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: 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 cordierite body is produced by providing cordierite-forming raw materials. The raw materials are intimately blended with effective amount of vehicle and forming aids to impart plastic formability and green strength to the raw materials and form a plastic mixture. A green body is formed which is dried and heated from room temperature up to a maximum temperature of about 1360° C. to 1435° C. at an average heating rate of at least about 315° C. per hour and held at maximum temperature for about 0.05 to 4.4 hours. The total heating time from room temperature to the end of the hold at the maximum temperature is less than about 4.5 hours. The resulting body is predominately cordierite, having a mean coefficient of thermal expansion from about 25° C. to 800° C. of less than about 15×10−7° C.−1 in at least one direction.

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: Cordierite body of CTE at 25-800.degree. C. of .ltoreq.4.times.10.sup.-7 C, at least 85% of porosity having pore diameter of 0.5-5.0.mu.; or >4-6.times.10.sup.-7 C.sup.-1, porosity at least 30 vol %, at least 85% of porosity has pore diameter 0.5-5.0.mu.. Raw materials talc, Al.sub.2 O.sub.3 source, and kaolin, calcined kaolin, and/or silica, and optionally spinel, particle diameter of talc .ltoreq.3.0.mu., of Al.sub.2 O.sub.3 source <2.0.mu., kaolin is <35 wt % of raw materials when particle diameter is <2.0.mu., are blended with vehicle and aids into plastic mixture. Green body is formed, dried, fired at 1370.degree. C.-1435.degree. C. When particle diameter of talc is <2.0.mu., and Al.sub.2 O.sub.3 source is <20 wt % of raw materials, and dispersible high surface area Al.sub.2 O.sub.3 source having particle diameter of <0.3.mu., is <5.0 wt % of raw materials, and particle diameter of kaolin is <2.0.mu., heating rate from 1150.degree. C.-1275.degree. C. is >200.degree. C./hr.

Abstract: Low expansion, low porosity cordierite bodies having a CTE at 25-800.degree. C. of <4.times.10-7C-1 and total porosity of <20%, or CTE of >4.times.10-7C-1 but <9.times.10-7C-1 and total porosity of <12%, or a CTE of >9.times.10-7C-1 but <15.times.10-7C-1 and total porosity of <10%. They are produced by selecting cordierite-forming raw materials in specific combinations of talc, spinel, kaolin, calcined kaolin, Al203-forming material, MgO-forming materials, and silica, in various particle size combinations. The raw materials are intimately blended with an effective amount of vehicle and forming aids and plastically shaped into a green body that is dried and fired at a temperature of about 1370.degree. C. to 1435.degree. C. Firing schedules vary according the raw material combination.

Abstract: A cordierite body is produced by providing cordierite-forming raw materials as talc, calcined talc, MgO-forming component, magnesium aluminate spinel, SiO.sub.2 -forming component, Al.sub.2 O.sub.3 -forming component, kaolin, calcined kaolin, and/or mullite, such that the quantity R is less than about 10.156. R is0.140 (wt. % mullite powder)+0.433 (wt. % SiO.sub.2 powder)+0.0781 (wt. % alpha Al.sub.2 O.sub.3 powder)(mean particle size of alpha Al.sub.2 O.sub.3 powder)+0.0872 (wt. % Al(OH).sub.3 powder)(mean particle size of Al(OH).sub.3 powder)+0.00334 (wt. % SiO.sub.2 powder)(wt. % spinel powder)+2.330 log.sub.10 (1+(wt. % MgO-forming component)(wt. % calcined kaolin))-0.244 (wt. % MgO-forming component)-0.167 (wt. % dispersible high surface area Al.sub.2 O.sub.3 -forming component)+1.1305 (heating time at maximum temperature).sup.-1.

Abstract: A cordierite body is produced by providing cordierite-forming raw materials as talc, calcined talc, MgO-forming component, magnesium aluminate spinel, SiO.sub.2 -forming component, Al.sub.2 O.sub.3 -forming component, kaolin, calcined kaolin, and/or mullite, such that the quantity R is less than about 1.207. R is0.253 (wt. % mullite powder)+0.278(wt. % SiO.sub.2 powder)+0.00590(wt. % SiO.sub.2 powder)(wt. % spinel powder)-0.0193(wt. % SiO.sub.2 powder)(heating time at maximum temperature)-0.348(heating time at maximum temperature)-0.00237(mean heating rate from 25.degree. C. to 1275.degree. C.)+0.0736(wt. % alpha Al.sub.2 O.sub.3 powder)(mean particle size of alpha Al.sub.2 O.sub.3 powder)+0.0892(wt. % Al(OH).sub.3 powder)(mean particle size of Al(OH).sub.3 powder)-0.215(wt. % dispersible high surface area Al.sub.2 O.sub.3 -forming component)+2.392(log.sub.10 (1+(wt. % MgO-forming component)(wt. % calcined kaolin))).

Abstract: A compound having the general formula AM.sub.1+y.sup.3+ M.sub.2-2y.sup.4+ M.sub.y.sup.5+ Si.sub.2 P.sub.6 O.sub.25, wherein A can be K, Rb, or Cs, M.sup.3+ can be Al, Ga, Cr, Fe, Sc, In, Y, lanthanide series elements, or combinations of these, M.sup.4+ can be Si, Ge, Ti, Ir, Ru, Sn, Hf, Zr, or combinations of these, M.sup.5+ can be V, Nb, Ta, or combinations of these, 0.ltoreq.y.ltoreq.1, the mean ionic radius of the M.sup.3+ cations and the mean ionic radius of the M.sup.5+ cations are each about 0.4 to 1.00 .ANG. when coordinated by six oxygen anions, and the mean ionic radii of the M.sup.4+ cations and the M.sup.5+ cations are each no greater than about 0.53+(0.30.times.the mean ionic radius of the M.sup.3+ cations). The compound can be made by a dry powder method that involves providing a homogeneous powder mixture of raw materials to form the compound, shaping the mixture into a preform, and firing the preform at a sufficient temperature and for a sufficient time to form the product compound.

Abstract: 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.

Abstract: Novel method and structure is disclosed for strengthening and mounting sloted metallic honeycomb structures by positioning rod members within the slots to prevent the slots from closing or deforming, and by utilizing the rod members to precisely engage positionable restraining inserts of an enclosing housing, so as to accurately mount the honeycomb structure within the housing.

Abstract: There is disclosed a highly densified, sintered aluminum nitride body having a thermal conductivity in excess of 200 W/m.degree.K. and a strong resistance to attack by hot HC1. There is also disclosed a method of sintering aluminum nitride bodies which employs a variable thermal cycle whereby the body is either heated slowly through a pre-sintering temperature range of 1300.degree. to 1750.degree. C., or held at a temperature within that range for at least a half hour. Optionally, a green aluminum nitride body may be provided with up to 10% by weight of at least one metal fluoride dopant, and may be provided with a sufficient weight to maintain flatness during firing.

Abstract: This invention is particularly directed to the preparation of inorganic ceramic laminated structures for use as substrates in integrated circuit packages. One lamina is composed of a high thermal conductivity material, the second lamina is composed of a low thermal conductivity material having a dielectric constant below 10, a sintering temperature below 1050.degree. C., and a linear coefficient of thermal expansion compatible with that of the other lamina, and a bonding medium sealing the two laminae together exhibiting flow at a temperature below the sintering temperature of the second lamina and a linear coefficient of thermal expansion compatible with those of the two laminae.

Abstract: This invention is directed to the production of nitride-based ceramic bodies selected from the group of AlN and Si.sub.3 N.sub.4 which can be sintered to near theoretical densities at temperatures at least 200.degree. C. lower than those required for the pure materials. Such bodies are densified through the addition of a metal fluoride selected from the group of aluminum, barium, calcium, srtrontium, yttrium, the lanthanide rare earth metals, and mixtures thereof. Up to 80% by weight of said metal fluoride may be included but, generally, such additions will be held between 5-30% by weight. AlN bodies exhibiting very high thermal conductivity can be prepared by sintering with a metal fluoride selected from the group of barium, calcium, strontium, yttrium, the lanthanide rare earth metals, and mixtures thereof.