Abstract: Self-supporting bodies are produced by reactive infiltration of a parent metal into boron carbide typically resulting in a composite comprising a boron-containing compound and metal. The mass to be infiltrated may contain one or more inert fillers admixed with the boron carbide, or at least one carbon donor material, to produce a composite by reactive infiltration, which composite comprises a matrix of metal and boron-containing compound embedding the filler. In one embodiment of the invention, a parent metal is reactively infiltrated into a mass comprising a boron carbide material mixed with a carbon-containing compound. In this embodiment, a self-supporting composite is formed typically comprising a boron-containing compound, a carbon-containing compound, and metal. The relative amounts of reactants and process conditions may be altered or controlled to yield a body containing varying volume percents of ceramic, metal and/or porosity.

Abstract: This invention is primarily directed to the production of transformation toughened ZrO.sub.2 -containing ceramic alloys wherein the toughening agent is selected from the group consisting of a rare earth metal vanadate and a magnesium and/or calcium tungstate/molybdate, and SnO.sub.2 can be utilized as a toughening agent and/or a stabilizing agent for ZrO.sub.2.

Abstract: Improved silicon-free, continuous zirconia fibers have diameters greater than 5 micrometers and high tensile strengths. In another aspect, strong, flexible, zirconia fibers are prepared in a process involving the addition of colloidal ZrO.sub.2 particles to a fiber precursor solution.

Abstract: A novel solid solution has a composition of R.sub.y Zr.sub.4 Si.sub.x P.sub.6-x O.sub.24 (R is at least one forming bivalent or trivalent element 0.ltoreq.x.ltoreq.2, 2/3.ltoreq.y.ltoreq.2). Furthermore, a heat-resistant sintered body and heat-resistant phosphate based compound sintered body comprises the above solid solution and has excellent heat resistance and high temperature stability. And also, a method of producing such sintered bodies is disclosed.

Abstract: In the present invention, there is provided a method for producing a self-supporting ceramic or ceramic composite body by the oxidation of a parent metal to form a polycrystalline ceramic material comprising the oxidation reaction product of said parent metal with an oxidant, including a vapor-phase oxidant, and optionally one or more metallic constituents dispersed throughout the polycrystalline ceramic material. The method comprises the steps of providing at least a portion of said parent metal with a barrier means at least partially spaced from said parent metal for establishing at least one surface of the ceramic body, and heating said parent metal to a temperature above its melting point but below the melting point of the oxidation reaction product to form a body of molten metal. At that temperature, the molten metal is reacted with the oxidant, thus forming the oxidation reaction product.

Abstract: The present invention relates to ceramic bodies suitable for use in high temperature applications such as molten metal filters and kiln furniture. The ceramic bodies are formed from partially stabilized zirconia and are characterized by the presence of from about 12% to about 80% by weight zirconia in a monoclinic phase and the balance essentially in a cubic phase at room temperature. The ceramic bodies possess an excellent combination of physical properties including high temperature strength and thermal shock resistance. The invention also relates to the process for forming the ceramic bodies and the thixotropic ceramic slurry used therein.

Abstract: Improved high temperature resistant molding materials containing customary filler materials and additives and a carbon forming bonding agent which is a phenol novolac with a molar ratio of phenol to formaldehyde of 1 to 0.2 to 1 to 0.35 of high quality and free of solvents useful as refractory products, carbon materials, abrasive wheels, friction lining and the like.

Abstract: A method of making self-supporting ceramic composite structures having filler embedded therein includes infiltrating a permeable mass of filler with polycrystalline material comprising an oxidation reaction product obtained by oxidation of a parent metal such as aluminum and optionally containing therein non-oxidized constituents of the parent metal. The structure is formed by placing a parent metal adjacent to a permeable filler and heating the assembly to melt the parent metal and provide a molten body of parent metal which is contacted with a suitable vapor-phase oxidant. Within a certain temperature region and optionally aided by one or more dopants in or on the parent metal, molten parent metal will migrate through previously formed oxidation reaction product into contact with the oxidant, causing the oxidation reaction product to grow so as to embed the adjacent filler and provide the composite structure.

Abstract: A process for the production of a raw material used for the production of a zirconia sintered body is disclosed. A power containing principally zirconium compounds and a stabilizing agent is added to a solution or slurry containing at least one metal element selected from the group consisting of Mn, Fe, Co, Ni, Cu, and Zn. The stabilizing agent is Y.sub.2 O.sub.3, CaO, MgO, CeO.sub.2, a yttrium compound, calcium compound, magnesium compound or cerium compound which can produce Y.sub.2 O.sub.3, CaO, MgO, or CeO.sub.2 by thermal decomposition. The selected metal element from the group will act as a coating on the zirconia sintered body.

Abstract: Zirconyl phosphate sintered bodies are disclosed, which each have a molar ratio of ZrO.sub.2 /P.sub.2 O.sub.5 being not less than 1.8 but less than 2.0 and contain .beta.-(ZrO).sub.2 P.sub.2 O.sub.7 as a main crystalline phase. The zirconyl phosphate sintered bodies have a coefficient of thermal expansion and a thermal expansion hysteresis in a temperature range from room temperature to 1,4000.degree. C. being not more than 20.times.10.sup.-7 /.degree.C. and 0.05 to 0.30%, respectively. A process for producing zirconyl phosphate sintered bodies is also disclosed, which comprises preparing a starting material powder of zirconyl phosphate, shaping the starting material powder, and firing the shaped bodies. The zirconyl phosphate sintered body has a molar ratio of ZrO.sub.2 /P.sub.2 O.sub.5 being not less than 1.8 but less than 2.0 and the average particle diameter of 0.5 to 20 .mu.m, and contains oxides of an alkali metal and an alkaline earth metal in a total amount of not more than 0.5% by weight.

Abstract: A refractory article and a process for making the same are provided. The article is derived from dissociated zircon and zirconia (99:1 to 80:20, weight basis). These components are formed into a slip, which can be conventionally processed to provide a sintered article. The resulting article can be subsequently heat treated to react any resulting glass phase with the zirconia present; further, the heat treated article can be subsequently redensified. These refractories are well-suited for such applications as tundish nozzle inserts and sliding gate valves.

Abstract: Heat resisting low expansion zirconyl phosphate-zircon composite bodies are disclosed, which contain zirconyl phosphate and zircon as a main crystalline phase and a secondary crystalline phase, respectively. The heat resisting low expansion zirconyl phosphate-zircon composite bodies have a coefficient of thermal expansion in a temperature range from room temperature to 1,400.degree. C. being not more than 30.times.10-7/.degree. C. and a melting point being not less than 1,600.degree. C. The composite bodies have a chemical composition essentially consisting of 58.2 to 65.4% by weight of ZrO.sub.2, 17.4 to 37.1% by weight of P.sub.2 O.sub.5, and 1.5 to 19.0% by weight of SiO.sub.2. The heat resisting low expansion zirconyl phosphate-zircon composite bodies optionally contain MgO and Al.sub.2 O.sub.3 in a total amount of not more than 2.5% by weight or 0.1 to 4% by weight of Nb.sub.2 O.sub.5. A process for producing such zirconyl phosphate-zircon composite bodies is also disclosed.

Abstract: Methods of producing ABO.sub.3 compounds in which A represents a first metal ion and B represents a second metal ion from mixed metal coordination complexes are disclosed. The methods involve reacting compounds serving as a source of the B metal ion with a substituted aromatic compound, in solution, and thereafter reacting the metal coordination complex formed with a compound serving as a source of the A metal, in solution. An example is the reaction of titanium tetraisopropoxide with catechol to form a titanium catecholate coordination complex which is thereafter reacted with barium hydroxide octahydrate to form a pentamethanol barium triscatecholatotitanate mixed metal coordination complex which can be calcined at elevated temperatures to produce the ABO.sub.3 compound, barium titanate (BaTiO.sub.3), which is known to have outstanding dielectric, ferroelectric and piezoelectric properties. Portions of the A and/or B ions can be substituted with other metals.

Abstract: A composite ceramic material having improved properties is disclosed as well as several methods for preparing the same. The composite powder is substantially comprised of zirconia and spinel phases, produced by precipitation and calcination of the precipitate of the oxide forming precursor salts. A preferred method for introducing the zirconium is as a soluble and/or decomposable salt during precipitation of the spinel forming hydroxyl or halo hydroxyl spinel forming salts. The zirconium salt decomposes to zirconia during calcining and/or sintering of the powder resulting from the precipitation. A preferred composite is that obtained from magnesium and aluminum salts, resulting in a MgAl.sub.2 O.sub.4 spinel and intimately admixed ZrO.sub.2 which contains a stabilizing agent.

Abstract: Organophilic clays useful for modifying the rheological properties of organic fluids are made from a smectite type clay, a quaternary ammonium compound and a zirconium-aluminum organic complex.

Abstract: A process for the production of a refractory boride or silicide which comprises producing an oxygen-containing polymeric product by reacting a compound of the metallic or non-metallic element having two or more groups reactive with hydroxyl groups and a compound of boron or silicon having two or more groups reactive with hydroxyl groups with an organic compound having two or more hydroxyl groups and heating the polymeric product in an inert atmosphere to pyrolyse the polymeric product and produce a refractory boride or silicide of the metallic or non-metallic element.

Abstract: A basic refractory shape resulting from firing a batch consisting essentially of a magnesite and a zirconia; said batch containing for each 100 percent by weight thereof about 3 to 20 percent by weight of coarse zirconia having a particle size of 150-mesh Tyler, or greater, and 0 to 20 percent by weight of fine zirconia having a particle size of finer than 150-mesh Tyler and a slide gate assembly comprising at least one such shape.

Abstract: Ultra-fine spherical particles of a metal oxide having an average particle diameter of 40 nm or smaller can be prepared by a method in which a vaporizable metal compound is vaporized and decomposed under heating to give ultra-fine particles of a metal oxide followed by immediate cooling down to a temperature at which coalescence of the fine particles are prevented from coalescence. The fine particles have characteristics such as an excellent power of ultraviolet scattering.

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: Crystalline solid solutions and diphasic mixtures having a composition of Ca.sub.1-x M.sub.x Zr.sub.4 P.sub.6 O.sub.24, where M is Ba and/or Sr and X is between about 0.25 and 0.75, have been produced which display both low anisotropy and near zero bulk thermal expansion behavior.

Abstract: A ceramic composition represented by the following general formula:Pb.sub.1-x La.sub.x (Zr.sub.y Ti.sub.1-y).sub.1-x/4 O.sub.3wherein O<x<1, O<y<1) is produced by a method which comprises adding a mixed solution of a titanium alkoxide and a zirconium alkoxide to an aqueous solution containing lead nitrate and/or lead acetate and lanthanum nitrate and/or lanthanum acetate thereby simultaneously effecting hydrolysis of said alkoxides and coprecipitation of lanthanum components, further adding an alkaline substance to the resultant system thereby effecting substantially thorough precipitation of lead and lanthanum components, and heating the produced precipitate.

Abstract: A multiphase, microcrystalline, nearly fully dense ceramic composite has grains comprising 0 to 95 volume percent aluminum nitride, 0 to 95 volume percent polytypes of aluminum nitride, 0 to 95 volume percent gamma-aluminum oxynitride, and 5 to 50 volume percent of at least one of titanium nitride, zirconium nitride and hafnium nitride. The composite is useful to prepare a ceramic abrasive grit or article.

Abstract: A composition of a metallic compound represented by the formula MT, and G is provided by sputtering an M.sub.x G.sub.100-x target. M is a metal selected from the group of titanium, hafnium, zirconium, and mixtures thereof. T is selected from the group of N, C, and mixtures thereof. G is a metal selected from the group of gold, platinum, and palladium. X is an integer from about 65 to about 95. Also provided are substrates coated with the composition and process for depositing the composition on substrates.

Abstract: A process for the production of a sinterable raw material powder to be used for the production of a partially stabilized ZrO.sub.2 sintered body or ceramic body containing 0 to 60 parts of alumina, and the process for the production of the sintered body or ceramic body using this powder.

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 low thermal expansion potassium zirconium phosphate is formulated using a metal oxide as a densifier. A mixture of these powders is sintered and quenched.

Abstract: A sintered zirconia material containing at least 50 mol % tetragonal zirconia and 1.5-5 mol % yttria, from which carbon is substantially absent, the porosity of which is not greater than 0.6%, the pore size of which is not greater than 0.1 .mu.m and the pores of which exist mainly at triple points of zirconia grain boundaries. The sintered zirconia material can be obtained by sintering the raw material zirconia powder, the green body or the presintered material containing tetragonal zirconia and yttria in a required amount and in an oxidizing atmosphere, by hot isostatic pressing.The sintered material thus obtained has a high strength and high toughness, and particularly excellent properties for use under conditions of higher than 600.degree. C. and can be used as a material of various industrial machines or tools.

Abstract: Zirconia powder is formed by dry grinding, and a slurry of the zirconia powder with a nonaqueous solvent is shaped and fired.

Abstract: High-strength, fine-grain, multi-phase substantially crystalline sintered ceramic bodies are produced by a process comprising the steps of cold pressing, followed by sintering at a high temperature, of a mixture of different powdered ceramic materials containing non-inhibitory components and a source of inhibitory components that can chemically interact at elevated temperatures generate gases which hinder densification or form phases undesirable for sintering provided that there is also included in the mixture an amount of a source of a component co-reactive with the gases produced by the inhibitory components at elevated temperature to achieve efficient densification and retention of properties in the sintered body.

Abstract: A jewelling and ornamental material comprising many amorphous silica spheres regularly arranged in a three-dimensional array and a zirconium compound filled in pores existing among the amorphous silica spheres, the amount of the zirconium compound being 0.005 to 8% by weight, as zirconium, based on the entire material; and a process for its production. This material has a play of colors inherent to natural opal, and excellent durability.

Abstract: In the production of low-thermal-expansive zirconyl phosphate ceramic, whose chemical formula is (ZrO).sub.2.P.sub.2 O.sub.7 and whose chemical composition is 2ZrO.sub.2.P.sub.2 O.sub.5 by sintering of the fine-powder compact, three kinds of reaction aids are employed. They are a densifying aid, a grain-growth-suppressing aid and a solid-solution-forming aid. The densifying aid is always employed, the grain-growth-suppressing aid is employed for producing a more thermal-resistant ceramic for high temperature use and the solid-solution-forming aid is employed for producing a more low-thermal-expansive ceramic.

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 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 ZrB.sub.2 composite sintered material consisting essentially of at least 1% by weight of SiC, at least 1% by weight of B.sub.4 C, at most 15% by weight of TiC, at most 35% by weight of TiN, at most 40% by weight of AlN, the rest being substantially ZrB.sub.2, provided that the total amount of SiC and B.sub.4 C is from 2 to 50% by weight.

Abstract: A low expansion ceramic material has a composition represented by the molecular formula i (Na) j (Zr.sub.2-z Na.sub.4z) k (P.sub.3-x Na.sub.x Si.sub.x)O.sub.12 in which the molar proportions i, j and k are each within the range from about 0.9 to about 1.1, and i+j+k equal 3; and, for molar proportions i, j and k each equal to 1.0, the ceramic composition falls within the area defined by the points A, B, C and D in a quarternary diagram of SiO.sub.2, Na.sub.2 O, P.sub.2 O.sub.5 and ZrO.sub.2, the coordinates of the points being:A: x=0.2, z=0B: x=0.6, z=0C: x=0, z=0.25D: x=0, z=0.125The ceramic material is especially suitable as a substrate for optically reflecting films.

Abstract: Zirconia powder is formed by dry grinding, and slurry of the zirconia powder with nonaqueous solvent is shaped and fired.

Abstract: Dielectric ceramic compositions consisting essentially of xZrO.sub.2 -yCeO.sub.2 -zSiO.sub.2 -TiO.sub.2 in which x+y+z=1 and x, y and z are represented within ranges by mole surrounded by a polygon having at its corners the points A, B, C and D of a ternary composition diagram of the attached drawing defined as follows,______________________________________ x y z ______________________________________ A 0.98 0.01 0.01 B 0.60 0.39 0.01 C 0.60 0.18 0.22 D 0.77 0.01 0.22 ______________________________________At least one oxide selected from the group consisting of Al.sub.2 O.sub.3, La.sub.2 O.sub.3 and Cr.sub.2 O.sub.3 may be further added to the above composition in an amount of from 0.05 to 1.0 parts by weight per 100 parts by weight of the above four components.

Abstract: A refractory material consists of a zircon matrix with zirconia particles dispersed in it. The zirconia particles comprise from 5 to 30 percent (by weight) of the material. A method of making this material involves milling zircon sand particles and zirconia particles until they have a respective predetermined particle size distribution, adding a fugitive binder, moulding a green ware, firing the green ware at a temperature in the range from 1400.degree. C. to 1800.degree. C., and furnace cooling the fired ware. Preferably the ware is held at the firing temperature for one hour.

Abstract: The present invention relates to materials and more particularly to particulate materials suitable for use as thermal spraying powders.There is disclosed a process for the preparation of a particulate material suitable for use as a thermal spraying powder which includes treating a mixture comprising an inorganic substance as a major component (as defined in the Specification) and a sol to gel the sol thereby to form an intermediate material comprising inorganic substance and gel and heating the intermediate material.One example of thermal spraying is plasma spraying.

Abstract: A powder composition for producing sintered ceramic, which composition contains fluororesin powder which has not been used in the prior art as one of the materials constituting a molding assistant to be blended in the composition. With this composition, it is possible to produce a high-density green molding with few molding defects under a relatively low molding pressure. The invention also provides a process for producing such a composition.

Abstract: The present invention is concerned with a ceramic formed body comprising a ceramic matrix and at least one phase of ceramic incorporation material dispersed therein, characterized by a dense, microcrack-free ceramic base matrix and compressive zones incorporated therein which consist of a mixture of the base matrix material with unstabilized zirconium dioxide particles which are predominantly monoclinic at ambient temperature.The present invention is also concerned with a process for the production of such ceramic formed bodies and with the use thereof as constructional elements in the hot region of heat engines.

Abstract: A refractory mix comprising an acid stabilized aqueous zirconia sol and an active refractory material in an amount effective to gel said sol and articles prepared therefrom.

Abstract: A low thermal expansion cordierite ceramic is produced by combining cordierite with a zirconium compound and a phosphorus compound and sintering the resultant mixture thereby giving rise to zircon therein.

Abstract: A powder composition for producing sintered ceramic, which composition contains fluororesin powder which has not been used in the prior art as one of the materials constituting a molding assistant to be blended in the composition. With this composition, it is possible to produce a high-density green molding with few molding defects under a relatively low molding pressure. The invention also provides a process for producing such a composition.

Abstract: A novel process for fabricating novel high zirconia content refractory articles directly from novel sinterable compositions including as the major ingredient thereof baddeleyite ore concentrates thereby reducing costs. Appropriate additives, particularly zircon, further provide enhanced resistance to thermal shock damage. Plasticizers, binders and other processing aids are identified for press forming exemplary compositions into continuous casting nozzles, shrouds and other ceramic products typically used in the processing of molten steel, specialty metals and glass.

Abstract: There is provided a refractory mix comprising an acid stabilized aqueous zirconia sol and an active refractory material in an amount effective to gel said sol.

Abstract: This invention provides a novel glass composition having numerous uses. More particularly, the invention provides a single phase, radiopaque glass composition.

Abstract: A sintered ceramics for cutting tools having a relative apparent density of not less than 98% is obtained by sintering a mixture substantially consisting of 80-95% by volume alumina and the balance of titanium nitride and Zr-containing component(s) such as Zr, ZrC and/or ZrN wherein the volumetric ratio of TiN /Zr-containing component(s) ranges 95/5-50/50 in vacuum and/or vacuum inert atmosphere. Although the present invention does not need any application of hot pressing or HIP process, the resultant ceramics has an improved abrasion resistance comparable to those obtained by the latter processes.

Abstract: A sintered ceramic body of high toughness, consisting of an isotropic ceramic matrix (e.g. Al.sub.2 O.sub.3) and at least one therein-dispersed phase (ZrO.sub.2, HzO.sub.2) of ceramic embedment material formed from a powder consisting of particles having an average diameter from 0.3 to 1.25 .mu.m, wherein the ceramic embedment material is present in different enantiotropic solid modifications at the firing temperature of the ceramic body and below the firing temperature, whose densities are substantially different, and the ceramic body is shot through with extremely fine microfractures in high density.

Abstract: The invention provides a novel class of sintered refractory and abrasive ies composed mainly of one or a combination of metal diborides such as titanium diboride TiB.sub.2, chromium diboride CrB.sub.2, tantalum diboride TaB.sub.2 and the like admixed with a minor amount of one or more kinds of metal borides exemplified by MnB, Mn.sub.3 B.sub.4, Mn.sub.2 B, Mn.sub.4 B, TiB, Ti.sub.2 B.sub.5, Ti.sub.2 B, W.sub.2 B.sub.5 and Mo.sub.2 B.sub.5. The sintered body can be prepared by conventional powder metallurgical processes such as hot pressing or sintering of a green body shaped in advance by molding in cold with the powder blend of the above described components. Further advantages are obtained by admixing the powder blend with small amounts of one or more of binder ingredients of relatively low melting points such as cobalt borides, iron borides, nickel borides and an alloy of nickel and phosphorus. So-called infusion process is also applicable for the preparation of the inventive sintered body.