Abstract: A honeycomb structure which includes an inlet end and an outlet end opposing each other and a plurality of cell channels extending along an axis from the inlet end to the outlet end, the cell channels having different hydraulic diameters and being arranged in a checkerboard pattern between large-diameter and small-diameter cell channels, and an extrusion die for making the same.

Abstract: A ceramic support element for a NOx trap which includes a NOx storage component comprising an alkali metal, the ceramic support having a composition lying within a ternary system selected from the group consisting of Al2TiO5—MgTi2O5—MgAl2O4 and Al2TiO5—FeTiO5—Al2O3, a coefficient of thermal expansion (22-800° C.) of less than 20×10−7/° C. and a modulus of rupture as measured on a solid rod of circular cross section of greater than 1000 pounds per square inch.

Abstract: A sintered ceramic that exhibits an average linear coefficient of thermal expansion (25-800 ° C.) below about 5.0×10−7° C., a total porosity between the range of 20% to about 30%. Furthermore, the sintered ceramic article exhibits a pore size distribution such that at least about 86% of pores are of a pore size of less than about 2 &mgr;m. Lastly, the ceramic article exhibits an interconnected pore structure with the pores exhibiting a generally elongated shape, i.e., the pores are predominately oriented with their long axis in the plane of the webs. This invention also relates to a method for producing a sintered cordierite ceramic article involving first compounding and plasticizing a cordierite-forming inorganic powder batch comprising a platy talc having median particle of size less than about 2 &mgr;m, and preferably a talc morphology index greater than about 0.75.

Abstract: A plasticizable raw material mixture for use in preparing a substrate having cordierite as its primary phase with a mixture of a chemical composition, percent by weight, of 11 to 17% MgO, 33 to 41% Al2O3 and, 46 to 53% SiO2, the mixture including the following (1) a platy talc having a morphology index of greater than 0.8 and exhibiting a mean particle size of less than about 5 &mgr;m; (2) an Al2O3 forming source comprising an alumina having a mean particle size of less than about 5 &mgr;m selected from the group consisting of ∝-alumina, transition aluminas, aluminum oxide monohydroxide, or aluminum trihydrate having; and, (3) one or more of the components of delaminated kaolin having a mean particle size of less than about 2 &mgr;m, calcined kaolin exhibiting a mean particle size of less than about 2 &mgr;m and a surface area of greater than about 10 m2/g and/or silica having a mean particle size of less than about 5 &mgr;m.

Abstract: Fine circumferential skin cracking in extruded thin-walled cordierite honeycombs having channel wall thicknesses not exceeding about 0.004 inches (100 &mgr;m) but skin layers of substantially higher thickness is prevented by extruding the honeycombs under conditions that enhance cordierite crystal alignment in the skin; thin-walled honeycomb products having skins free of fine cracks that are well-matched in thermal expansion to the honeycomb cores are provided.

Abstract: This invention relates to a method of producing a honeycomb ceramic body exhibiting a predetermined radial dimension comprising producing a green ceramic honeycomb body that exhibits a radial dimension at least 9% greater than the predetermined radial dimension and a cell density of at least 500 cpsi. The method further involves shrinking the green body during firing to form a sintered honeycomb ceramic body exhibiting the final predetermined radial dimension.

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: Fine circumferential skin cracking in extruded thin-walled cordierite honeycombs having channel wall thicknesses not exceeding about 0.004 inches (100 &mgr;m) but skin layers of substantially higher thickness is prevented by extruding the honeycombs under conditions that enhance cordierite crystal alignment in the skin; thin-walled honeycomb products having skins free of fine cracks that are well-matched in thermal expansion to the honeycomb cores are provided.

Abstract: A ceramic article which consists essentially, by weight on the oxide basis, of 10-25% SiO2, 65-85% Al2O3, and 2-12% Li2O and comprises beta-eucryptite as a first phase having a negative component in thermal expansion and a melting point Tm1, and a second phase having a positive component in thermal expansion which is higher than the component in thermal expansion of the first phase and a melting point Tm2, wherein Tm2>Tm1, wherein the first phase is at most 50% by weight of the ceramic, and wherein the ceramic is characterized by microcracking. Tm2 is at least 1800° C. The ceramic article exhibits a near zero coefficient of thermal expansion from room temperature to 800° C., a high refractoriness, and a high resistance to thermal shock properties which make the inventive ceramic extremely desirable in high temperature applications, such as filters for diesel exhaust engines.

Abstract: A binder system for use in the formation of ceramic or other powder-formed greenware comprising a binder, a solvent for the binder, a surfactant, and a component that is non-solvent with respect to the binder and solvent. The non-solvent component exhibits a lower viscosity than the solvent when containing the binder and comprises a low molecular weight oil having a 90% recovered distillation temperature range of between about 220 to 400° C. Also disclosed is a process of forming and shaping plasticized powder mixtures and a process for forming ceramic articles utilizing the binder system.

Abstract: A binder system for use in the formation of ceramic or other powder-formed greenware comprising a binder, a solvent for the binder, a surfactant, and a component that is non-solvent with respect to the binder and solvent. The non-solvent component exhibits a lower viscosity than the solvent when containing the binder and comprises at least a portion of an organic liquid having a 90% recovered distillation temperature of no greater than about 225° C. and more preferably less than 220° C. Also disclosed is a process of forming and shaping plasticized powder mixtures and a process for forming ceramic articles utilizing the binder system.

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.

Abstract: A ceramic comprising predominately a cordierite-type phase approximating the stoichiometry Mg2Al4Si5O18 and having a coefficient of thermal expansion (25-800° C.) of greater than 4×10−7/° C. and less than 13×10−7/° C. and a permeability and a pore size distribution which satisfy the relation 2.108 (permeability)+18.511 (total pore volume)+0.1863 (percentage of total pore volume comprised of pores between 4 and 40 micrometers)>24.6. The ceramic is suitable in the fabrication of cellular, wall-flow, diesel particulate filters having a pressure drop in kPa that at an artificial carbon soot loading of 5 grams/liter and a flow rate of 26 scfm is less than 8.9−0.035 (number of cells per square inch)+300 (cell wall thickness in inches), a bulk filter density of at least 0.60 g/cm3 and a volumetric heat capacity of at least 0.67 J cm−3 K−1 as measured at 500° C.

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 binder system for use in the formation of ceramic or other powder-formed greenware comprising a binder, a solvent for the binder, a surfactant, and a component that is non-solvent with respect to the binder and solvent. The non-solvent component exhibits a lower viscosity than the solvent when containing the binder and comprises at least a portion of a branched chain paraffin exhibiting a 90% recovered distillation temperature ranging between 205° C. to about 225° C. and a carbon chain length comprised predominantly of carbon chain distributions ranging from 12 to 14. Also disclosed is a process of forming and shaping plasticized powder mixtures and a process for forming ceramic articles utilizing the binder system.

Abstract: A plasticizable raw material mixture for use in preparing a substrate having cordierite as its primary phase with the mixture comprised of a chemical composition, percent by weight, of 11 to 17% MgO, 33 to 41% Al2O3 and, 46 to 53% SiO2. The raw material mixture specifically comprises the following: (1) one source of Al2O3 and SiO2 comprising a clay mixture having less than about 22%, by weight based on the total raw materials in the plasticizable mixture, of calcined clay; (2) an alumina yielding precursor comprising alumina having an average particle diameter of about 1 &mgr;m or less; and, (3) at least one source of magnesia having an average particle diameter of between about 3 to 15 microns.

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.

Abstract: A binder system for use in the formation of ceramic or other powder-formed greenware including a binder, a solvent for the binder, a surfactant, and a component that is non-solvent with respect to the binder and solvent. The non-solvent component exhibits a lower viscosity than the solvent when containing the binder and includes a low molecular weight oil having a 90% recovered distillation temperature range of between about 220 to 400° C. Also disclosed is a process of forming and shaping plasticized powder mixtures and a process for forming ceramic articles utilizing the binder system.

Abstract: Cordierite honeycomb bodies having low coefficients of thermal expansion (CTE) and correspondingly high resistance to thermal shock, and a method for making them, wherein an alumina-yielding raw material having high specific surface area and which disperses into very fine particles in the batch, preferably together with fine talc as the sole batch source of magnesium, are disclosed; the use of fine talc enables the production of thin-walled extruded honeycomb structures exhibiting both low average CTE and high porosity, a combination particularly desirable for applications such as catalytic substrates for the control of combustion engine exhaust emissions.

Abstract: A family of aluminoborate glasses that are compatible with aluminum at elevated temperatures, and an article comprising such a glass with either an aluminum coating, or with aluminum particles dispersed within the glass, whereby the glass may be rendered polarizing. The base glass consists essentially of, 15-85% B2O3, 5-45% Al2O3 and 10-75% Li2O+RO, where RO represents the alkaline earth metal oxides MgO, CaO, SrO and BaO, and is free of oxides reacting with aluminum at elevated temperatures.