Abstract: An adhesive agent having, as its active components, copper sulfide and at least one member selected from the group consisting of alumina, silica, and kaoline enables the opposed surfaces of two oxide-type ceramic articles to be joined to each other with high adhesive strength, this fast union being accomplished by interposing the adhesive agent between the opposed surfaces of the ceramic articles and heating the adhesive agent to a temperature of not less than 1000.degree. C.

Abstract: A refractory composition having a high resistance to corrosion by molten metal chlorides and chlorine gas at elevated temperatures. The composition comprises about 100 parts by weight of a nitride refractory filler, a suitable quantity of a colloidal sol binder and less than about 4 parts by weight of the oxides or hydroxides of magnesium, calcium, chromium and manganese.

Abstract: A ceramic useful as an electrically insulating material is produced by calcinating wollastonite powder, admixing the calcined powder with phosphoric acid of certain P.sub.2 O.sub.5 concentration range, die-pressing the resulting mixture, and firing the resulting pressed piece. The ceramic is employed within arc circuit breakers as a substitute for asbestos liners, dividers and arc splitters.

Abstract: Sub-micron sized powders of the ceramic metal oxides such as zirconia, alumina, titania, etc. are produced by precipitation from substantially anhydrous solutions of salts of the corresponding metal(s) with substantially anhydrous solutions of alkali metal hydroxides. The precipitates are subsequently washed with water to remove any residual soluble salt and/or solvent, then are dried and usually calcined. The powders thus produced are readily sintered to high density ceramic bodies after conventional pressing into the desired shape.The process is especially suited to the production of zirconia powders, either pure or doped with conventional stabilizing oxides such as yttria. In a typical example, a zirconia powder doped with 5.4% by weight of yttria is prepared by adding a solution of zirconium tetrachloride and yttrium chloride in anhydrous ethanol to a solution of sodium hydroxide in anhydrous ethanol. After washing, drying at 105.degree. C., and calcining at 500.degree. C.

Abstract: A process for preparing a heat resistant soft composite which comprises hot-pressing a mixture comprising talc powder and mica powder as major components and a bonding material composed of normal boric acid, boric acid anhydride and zinc oxide, at a temperature of from 160.degree. to 200.degree. C. under pressure of from 50 to 100 kg/cm.sup.2 to form a composite, and subjecting the composite to heat treatment at a temperature of from 450.degree. to 500.degree. C.

Abstract: A method for producing a cordierite body having no anisotropic property in coefficient of thermal expansion comprises the steps of preparing a raw material containing kaolin mineral and talc as main ingredients, and preformed cordierite particles formed from the raw material, mixing and kneading the raw material together with the preformed cordierite particles into a slurry, forming the slurry into a formed body and firing the formed body.

Abstract: The method concerns forming a relatively stable slip of silicon metal particles and yttrium containing particles. In one embodiment, a casting slip of silicon metal particles is formed in water. Particles of a yttrium containing sintering aid are added to the casting slip. The yttrium containing sintering aid is a compound which has at least some solubility in water to form Y.sup.+3 ions which have a high potential for totally flocculating the silicon metal particles into a semiporous solid. A small amount of a fluoride salt is added to the casting slip which contains the yttrium containing sintering aid. The fluoride salt is one which will produce fluoride anions when dissolved in water. The small amount of the fluoride anions produced are effective to suppress the flocculation of the silicon metal particles by the Y.sup.

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 is a mixture of particulate silicon, silicon carbide and boron. The mixture contains between about 25% and 40% silicon by weight of the total composition, between about 50% and 70% by weight silicon carbide by weight of the total composition, between about 1% and 15% boron by weight of the total composition and a minor amount of magnesium oxide. The 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: This invention is directed to the preparation of neutralized polyelectrolyte complexes exhibiting hydrophobic behavior containing crystals of an organic polycation exchanged lithium and/or sodium water-swelling mica. The process for making such products comprises:(1) forming a glass-ceramic body containing crystals selected from the group of fluorhectorite, hydroxyl hectorite, boron fluorphlogopite, hydroxyl boron phlogopite, and solid solutions among those and between those and other structurally-compatible species selected from the group of talc, fluortalc, polylithionite, fluorpolylithionite, phlogopite, and fluorphlogopite;(2) contacting that body with a polar liquid to cause swelling and disintegration of the body accompanied with the formation of a gel; and(3) contacting said gel with a source of organic polycations to cause a reaction between the Li.sup.+ and/or Na.sup.

Abstract: There is disclosed a method of producing a slurry composed of ion-exchanged, synthetic mica crystals dispersed in a polar liquid. The method comprises providing a synthetic, lithium and/or sodium, water-swelling body of selected crystal type, and dispersing the mica body in the polar liquid while simultaneously effecting an exchange of larger cations from a contacting source with lithium and/or sodium ions from the mica crystals. The synthetic mica body may be vigorously mixed in a dilute solution of the exchangeable ion source. Alternatively, the mica body may be disintegrated in a mixer, the exchangeable ion source added to form a paste and more liquid added to dilute the paste.

Abstract: Optically translucent theoretically dense body of mullite is produced by pressing an amorphous mixed oxide powder composition of from about 72.5 weight % to about 76.5 weight % Al.sub.2 O.sub.3 /balance SiO.sub.2 into a compact of density of at least 1.0 g/cc, sintering the compact in oxygen or a vacuum of 0.05 torr to 1 torr producing a gas-impermeable compact, hot isostatically pressing the gas-impermeable compact to theoretical density, and with respect to compositions ranging from higher than about 74 wt % Al.sub.2 O.sub.3 /balance SiO.sub.2, annealing the theoretically dense body.

Abstract: A refractory powder for use in a light guide assembly for transmitting a thermal radiation from a melt to a pyrometer through the lining of a metallurgical vessel.The proposed powder has the following composition (by wt. %); aluminum oxide from 40 to 70, silicon dioxide from 29 to 59, and a sintering agent from 0.3 to 2.0. As the sintering agent use is made, in particular, of a boric acid.According to the proposed method the aluminum oxide powder and the silicon dioxide powder are heated to a temperature of from 1200.degree. to 1400.degree. C. and from 900.degree. to 1200.degree. C. respectively, then cooled to a room temperature and mixed with simultaneously adding thereto a sintering agent until a uniform mixture is produced.

Abstract: An improved modified silicon aluminum oxynitride based composite cutting tool is made by forming a homogeneous matrix of a modified silicon aluminum oxynitride prior to uniformly dispersing a hard refractory material throughout the homogeneous matrix, then densifying the combined materials to form a composite cutting tool having a density greater than 98 percent of the theoretical density of the combined materials.

Abstract: Amorphous mixed oxide powder composed of from about 74 weight % to about 76.5 weight % Al.sub.2 O.sub.3 balance SiO.sub.2 is pressed into a compact with a density of at least 1 g/cc and sintered in oxygen producing an optically translucent theoretically dense body of mullite.

Abstract: Amorphous mixed oxide powder composed of from about 74 weight % to about 76.5 weight % Al.sub.2 O.sub.3 balance SiO.sub.2 is pressed into a compact with a density of at least 1 g/cc, fired in oxygen or vacuum of 0.05 to 1 torr producing a gas-impermeable compact, and sintered in air, argon, helium, nitrogen or mixtures thereof producing an optically translucent theoretically dense body of mullite.

Abstract: A ceramic useful as an electrically insulating material is produced by calcining wollastonite powder, admixing the calcined powder with phosphoric acid of certain P.sub.2 O.sub.5 concentration range, die-pressing the resulting mixture, and firing the resulting pressed piece.

Abstract: In the production of silicon or silicon-alloy bodies in which a shaped pre-form, blank or like member containing a silicon carrier and carbon is subjected to an electric furnace, the fine-grain silicon carrier intimately mixed with preferably a stoichiometric amount of caking coal and the mixture is molded to form the body which is subjected to hot briquetting at a temperature of 350.degree. to 550.degree. C. as is used for the hot briquetting of coal.

Abstract: A thermally stable, oxidation resistant ceramic Si.sub.3 N.sub.4 material is disclosed. The material has a substantially pure primary phase formed of substantially pure silicon nitride. A substantially pure secondary phase of the material is formed of a material selected from the group consisting essentially of Si.sub.3 N.sub.4 /SiO.sub.2 /4Y.sub.2 O.sub.3, Si.sub.3 N.sub.4 /SiO.sub.2 /2Y.sub.2 O.sub.3 and Si.sub.3 N.sub.4 /4SiO.sub.2 /5Y.sub.2 O.sub.3. The primary phase may be in the form of individual grains and the secondary phase may be in the form of grain boundaries between the individual grains.

Abstract: Method for producing .alpha.-silicon nitride whiskers. Silicon is blended with composition particles able to sublime without leaving a residue, such as naphthalene particles. The blend is compacted to a desired shape, after which the composition particles are sublimed from the blend 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 2100.degree. F. and 2750.degree. F. The shaped porous compact of .alpha.-silicon nitride whiskers may be impregnated with a resin binder, a liquid metal, a colloidal suspension, an ionic solution or a gaseous material to form an isotropic composite.

Abstract: Disclosed herein are fired ceramic wares possessing hydrophobic properties throughout the bodies thereof. The ware is prepared utilizing a water-reduced ceramic body composition containing a quantity of a finely-divided sub-micron amorphous silica or alumina. This ceramic body composition is formed into a green ware, the ware dried and fired at relatively low temperature and the fired ware treated with one or more reactive organosilicon compounds whereby organosilicon groups are caused to chemisorb onto the surface of the finely-divided amorphous oxide component.

Abstract: A method for producing a cordierite body having isotropic coefficient of thermal expansion comprises the steps of preparing a batch by mixing and kneading particles of fired talc, alumina supplying substance such as alumina and aluminum hydroxide, and silica supplying substance such as silica and kaoline, anisostatically forming the batch and drying and firing the obtained formed body.

Abstract: A low cost beautiful blue colored artificial stone stock is obtained by using a high carbon or low carbon slag formed at the time of preparing ferrochromium, as it is or after incorporated with an expensive addition. The stone stock has a composition of 40-70% by weight of SiO.sub.2, 0.1-5% by weight of a low grade chromium oxide and the balance of CaO, MgO and Al.sub.2 O.sub.3.

Abstract: A silicon nitride compact with a density of 95% to 100% is produced by forming a particulate dispersion of silicon nitride and beryllium additive into a compact, firstly sintering the compact from about 1900.degree. C. to about 2200.degree. C. in nitrogen at superatmospheric pressure sufficient to prevent thermal decomposition of the silicon nitride until the entire outside surface of the compact becomes impermeable to nitrogen gas, and then secondly sintering the compact from about 1800.degree. C. to about 2200.degree. C. under a nitrogen pressure having a value at least twice the first nitrogen sintering pressure.

Abstract: A compact composed of a mixture of silicon nitride with less than about 0.5 weight % cation impurities and containing beryllium additive, and having an oxygen content of at least about 1.4 weight %, is sintered from 1900.degree. C. to 2200.degree. C. in nitrogen at superatmospheric pressure producing a sintered compact of at least about 80% density.

Abstract: A powder composition for producing cordierite is obtained by mixing a water-soluble magnesium salt; a water-soluble aluminum salt; a silicon source selected from the group consisting of organic silicon compounds, silica, silica sol and, silica gel; and an organic solvent, adding to the resultant mixture an ammonia-alkaline solution of ammonium carbonate thereby producing a precipitate, separating the precipitate, and drying the separated precipitate.

Abstract: A multi-layer metallized substrate comprises a matrix of sintered silicon particles joined by a thin insulating layer of silicon dioxide or silicon nitride. Semiconductor circuit chips are bonded to the surface of the substrate to form an electrically connected, unitary integrated circuit module structure.

Abstract: The invention provides an improved method for producing plate-shaped or tape-shaped silicon crystal bodies having pillar-like structures therein which are equivalent to columnar structures comprising conducting the sintering process, for purposes of particle enlargement, in a gas atmosphere comprised of argon and a minimum amount of hydrogen. In a preferred embodiment, the hydrogen concentration in such atmosphere is about 6% by volume. The so-produced silicon bodies are useful for further processing into large-surface solar cells.

Abstract: Sintered silicon nitride articles are prepared by sintering a silicon nitride compact of a density of at least 1.3 g/cm.sup.3 in nitrogen gas atmosphere at substantially atmospheric pressure, while the compact is embedded in a protective powder comprising silicon nitride, boron nitride, or a mixture of silicon nitride and boron nitride, and one or more sinterization additives for silicon nitride, said additives being present in the protective powder in an amount of from 3 to 20% by weight.

Abstract: Sintered silicon nitride articles are prepared from a silicon nitride compact by forming a silicon powder containing one or more sintering additives for silicon nitride into a compact having at density of at least 1.3 g/cm.sup.3, said additives being present in the powder in an amount such as to ensure an additive content of from 0.5 to 20 wt. % in the silicon nitride compact, nitriding the silicon compact by heating under nitrogen gas blanket at a temperature not exceeding 1500.degree. C., to convert said silicon into reaction bonded silicon nitride, and sintering the reaction bonded silicon nitride compact by heating in a nitrogen gas atmosphere at a temperature of at least 1500.degree. C.

Abstract: A semiconducting internal boundary layer ceramic composition having a fine grain structure suitable for use in thin-layer multilayer capacitors is made in one step by firing a mixture comprising a major amount of finely divided strontium titanate, a minor amount of a compound containing either strontium or titanium, or an element functionally equivalent thereto, a minor amount of a semiconductor forming ingredient (dopant), the identity of which depends on whether the mixture is rich in strontium or in titanium, and a minor amount of a counterdopant selected from cuprous oxide or silver oxide. When the mixture is rich in titanium, the chemical doping agent used to produce semiconductivity is an oxide of a trivalent metal selected from bismuth, boron, iron, antimony, lanthanum and the rare earth and transition metals. When the mixture is rich in strontium, the dopant is an oxide of a pentavalent or hexavalent metal selected from tungsten (+6), niobium (+5), tantalum (+5), and molybdenum (+6).

Abstract: A method of manufacturing nitrided silicon parts which retain their mechanical properties after hot oxidation, said method consisting of sintering silicon powder in an atmosphere which is rich in nitrogen. 1% to 10% by weight of aluminium powder is added to the silicon before sintering thereof and preliminary hot oxidation is effected in conditions which allow acicular mullite to form by the direct action of the aluminium and of a complement of oxygen molecules supplied by the outside medium on the silicon formed.

Abstract: A glaze resistor composition composed of a glass frit, molybdenum disilicide, tantalum disilicide, magnesium silicide and aluminum. This glaze resistor composition has a small temperature coefficient of resistivity, a high resistivity stability and small current noises, and can be used in a wide resistivity range.

Abstract: A cutting tool tip is formed at least at a cutting edge of the tip from a ceramic product consisting essentially of at least 75% by volume of a single phase compound having an expanded .beta.-phase silicon nitride lattice and having the general formula Si.sub.6-z Al.sub.z N.sub.8-z O.sub.z, where O<z.ltoreq.5, together with a second phase containing a metal from the list yttrium, lanthanum, cerium and scandium, or other rare earth metal.

Abstract: In a process for the production of dispersion ceramics by sintering or hot pressing of a mixture of a matrix-forming ceramic material and of at least one ceramic embedment material dispersible therein which at the sintering temperature of the ceramic and at room temperature is present in different enantiotropic solid modifications of different densities, a ceramic embedment material is employed which is divided into at least two groups of different, substantially uniform particle sizes, each group having different lower phase-transition temperatures.

Abstract: The invention relates to low-expansion ceramics, the chemical composition of which consists of 1.2 to 20% by weight of magnesia (MgO), 6.5 to 68% by weight of alumina (Al.sub.2 O.sub.3), 19 to 80% by weight of titanium in terms of titanium oxide (TiO.sub.2), 1 to 20% by weight of silica (SiO.sub.2), and 0.5 to 20% by weight of iron in terms of ferric oxide (Fe.sub.2 O.sub.3); the major component of crystalline phase thereof is a solid solution of magnesium oxide-aluminum oxide-titanium dioxide-silicon oxide-iron oxide; the ceramics have a coefficient of thermal expansion of not more than 20.times.10.sup.-7 (1/.degree.C.) in a temperature range of 25.degree. C. to 800.degree. C., a four-point flexural strength of not smaller than 50 kg/cm.sup.2 at room temperature, and a melting point of not lower than 1,500.degree. C.

Abstract: The invention provides a particulate sealing material for use in preparing hermetic seals between ceramic and cermet members, which material comprises at least 70 wt. % refractory oxide and minor quantities of non-vitreous additive comprising SiO.sub.2, MgO and B.sub.2 O.sub.3. This particulate sealing material is conveniently pressed into the form of a coherent element shaped to suit the particular sealing operation concerned, e.g. the sealing of an open end of a ceramic arc tube to a cermet closure therefor. The invention also provides a method of sealing a ceramic component to a cermet member by interposing said sealing material between the opposed faces of the component and member and applying heat and pressure to sinter the sealing material and achieve a seal between the component and member.

Abstract: SIALON sintered product having the formulaSi.sub.6-z Al.sub.z O.sub.z N.sub.8-z(z is 0 to 4.2) is produced by sintering a molded product of the starting materials for SIALON in the condition of covering the surface of said molded product with a mixed powder of Si.sub.3 N.sub.4 and SiO.sub.2 as main components in nitrogen gas atmosphere.

Abstract: A low temperature sealing glass composition consisting of 60-80% by weight of vitreous solder glass of PbO-B.sub.2 O.sub.3 system having a deformation point of 350.degree. C. or less, and 20-40% by weight of willemite. The vitreous PbO-B.sub.2 O.sub.3 system glass comprises 70-90% by weight of PbO, 10-15% by weight of B.sub.2 O.sub.3, 0.5-5% by weight of SiO.sub.2, 0-5% by weight of Al.sub.2 O.sub.3, 0-5% by weight of ZnO, 0-15% by weight of PbF.sub.2 and 0-5% by weight of Bi.sub.2 O.sub.3.

Abstract: The present invention relates to a composition particularly suitable for as structural components subject to high-temperature environments containing gaseous hydrogen and fluorine. The composition of the present invention consists essentially of lanthanum hexaboride-molybdenum diboride with dispersed silicon. The composition is formed by hot pressing a powder mixture of lanthanum hexaboride as the major constituent and molybdenum disilicide. This composition exhibits substantial resistance to thermal shock and corrosion in environments containing hydrogen and fluorine gases at material surface temperatures up to about 1850.degree. K. Upon exposure of the hot-pressed composition to high-temperature environments containing fluorine gases, a highly protective layer of lanthanum trifluoride containing dispersed molybdenum is formed on exposed surfaces of the composition.

Abstract: Thick film resistors, based on pyrochlore conductive phase, glass, and refractory fillers having a thermal expansion coefficient range of 40.times.10.sup.-7 -60.times.10.sup.-7 /.degree. C. and low solubility in the glass, are provided. Such thick film resistor pastes afford resistors having excellent stability to mechanical or thermal stresses.

Abstract: Silicon ceramic articles having a complicated shape and a high strength can be obtained in a high dimensional accuracy by fitting a silicon ceramic member having a lower firing shrinkage into another silicon ceramic member having a higher firing shrinkage, and firing the resulting assembly to bond firmly both the members into one integral body. The silicon ceramic article can be used as gas turbine parts, engine parts and the like.

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: Foamable particulate cement is capable of forming sintered cordierite foamed ceramic masses. It consists essentially, by weight, of 1-40% cordierite grog, 99-60% ceramic base material and foaming agent, such as SiC. The ceramic base material is raw ceramic material that has an analytical molar composition consisting essentially of about 1.7-2.4 MO . 1.2-2.4 Al.sub.2 O.sub.3 . 4.5-5.4 SiO.sub.2 wherein MO comprises about 0-55 mole % MgO and at least 45 mole % MnO. The grog is ceramic material that has been previously fired and comminuted, and that has an analytical molar composition consisting essentially of about 1.7-2.4 RO . 1.9-2.4 Al.sub.2 O.sub.3 . 4.5-5.2 SiO.sub.2 wherein RO comprises MnO in an amount of 0 mole % up to a mole % that is about 20 mole % lower than the mole % of MO that is MnO and the balance is substantially MgO.

Abstract: A method for providing strong adhesion of two ceramic articles to each other or one ceramic article to an article of metallic copper, which method comprises applying, in the former adhesion, a powder mixture of CuS-LaCrO.sub.3 -SiO.sub.2 -Cu to the opposed surfaces of the two ceramic articles or, in the latter adhesion, a powder mixture of CuS-LaCrO.sub.3 -SiO.sub.2 to the opposed surfaces of the ceramic article and the article of metallic copper and, thereafter, heating the pair of articles in the air at a temperature of from 1000.degree. to 1200.degree. C.

Abstract: Metal or ceramic powders having a narrow size distribution are produced by passing a gas entrained powder through an intense light beam which couples preferentially with the larger particles to heat and selectively vaporize a portion of the larger particles until their diameter approximates the desired size.

Abstract: Foamable particulate cement is capable of forming sintered cordierite foamed ceramic masses. It consists essentially, by weight, of 1-40% cordierite grog, 99-60% ceramic base material and foaming agent, such as SiC. The ceramic base material is raw ceramic material that has an analytical molar composition consisting essentially of about 1.7-2.4 MO.1.2-2.4 Al.sub.2 O.sub.3.4.5-5.4 SiO.sub.2 wherein MO comprises about 0-55 mole % MgO and at least 45 mole % MnO. The grog is ceramic material that has been previously fired and comminuted, and that has an analytical molar composition consisting essentially of about 1.7-2.4 RO.1.9-2.4 Al.sub.2 O.sub.3.4.5-5.2 SiO.sub.2 wherein RO comprises MnO in an amount of 0 mole % up to a mole % that is about 20 mole % lower than the mole % of MO that is MnO and the balance is substantially MgO.