Abstract: A honeycomb filter includes an array of interconnecting porous walls which define an array of first channels and second channels. The first channels are bordered on their sides by the second channels and have a larger hydraulic diameter than the second channels. The first channels have a square cross-section, with corners of the first channels having a shape, such as a bevel or fillet, such that the thickness, t3, of the porous walls adjoining the corners of the first channels is comparable to the thickness, t4, of the porous walls adjoining edges of the first and second channels. Embodiments having a corner fillet with a radius, Rc, are also disclosed. Embodiments wherein 0.30 t4?Rc?1.0 t4 exhibit combinations of low wall pressure drop and low thermal stress.

Abstract: A honeycomb filter includes an array of interconnecting porous walls which define an array of first channels and second channels. The first channels are bordered on their sides by the second channels and have a larger hydraulic diameter than the second channels. The first channels have a square cross-section, with corners of the first channels having a shape, such as a bevel or fillet, such that the thickness, t3, of the porous walls adjoining the corners of the first channels is comparable to the thickness, t4, of the porous walls adjoining edges of the first and second channels. Embodiments having a corner fillet with a radius, Rc, are also disclosed. Embodiments wherein 0.30 t4?Rc?1.0 t4 exhibit combinations of low wall pressure drop and low thermal stress.

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 method of preparing beta-spodumene bodies from a plastic batch comprised entirely of minerals, absent a glass component. The resulting structure has a stoichiometry of 1:1:4 (Li2O:Al2O3:SiO2) to 1:1:11 (Li2O:Al2O3:SiO2), and exhibits a low coefficient of thermal expansion, high porosity and high strength, and is suitable for automotive catalytic converter substrates requiring a fast light-off time. There is also provided a ceramic article having a solid-solution of beta-spodumene ranging in molar ratio from 1:1:4 Li2O—Al2O3—SiO2 to 1:1:11 LiO2—Al2O3—SiO2 wherein a component selected from the group consisting of magnesium oxide (MgO), manganese oxide (MnO), and cobalt oxide (CoO) is substituted for lithium oxide (LiO2) at 10 to 65 mole %, and optionally a minor phase of mullite (3Al2O3-2SiO2) in an amount of up to 50% by weight.

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 non-equal, square cross-sections, and an extrusion die for making the same.

Abstract: A method of preparing beta-spodumene bodies from a plastic batch comprised entirely of minerals, absent a glass component. The resulting structure has a stoichiometry of 1:1:4 (LiO2:Al2O3:SiO2) to 1:1:11 (LiO2:Al203:SiO2), and exhibits a low coefficient of thermal expansion, high porosity and high strength, and is suitable for automotive catalytic converter substrates requiring a fast light-off time. There is also provided a ceramic article having a solid-solution of beta-spodumene ranging in molar ratio from 1:1:4 LiO2—Al2O3—SiO2 to 1:1:11 LiO2—Al2O3—SiO2 wherein a component selected from the group consisting of magnesium oxide (MgO), manganese oxide (MnO), and cobalt oxide (CoO) is substituted for lithium oxide (LiO2) at 10 to 65 mole %, and optionally a minor phase of mullite (3Al2O3-2SiO2) in an amount of up to 50% by weight.

Abstract: Compositions, articles and methods for making such articles are disclosed. The compositions, articles and methods include calcium aluminate materials having a low coefficient of thermal expansion.

Abstract: A sintered ceramic 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%. 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 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 non-equal, square cross-sections, and an extrusion die for making the same.

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 non-equal, square cross-sections, and an extrusion die for making the same.

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: Compositions, articles and methods for making such articles are disclosed. The compositions, articles and methods include calcium aluminate materials consisting essentially of a main phase of CaAl4O7 and having a low coefficient of thermal expansion produced by utilizing an additive and firing to temperatures below about 1600°0 C.

Abstract: Methods of making ceramic bodies are disclosed. The methods include manufacturing calcium aluminate material having a low coefficient of thermal expansion.

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 coefficent 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: Compositions, articles and methods for making such articles are disclosed. The compositions, articles and methods include calcium aluminate materials having a low coefficient of thermal expansion.

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: 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 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 non-equal, square cross-sections, and an extrusion die for making the same.

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.