Abstract: Low mass kiln furniture for supporting ceramic ware during the firing thereof is provided having excellent thermal shock resistance and high temperature stability, the kiln furniture being comprised of a porous refractory ceramic body of low density prepared by the firing of a porous aluminosilicate-bound aggregate of refractory ceramic compounds, and wherein the ceramic body has on one or more of its surfaces a smooth skin in the form of an integral thin porous ceramic membrane layer.

Abstract: A method of producing self-supporting ceramic structures comprising (i) a polycrystalline oxidation reaction product formed upon oxidation of a body of molten parent metal with an oxidant, and (ii) interconnected porosity at least partially accessible from one or more surfaces of said ceramic body. A second polycrystalline ceramic material is incorporated into the porosity of said ceramic body to modify or contribute to its properties.

Abstract: A ceramics-based manufacturing material and a coating material are disclosed, both of which are used in high-temperature structures and applications. The ceramics-based manufacturing material may be used for building structural blocks or members, such as refractory bricks, that require the mechanical strength and thermal resistance when they are exposed to the high temperatures of 1,500.degree. C. or above. Those bricks made of the material disclosed provides the mechanical strength and heat resistance better than the conventional ones. The coating material may be used for forming a thermal resistant layer on metal or other material bases. Both materials have substantially the similar compositions, either of which may have the alternative use, such as the manufacturing material or the coating material. Simply adding an appropriate amount of water to either makes it a coating material. In either case, the requirements for the high temperature resistance and mechanical strength can be satisfied.

Abstract: A castable refractory mix composition is disclosed which when fired at a temperature of about 2300.degree. F. will yield a cast refractory article having improved thermal shock resistance and when fired at a higher temperature of about 2750.degree. F. will yield a cast refractory article having improved abrasion resistance. The castable refractory mix composition comprises from about 10 to 15% by weight of an aqueous slip of fine ground fused silica particles, from 25% to 32% by weight of fine alumina particles, from about 55 to 70% by weight of relatively large particle size silican carbide refractory particles, from about 0.015 to 0.04% by weight of a water-soluble wetting agent, and from 0 to about 5% by weight added water.

Abstract: A dielectric ceramic composition for high frequencies consisting essentially of a basic composition expressed by the general formula:xMgO--yAl.sub.2 O.sub.3 --zSiO.sub.2wherein x, y and z are mole percentage of the respective components, x+y+z=100, 65.ltoreq.x.ltoreq.77, 1.ltoreq.y.ltoreq.15, and 8.ltoreq.z.ltoreq.34 and an exclusive additive of 0.1 to 10.0 weight % of Li.sub.2 O. The basic composition has a set of x, y and z falling within an area defined by a polygon ABCD encompassed by the points A, B, C and D in FIG.

Abstract: An insulative ceramic composition comprising from 25 to 60 wt % of Al.sub.2 O.sub.3, from 10 to 40 wt % of SiO.sub.2, from 3 to 30 wt % of from B.sub.2 O.sub.3, from 1 to 15 wt % of MgO, from 0.2 to 10 wt % of Cr.sub.2 O.sub.3, from 0.1 to 3 wt % of Li.sub.2 O, and from 1 to 20 wt % of at least one member selected from the group consisting of CaO, SrO and BaO. The ceramic composition has a small coefficient of linear expansion and can avoid cracking when undergoing thermal shock.

Abstract: Novel compositions are disclosed for the manufacture of gunning mixes and strong castable products for use as monolithic refractory and construction materials which may contain no lime bearing cements. Bonding is based on the setting reaction of fumed silica with an alkali metal silicate preferably a particulate sodium or potassium silicate that slowly dissolves in water such as an anhydrous sodium silicate of SiO.sub.2 :Na.sub.2 O molar ratio of 1:1 to 4:1; or an anhydrated potassium silicate having an SiO.sub.2 :K.sub.2 O molar ratio of 3:1, or a hydrated sodium silicate having an SiO.sub.2 :Na.sub.2 O molar ratio of 3:1. Setting and mechanical characteristics allow this class of castable and gun mixes to be placed more rapidly into service since the time required for curing is much less. Although initial set strengths are not as high as those of conventional castables, very high strengths can be made to occur shortly after setting by heating.

Abstract: Mullite of high purity is obtained by neutralizing an aqueous solution containing a basic aluminum salt and colloidal silica thereby causing formation of a precipitate in the aqueous solution, and subsequently heating the precipitate.

Abstract: Provided is a sintering air suitable for use in forming aluminum borate into a ceramic product, the sintering aid comprised of an aluminum borate compound having a melting point lower than the sintering temperature of aluminum borate.

Abstract: A method of predicting the fired shrinkage of a ceramic oxide slurry which comprises measuring the ionic impurity concentration in the ceramic oxide slurry. A ceramic oxide slurry which exhibits a predetermined fired shrinkage can be formulated by the step of adding a predetermined amount of at least one ionic dopant to the ceramic oxide slurry in another embodiment.

Abstract: In a process for forming elements from a slurry that includes particulate ceramic and/or glass, an organic binder resin, and a solvent for the resin, where the element is shaped from the slurry, and the element heated to remove the organic materials of the slurry and subsequently fuse the ceramic and/or glass particles, the improvement comprised of coating the ceramic and/or glass particles prior to forming the slurry with a surface modification compound selected from the group consisting of organo silanes, organo silazanes, titanium chelates, titanium esters, and mixtures thereof.

Abstract: Sintered article suitable for artificial bones, for example, containing a calcium phosphate compound as a main component and additionally containing spinel or magnesium oxide formed by sintering magnesium oxalate dihydrate. This sintered article is produced by adding alumina and silica or magnesium oxalate dihydrate to a calcium phosphate compound and firing the resultant mixture.

Abstract: A silicon nitride sintered material for cutting tools comprising from about 3 to 10 wt % of partially stablized zirconium oxide, from about 1 to 5 wt % of aluminum oxide, and from about 1 to 10 wt % of yttrium oxide, the balance being silicon nitride, and the process for making the same.

Abstract: A sintered aluminum titanate-mullite base ceramic having a chemical composition of not more than 0.8% of MgO, from 53 to 74% of Al.sub.2 O.sub.3, from 14 to 33% of TiO.sub.2, from 1.2 to 5% of Fe.sub.2 O.sub.3, from 6 to 20% of SiO.sub.2, and not more than 0.3% of (CaO+Na.sub.2 O+K.sub.2 O), and an amount of glass in mullite base matrices of the sintered body being not more than 5% when measured at a section of the sintered body. This aluminum titanate-mullite base ceramic is obtained by compounding from 40 to 65% of a starting material of aluminum titanate essentially consisting of from 45 to 62% of Al.sub.2 O.sub.3, from 34 to 50% of TiO.sub.2, from 3 to 7% of Fe.sub.2 O.sub.3, not more than 1% of SiO.sub.2 and not more than 0.3% of (CaO+Na.sub.2 O+K.sub.2 O) with from 35 to 60% of a starting material of mullite essentially consisting of from 18 to 32% of SiO.sub.2, from 68 to 82% of Al.sub.2 O.sub.3, and not more than 0.85% of (Fe.sub.2 O.sub.3 +TiO.sub.2 +CaO+MgO+Na.sub.2 O+K.sub.

Abstract: An improved thermal shock resistant and generally thermal resistant ceramic composition is disclosed. The ceramic composition is compounded of aluminum oxide as a primary constituent with additives in a preferred form comprising zirconium oxide plus manganese oxide or titanium oxide, or both, interacted by exposure to high temperature. The additives increase the thermal shock resistance of the fired ceramic composition, with retention of elevated temperature strength properties. The ceramic compositions are prepared as high density solid shapes or as porous structures. The solid shapes formed into machine components show improved resistance to rapid thermal excursions, differential thermal gradients and elevated temperatures. Open cell ceramic foams of the ceramic composition are useful for hot filters, such as for filtering molten metal as well as in reaction supporting applications, where such ceramic foam structures are subject to rapid temperature and pressure transients.

Abstract: Refractory compositions which can be gun-applied, or refractory, unfired shapes containing sintered magnesite and/or sintered dolomite as the principal refractory component, 0.5 to 5% by weight of bentonite, 1 to 5% by weight of aluminum sulfate and 0.5 to 5% by weight of an alkaline earth compound, characterized by the fact that they contain magnesium hydroxide and/or caustic-calcined MgO as the alkaline earth compound. The compositions and shapes of the invention have the advantage that they do not exhibit binder migration, and no damping-reduction cracks or chipping occurs therein.

Abstract: A dense, sintered ceramic material having a low dielectric constant and a low coefficient of thermal expansion is provided from a mixture of 10-50 wt. % alumina, 0-30 wt. % fused silica, and 50-60 wt. % of a frit comprised of CaO, MgO, Al.sub.2 O.sub.3, B.sub.2 O.sub.3, and SiO.sub.2. The mixture has a minimum sintering temperature in the range of 850.degree.-1000.degree. C., and can be formed by conventional manufacturing techniques. It is particularly useful for the fabrication of single or multilayer electronic circuit substrates.

Abstract: This invention is directed to the production of ceramic alloys consisting essentially of ZrO.sub.2, titania, and yttria or rare earth oxides such as gadolinia, ytterbia, neodymia, and ceria. Mole % concentration values as low as 0.25 mole % for yttria have been found to provide a hard and tough ceramic alloy in the presence of the titania-zirconia body. These compositions have been found to produce effective hard and tough ceramic bodies when mixed with refractory fibers and/or whiskers and hard refractory ceramics.

Abstract: A ceramic consisting essentially of from 1 to 15 percent of glass and 99 to 85 percent of a mixture of particulate Al.sub.2 O.sub.3 and particulate ZrO.sub.2 is disclosed. ZrO.sub.2 is present in a sufficient amount, usually from 1/4 to 6 percent based on the weight of the ZrO.sub.2 and Al.sub.2 O.sub.3, to strengthen the ceramic significantly, by comparison with an otherwise identical ceramic where the particulate ZrO.sub.2 is replaced either by the glass or by particulate Al.sub.2 O.sub.3. The glass constitutes a vitreous phase bonding the particulates into a dense, gas impervious structure, and can be a calcium magnesium silicate glass containing from 45 to 80 percent of SiO.sub.2, from 8 to 55 percent of CaO and MgO, and not more than 15 percent of Al.sub.2 O.sub.3.

Abstract: Improved ceramic tool compositions comprising primarily aluminum oxide are provided. The aluminum oxide can be supplemented with other oxides including zirconium oxide, magnesium oxide, hafnium oxide. In addition are added silicon nitride or aluminum nitride together with dispersed particles comprising carbides, nitrides and/or carbonitrides. These compositions are prepared by e.g., a reaction hot pressing process and ceramic bodies prepared in accordance with the invention display superior wear resistance to conventional tool compositions.

Abstract: A low-temperature sinterable ceramic composition comprising 1 to 20% by weight of Al.sub.2 O.sub.3, 15 to 50% by weight of SiO.sub.2, 0 to 5% by weight of MgO, 3 to 18% by weight of CaO, 0 to 5% by weight of TiO.sub.2, 1 to 8% by weight of B.sub.2 O.sub.3, 0 to 2% by weight of Li.sub.2 O, 20 to 80% by weight of at least one of zircon, mullite and spinnel, and 1 to 12% by weight of a fluoride selected from CaF.sub.2, MgF.sub.2, LiF, AlF.sub.3, MnF.sub.2, BaF.sub.2 and SrF.sub.2.

Abstract: Ceramic insulating substrate layers (1) for a multilayered ceramic wiring circuit board (3) consist essentially of crystals of mullite and sillimanite, non-crystalline silicon dioxide occupying the interstices between the crystals and magnesium oxide dissolved substantially in the crystals in solid solution and have a thermal expansion coefficient of 40-60.times.10.sup.-7 /.degree. C. and a dielectric constant below 6.7.

Abstract: Low temperature fired ceramics are produced by a highly improved method, using a specially designed apparatus and the obtained ceramic products are very useful in various applications, such as electronic components, heat resistant articles, tablewares, kitchen utensils or decorative articles because of a combination of superior properties, particularly high heat resistance, high mechanical strength, low thermal expansion and low dielectric constant. In practicing the method, a low firable ceramic material is shaped into a green sheet and then converted to a dense fired ceramic product by rapid firing in an adequate air. In the firing step, the air feed ratio (the ratio of the quantity of feed of air to the theoretical quantity of air required for combustion) is controlled so as to be at least 1.5 thereby the aimed fired products can be obtained in a greatly reduced firing time, without causing deformation or warpage of the ceramics or ignition of the decomposition gases of a binder.

Abstract: Novel self-supporting ceramic structures are produced by the oxidation reaction of a molten metal precursor with a vapor-phase oxidant to form an oxidation reaction product. Molten metal is drawn through the oxidation reaction product towards the oxidant to cause continued growth of the product at the interface between oxidant and previously formed product. This reaction or growth is continued to form a thick, self-supporting ceramic body. The resulting ceramic material of the polycrystalline growth product consists essentially of an oxidation reaction product and, optionally, one or more non-oxidized constituents of the metal precursor.

Abstract: A process for producing an artificial light-weight aggregate comprising SiO.sub.2, Al.sub.2 O.sub.3, Fe.sub.2 O.sub.3 and at least one oxide selected from the group consisting of MgO and CaO which has an absolute dry specific gravity of not higher than 1.5, a crushing strength of not less than 55 kfg/cm.sup.2 and a 24 hour water-absorption ratio of not greater than 2.4%. The process comprises granulating a raw powder material comprising SiO.sub.2, Al.sub.2 O.sub.3, Fe.sub.2 O.sub.3 and at least one oxide selected from the group consisting of MgO and CaO, in which the total amount of SiO.sub.2 and Al.sub.2 O.sub.3 is from 75 to 92 wt. %, the weight ratio of Al.sub.2 O.sub.3 /SiO.sub.2 is from 0.25 to 0.70, and the total amount of Fe.sub.2 O.sub.3 and MgO and/or CaO is from 6-20 wt. % and containing at least 80% by weight of a coal ash having a Blaine specific surface area of 2,000 to 9,000 cm.sup.2 /g to give granules having an average apparent specific gravity of 1.1 to 1.8 and a crushing strength of 0.

Abstract: A medium weight abrasion-resistant castable for use as a refractory lining having a bulk density of no greater than 130 lbs/cu ft, and abrasion loss of no greater than about 25 cc and a thermal conductivity of no greater than 5.5 BTU/hr/ft.sup.2 /in/.degree.F. includes a coarse aggregate of cordierite. The composition also includes an intermediate sized aggregate of calcined kaolin or calcined flint and a finer sized aggregate of calcined kaolin or calcined flint, fly ash cenospheres, clay, fume silica, and cement.

Abstract: A method for preparing mullite (3Al.sub.2 O.sub.3.2SiO.sub.2) by partially hydrolyzing a dilute silicon alkoxide solution, combining an aluminum alkoxide with the partially hydrolyzed silicon alkoxide, eliminating terminal alkoxide groups and firing the material to about 985.degree. C.

Abstract: A cofired structure comprised of a refractory metal metallization supported by a substrate free of large voids is produced by forming a liquid phase sinterable ceramic composition containing SiO.sub.2 in some form and a sulfate of an alkali metal and/or an alkaline earth metal, admixing the composition with an organic binding medium, shaping the mixture into a thin sheet, contacting the sheet with refractory metal metallization material, and cofiring the resulting structure whereby the free carbon produced by pyrolysis of the organic medium is removed by reaction with the sulfate before closed porosity is initiated.

Abstract: A casting composition for making dielectric green tapes comprising a dispersion of finely divided solids of (a) a noncrystallizable glass and (b) a mixture of refractory oxides in a solution of (c) organic polymer, which is readily depolymerizable at 825.degree.-1025.degree. C. in a nonoxidizing atmosphere, dissolved in (d) volatile nonaqueous solvent.

Abstract: A refractory composition characterized by abrasion resistance and low thermal conductivity comprising about 40 to about 96 weight percent amorphous silica, about 2 to about 50 weight percent -65 mesh calcined refractory aggregate having a density of at least about 140 lb/ft.sup.3 and about 2 to about 40 weight percent calcium aluminate cement.

Abstract: A dielectric composition comprising an admixture of finely divided solids comprising (a) a noncrystallizable glass of which the deformation temperature (T.sub.d) is 580.degree.-625.degree. C. and the softening point (T.sub.s) is 630.degree.-700.degree. C., and (T.sub.s -T.sub.d) is 50.degree.-75.degree. C., and (b) a refractory which is substantially insoluble in the glass at temperatures of 825.degree.-900.degree. C.

Abstract: A high temperature resistant refractory mortarless joint wall and method made from pre-formed, unburned plastic refractory blocks having siliceous clay, and from ten percent to seventy-five percent pyrophyllite, by weight, and workability from twenty percent to forty percent when erected before drying and firing.

Abstract: A packing material for a reactor for producing ethylene oxide by the catalytic oxidation of ethylene in the presence of molecular oxygen, wherein the packing material is used at the inlet side of a catalyst layer of the reactor, is silica-alumina containing 10 to 8 wt. % of silica, and is produced by sintering the silica-alumina at 1200.degree. to 1500.degree. C.

Abstract: A mixture of alumino-silicate glass and alumina having a composition corresponding to mullite and containing a nucleating mullite powder is hot pressed producing a dense polycrystalline mullite body having an average grain size of less than 15 microns.

Abstract: A mixture of alumino-silicate glass, alumina and filler is hot pressed to produce a mullite composite.

Abstract: Aluminous proppant media in the form of sintered bauxite spheres containing silica are improved in resistance to stress corrosion by inclusion of zirconia in the mix prior to firing in the amount of a silica to zirconia ratio of from 6/1 to 20/1.

Abstract: Low temperature fired ceramics produced by firing at a low temperature a mixture consisting of, in weight percentages:(a) 50 to 65% of powder glass consisting of 10 to 55% of CaO, 45 to 70% of SiO.sub.2, 0 to 30% of Al.sub.2 O.sub.3 and up to 10% of impurities; and(b) 50 to 35% of powder Al.sub.2 O.sub.3 containing up to 10% of impurities. The glass component (a) may further contains B.sub.2 O.sub.3 up to 20% based on the total weight of the former glass-forming components. The ceramics exhibit excellent thermal conductivity, high mechanical strength, low thermal expansion and small dielectric constant and such advantageous combination of properties make them useful in many applications, more especially highly suited to the use as substrate of various electronic parts, components or multilayer integrated circuits. Also, since the ceramics can be prepared at lower firing temperatures and a higher heating rate, the production cost and time can be advantageously saved.

Abstract: Silicon nitride sintered bodies which contain no more than 15% by weight metallic non-oxide compounds as silicon nitride high temperature grain growth inhibitors and total amount of 4-25% of MgO and Al.sub.2 O.sub.3 as densifying aids in MgO/Al.sub.2 O.sub.3 weight ratio being 19 to 2.

Abstract: A fiber-free refractory coating composition consisting essentially of an aluminosilicate mineral selected from the group consisting of kyanite, andalusite, and sillimanite; alumina; colloidal silica; and water. This mixture is characterized by good adhesion to substrate material, and excellent resistance to thermal shock and chemical attack through a wide range of firing temperatures up to 3000.degree. F.

Abstract: A refractory for use in a non-ferrous metal melting furnace, comprising a mixture of high-alumina aggregate particles containing at least 60% by weight of aluminum oxide and silicon nitride particles, admixed with particles of a solid substance; e.g., graphite, which generates carbon monoxide by reaction with the melt of said non-ferrous metals. This refractory has an advantage of being highly difficult to be corroded by slag formed during melting of said non-ferrous metal.

Abstract: A high alumina sintered body composed of a substrate consisting substantially of .alpha.-Al.sub.2 O.sub.3 and a surface layer of mullite precipitated in situ on the substrate. The sintered body is obtained by molding and sintering a composition comprising a main component containing at least 75% by weight, based on the total weight of the composition, of .alpha.-Al.sub.2 O.sub.3 and a predetermined amount of silica, a mullite mineralyzing agent and B.sub.2 O.sub.3. The sintered body has a combination of excellent thermal shock resistance and mechanical properties such as flexural strength.

Abstract: A thermal spray powder comprising particles with a central core of a material selected from the group consisting of zirconium oxide, magnesium oxide, hafnium oxide, cerium oxide, yttrium oxide and combinations thereof. The core then has discrete aluminum particles and silicon dioxide homogeneously disposed in a binder deposited thereon to form the thermal spray powder which may be thermal sprayed to produce an abradable and erosion resistant coating.

Abstract: A zirconia type sintered body consisting essentially of 50 to 98% by weight of zirconia (ZrO.sub.2) containing 1.5 to 5 mole % of yttria (Y.sub.2 O.sub.3) and 50 to 2% by weight of alumina (Al.sub.2 O.sub.3), spinal (MgAl.sub.2 O.sub.4) or mullite (3Al.sub.2 O.sub.3.2SiO.sub.2), and having a three-point bending strength of at least 1700 MPa is provided. This sintered body is prepared by a process wherein a powdery composition consisting essentially of 50 to 98% by weight of (a1) a powder of zirconia containing 1.5 to 5 mole % of yttria or (a2) a mixture comprising 1.5 to 5 mole % of a yttria powder and 95 to 98.5 mole % of a zirconia powder and 2 to 50% by weight of (b) a powder of an alumina type oxide selected from alumina, an alumina-magnesia type oxide, an alumina-silica type oxide, a mixture of alumina and magnesia and a mixture of alumina and silica is subjected to a hot isotactic pressing treatment under a pressure of at lesast 50 MPa at temperature of 1300.degree. C. to 1700.degree. C.

Abstract: Sintered alumina product comprising 90 to 98 wt % of alumina as the main component, and which further contains as auxiliary components not more than 1 wt % of BaO and 1 to 10 wt % of a composite oxide having the composition included within the hexagon ABCDEF (except for the line AF) in an SiO.sub.2 -CaO-MgO phase diagram, the respective apexes having the following definitions:______________________________________ SiO.sub.2 CaO MgO ______________________________________ A 60 40 0 B 60 25 15 C 45 25 30 D 40 30 30 E 40 55 5 F 45 55 0.

Abstract: A thermoplastically moldable ceramic composition comprised of from about 40% to about 60% by volume of a ceramic powder and a binder comprised of an organic acid and a copolymer of ethylene and from greater than about 12 weight % to about 33 weight % vinyl acetate, said organic acid having a melting point ranging from about 44.degree. C. to about 88.degree. C. and ranging from greater than about 18% by weight up to about 45% by weight of the binder. The ceramic composition is thermoplastically molded into a body which is baked to remove the binder and then densified to produce a polycrystalline body having a porosity of less than about 20% by volume.

Abstract: Novel aqueous inorganic particle slurries, wherein some of the particles have had their charge potential altered to a sufficient extent to prevent segregation or settling of the particles, are described, along with a method for their preparation. The method of forming slurries of negatively charged particles comprises treating some of the particles with a cationic agent to reduce their charge and mixing these treated particles with the remainder of the particles to form a thick, cream-like flowable composition of a thixotropic nature. When slurries of positively charged particles are to be formed, an anionic agent is used instead of a cationic agent.

Abstract: A method for improving the high temperature properties of 42 to 70 percent by weight Al.sub.2 O.sub.3 containing alumina refractories by adding thereto a soluble metal compound and firing to at least 1450.degree. C. for a time sufficient to convert the soluble metal compound to a refractory oxide or phase and for the refractory oxide or phase to react with the non-Al.sub.2 O.sub.3 constituents of the refractory for preventing or reducing the presence or effect of detrimental compounds or phases on the high temperature properties of the refractory. The resulting relatively low Al.sub.2 O.sub.3 content, porous, alumina refractory includes within its pores from 1 to 10% by weight of a refractory oxide or phase and is characterized by high temperature property values substantially greater than the corresponding values for the same refractory body without said refractory oxide or phase in its pores.

Abstract: A carbonaceous article, e.g., a carbon or graphite electrode, is provided with an oxidation prohibitive coating comprising a compliant, low strength, porous, sintered, particulate, refractory, ceramic material. A cover layer is preferably applied over this compliant, low strength, ceramic layer, the cover layer comprising a rigid, glassy substance which is plastic and flowable at temperatures above about 750.degree. C.

Abstract: An inorganic binder usefully employed in providing refractory coatings on fabric substrates is prepared from colloidal silica, monoaluminum phosphate, aluminum chlorohydrate and a catalyst of an alkyl tin halide.

Abstract: What is disclosed is a method of preparing carbon-containing monolithic glassy ceramics from organosilsesquioxanes, metal oxides and metal alkoxides through pyrolysis of their gels. Also disclosed are certain gel compositions used in the method and the glassy ceramics.