Abstract: There is disclosed a partially sintered setter tile for use in the removal of carbon from multilayer ceramic substrate laminate during the sintering thereof. A multilayer ceramic substrate laminate having metallic lines and vias is provided with a reducible metal oxide in a partially sintered setter tile in close proximity to the substrate laminate. The multilayer ceramic substrate laminate contains a polymeric binder which upon heating depolymerizes into carbon. The substrate laminate and partially sintered setter tile are sintered in an atmosphere which is reducing with respect to the reducible metal oxide and which is oxidizing with respect to the carbon.

Abstract: The ceramic sinter is composed of a metal oxide such as ZrO.sub.2 and 10-90 vol. % of metal fluoride which is selected from the group having not less than 2.5 electronegativity difference between fluoride and the metal element.The ceramic sinter has a thermal expansion coefficient of 15-20.times.10.sup.-6 /.degree.C. and is suitable for bonding with general use metals such as stainless steel to form a composite body of the ceramic sinter and the metal without causing a substantial thermal stress at the juncture thereof.

Abstract: A novel oxidation catalyst or refractory and the method for its preparation. The material comprises substitutional solid solutions involving MgO, V.sub.2 O.sub.3 and TiO.sub.2 and having compositions that fall within a specific polygon in a ternary composition diagram of MgO, V.sub.2 O.sub.3 and TiO.sub.2. A typical material has the composition in Wt %; MgO 17, V.sub.2 O.sub.3 61 and TiO.sub.2 22, and consists of the phases spinel having the formula Mg.sub.1.21 V.sub.1.58 Ti.sub.0.21 O.sub.4 and pseudobrookite having the formula Mg.sub.0.20 V.sub.1.60 Ti.sub.1.20 O.sub.5.

Abstract: A process for the production of a magnesium oxide having high hydrolysis resistance and high fluidity, which comprises:(A) a step of reacting a water-soluble magnesium salt with an alkaline substance in such an amount that is not more than 0.95 equivalent weight based on 1 equivalent weight of the water-soluble magnesium salt, at a temperature of not more than 40.degree. C.,(B) a step of heating the resultant reaction product and its reaction mother liquor at about 50.degree. to 120.degree. C. to form a magnesium hydroxide,(C) a step of forming particles having an average secondary particle diameter of about 5 to 500 .mu.m by using a spray drier,(D) a step of firing the particles at about 1,100.degree. to 1,600.degree. C., and(E) a step of pulverizing the resultant fired product under conditions which do not substantially destroy the average secondary particle diameter obtained in the above step (C).

Abstract: A particulate composition suitable for use in a process of dressing a refractory structure which includes the steps of projecting against a site of refractory structure to be dressed a comburent gas stream carrying a mixture comprised of fuel particles and refractory oxide particles, which fuel particles are comprised of at least one element which is oxidisable to form at least one refractory oxide; and causing or allowing the fuel particles to burn, the particulate composition being a mixture including fuel particles comprised of at least one element which is oxidisable to form a refractory oxide; refractory oxide particles; and particles of fluxing agent the fluxing action of which is such that when the mixture is projected in a comburent gas stream and the fuel particles are caused or allowed to burn, the refractory structure becomes softened to an extent such that the refractory structure becomes dressed by removal or displacement of material thereof under the mechanical action of the impinging comburent

Abstract: A refractory composition is disclosed which consists essentially of sized refractory aggregate including at least 10%, based on the total weight of the composition, MgO containing grain having at least 50% MgO and passing a 5 mesh screen, from about 0.1 to about 1.5%, on the dehydrated basis, of chrome sulfate or sodium sulfate, from about 0.1 to about 1.5% of an organic acid or salt thereof; and up to about 1.1% of a plasticizer.

Abstract: Ceramic molding or casting powders, particularly nitride, oxide and carbide powders, that have substantial internal surface and volume produce improved dispersions after being coated with a cover material, such as polyethylene glycol, that reduces the specific surface area of the powder by at least about 10% and reduces the amount of penentration of the binder used for dispersion into the internal volume of the powder. The viscosity of dispersions of such coated powders, or of conventional uncoated ceramic powders, can be further reduced by treatment of the powders with organotitanate, organozirconate, or organosilane coupling agents that are chosen to interact favorably with the specific powders and binders used.

Abstract: An alumina-spinel monolithic refractory consists essentially of 50-90 percent by weight of alumina clinker, 5-40 percent by weight of MgO--Al.sub.2 O.sub.3 spinel clinker not larger than 1 mm in size and 1-25 percent by weight of alumina cement. Another alumina-spinel monolithic refractory consists essentially of 50-90 percent by weight of alumina clinker, 5-40 percent by weight of MgO--Al.sub.2 O.sub.3 spinel clinker, 1-25 percent by weight of alumina cement and not more than 5 percent by weight of magnesia clinker. The alumina-spinel monolithic refractories are used for lining the inner walls of ladles, vacuum degassing vessels, hot-metal mixers, blast-furnace troughs and their covers, not-metal mixer cars, tundishes and the like.

Abstract: A ceramic article made from a mixture comprising (on a dry weight basis) magnesium oxide (MgO) in an amount up to 2% by weight, a defined rare earth oxide in amount up to 10% by weight, balance beryllium oxide, and trace elements, the defined rare earth oxide being zirconium oxide (ZrO.sub.2), hafnium oxide (HfO.sub.2), cerium oxide (Ce.sub.2 O.sub.3), yttrium oxide (Y.sub.2 O.sub.3), ytterbium oxide (Yb.sub.2 O.sub.3) or thorium oxide (ThO.sub.2). Such ceramic articles have much improved properties in particular higher densities than attainable hitherto and better crossbreak strength and surface smoothness as fired. The ceramic compositions can also be admixed with supplementary ceramic materials such as silicon carbide to produce microwave absorbing materials.

Abstract: A refractory brick for use in rotary cement kilns has improved properties by the addition of small quantities of MnO.sub.2 to the composition used to form the brick.

Abstract: By adding an appropriate amount, 1 to 12 weight percent, based on the amount of magnesium oxide present and Loss On Ignition values of powdered magnesium metal to the magnesium oxide aqueous slurry composition used to make a separating-agent composition in the making of grain-oriented silicon electrical steel, there are obtained composition, an article, and a method characterized principally by a substantial decrease in the rate of rejections of the produce of the final texturizing anneal because of coating defects--such difficulties as bare spots, and metal-overlay pattern. Moreover, the magnetic properties may be improved because of improved control of the propagation of the internally oxidized zone of the steel.

Abstract: Oxidizable metallic particles having a grain size of 60 microns or less of the combination of zinc and magnesium used as heat sources in the flame spraying of refractory masses wherein the zinc magnesium form 5% or less by weight of the total mixture of oxidizable particles and refractory particles, and are used with oxidizable metallic silicon in an amount between 8 and 20% by weight, wherein one or more of silica, alumina, magnesite, chromia and/or zirconia, or silicon carbide form the incombustible refractory particles.

Abstract: A lightweight magnesia clinker containing magnesium oxide in an amount of more than 85 wt. % and having an apparent porosity of more than 40 vol. % and a bulk specific gravity of less than 2.0 g/cm.sup.3 is disclosed. In the lightweight magnesia clinker, the amount of magnesia clinker particles having a particle diameter of smaller than 3 mm is more than 90 wt. % of the amount of all magnesia clinker particles, and the amount of pores formed in the magnesia clicker particles having a pore size of smaller than 50 .mu.m is more than 90 vol. % of the amount of all pores. A process for the preparation of said lightweight magnesia clinker is also disclosed.

Abstract: Disclosed are a magnesia-calcium oxide refractory product comprising (i) about 100 parts by weight of a refractory aggregate consisting essentially of about 20 to about 95% by weight of MgO and about 80 to about 5% by weight of CaO and (ii) about 0.5 to about 5 parts by weight of aragonite-type calcium carbonate, and a process for preparing the same.

Abstract: In processes of forming a refractory mass on a surface, a mixture of refractory particles and oxidizable particles which react exothermically with oxygen to generate sufficient heat to soften or melt at least the surfaces of the refractory particles are sprayed against that surface to bring about formation of said refractory mass. To promote the reliable and consistent formation of a durable refractory mass, the granulometry of the particles which are sprayed in the mixture is such that the 80% and 20% grain sizes of the refractory particles (that is, the screen mesh sizes G.sub.80 and G.sub.20 through which respectively 80% and 20% by weight of the particles will pass) have a mean greater than the mean of the 80% and 20% grain sizes of the oxidizable particles and the size range spread factor f(G) of the refractory particles is at least 1.

Abstract: The invention concerns a method for the manufacture of oxide ceramic bodies with a high ratio of surface area to mass and high strength.These bodies manufactured by the method according to the invention are particularly suitable for forming composite materials, to increase the strength and refractoriness of components, for example and above all those of plastic and light metal components.The method according to the invention consists of the solidification of eutectic, eutectoid or peritectic oxide-halide system, wherein the halides can subsequently be removed by dissolution and re-used. According to the system of raw materials, selected composition, temperature gradient and rate of solidification, plates firmly bonded together by twinning, separate plates or columnar oxide bodies can be produced, with particularly low wall thicknesses or diameters of, for example, approximately 0.1 to 0.2 .mu.m.

Abstract: Porous ceramic greenware comprising finely divided ceramic filler, finely divided metal, and polyolefin controls shrinkage in fired shape. In a preferred embodiment the metal and ceramic filler are bound together with the clean burning polyolefin and a plasticizer. After molding the mixture into the final shape, the plasticizer is removed to introduce porosity into the shaped article. Next the article is heated to decompose the polyolefin which can exit as a gas through the pore openings. Finally, the article is fired to a high temperature to oxidize the metal to metal oxide which becomes sintered with the ceramic filler particles to form a sintered porous article where the oxidized metal bonds the filler particles together in the desired shape.

Abstract: The invention relates to method for producing composite ceramic articles by infiltration of a particulate, permeable bed or permeable preform with a polycrystalline matrix a metal-oxidant reaction product, and the bed or preform includes a dross material.

Abstract: A method for producing a magnesia powder for use as an electrical insulating material. A magnesia clinker powder is washed with an aqueous solution of an acid. The acid radical content of the powder is subsequently reduced to 0.015% by weight or less by washing the powder with water or by subjecting the powder to a heat treatment.

Abstract: A sliding member formed of sintered silicon nitride shows improvement in strength and abrasion resistance when substantially all the .beta.-phase type fine silicon nitride particles present as a main component in the sintered silicon nitride have major diameters not exceeding 60 .mu.m and aspect ratios of not less than 5 and the aforementioned fine silicon nitride particles have a relative density of not less than 98%.

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: An interior coating material for continuous caster tundishes which consists of a mixture of 5 to 60% by weight of a lightweight magnesia aggregate having a bulk density of 2.0 or less, and 40 to 95% by weight of an aggregate which is one or more substances selected from the group consisting of electrically molten magnesia clinker, seawater magnesia clinker, burnt clinker prepared from natural magnesite, dolomite clinker and spinel clinker, plus binder, hardening agent and fibers.

Abstract: A low temperature sintering ceramic material, having low temperature sinterability and excellent thermal conductivity, is particularly suitable for use in making an IC substrate of a ceramic printed plate board. This low temperature sintering ceramic material has two composition types. One is a binary composition type ceramic material consisting essentially of MgO and B.sub.2 O.sub.3, and the other is a ternary composition type ceramic material composed of principal components consisting of MgO and B.sub.2 O.sub.3 and assisting components consisting of one or more selected from Li.sub.2 O, Na.sub.2 O, K.sub.2 O, a fluoride of an alkali metal and a fluoride of an alkaline earth metal. After sintering, MgO and B.sub.2 O.sub.3 are respectively contained at 50 to 90 mol% and 10 to 50 mol% on 100 mol% of the total amount of MgO and B.sub.2 O.sub.3.

Abstract: A process is described for the preparation of a ceramic green body by hydrolyzing at least one alkoxide selected from each of two specified groups to form a dispersion of their reaction product, concentrating the dispersion to a sediment without drying it, and admixing a binder and a plasticizer with the sediment to make a ceramic slip formulation. A release agent can optionally be admixed. The slip formulation is then cast as a ceramic green body. The proportions of alkoxides can be adjusted, as desired, to produce a ceramic green body which is dielectric and useful for microcapacitors or as a conductor.

Abstract: Solid, transparent, non-vitreous, zirconia and zirconia-silica ceramic microspheres, useful as lens elements in retroreflective pavement markings. The microspheres are characterized by:(a) containing at least one additive metal oxide selected from alumina, magnesia, yttria and mixtures thereof;(b) an index of refraction greater than 1.6; and(c) being virtually free of cracks.These microspheres are formed by a sol-gel technique of extractive gelation (extracting carboxylic acid away from zirconyl carboxylate) of a sol in liquid medium such as hot peanut oil. The microspheres of this ceramic composition have been made with relatively large diameters, (e.g. 200-1000 micrometers) making them quite useful as lens elements in pavement marking sheet materials.

Abstract: A composite ceramic extrusion die consisting of a silicon carbide wisker-reinforced cordierite ceramic wherein the predominant matrix phase is cordierite or, preferably, barium-stuffed cordierite having a crystal compositon xBaO.4MgO.(4+x)Al.sub.2 O.sub.3.(10-2x)SiO.sub.2 wherein x ranges from zero up to about 0.5, such extrusion die exhibiting excellent durability under the conditions of non-ferrous metal alloy extrusion at temperatures of 700.degree.-900.degree. C., is described.

Abstract: A cement for vessels for containing molten alloys of aluminum with metals selected from the group consisting of lithium, magnesium, zinc and copper is shown that forms a hard sintered crust for containing the molten alloy in the vessel with a backing of granular cement for controlling thermal stress while also providing a vitrifying flux means in the cement mix for effecting a sealing of any cracks that may form in the crust by reacting with any hot alloy flowing through such a crack to contain the leak as a metal spur.

Abstract: Coal gasifiers for the production of reducing gas are protected--at least in parts--by a refractory lining of unburned, carbonaceous magnesia bricks having a carbon content of 5 to 30 percent by weight. The component of these magnesia bricks consisting of sinter and/or fused magnesia suitably has a Fe.sub.2 O.sub.3 content below 6 percent by weight, preferably below 1.5 percent by weight, and a SiO.sub.2 content below 3 percent by weight, preferably below 1 percent by weight.

Abstract: Ultrafine particles of ceramic or metallic material are obtained at low temperatures from a nitrate source capable of endothermic decomposition by molecularly combining under a nitrogen atmosphere the nitrate source with an inorganic reducing fuel compound, such as hydrazine, to provide a chemical precursor for the ceramic or metallic material and then exothermically decomposing the precursor in a controlled atmosphere by heating to a temperature up to about 200.degree. C. below the endothermic decomposition temperature of the nitrate source. The nitrate source is a metal nitrate or a mixture of nitrate salts. Ferrite particles are recovered when the nitrate source is a mixture of nitrate salts containing ferric nitrate in a 2:1 molar ratio with at least one additional metal nitrate.

Abstract: Synthetic raw materials are used to prepare a sintered refractory body consisting essentially of doped cordierite having from about 47.5 to about 56 weight percent SiO.sub.2, from about 31 to about 40 weight percent Al.sub.2 O.sub.3, from about 12 to about 19 weight percent MgO, from about 0.15 to about 1 weight percent CaO, from zero to 250 ppm Na.sub.2 O, and from zero to about 150 ppm K.sub.2 O, the body having a flexural strength of at least about 20,000 psi (about 140 MPa).

Abstract: The invention relates to a refractory brick on the basis of sintered magnesium oxide and MgO.Al.sub.2 O.sub.3 spinel and possibly up to three percent by weight of customary impurities. Such customary impurities are primarily CaO, Fe.sub.2 O.sub.3 and SiO.sub.2, which are included as impurities in the MgO used in the production of the spinel. The refractory brick according to the invention is characterized by the fact that it has a refractoriness under load of more than 1740.degree. C. and a compression settling of -3 to -5% at 1400.degree. C. after 24 hours under a load of 0.2N/mm.sup.2. The refractory brick according to the invention exhibits the advantage that as a result of the combination of its characteristics of gas permeability, pore volume, refractoriness under load and compression settling, it is particularly well suited for use in rotary hearth furnaces for the cement industry.

Abstract: The present invention disclosed a magnesia clinker excellent in corrosion resistance, which is useful for a magnesia carbon refractory and also for a refractory for steel manufacturing furnace, and the magnesia clinker is characterized by:(a) having a purity of MgO of 97 wt. % or higher;(b) containing 2.0 wt. % or less of CaO;(c) containing 0.01 wt. % or more of B.sub.2 O.sub.3 ;(d) containing 0.3 wt. % or less of SiO.sub.2 ;(e) containing impurities other than MgO, CaO, B.sub.2 O.sub.3 and SiO.sub.2 of 2 wt. % or less;(f) having a bulk density of 3.35 (g/cc) or higher and an apparent porosity of 3.0 (vol. %) or less; and(g) having a mean crystal size of magnesia of 100 .mu.m or larger.

Abstract: Preparation of a ceramic green body by hydrolyzing two groups of alkoxides to form a dispersion of their reaction product, concentrating the dispersion to a sediment without drying it, and admixing a binder solution, plasticizer and release agent with the sediment to make a ceramic slip formulation. The slip formulation is then cast as a ceramic green body. The proportions of alkoxides can be adjusted to produce a ceramic green body which is dielectric and useful for microcapacitors.

Abstract: A process for producing ultra-fine ceramic particles with the particle size of less than 1000 .ANG., which comprises the steps of forming powdered dust cloud of metal powder such as Si constituting a portion of aimed ceramic particles in a reaction gas containing the other portion of said aimed ceramic particles, igniting said powdered dust cloud to cause explosive burning and synthesizing said aimed ceramic particles and gathering said resulting ceramic particles. By the process, ceramic particles such as Al.sub.2 O.sub.3, MgO, SiO.sub.2, TiO.sub.2, TiN having particle size of 10-100 nm can be produced.

Abstract: This disclosure relates to an electrically insulating filler for sheathed heaters. The filler includes globular and nonglobular particles containing at least 95 wt. % MgO, and the percentage of globular particles being at least 5 wt. %. The globular magnesia includes at least one single magnesia or a combination of magnesias selected from groups of sintered magnesias and electro-fused magnesias.

Abstract: A magnesia-calcia clinker having a high density, said clinker containing MgO, CaO and Fe.sub.2 O.sub.3 as oxides, having the following chemical composition in percent by weightMgO, CaO and Fe.sub.2 O.sub.3 : at least 99% in totalMgO: at least 10%Fe.sub.2 O.sub.3 : 0.2-5%and having a density corresponding to at least 97.5% of the theoretical density. The above magnesia-calcia clinker can be produced by adding a water-soluble iron compound to sea water, bittern or brine, simultaneously with, or after, the addition of the water-soluble iron compound, adding a calcined product of dolomite, lime or a hydrate thereof to form a precipitate composed mainly of magnesium hydroxide, mixing the resulting magnesium hydroxide with a calcium compound, and dead-burning the resulting mixture.

Abstract: The invention discloses an improvement in a process wherein a first reactant comprising one or more metals or metal compounds exothermically reacts with a second reactant comprising at least one or more metals or metal compounds in the presence of a third reactant to form an interwoven matrix of a conductive material and an insulating material. The improvement comprises locally applying, to a selected region of a shaped body formed from a mixture of the reactants, sufficient energy to initiate an exothermic reaction which then propagates throughout the remainder of the body to form the interwoven matrix.

Abstract: Magnesium oxide ceramic bodies may be strengthened by inclusion of zirconium oxide particles, and may be further sintered to a density approaching theoretical density by conventional sintering techniques by inclusion of sintering aids, such as manganese oxide and iron oxide.

Abstract: An annealing separator used in a finishing annealing step for producing a grain-oriented electrical steel sheet usually contains magnesia. The present invention is characterized by including, based on 100 parts by weight of magnesia, from 0.2 to 20 parts by weight of ferromanganese nitride or manganese nitride which consists of a composition (Mn.sub.1-x Fe.sub.x)N.sub.y having x and y values corresponding to A, B, C, and D and falling within a region surrounded by A, B, C, and D shown in the appended FIG. 1.The annealing separator according to the present invention is effective for stabilizing secondary recrystallization and improving the properties of a forsterite film.

Abstract: An improved process and apparatus for producing sintered material such as dead burned clay, dolomite, magnesite or periclase with the highest particle specific gravity capable from each material. A grinding mill produces raw material which is 100% minus 20 mesh. The ground raw material is supplied to a suspension type preheater and then to a stationary flash calcining system where the material is soft burned at temperatures in the range of 1000.degree. to 1200.degree. C. From the calcining system, the calcined material is immediately supplied to hot briquetting machine where briquettes or nodules are formed. The hot nodules at a temperature of approximately 800.degree. C. are then immediately supplied to a rotary kiln which serves as a sintering furnace where the soft burned material is dead burnt at a temperature in the range of 1650.degree. to 1850.degree. C. Hot spent combustion gas from the sintering furnace is supplied to the calcining furnace to serve as preheated secondary air for combustion.

Abstract: This invention relates to a sheathed resistance heater which comprises a metal pipe (3), a heating wire (2) received in the metal pipe, and an electrically insulating powder (4) filled in the pipe and also to a method for fabricating same. The electrically insulating powder (4) contains 0.1-10 wt % of the specific type of an oxide by which the heater has a prolonged life because the oxide serves to suppress the metallic component of the heating wire (2) from evaporating, and its insulation resistance under self-heating conditions can be prevented from lowering. The heater has wide utility in both domestic and industrial fields.

Abstract: High density magnesia clinker characterized by having a chemical composition, as oxides in weight %, ofMgO: 97.5% or moreCaO: 0.8-2.0%SiO.sub.2 : 0.12-1.0%Fe.sub.2 O.sub.3 : 0.3% or lessAl.sub.2 O.sub.3 : 0.15% or lessB.sub.2 O.sub.3 : 0.03% or lesswith a bulk density of at least 3.48 g/cm.sup.3. The said high density magnesia clinker can be produced by forming magnesium oxide by calcination of naturally occurring magnesite having a composition, based on ignition in weight %,MgO: 97.5% or moreCaO: 0.8-2.0%SiO.sub.2 : traces to 0.15%Fe.sub.2 O.sub.3 : 0.3% or lessAl.sub.2 O.sub.3 : 0.15% or lessB.sub.2 O.sub.3 : 0.1% or less,grinding the same after, or with, addition of amorphous silica, silica gel or a silicon compound capable of forming SiO.sub.2 by dead-burning in such a manner as to have the SiO.sub.2 content of 0.12-1.0% after dead-burning and dead-burning.

Abstract: Method of producing a refractory light-weight brick from a mixture of a granular refractory material, a binder, a foaming agent, further addition agents, and water, wherein the mixture is poured as a foamed, aqueous slurry into molds and the set moldings are dried and fired. The mixture contains, by weight, 1-10% hydrated aluminumhydroxychloride, 0.1-3% magnesia (MgO) and 87-97% refractory material. The slurry sets rapidly in the molds.

Abstract: A periclase refractory composition comprising magnesium oxide granules, carbon granules and a carbonaceous binding material capable of undergoing pyrolytic decomposition. Added to the periclase refractory composition is at least one oxyhydrocarbon compound selected from the group consisting of (a) acyclic carboxylic acids, (b) oxidized polyolefin waxes, (c) poly(alkylene oxides) and ethers thereof, (d) olefin copolymers, (e) polyvinyl alcohol, and (f) furan polymers.

Abstract: Molten alkaline earth metal halides are used to convert highly stable oxides into the corresponding anhydrous halides. Usually a third reactant, such as silica, is added in order to bind the basic oxide thus formed. The solid oxide compounds (e.g. silicates) which result are wellknown ceramic phases of a high degree of purity.

Abstract: This invention relates to a sheathed resistance heater which comprises a heating wire (2) received in a metallic pipe 3 and electrically insulating powder (4) packed in the pipe. A metallic powder of the specific type is added to the electrically insulating powder (4), by which the heating wire (2) has a prolonged life by suppressing metal components in the wire from evaporating, the heater being widely applicable for domestic and industrial purposes.

Abstract: Satisfactory bonding of refractory aggregate is obtained by providing the aggregate with at least 5.0% by weight of free CaO of minus 200 mesh (Tyler Standard Sieve) particle size, adding a small amount of a lithium compound to the aggregate and heating to a temperature of about 450.degree. C. The modulus of rupture at room temperature of a brick made from dead burnt dolomite aggregate containing a fine fraction providing the finely divided CaO and the lithium compound additive and fired to 450.degree. C. is well above 400 psi and may be substantially equivalent to that of a brick made of the same aggregate without the lithium compound additive and fired to 1200.degree. C. The invention comprises the method of increasing the low temperature bonding strength of refractory aggregates, the unfired mixtures of the refractory aggregate containing the requisite CaO and the lithium compound with or without temporary liquid or solid binding agents, and the fired products made therefrom.

Abstract: A low cost stabilized lime aggregate, preferably with dicalcium silicate as a major constituent, is obtained from slags of specified composition, and finds use in refractory gun mixes. Briefly, the slags which are suitable for this application contain at least 75% total CaO+Fe.sub.2 O.sub.3 +SiO.sub.2 +MgO, have a CaO:SiO.sub.2 weight ratio of at least 1.8, less than 7% total calcium carbonate (CaCO.sub.3), calcium hydroxide (Ca(OH).sub.2), and CaO, and preferably contain at least 20% CaO.

Abstract: The invention is a ceramic composition containing a new class of dispersant for hindering crack propagation by means of one or more energy-dissipative mechanisms. The composition is composed of a ceramic matrix with dispersed particles of a transformation-prone rare-earth niobate, tantalate or mixtures of these with each other and/or with a rare-earth vanadate. The dispersants, having a generic composition tRMO.sub.4, where R is a rare-earth element, B is Nb or Ta and O is oxygen, are mixed in powder form with a powder of the matrix ceramic and sintered to produce a ceramic form or body. The crack-hindering mechanisms operates to provide improved performance over a wide range of temperature and operating conditions.

Abstract: A method of synthesizing ceramic oxides using the Sol-Gel process to control particle size distribution, crystal structure and to achieve the selective incorporation of transition metals within a ceramic oxide matrix in order to produce tailored oxides with specific particle morphology and near zero expansion optical ceramics.