Corning Incorporated

Martin Joseph Murtagh

Douglas Munroe Beall

Gregory A Merkel

Bryan Ray Wheaton

Evelyn McGee DeLiso

Chris Maxwell

George Halsey Beall

Donald L Guile

Robert John Locker

Mark Allen Spetseris

David Jack Bronfenbrenner

Thomas Jean Glasson

Kimberly Errin Hill

Donna R Seyler

Thomas E Landon

Chris Brian Maxwell

Gregory Albert Merkel

A method of preparing an aluminum metaphosphate (ALMP) particulate product includes charging a milling chamber of a ball mill with grinding media and loading an ALMP feedstock into the milling chamber. The ALMP feedstock is milled with the grinding media into ALMP particles at a particle reduction index in a range from 0.25 to 0.5. At a plurality of time steps during a period in which the milling is carried out, a fine fraction of the ALMP particles is removed from the milling chamber while a coarse fraction of the ALMP particles remains in the milling chamber for additional milling. An ALMP particulate product with a particle size distribution having a median particle size in a range from 100 &#x3bc;m to 700 &#x3bc;m is prepared from the ALMP particles removed from the milling chamber.

Method of ball milling aluminum metaphosphate

A porous ceramic honeycomb article includes a primary cordierite phase and an intercrystalline glass phase. In an as-fired condition, the porous ceramic honeycomb article exhibits microcrack parameter Nb&#x2266;0.06 and an as-fired E/Eratio &#x2266;0.99. The article exhibits a coated microcrack parameter Nb&#x2266;0.14 and a coated E/Eratio &#x2266;1.06 after the porous ceramic honeycomb article has been washcoated and calcined at a temperature of 550&#xb0; C. After the article is exposed to a thermal treatment at a temperature &#x2267;800&#xb0; C. following washcoating and calcining, at least a first portion of the porous ceramic honeycomb article has a first treated microcrack parameter Nb&#x2267;0.18, and a first treated mean coefficient of thermal expansion of not more than 12&#xd7;10/&#xb0; C. over a temperature range of 25&#xb0; C. to 800&#xb0; C. Methods of forming the porous ceramic honeycomb article are also disclosed.

Cordierite porous ceramic honeycomb articles with delayed microcrack evolution

A method of making ceramic articles includes compounding ceramic precursor batch components that include hydrous clay. The hydrous clay includes particle components having a platy geometry. The crystallite size of the platy hydrous clay particle components is greater than a predetermined amount. Controlling such crystallite size can result in reduced shrinkage of green ware during the clay dehydroxylation stage of firing.

Control of clay crystallite size for shrinkage management

A method of making ceramic articles includes compounding ceramic precursor batch components that include hydrous clay. The hydrous clay includes particle components having a platy geometry. The crystallite size of the platy hydrous clay particle components is less than a predetermined amount. Controlling such crystallite size can result in fired ceramic articles with a lower coefficient of thermal expansion and improved thermal shock resistance.

Control of clay crystallite size for thermal expansion management

The present disclosure relates to cordierite-forming batch materials and methods of using the same, and in particular batch materials for forming porous cordierite bodies suitable for treating engine emissions. The batch materials include sources of magnesium, alumina, silica, and high BET specific surface area raw kaolin clay. In some embodiments, the BET specific surface area of the raw kaolin clay is greater than 22 m/g. In other embodiments, the BET specific surface area of the raw kaolin clay is greater than 13 m/g, and the source of magnesium oxide and the source of non-kaolin clay source of silica both have relatively coarse particle size.

Cordierite-forming batch materials and methods of using the same

A method for treating a microcracked, ceramic substrate is provided that obviates the need for filling the microcracks of the substrate via a passivation step prior to sintering a layer of washcoat to the surfaces of the substrate that may either contain a catalyst, or provide a support layer for a catalyst subsequently applied. In the first step of the method, a slurry of particles of a washcoating composition is applied over the surface of the substrate such that particles of the composition are lodged into microcracks of the substrate. Next, the substrate is heat treated to between about 700&#xb0; C. and 1300&#xb0; C. The method is particularly applicable to ceramic honeycomb structures used as catalytic converters in automotive exhaust systems.

Methods for applying a washcoat and heat treating a ceramic honeycomb, and treated articles

A thermally shock resistant ceramic body, such as a porous ceramic honeycomb structure for a wall flow diesel engine exhaust filter or a flow-through ceramic catalyst support, is formed of a composite ceramic material comprising a major first ceramic phase exhibiting good thermal shock resistance and a minor second phase material that substantially reduces the elastic modulus of the composite ceramic material at elevated temperatures.

High porosity thermally shock resistant ceramic structures

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 d/(d+d) as related to pore size distribution is less than 0.70, a soot loaded permeability factor S, as defined by the equation [d/(d+d)]/[% porosity/100], of less than 1.55, and, a coefficient of thermal expansion (25&#x2013;800&#xb0; C.) of no greater than 17&#xd7;10/&#xb0; C. The ceramic filter further exhibits a median pore diameter, d, of at least 4 micrometers and up to 40 micrometers. A method of making the filter is provided.

Magnesium aluminum silicate structures for DPF applications

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% SiO,, 35-49% Al,O,, 7-16% MgO. Furthermore, the ceramic articles exhibit an effective strength of greater than about 3000, a CTE of less than about 15&times;10,/&deg; C., over the temperature range of 25&deg; C., to 1000&deg; 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.

Fabrication of low thermal expansion, high strength cordierite structures

Cordierite-containing articles are produced by a method comprising the steps of providing raw materials including including alumina-yielding ingredients, magnesia-yielding ingredients, and silica-yielding ingredients, suitable to form an analytical batch composition by weight on an oxide basis of 9-20 weight percent MgO, 30-50 weight percent Al.sub.2 O.sub.3, and 41-56.5 weight percent SiO.sub.2. The raw materials include talc having a BET surface area of no greater than about 4.0 m.sup.2 /g, and uncalcined clay having an average particle size of no greater than about 2.0 .mu.m. The raw materials are blended with an effective amount of vehicle and forming aids to form a plastic mixture. The plastic mixture is anisostatically formed into a green body and dried. The dried green body is fired at a temperature and for a time effective to form a cordierite/containing ceramic article. The cordierite-containing articles exhibit a coefficient of thermal expansion of not greater than about 4.0.times.10.sup.-7 /.degree.C. and transverse I ratios of not less than about 0.85. The method of the present invention is particularly useful in forming cordierite honeycomb structures used as catalyst supports for automobiles or as particulate filters for the exhaust fluids of diesel engines.

Modified cordierite precursors

A body is made up of at least about 93% by weight cordierite, having a coefficient of thermal expansion of no greater than about 4.times.10.sup.-7 .degree.C.sup.-1, from about 25.degree. C. to about 800.degree.0 C., and a total porosity of greater than about 42%. A method for producing the body which includes selecting raw materials to form a composition which forms cordierite on firing, the raw materials being composed of: talc having a BET surface area of no greater than about 5 m.sup.2 /g, 0 to about 48% by weight of clay, which can be platelet clay, stacked clay which can be delaminated into platelets during processing, and mixtures thereof, an aluminum oxide yielding component having an average particle size of either about 3 to about 8 micrometers in diameter, or no greater than about 3 micrometers in diameter, and free silica, intimately blending the raw materials with an effective amount of vehicle and forming aids to impart plastic formability and green strength to the raw materials and to form a plastic mixture therefrom. If the particle size of the aluminum oxide yielding component is no greater than about 3 micrometers in diameter, the raw materials are blended additionally with a burnout agent. The raw materials are formed into a green body which is dried and fired at a sufficient temperature for a sufficient time to form the cordierite body.

Fabrication of low thermal expansion, high porosity cordierite body

A method of preparing a precursor or cordierite-forming particulate raw material mixture is improved upon by characterizing the talc particles utilized in the raw material mixture in accordance with a Morphology X-ray Diffraction Index or the surface area of the talc particles. Talc particles having a predetermined or desired Morphology X-ray Diffraction Index or surface area are utilized in preparing the raw material mixture. A cordierite article is produced having pores therethrough, which pores have shapes that are 'blocky' or 'platy' as a result of the talc morphology. 'Platy' pores in the fired cordierite article result in higher Water Absorption values and an increase in coatability by high surface area washcoat and catalyst; conversely, 'blocky' pores result in lower Water Absorption values and a decrease in coatability by high surface area washcoat and catalyst.

Method for producing cordierite articles

A body is disclosed which is at least about 90% by weight cordierite, has a mean pore size of less than about 10.0 microns, and a coefficient of thermal expansion of no greater than about 9.0.times.10.sup.-7 /.degree.C. from about 25.degree. C. to 1000.degree. C. Also disclosed is a method of fabricating the body. Raw materials are selected to form a composition consisting essentially of in percent by weight about 12 to 16 magnesium oxide, about 35 to 41 aluminum oxide, and about 43 to 53 silica. The raw materials are absent of clay and talc. The magnesium oxide is supplied by a magnesium oxide component having an average particle size of no greater than about 15.0 micrometers in diameter. The aluminum oxide is supplied by an aluminum oxide component having an average particle size of no greater than about 8.0 micrometers in diameter. The composition is capable of forming cordierite in the subsequent firing step. The raw materials are blended with an affective amount of vehicle and forming aids to impart plastic formability and green strength thereto and form a plastic mixture. The raw materials are formed into a green body which is dried and fired. The firing is done by heating to a first temperature of about 1000.degree. C. to 1200.degree. C. and thereafter raising the temperature at a rate of less than about 100.degree. C. per hour to a second temperature sufficient to form cordierite, and maintaining the second temperature for a sufficient time to form the cordierite body.

Fabrication of cordierite bodies

A body is disclosed which is at least about 90% by weight cordierite, and has a coefficient of thermal expansion of less than about 16.times.10.sup.-7 /.degree.C. from about 25.degree. C. to about 1000.degree. C. Also disclosed is a method of fabricating the body. Raw materials are selected to form a nominal composition consisting essentially of in percent by weight about 11.5 to about 16.5 MgO, about 33.0 to about 41.0 Al.sub.2 O.sub.3, and about 46.5 to about 53 SiO.sub.2. The raw materials can be a combination of silica and magnesium aluminate spinel, a combination of silica, magnesium aluminate spinel, and a MgO yielding component, or a combination of silica, magnesium aluminate spinel, and a Al.sub.2 O.sub.3 yielding components. The raw materials are provided absent of clay and talc. The raw materials are blended with an effective amount of vehicle and forming aids to impart plastic formability and green strength thereto form a plastic mixture. The raw materials are formed into a green body which is dried and fired at a sufficient temperature for a sufficient time to form the cordierite body.

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Trumansburg, NY, United States of America

Martin Joseph Murtagh