first ceramic material, and the interlayer constraining layer includes a second powder including a second ceramic material that will not be sintered at a temperature for melting the glass material, and is in such a state that the second powder adheres together by diffusion or flow of a portion of the first powder including the glass material included in the base material layer at the time of baking. The incorporated element is in such a state that an entire periphery thereof is covered with the interlayer constraining layer.

Abstract: A ceramic having at least about 90% by weight magnesium aluminate and having a bulk scattering and absorption loss of less than about 1/cm at any wavelength in a range of about 0.23 to about 5.3 microns or 0.2/cm at any wavelength in a range of about 0.27 to about 4.5 microns. A method of making a ceramic by providing a plurality of particles having a magnesium aluminate core and a fluoride salt coating; heating the particles in an oxidizing atmosphere to a temperature in the range of about 400° C. to about 750° C.; and sintering the particles to form a solid ceramic.

Abstract: A ceramic having at least about 90% by weight magnesium aluminate and having a bulk scattering and absorption loss of less than about 1/cm at any wavelength in a range of about 0.23 to about 5.3 microns or 0.2/cm at any wavelength in a range of about 0.27 to about 4.5 microns. A method of making a ceramic by providing a plurality of particles having a magnesium aluminate core and a fluoride salt coating; heating the particles in an oxidizing atmosphere to a temperature in the range of about 400° C. to about 750° C.; and sintering the particles to form a solid ceramic.

Abstract: Ceramic coatings for a component that is subjected to high temperatures, especially for a turbine blade are provided. The ceramic coatings contain one or more compounds that are selected from alkaline earth silicates, ZrV2O7 and Mg3(VO4)2. A layer system including at least one coating of the ceramic coating is also provided.

Abstract: A monolithic refractory material is provided by a method including the steps of kneading cordierite powder having a median diameter in a range of 10 to 50 ?m, and having a sharp mountain-like particle size distribution in which the content of particles smaller than 10 ?m is 1% or more to 36% or less, the content of particles ranging from 10 ?m or more to 50 ?m or less is 50% or more to 75% or less, and the content of particles of 51 ?m or more is 1% or more to 14% or less, and a solvent including water and alumina sol or silica sol solution.

Abstract: A refractory mortar cured material is formed in the surface or joint portions of a ceramic refractory material, such as fire bricks used in the lining of melting furnace or firing furnace used at high temperature, and includes ceramic particles with an inorganic binder having silanol group that are kneaded together with water. The kneaded mortar is applied on the surface of a ceramic base material. The average particle size of ceramic particles in the refractory mortar is 10 to 50 ?m, and the difference between the 90% particle size and the 10% particle size is 10 ?m or more to 60 ?m or less. The average pore size of the refractory mortar cured material is 5 to 25 ?m, and the width of pore size distribution is 20 to 80 ?m, so that the cracks are suppressed. In addition, the bulk density is 0.9 to 1.5 g/cm3.

Abstract: A non-conductive ceramic material contains a base ceramic material and at least one other ceramic material having a lower coefficient of thermal expansion than that of the base material so that the coefficient of thermal expansion of the non-conductive ceramic material is identical to that of a metallic material to which it will be matched. Methods of making and using same are disclosed.

Abstract: The invention relates to a sintered product containing: in mass percent based on oxides, more than 99.5% of a material having a cubic crystallographic structure for more than 95% of the mass thereof, known as a material with a cubic structure, and having a refractive index of less than 2.75 in the wavelength range between 0.2 ?m and 5 ?m; and more than 50 ppma of dopants which must contain titanium oxide TiO2 and at least one additional dopant selected from ZrO2, CaO, and MgO, in which said at least one additional dopant is different from the oxide(s) forming the material with a cubic structure, but can be MgO when the material with a cubic structure is spinel MgAl2O4.

Abstract: Calcium magnesium aluminosilcate (CMAS) mitigation compositions selected from zinc aluminate spinel, alkaline earth zirconates, alkaline earth hafnates, rare earth gallates, beryl, and combinations thereof wherein the CMAS mitigation composition is included as a separate CMAS mitigation layer in an environmental barrier coating for a high temperature substrate component.

Abstract: A low-cost spinel sintered body having small polarization and high heat-conductivity is provided. Also, a useful light-transmitting window and light-transmitting lens for light-emitting device is provided. For such purpose, the spinel sintered body of the present invention has a contrast ratio of 300 or more in the case of white light, where the contrast ratio is defined as the quotient obtained by dividing an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being parallel to each other, by an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being orthogonal to each other.

Abstract: The invention provides a fused cast refractory product having the following mean chemical composition by weight, as a percentage by weight based on the oxides: 25%<MgO<30%; 70%<Al2O3<75%; other species: <1%. The invention is applicable to a regenerator associated with a soda-lime glass fusion furnace operating under reducing conditions.