Abstract: A ceramic filter for trapping and combusting diesel exhaust particulates composed of an end-plugged cordierite honeycomb structure exhibiting a pore size distribution as determined by mercury porosimetry in which the quantity d50/(d50+d90) as related to pore size distribution is less than 0.70, a soot loaded permeability factor Sf, as defined by the equation [d50/(d50+d90)]/[% porosity/100], of less than 1.55, and, a coefficient of thermal expansion (25-800° C.) of no greater than 17×10−7/° C. The ceramic filter further exhibits a median pore diameter, d50, of at least 4 micrometers and up to 40 micrometers. A method of making the filter is provided.

Abstract: A ceramic including a first phase having a general formula R1+(x/2)Zr4P6-xSixO24 where R is selected from the group consisting of Ba, Ca, and Sr and 0≦x≦2, wherein the first phase has a volumetric heat capacity (Cp1), and at least 10 weight percent of a second phase having a volumetric heat capacity (Cp2), wherein Cp2>Cp1. The ceramic has a coefficient of thermal expansion from 22° to 1000° C. of −15×10−7/° C. to +15×10−7/° C., a permeability of at least 0.25×10−12 m2, a total porosity of at least 35% by volume, and a median pore diameter of at least 6 micrometers, and a volumetric heat capacity of the solid Cp(solid) of at least 3.15 J/cm3 K.

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. This invention also relates to a method of producing a ceramic body comprising the following steps: (a) compounding and plasticizing a ceramic raw material mixture and forming the plasticizable raw material mixture into a green ceramic body by extrusion through an extrusion die; (b) drying the green body and thereafter firing the green body at a time and at a temperature sufficient to sinter the ceramic body resulting in a radial shrinkage of the green ceramic body in the radial dimension due to the firing of at least 9%.

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: 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: The present invention provides a method of making a ceramic filter, by forming a mixture from NZP-forming raw material powders selected from metal oxide sources capable of reacting to form a reaction product comprising an NZP-type phase having the general formula R1+(y/2)Zr4P6−ySiyO24 where 0≦y≦1.0 and R is one or more of the metals Ca, Sr, and Ba, pre-reacted powder having the same general formula, and mixtures thereof; and a precursor additive selected from the group consisting of silica precursor, zirconia precursor, and mixtures thereof; shaping the mixture into a green structure; and, firing the green structure to produce a ceramic filter having an open porosity of at least 35% by volume, a median pore size of at least 8 micrometers and a permeability of at least 0.30×10−12 m2, and being suitable as a diesel particulate filter.

Abstract: A structure made predominately of an NZP-type phase having the general formula RxZ4P6−ySiyO24, where 0≦x≦8, 0 ≦y≦6, R is Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Y, and/or lanthanides, and Z is Zr, Ti, Nb, Ta, Y, and/or lanthanidess, and optionally a sintering additive. The structure has an open porosity of at least 20% by volume, median pore diameter in micrometers of at least a value defined by the quantity [10-0.10 (% open porosity)], both as measured by mercury porosimetry, and four-point modulus of rupture as measured on a solid rod of circular cross section, of at least 300 psi. Method of making the structure involves forming a mixture of NZP-forming raw material powders that are metal oxide sources capable of reacting to form an NZP-type reaction product, and/or pre-reacted powder having the above general formula.

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: A structure made predominately of an NZP-type phase having the general formula RxZ4P6−ySiyO24, where 0≦x≦8, 0≦y≦6, R is Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Y, and/or lanthanides, and Z is Zr, Ti, Nb, Ta, Y, and/or lanthanidess, and optionally a sintering additive. The structure has an open porosity of at least 20% by volume, median pore diameter in micrometers of at least a value defined by the quantity [10−0.10(% open porosity)], both as measured by mercury porosimetry, and four-point modulus of rupture as measured on a solid rod of circular cross section, of at least 300 psi. Method of making the structure involves forming a mixture of NZP-forming raw material powders that are metal oxide sources capable of reacting to form an NZP-type reaction product, and/or pre-reacted powder having the above general formula.

Abstract: A ceramic including a first phase having a general formula R1+(x/2)Zr4P6−xSixO24 where R is selected from the group consisting of Ba, Ca, and Sr and 0≦x≦2, wherein the first phase has a volumetric heat capacity (Cp1), and at least 10 weight percent of a second phase having a volumetric heat capacity (Cp2), wherein Cp2>Cp1. The ceramic has a coefficient of thermal expansion from 22° to 1000° C. of −15×10−7/° C. to +15×10−7/° C., a permeability of at least 0.25×10−12 m2, a total porosity of at least 35% by volume, and a median pore diameter of at least 6 micrometers, and a volumetric heat capacity of the solid Cp(solid) of at least 3.15 J/cm3 K.

Abstract: The invention is directed at sintered ceramic articles exhibiting a primary crystalline phase of cordierite and an analytical oxide composition, in weight percent, of 44-53% SiO2, 30-38 Al2O3, 11-16% MgO and 0.05 to 10% of a metal oxide. The ceramic article exhibits a coefficient of thermal expansion in at least one direction no greater than about 15.0×10−7° C. over the temperature range of about 25° C. to about 800° C. The sum of the weight percentages of residual mullite, corundum, and spinel, as measured by X-ray diffractometry of the crushed and powdered body, is not greater than 15%.

Abstract: Negative thermal expansion materials, methods of preparation and uses therefor are disclosed. The materials are useful for negative thermal expansion substrates, such as those used for optical fiber gratings.

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: A filter for trapping and combusting diesel exhaust particulates and method of making the same. The filter comprises a monolithic substrate coated with a refractory oxide material which at a frequency of 2.45 GHz heats up said filter from room temperature to about 600° C. in 5 minutes or less, and wherein said refractory oxide material has a loss tangent which decreases with increasing temperature such that an equilibrium in said filter temperature is reached at no greater than 1100° C.

Abstract: A filter for trapping and combusting diesel exhaust particulates comprising a microwave-absorbing filter body formed from a ceramic material having a general formula selected from the group consisting of A1−xMxB1−yM′yO3−&agr;, where A and M are selected from the group consisting of Na, K, Rb, Ag, Ca, Sr, Ba, Pb, La, Pr, Nd, Bi, Ce, Th and combinations thereof; where B and M′ are selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Rh, Ru, Pt, Zn, Nb, Ta, Mo, W and combinations thereof; wherein, the chemical formula is electrostatically balanced; (A′aRrM″m)(Z)4(X)6O24, where A′ is from Group IA metals; where R is selected from Group IIA metals; where M″ is selected from the group consisting of Mn, Co, Cu, Zn, Y, lanthanides and combinations thereof; where Z is selected from the group consisting of Zr, Hf, Ti, Nb, Ta, Y, lanthanides, Sn, Fe, Co, Al, Mn, Zn, Ni, and combinations thereof; where X is selected from the group consisting of P, Si, As,

Abstract: A crystalline glass-ceramic article composed of a cordierite phase of cordierite crystals or aggregates of near-parallel crystallites, having a formula of either Mg2Al4Si5O18 or AxByMg2Al4+x+2ySi5−x−2yO18. With the first formula, the average size of the cordierite crystals or aggregates is less than 70 micrometers, and the mean coefficient of thermal expansion from 22° C. to 800° C. (CTE) is less than 9×10−7/° C. With the second formula, A is either sodium or potassium, B is either strontium or barium, the sum of x and y is not less than 0.01, and when either x or y equal zero, the CTE is not more than 14×10−7/° C. The article is especially suitable as a filter or catalyst substrate.

Abstract: Negative thermal expansion materials, methods of preparation and uses therefor are disclosed. The materials are useful for negative thermal expansion substrates, such as those used for optical fiber gratings.