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.

Abstract: A method of making a cristobalite-free, mullite grain capable of withstanding reaction with molten aluminum, comprising the steps of: producing a clay slurry comprised of water and kaolin clay of a specific particle size; mixing a water insoluble barium or strontium containing compound into the clay slurry in an amount wherein the barium or strontium containing compound content of the slurry is equal to about 8% by weight of the kaolin clay in the slurry; removing sufficient water from the slurry to form a material having an pelletizable consistency; forming the material into pellets; heating the pellets by continuously moving them through a furnace having a zone, wherein the material is exposed to temperatures of at least 2,650° F. (1,455° C.) for at least 30 minutes.

Abstract: An economical and environment-friendly processes for the synthesis of anionic clays and the products made therefrom. It involves reacting a slurry comprising non-peptized boehmite with a magnesium source. 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 that contain anionic clays.

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

Abstract: A process of making ceramic spheroids by firing clay spheroids comprising by weight percent: FeO (3.22-5.21), Fe3O4 (3.40-5.11), SiO2 (52.49-59.42), CaO (1.99-7.96), MgO (2.81-4.69), Al2O3 (12.05-17.65), TlO2 (0.58-0.71), MnO (0.07-0.19), Na2O (0.47-0.86), K2O (1.70-2.37), P2O3 (0.13-0.19), S (0.03-0.29), CO2 (0.90-8.23), Organic C (0.22-1.04), H2O+ (4.14-7.28), H2O− (2.12-5.48) in contact with a particulate parting agent selected from aluminum oxide, magnesium oxide, and their precursors at a sufficiently high temperature and for a sufficiently long time to form a shell. Preferably, the clay spheroids are obtained from a deposit located at Hallock in Kittson County Minn., U.S.A.

Abstract: To provide an optically transparent film containing 0.01 to 20% by weight glass forming oxide consisting of Nb2O5, V2O5, B2O3, SiO2, and P2O6; 0.01 to 20% by weight Al2O3 or Ga2O3; and 0.01 to 5% by weight hard oxide of ZrO2 and TiO2 as required; balance being ZnO, and a sputtering target for forming such a film. This sputtering target reduces occurrence of particles during sputtering, decreases the number of interruption or discontinuance of sputtering to improve production efficiency, and forms a protective film for optical disks with large transmittance and low reflectance.

Abstract: A sintered alumina ceramic obtained by preparing a raw material powder mixture containing alumina and a Group 3A metal oxide or a Group 3A metal compound which provides a Group 3A metal oxide on heating, and firing said raw material powder mixture. The sintered ceramic contains alumina particles having an average particle diameter of 4.0 &mgr;m or smaller. In the sintered ceramic, the total content of alkali metal elements, alkaline earth metal elements, Si, and Ti as converted to oxides accounts for 0.1 mol or less with respect to 100 mols of alumina, the total peak intensity for the principal peaks for ReAlO3 and Re3Al5O12 (Re: Group 3A metal) amounts to from 1 to 75% of the intensity of the principal peak of alumina as measured by X-ray diffraction, and the relative density is 99.0% or higher with respect to the theoretical density.

Abstract: Sintered aluminas 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: A high-purity alumina sintered body having an alumina purity of not less than 99.9% by mass and a relative density of not less than 97% and exhibiting a weight loss of not greater than 100×10−4 kg/m2 when immersed in boiling 6N H2SO4 or 6N NaOH aqueous solution for 24 hours as measured according to JIS R1614 (1993). The high-purity alumina sintered body is obtained by firing a green body formed from an alumina powder having an alumina purity of not less than 99.9% by mass and containing, as impurities, Si, an Mg, Fe and alkali metals including Na, K and Li in a total amount of less than 100 ppm.

Abstract: An object of the invention is to provide a low temperature fired porcelain having an optimum firing temperature not higher than 1000° C., a reduced dielectric constant &egr; r, an improved quality coefficient and a low incidence of cracks.

Abstract: A plastically deformable aqueous ceramic slurry wherein the ceramic particles have on the surfaces thereof a closely-packed anionic surfactant bilayer or an anionic/nonionic surfactant bilayer. Such slurries are produced by: a) dispersing an amount of ceramic particles in an amount of water to form an aqueous ceramic slurry; b) adding an amount of an anionic surfactant or a mixture of an anionic surfactant and nonionic surfactant to such slurry; c) adjusting the pH value of such slurry to adsorb on the ceramic particle surfaces a closely-packed anionic surfactant bilayer or anionic/nonionic surfactant bilayer. Preferably a mixture of surfactants is used, with a mixture of anionic and nonionic surfactants being highly preferred. Examples of preferred combinations are mixtures of the anionic surfactant SDS and a nonionic surfactant selected from octylphenol polyether alcohols (OPE), in particular C8H15Ph(EO)Rwherein R was 3, 5, 9.5 and 12.5.

Abstract: The invention is a method of producing a ceramics material comprising the steps of: preparing a raw powder in which alumina particles having an average particle diameter of 0.1-1.0 &mgr;are doped with at least magnesia of 0.01-1 weight % and a solution containing yttrium of 0.1-15 weight % in yttria; molding said raw powder and calcining a molding thus created; and heating the calcined molding in an atmosphere containing a hydrogen gas to create YAG which is leached to the surface to deposit YAG on the surface and sintering the molding.

Abstract: A translucent alumina sintered body wherein the total content of an alkali metal element and an alkaline earth metal element is 50 ppm or less, and the linear transmittance of a light having a wavelength of 600 nm is 40% or more at a thickness of the sintered body of 0.85 mm.

Abstract: A sintered ceramic for a scintillator having a composition represented by the general formula of Gd3-xCexAlySizGa5-y-zO12, wherein 0.001≦x≦0.05, 1≦y≦4, and 0.0015≦z≦0.03, is produced by mixing gadolinium oxide, aluminum oxide, gallium oxide, a cerium salt, a silicon compound and a fluorine compound in such proportions as to provide the above composition; calcining the resultant mixture at a temperature of 1400-1600° C.; disintegrating the resultant calcined body to ceramic powder; pressing the ceramic powder to provide a green body; and sintering the green body at a temperature of 1600-1700° C. in a non-oxidizing atmosphere at 5×104 Pa or more, and optionally further by hot isostatic pressing at a temperature of 1400-1600° C. in an argon atmosphere.

Abstract: A process for converting a polycrystalline ceramic material to a single crystal material includes the steps of doping at least a first portion of the polycrystalline ceramic material with a conversion-enhancing dopant having a +6 valence state in the unfired ceramic material and heating the polycrystalline ceramic material to convert at least a second portion of the polycrystalline ceramic material to a single crystal ceramic material. Preferably, the ceramic material is alumina and the conversion-enhancing dopant is molybdenum or tungsten.

Abstract: The bolus is intended to be received in the reticulum of a ruminant. It comprises a body (10) having a housing (12) for containing a data interchange device (14). According to the invention, the body (10) is made of a material based on alumina, Al2O3, and/or on silica, SiO2.

Abstract: A ceramic polycrystal and a method of manufacturing such a ceramic polycrystal having thermal stability enough to be used in an arc tube are provided. The ceramic polycrystal has crystalline particles. Each of crystalline particles has a crystalline structure selected from triclinc, monoclinic, rhombi, tetragonal, trigonal, and hexagonal systems, with an average grain size being not less than 5 &mgr;m and a linear transmittance being not less than 8%.

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: Acicular bodies of a metal compound are produced by slowly precipitating an organic salt of the metal from a solution of an ester of a dicarboxylic acid having 1-5 carbon atoms and firing the precipitate in an oxidizing atmosphere. These acicular bodies have a cross-sectional dimension less than about 20 &mgr;m and are useful for providing reinforcement of a larger ceramic body. Acicular bodies of rare-earth metal oxides also are useful in reinforcing x-ray scintillator bodies without diminishing their luminescent capacity.

Abstract: Fused, crystalline eutectic material comprising aluminum oxycarbide/nitride-Al2O3.Y2O3 eutectics. Examples of useful articles comprising the fused eutectic material include fibers and abrasive particles.

Abstract: An optical system is provided in a projection exposure apparatus for processing an excimer laser beam. The optical system includes at least one optical member made of silica glass having a chlorine concentration of about 1 ppm or less, and at least one optical member made of silica glass having a chlorine concentration of about 1 ppm to about 200 ppm.

Abstract: A silicon-aluminum mixed oxide produced by flame hydrolysis and having a composition of from 1 to 99.999 wt. % Al2O3, the remainder being SiO2, which mixed oxide exhibits an amorphous structure in the X-ray diffraction pattern and consists of intergrown primary particles, and in these primary particles crystallites are present. These crystallites having sizes of between one and 200 namometers and the specific surface of the powder being between 5 and 300 m2/g. These products are produced by a process wherein silicon halide and aluminum halide are vaporized in a particular ratio to one another and are homogeneously mixed with air, oxygen and hydrogen in a mixing unit by means of any carrier gas, this mixture undergoes combustion in a burner of known construction and, after the separation of the solids from the vapour phase, any traces of halide possibly adhering to the product are separated off in a further processing step by means of moist air at elevated temperature.

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

Abstract: A member used within a plasma processing apparatus and exposed to a plasma of a halogen gas such as BCl3 or Cl2 is formed from a sintered body of metals of Group IIIa of Periodic Table such as Y, La, Ce, Nd and Dy, and Al and/or Si, for example, 3Y2O3·5Al2O3, 2Y2O3·Al2O3, Y2O3·Al2O3 or disilicate or monosilicate, and in particular, in this sintered body, the content of impurity metals of Group IIa of Periodic Table contained in the sintered body is controlled to be 0.15 wt % or more in total. Specifically, for this member, an yttrium-aluminum-garnet sintered body having a porosity of 3% or less and also having a surface roughness of 1 &mgr;m or less in center line average roughness Ra is utilized.

Abstract: A continuous 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 aluminum trihydrate and/or its calcined form, with a magnesium source. There is no necessity to wash or filter the product. It can be spray dried directly to form microspheres or it 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.

Abstract: A sintered ceramic honeycomb article that exhibits an average linear coefficient of thermal expansion (25-800° C.) below about 5.0×10−7° C.−1, a total porosity between the range of 20% to about 30%, and a pore size distribution such that at least about 86% of pores are of a pore size of less than about 2 &mgr;m with the pores exhibiting a generally elongated shape oriented with their long axis in the plane of the webs, the article being made from a cordierite-forming inorganic powder batch comprising a platy talc having median particle of size less than about 2 &mgr;m, at least 4% by weight of a dispersible Al2O3-forming source having a specific surface area in excess of 50 m2/g, and one or more of the components of kaolin, calcined kaolin, silica, and corundum, each having a median particle sizes less than 5 &mgr;m.

Abstract: A ceramic structure which is pollucite-based and has high refractoriness and high resistance to thermal shock. The inventive structure is suitable in high temperature applications such as a filtering particulates from diesel engine exhaust.

Abstract: An translucent polycrystalline ceramic capable of transmitting a visible light and excellent in strength, hardness, abrasion resistance, light transmittance, transparency and high-temperature characteristics and usable as a material, for instance, for cutting tools, outer tubes for high pressure sodium lamps and high temperature furnace window plates. The translucent polycrystalline ceramic has at least one characteristic features that (1) a mean particle size of crystal particles formed inside the ceramic is not larger than 1.0 &mgr;m, (2) a mean aspect ratio thereof is from 1.0 to 1.5, (3) a density thereof is substantially a theoretical density, (4) a light transmittance through its thickness of 1 mm is at least 50%, (5) a mean facet length of crystal particles formed inside the ceramic is not longer than a maximum wave length of the light. One of the embodiments is a translucent polycrystalline Al2O3 ceramic containing 0.02-2.

Abstract: A component of a thermal processing apparatus for a fluid stream of hydrocarbons, a precursor glass for a glass-ceramic coating on such component and a method of inhibiting deposition of a material, such as carbon, on a surface of the component.

Abstract: A method of making a cristobalite-free, mullite grain capable of withstanding reaction with molten aluminum, comprising the steps of: producing a clay slurry comprised of water and kaolin clay of a specific particle size; mixing a water insoluble barium or strontium containing compound into the clay slurry in an amount wherein the barium or strontium containing compound content of the slurry is equal to about 8% by weight of the kaolin clay in the slurry; removing sufficient water from the slurry to form a material having an pelletizable consistency; forming the material into pellets; heating the pellets by continuously moving them through a furnace having a zone, wherein the material is exposed to temperatures of at least 2,650° F. (1,455° C.) for at least 30 minutes.

Abstract: The present invention relates to a porous aluminum oxide structure comprising Al2O3 and Zr, the structure having an open porosity greater than about 30% and an average pore size from about 20 nm to about 1000 nm, wherein the Zr, expressed as ZrO2, has a concentration less than about 5 weight % of the weight of the Al2O3.

Abstract: Alumina-based ceramics are thermally stable because of their high melting point and excellent materials in wear resistant properties and chemical stability. However, they contradictly have such a problem that fracture toughness is low, and its improvement is desired. The present invention provides such sintered alumina-based ceramics and their production process that have rendered to grow alumina grains anisotropically and fracture simultaneously attain high flexural strength and fracture toughness by sintering the formed mixture comprising Al2O3, 0.05-2.5 mol % of VA metal oxide and 0.01-4 mol % SiO2, relative to Al2O3, respectively.

Abstract: The present invention relates to a zirconia/alumina composite and a manufacturing method thereof which provide a zirconia ceramic powder having a composition in a triangle composition range formed of three composition points of 92 mol % ZrO2-4 mol % Y2O3-4 mol % Nb2O5 (or Ta2O5), 89 mol % ZrO2-7 mol % Y2O3-4 mol % Nb2O5 (or Ta2O5), 86 mol % ZrO2-7 mol % Y2O3-7 mol % Nb2O5 (or Ta2O5) in a ternary system of ZrO2—Y2O3—Nb2O5 or Ta2O3 for thereby manufacturing a zirconia/alumina composite having a high strength and high toughness in a state that a low temperature degradation does not occur.

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 including an aluminum source and a magnesium source, the aluminum source including 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 it 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.

Abstract: A method of manufacturing oriented sintered ceramic product which enables to manufacture an oriented sintered product with an average crystal grain size of 20 &mgr;m or less and a grain width 0.4 times or less of the grain size, or an oriented sintered product with an average crystal grain size of 20 &mgr;m or more and a grain width 0.5 times or more of the grain size with no grain growth of plate-like seed crystals, the method comprising dispersing a non-ferromagnetic powder having a not-cubic crystal structure into a slurry, consolidating the slurry under a magnetic field and sintering the molding product.

Abstract: A foundry exothermic assembly is formed by mixing hollow glass microspheres and an inorganic or organic binder with matrix forming constituents including an oxidizable metal, an oxidizing agent, a foundry refractory aggregate and, optionally, a pro-oxidant, and shaping and curing the mixture. The hollow glass microspheres are dispersed and embedded in the assembly matrix.

Abstract: An aqueous nanoparticle ceramic agglomerate dispersion, for forming an ink-absorbing layer of an ink-jet recording medium, containing a nanoparticle ceramic agglomerate dispersed in deionized water. The nanoparticle ceramic agglomerate has an average diameter of 0.05 to 0.3 &mgr;m at a viscosity suitable for coating of 10 to 200 mpa.s as measured by a laser diffraction particle size distribution measurement apparatus, and the ratio of the peak width (half width) at a height which is half the maximum height in a size distribution curve of the nanoparticle ceramic agglomerate, determined according to the results of the measurement, to the maximum height is 0.7 or less. This aqueous ceramic dispersion provides an ink-jet recording medium which enables the printing of sharp and clear images.

Abstract: Doped, pyrogenically prepared oxides of metals and/or non-metals which are doped with one or more doping components in an amount of 0.00001 to 20 wt. %. The doping component may be a metal and/or non-metal or an oxide and/or a salt of a metal and/or a non-metal. The BET surface area of the doped oxide may be between 5 and 600 m2/g. The doped pyrogenically prepared oxides of metals and/or non-metals are prepared by adding an aerosol which contains an aqueous solution of a metal and/or non-metal to the gas mixture during the flame hydrolysis of vaporizable compounds of metals and/or non-metals.

Abstract: An alumina ceramic composition comprising 10 weight % or less (calculated as MgO) of Mg, and 0.2-10 weight % or more (calculated as TiO2) of Ti, the balance being substantially an Al2O3 phase and inevitable impurities. An Al2TiO5 phase is precipitated in grain boundaries. The Al2TiO5 phase surrounds inevitable impurities in the grain boundaries. The alumina ceramic composition exhibits a Q factor of 850 or more when measured at a frequency of 10 GHz.

Abstract: A method of making a component of a ceramic discharge chamber comprising the steps of forming a ceramic composition including an aluminum powder, a binder and a grain growth inhibitor. The alumina powder has a tap density greater than 1.0 gram per cc. The ceramic composition is then die pressed to form a component preform. Next, the component preform is heated to remove at least a substantial portion of the binder.

Abstract: A material for a bismuth substituted garnet thick film comprising Gd, Yb, Bi, Fe and Al as the main ingredient grown by a liquid phase growing method on a garnet substrate in which the composition of the garnet thickness is represented by the general formula:

Abstract: A wiring board having an insulating substrate of aluminum oxide ceramics and a surface wiring layer formed on the surface of said insulating substrate, wherein the aluminum oxide ceramics constituting said insulating substrate contains a manganese compound in an amount of from 2.0 to 10.0% by weight in terms of MnO2, and has a relative density of not smaller than 95%, and said surface wiring layer contains copper in an amount of from 10 to 70% by volume and at least one high-melting metal selected from the group consisting of tungsten and molybdenum in an amount of from 30 to 90% by volume, and further contains copper as a matrix, said copper matrix having a diffusion structure in which are diffused the particles of said high-melting metal having an average particle diameter of from 1 to 10 &mgr;m.

Abstract: An object of the invention is to provide a dielectric porcelain composition with low rate of phase change of a cordierite phase as a primary crystal phase, in which as a result of the low rate of phase change the dielectric constant is from 4.5 to 6 and Q value is 1,000 or more at 60 GHz, and to provide a dielectric resonator and nonradiative dielectric strip using the same. The dielectric porcelain composition comprises, as a principal component, a complex oxide having a molar composition xMgO.yAl2O3.zSiO2 (wherein 10≦x≦40, 10≦y≦40, 20≦z≦80 , and x+y+z=100), and a ratio of a (241) peak intensity &bgr;p(241) and a (222) peak intensity &bgr;p(222) of X-ray diffraction of a &bgr; phase of a 2MgO.2Al2O3.5SiO2 phase, which is a primary crystalline phase of the complex oxide, is 0.8≦&bgr;p(241)/&bgr;p(222)≦1.3.

Abstract: The present invention is directed at sintered ceramic articles exhibiting a crystalline phase assemblage comprising, by weight, of 65-95% cordierite and 5-35% of a secondary phase selected from the group consisting of mullite, magnesium-aluminate spinel, and sapphirine and having a bulk analytical composition consisting essentially of about, by weight, 32-51% SiO2, 35-49% Al2O3, 7-16% MgO. Furthermore, the ceramic articles exhibit an effective strength of greater than about 3000, a CTE of less than about 15×10−7/° C., over the temperature range of 25° C., to 1000° C., and a total intrusion porosity, as measured by a Hg intrusion method, of at least 20%. This invention also relates to a method for producing a sintered ceramic article having the aforementioned cordierite and secondary minor phase mixture.

Abstract: A method for producing a translucent alumina sintered body comprising the steps of: forming a raw material powder, and sintering the formed product under the condition of hydrogen atmosphere from atmospheric pressure to vacuum at a temperature of from 1600 to 1900° C., wherein the raw material powder is a mixed powder comprising an &agr;-alumina powder (1) which comprises a polyhedral primary particle having substantially no fractured surface, has a BET specific surface area of 1 to 7 m2/g, and has a purity of 99.99% or more, an alumina powder (2) having a BET specific surface area of 5 to 200 m2/g in an amount of 10% by weight or less based on said &agr;-alumina powder, and a sintering agent, and satisfies the following formula: (BET specific surface area of alumina powder (2))−(BET specific surface area of &agr;-alumina powder (1))>2 m2/g.

Abstract: This invention pertains to separators for electrochemical cells which comprise a microporous pseudo-boehmite layer; electrolyte elements comprising such separators; electrical current producing cells comprising such separators; and methods of making such separators, electrolyte elements and cells.

Abstract: Ceramics comprising filler crystal particles having an average particle diameter of not smaller than 2.5 &mgr;m and a matrix crystal phase present on the grain boundaries of the filler crystal particles, the filler crystal particles being Al2O3 and the matrix crystal phase being diopside-type oxide crystals precipitated from the crystallized glass. The ceramics has a dielectric loss tangent at 60 to 77 GHz of not higher than 50×10−4, and can be effectively used as an insulating substrate in a wiring board for transmitting high-frequency signals.

Abstract: Disclosed is sintered ceramic article that exhibits a primary crystalline phase of cordierite and analytical oxide composition, in weight percent, of 49-53% SiO2, 33-38% Al2O3, 12-16% MgO and exhibits a coefficient of thermal expansion no greater than about 4.0×10−7/° C. over the temperature range of about 25° C. to about 800° C. and a transverse-I ratio of not less than about 0.92. Also disclosed is a method for producing a sintered cordierite ceramic article involving preparing a plasticizable raw material, comprising a magnesium source, a SiO2-forming source and an additional component of either: (a) a clay-free, Al2O3-forming source having a surface area of greater than about 5 m2/g; or, (b) a clay and Al2O3-forming source combination wherein the clay comprises no greater than about 30%, by weight, of the total inorganic mixture, and the Al2O3-forming source exhibits a surface area of greater than about 40 m2/g.