Abstract: The reaction of 1,1-dichlorosilacyclobutanes with nitrogen-containing difunctional nucleophiles gives polysilacyclobutasilazanes which can be crosslinked and also converted to ceramic materials.

Abstract: In accordance with the invention, a composition of matter is provided for forming a coating for protecting carbonaceous substrates from degradation at elevated temperatures. The composition of matter is a mixture of particulate silicon, silicon carbide and alumina. The mixture contains between about 40% and 50% silicon by weight of the total composition, between about 30% and 50% silicon carbide by weight of the total composition and between about 20% and 30% alumina by weight of the total composition. A method is provided for forming a primary protective coating on carbonaceous substrates utilizing the aforesaid mixture. An enhancement coating is provided for sealing the primary coating in applications where the substrate will be subjected to elevated temperatures and temperature cycling.

Abstract: A process for preparing a cartridge for disposal of a radioactive waste liquid, which comprises filling glass fibers in a mold, heat-treating the fibers for partial fusion and molding them into a molded product of a predetermined shape, wherein at least one member selected from the group consisting of boric acid, silicic acid, lithium borate, lithium silicate, zinc borate, zinc silicate, an organic silane, a silica sol, an oil emulsion, and an alumina sol, is applied to the glass fibers or to the molded product.

Abstract: A process for preparing a stabilized high cristobalite from a gel comprising ultramicroscopic particles of SiO.sub.2, Na.sub.2 O, and Al.sub.2 O.sub.3 where the ratio of moles of Na.sub.2 O to Al.sub.2 O.sub.3 is from about 0.95 to about 1.1, and the molar ratio of SiO.sub.2 to Al.sub.2 O.sub.3 is between about 10 and about 40. After the gel is formed, it is heated at 800-1400.degree. C. for a time sufficient to form stabilized high cristobalite.

Abstract: A dielectric ceramic composition for temperature compensating monolithic ceramic capacitors consists essentially of a solid solution composed of barium oxide, strontium oxide, silicon oxide and zirconium oxide, which, when calculated in terms of BaO, SrO, SiO.sub.2 and ZrO.sub.2 respectively and expressed by the formula:x(BaO.sub.1-.alpha. SrO.sub..alpha.)--ySiO.sub.2 --zZrO.sub.2(wherein x, y, z are the weight percentages of the respective components, x+y+z=100, and 0.ltoreq..alpha..ltoreq.0.9), have compositional proportions falling within the polygonal area defined by the points A, B, C and D in FIG. 1, the sets of x, y and z at said points A, B, C and D being as follows:______________________________________ x y z ______________________________________ A 50 49 1 B 50 20 30 C 15 20 65 D 15 84 1 ______________________________________The composition may contain, as an additive, aluminum oxide in an amount of not more than 20 parts by weight in terms of Al.sub.2 O.sub.

Abstract: A brush seal for use in thermal turbomachines comprising bristles which consist of oxidic or non-oxidic ceramic fiber.

Abstract: Ceramic foams in which the open cells are connected by a three-dimensional, substantially continuous ceramic matrix formed of interconnected hollow ligaments, are made from an open-cell, reticulated precursor metal, i.e. a metal foam. The precursor metal first is treated so as to allow a support coating to form thereon, and thereafter the coated precursor is heated above the melting point of the metal in the presence of an oxidant to form an oxidation reaction product.

Abstract: X-ray attenuating ceramic materials having at least one substance selected from the group including compounds of strontium, zirconium, yttrium, niobium, molybdenum, neodymium and tungsten are disclosed. A zinc compound can be used for fluxing and X-ray attenuation in certain ceramic materials. The materials can be formed into strong, non-porous bodies such as cathode ray tube funnels. Such materials include forsteritic porcelains manufactured from batches containing strontium zirconate. Other X-ray attenuating ceramics contain a mixture of X-ray attenuating substances, including a compound of barium.

Abstract: A radioactive microsphere for radiation therapy of a mammal comprising a biologically compatible glass material containing a beta or gamma emitting radioisotope distributed substantially uniformly throughout the glass. Advantageously, the radioisotope is produced by irradiation of the microsphere.

Abstract: There is disclosed a natural phyllosilicate and, in solid solution therewith, at least one additional silicate or spinel phase such as beta-quartz, beta-spodumene, biotite, donathite, magnetite and Ca.sub.2 MgFe.sub.2 O.sub.6. There is also disclosed a method of producing such solid solution by introducing a phyllosilicate into a salt bath to effect an ion exchange between the salt of the bath and the phyllosilicate and subjecting the ion-exchanged phyllosilicate to a thermal treatment to develop a new phase which forms a solid solution.

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: The invention relates to a process for the immobilization of nuclear waste in a borosilicate glass.In the process, the following are mixed simultaneously:a silica-based gel precursor,a concentrated aqueous solution of a boron compound, and concentrated aqueous solutions of the other constituents of the final glass, i.e. a solution (solutions) of the waste to be treated and a solution of the vitrification adjuvant,with vigorous stirring, mixing taking place at between 20.degree. and 80.degree. C., preferably at 65.degree.-70.degree. C., in proportions corresponding to the desired composition of the glass, the said mixture having an acid pH, preferably a pH of between 2.5 and 3.5, and the said mixture is dried, calcined at between 300.degree. and 500.degree. C. and then melted.The invention is applied to the treatment of solutions of nuclear waste, especially to solutions of fission products.

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: An alkoxide glass former composition has silica-containing constituents present as solid particulates of a particle size of 0.1 to 0.7 micrometers in diameter in a liquid carrier phase substantially free of dissolved silica. The glass former slurry is resistant to coagulation and may contain other glass former metal constituents. The immobilization of nuclear waste employs the described glass former by heating the same to reduce the volume, mixing the same with the waste, and melting the resultant mixture to encapsulate the waste in the resultant glass.

Abstract: Glaze compositions for ceramic substrates such as an alumina substrate are described. In a first embodiment, the glaze composition consists of 55 to 75 mol % SiO.sub.2, 1 to 15 mol % Al.sub.2 O.sub.3, 3 to 20 mol % CaO, 1 to 13 mol % BaO and 0.1 to 5 mol % Y.sub.2 O.sub.3. In a second embodiment, the glaze composition consists essentially of 55 to 75 mol % SiO.sub.2, 1 to 15 mol % Al.sub.2 O.sub.3, 3 to 20 mol % CaO, 1 to 13 mol % BaO, 1 to 5 mol % Y.sub.2 O.sub.3, 25 mol % or less SrO, 7 mol % or less B.sub.2 O.sub.3, 2 mol % or less ZnO and 2 mol % or less MgO. In a third embodiment, the glaze composition consists essentially of 58 to 75 mol % SiO.sub.2, 2 to 15 mol % Al.sub.2 O.sub.3, 0.5 to 5 mol % La.sub.2 O.sub.3, 2 to 20 mol % CaO and 1 to 13 mol % BaO. In a fourth embodiment, the glaze composition consists essentially of 58 to 75 mol % SiO.sub.2, 2 to 15 mol % Al.sub.2 O.sub.3, 0.5 to 5 mol % La.sub.2 O.sub.

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: A process for treating solid substantially non-volatile wastes contaminated with a heat sensitive contaminant is disclosed. The wastes are heated to form a liquid slag. The liquid slag is held at elevated temperature until at least a portion of the contaminating components have either decomposed or evolved from the melt as a gas. The slag is subjected to cooling and the contaminating compounds are bound or encapsulated into a solid glassy slag. The process is particularly suitable for handling fluoride and cyanide contaminated aluminum smelting wastes such as spent potliner material. It is advantageous to add silica to such wastes. The residue from the slagging reaction is a glassy solid sodium metal silicate matrix such that the fluoride residues remaining in the wastes are encapsulated. The amount of silicate blended with the feed material is selected to substantially tie up all of the sodium remaining in the residue after slag melting and is typically 7.5 to 50 weight percent of the feed.

Abstract: A process for producing toughened ceramic composites from ceramic precursor materials by forming microcomposite particles from the ceramic precursor materials to produce microstructures that impart enhanced toughness to the particles. The microcomposite particles are consolidated at a pressure, a temperature and for a time sufficient to form bulk ceramic components that exhibit the general microstructure and toughness of the microcomposite particles while the temperature is maintained above that where particle consolidation occurs but below the eutectic or melting temperature of the matrix. The consolidated product retains the toughness of the microcomposite particles.

Abstract: A silicate raw material for ceramics containing alkali oxides, zinc oxide and silicon dioxide is characterized in that the three components alkali oxide, zinc oxide and silicon dioxide are present as calcined three-component silicates in a molar ratio of from 1:1:2 to 1:2:6, preferably in integral molar ratios, are employed.

Abstract: Disclosed herein is an alumina-base abrasion resistant material obtained by adding, as sintering agents, 0.5-4.0 parts by weight of each of TiO.sub.2 and CuO and 0.5-4.0 parts by weight of each of 3 or 4 oxides selected from the group consisting of Fe.sub.2 O.sub.3, MnO.sub.2, ZrO.sub.2 and SiO.sub.2 to 100 parts of Al.sub.2 O.sub.3 powder and then sintering the resultant raw batch.

Abstract: The invention relates to a ceramic molding which is manufactured from high-temperature resistant, fire-resistant or refractory fibers and fine-grain, fire-resistant or refractory materials and, in certain cases, from other customary additives. The ceramic molding is characterized by the fact that its porosity gradually and continuously increases along an axis of the molding from less than 20% to more than 70%. The areas with low porosity comprise the fine-grain, fire-resistant or refractory materials. The areas of high porosity comprise ceramic fiber, such as, fibers of Al.sub.2 O.sub.3, SiO.sub.2, ZrO.sub.2, C, SiC or mixtures thereof. The intermediate areas are constructed of mixtures of ceramic fiber and fire-resistant or refractory materials. The invention also relates to the use of such a ceramic molding method for the manufacture of compound moldings saturated or infiltrated with organic resins, pitch, tar, metals, metal alloys or glasses.

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: A sliding-contact type ceramics article having a high density portion for increasing the mechanical strength of its slide-contact portion with an associated article. A method for manufacturing such a sliding-contact type ceramics article which is characterized in that, at first a compact body having a configuration which is approximate to a final article is molded in such a manner that a slide-contact portion with an associated article is intensively compressed, and then the compact body is grinded to obtain a compact body of a final configuration.

Abstract: The present invention provides an improved compositional material for a low melting point metal casting equipment and a method for producing the same, wherein said composition does not cause large cracks during operation even if there is a reduction in its physical strength resulting from the non-use of reinforcing asbestos fiber.This material actually has a durability equivalent to/or greater than that of products reinforced with asbestos fiber.

Abstract: The present invention relates to a process for the treatment of polysilazane in a homogeneous phase with a catalytically effective quantity of an acid catalyst selected from HClO.sub.4 and CF.sub.3 SO.sub.3 H. The polysilazane is preferably selected from the group consisting of organopolysilazane, organopoly(disilyl)silazane and mixtures thereof. The organic radicals bonded to the silicon atoms are preferably saturated or aromatic hydrocarbon radicals and the silicon atoms of the polysilazane are substantially free from any hydrogen atom bonded directly to the silicon atoms.The polysilazanes treated in this manner have good thermal behavior and, are particularly useful as precursors of ceramic products.

Abstract: This invention provides a shaped body of calcium silicate of which the whole or the surface layer comprises a mixture of calcium silicate crystal and at least one inorganic compound selected from the group consisting of spodumene, petalite, eucryptite, lithium orthoclase, quartz glass, Vycor glass, cordierite, beryl, aluminum titanate and zirconium phosphate and a process for preparing the same.

Abstract: A homogeneous composition comprising(1) at least one particulate ceramic material, and(2) a liquid medium, in which the composition comprises at least 50% by volume of particulate ceramic material, in which the particulate ceramic material and liquid medium are selected such that a test composition has a friction coefficient of less than 0.2, and in which the particulate ceramic material has a mean aspect ratio of less than 1.70, a shaped article produced from the composition, a shaped article from which the liquid medium has been removed, and a product in which the particles of ceramic material have been sintered.

Abstract: A low expansion ceramic composition is represented by the formula Ca.sub.0.5 Ti.sub.2 P.sub.3 O.sub.12 in which up to 100 percent of the Ca is replaced by one or more of the other alkaline earth metals and alkali metals, the alkali metals being selected from the group consisting of Na, Li, K and combinations thereof and substituted in the ratio of two units of alkali metal for each unit of Ca replaced. Up to 100 percent of the Ti is replaced by one or more members selected from the group consisting of Zr, Sn, Nb, Ta and Cr. For each unit of Cr replacement an approximately equal unit of alkali metal is added. For each unit of Nb and/or Ta replacement an approximately equal unit of Na and/or K replaces a unit of Ca. Up to 100 percent of the P may be replaced by Si and/or S. The total of the amounts of Ca, other alkaline earth metals, Li, K, Ti, Sn, Nb, Ta and Cr is greater then zero. Preferably up to 100 percent of the Ca is replaced by Na, and up to 100 percent of the Ti is replaced by Zr or NaCr.

Abstract: A method of preparing silazane polymers, with 3 or more repeating units, of the general formula--((CH.sub.3).sub.2 N).sub.e Si(R).sub.a (R'HN).sub.f H.sub.c (NR').sub.g --and a (CH.sub.3).sub.2 NH byproduct group where R is hydrogen, an alkyl group having 1-6 carbon atoms or an aryl group having 6-12 carbon atoms, a=0, or 1, b=2-4, C=0-2, d=0 or 1, e=0-2, f=0-2, g=1-3 and a+c+e+f+g=4 for the polymer units; and R' is hydrogen or methyl, whereby the silazane polymer is substantially free of halide impurities, and wherein this method comprises:transaminating an aminosilane of the general formula (R).sub.a ((CH.sub.3).sub.2 N).sub.b H.sub.c S; where R is defined as above and a+b+c=4 with an amine of the general formula (CH.sub.3).sub.d NH.sub.3-d whereby d is defined as above and the amine has a molecular weight lower than 45 all in the presence of an acid catalyst or the ammonium salt of the acid and thereafter condensing to form the polymer.

Abstract: A process for making a structural ceramic article, such as, an electromagnetic window, is disclosed, wherein the ceramic article is comprised of a densified mixture of not less than 50% by volume aluminum nitride and up to about 50% by volume boron nitride. The ceramic article of the present invention may be used as a shield or protective barrier such as an electromagnetic window for communication or detection devices on high speed transportation or delivery vehicles passing through extremely hostile environments, where it exhibits radar transparency, congruent vaporization kinetics, tailorable dielectric properties, improved thermal shock resistance, improved mechanical toughness and strength, improved spall resistance, improved recession rate, i.e. erosion rate and ablation rate, and high refractoriness.

Abstract: According to the method of this invention for fixation of incinerator ash, incinerator ash containing SiO.sub.2 and Al.sub.2 O.sub.3 is incorporated with NaOH or NaOH and an SiO.sub.2 -containing substance in such an amount that the resulting mixture contains 25 to 90 wt % of SiO.sub.2, 2 to 10 wt % of Na.sub.2 O, and more than 3 wt % of Al.sub.2 O.sub.3 which is less than the content of SiO.sub.2 in terms of mol %; 100 parts by weight of the mixture is mixed with more than 5 parts by weight of water; and the resulting mixture is subjected to hydrothermal reaction under a pressure of 70 kg/cm.sup.2 or above and at a temperature of 150.degree. C. and above, whereby the fixation is accomplished.

Abstract: Disclosed herein is a method and composition of matter for constructing temperature resistant parts for the metal making industry from a mix of refractory fibers and Silca-carbon in the form of burned rice hull ash.

Abstract: A silicon nitride cutting tool primarily for cutting cast iron comprises a granular phase consisting essentially of silicon nitride and an intergranular amorphous phase consisting essentially of magnesium oxide, yttrium oxide and silicon oxide wherein the components are present in specified amounts and ratios.

Abstract: A process for producing fine non-oxide powder from an alkoxide selected from the group consisting of a silicon alkoxide and an aluminum alkoxide, which comprises dispersing carbon powder in the alkoxide, hydrolyzing the dispersion, and heating the hydrolyzate mixture thereby obtained, in a nitrogen atmosphere at a temperature of from 1350.degree. C. to 1650.degree. C. for from 30 minutes to 30 hours.

Abstract: A process for the production of shaped articles from silicate material by extrusion and/or pelleting and subsequent annealing is described. In this process, pulverulent layered silicic acids of the general formula H.sub.2 Si.sub.y O.sub.2y+1, in which y is a number from 1.7 to 24, or salts thereof, in which all or some of the H is replaced by at least one cation from the group comprising Li.sup.+, Na.sup.+, K.sup.+, NH.sub.4.sup.+, Ca.sup.2+, Cu.sup.2+, Co.sup.2+, Ni.sup.2+ and Mg.sup.2+, are mixed with water or an organic solvent, the mixture is extruded and/or pelleted to give roll-shaped or tube-shaped pieces and these are then dried and annealed under conditions such that the starting material is chiefly converted into cristobalite and/or tridymite. The same material can also be pressed in a molding tool under pressure. Under these conditions, shaped articles which predominantly consist of cristobalite or tridymite and have a Shore hardness of at least 70 can be obtained.

Abstract: A backfill composition for use with sacrificial magnesium anodes used in the cathodic protection of ferrous metal structures comprises an anion-releasing material capable of releasing fluoride, phosphate or zincate ions in water-soluble form and a magnesium-transporting adjuvant capable of transporting magnesium ion by ion exchange conduction. Suitable anion-releasing materials include calcium fluoride, cryolite, magnesium silicate and sodium silicofluoride, while suitable magnesium transporting adjuvants include bentonite clay, calcium sulfate, calcium carbonate, calcium hydroxide and magnesium silicate.

Abstract: A novel target material for use in the sputter formation of a metal silicide film in electrode wiring in a semiconductor device, and a process for producing such target material are disclosed.The process for producing the target material is characterized by first impregnating molten silicon into a calcined body containing at least one silicide forming metal component and a silicon component and then forming a sintered body with a reduced oxygen content containing both a metal silicide and silicon.The target material prepared in accordance with the invention is extremely low not only in oxygen content but also in the concentrations of other impurities and has high deflective strength as compared with the conventional sintered target.The film formed by sputtering the target of the invention has appreciably reduced impurity levels and hence, very low electric resistivities. The target of the invention enables sputtering to be performed 5 times as fast as in the case using the conventional sintered target.

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 crystalline metal oxide in the form of a solid solution comprising an oxide of a metal of Group II of the periodic table, titanium oxide and silicon dioxide as main components and having main peaks at about 26.7.degree. and about 20.9.degree. in its Cu-K.alpha. X-ray diffraction pattern (2.theta.) and a specific refractive index. The crystalline metal oxide is produced, for example, by dissolving a compound of a metal of Group II of the periodic table, a hydrolyzable organic silicon compound and a hydrolyzable titanium compound in an organic solvent, hydrolyzing said starting compounds in said solution or after said solution is added to a separately prepared solvent incapable of dissolving the reaction product, thereby to form a sol- or gel-like product, and thereafter calcining the sol- or gel-like product at a temperature and for a period of time sufficient to crystallize said product.

Abstract: A refractory assembly for containment of molten aluminum-lithium alloys, comprising a nitride bonded silicon carbide refractory brick and a seam joined to the brick. The seam is formed from a mortar mix comprising particulate nitride refractory filler and colloidal sol binder. The brick and seam both exhibit good resistance to attack by molten aluminum-lithium alloys at elevated temperatures.

Abstract: A method for producing .alpha.-silicon nitride whiskers. Silicon is blended with amorphous silicon nitride and a pore-forming composition particles able to be removed without leaving a residue, such as naphthalene particles. The mixture is compacted to a desired shape, after which the pore-forming particles are removed from the mixture to form a porous silicon precursor compact having the desired shape. The silicon precursor is reacted with a substance that releases free nitrogen, such as nitrogen or dry ammonia. The reaction is carried out at a temperature sufficiently high to form an identically shaped porous compact of .alpha.-silicon nitride whiskers but sufficiently low to avoid subliming substantially all of the formed whiskers. Preferably, the reaction is carried out in a range between about 1100.degree. C. and 1500.degree. C. The shaped porous compact of .alpha.

Abstract: Disclosed is a lightweight silicate aggregate produced by the steps of mixing together dry rice hull ash, an alkali metal hydroxide, boric acid, and water; heating the mixture to a temperature sufficient to initiate reaction; curing the composition at a temperature less than the boiling point of water until the reaction is complete; comminuting the cured product and heating the comminuted product to form the expanded aggregate. The expanded aggregate is useful as, inter alia, a sorbent, filler, energy insulator or filter.

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 composite is provided which is adaptable to be a substrate for an electronic application. The composite comprises first material particles having a coefficient of thermal expansion in the range of about -20.times.10.sup.-7 to about 50.times.10.sup.-7 in/in/.degree.C. Second material particles having a coefficient of thermal expansion in the range of about 100.times.10.sup.-7 to about 200.times.10.sup.-7 in/in/.degree.C. are mixed with the first material particles. A bonding agent adheres the first and second material particles into a coherent composite having a coefficient of thermal expansion in the range of about 1.times.10.sup.-7 to about 50.times.10.sup.-7 in/in/.degree.C.

Abstract: A ceramic-like high temperature insulation for electrical coils is provided by mixing a silicone resin, synthetic fluoro-mica and a devitrified mica glass, impregnating an electrical coil with such material, curing the material and then treating the material to an elevated temperature about 300.degree. C. The elevated temperature treatment may be effected either prior to or during use of the coil.

Abstract: Highly densified silicon nitride sintered bodies having excellent mechanical strength and oxidation resistance consist essentially of Si.sub.3 N.sub.4 and contain Y, Mg and Zr, in which a content of Si.sub.3 N.sub.4 is 95-70% by weight, a content of yttrium is 15-2% by weight calculated as Y.sub.2 O.sub.3, a content of magnesium is 15-0.5% by weight calculated as MgO and a content of zirconium is 13-0.5% by weight calculated as ZrO.sub.2 and are produced by forming a mixed raw powder consisting of 95-70% by weight of silicon nitride raw powder, yttrium compound of 15-2% by weight calculated as Y.sub.2 O.sub.3, magnesium compound of 15-0.5% by weight calculated as MgO and zirconium compound of 13-0.5% by weight calculated as ZrO.sub.2 into a shaped body, said yttrium compound, magnesium compound and zirconium compound being sintering aids, and firing the shaped body at a temperature of 1,650.degree.-1,800.degree. C. under ambient pressure in a nitrogen or an inert gas atmosphere.

Abstract: A process is disclosed for reacting oxides of yttrium and aluminum.

Abstract: An ionically conductive glass is disclosed for use as electrolyte in a high temperature electrochemical cell, particularly a cell with sodium anode and sulfur cathode. The glass includes the constituents Na.sub.2 O, ZrO.sub.2, Al.sub.2 O.sub.3 and SiO.sub.2 in selected proportions to be a single phase solid solution substantially free of crystalline regions and undissolved constituents. Other advantageous properties are an ionic conductivity in excess of 2.times.10.sup.-3 (ohm-cm).sup.-1 at 300.degree. C. and a glass transition temperature in excess of 500.degree. C.

Abstract: A process for producing solid vermiculite products which are stable in water which comprises incorporating a source of ammonia or ammonium ions or a basic substance, preferably urea, in an aqueous suspension of vermiculite lamellae, shaping the suspension and removing water from the suspension by heating the shaped suspension at a temperature above 100.degree. C., preferably above 150.degree. C., such that ammonia or a basic substance is liberated within the suspension. The invention includes an aqueous suspension of vermiculite lamellae containing a source of ammonia or ammonium ions or a basic substance and a dry-powder mixture of vermiculite lamellae and a source of ammonia or ammonium ions or a basic substance.

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.