Abstract: A composition suitable for use as a binder of ceramic materials and a method for preparing a ceramic material which provides relatively greater green ceramic strength is disclosed. The improved binder contains a substantially hydrolyzed copolymer made from monomers having ester or amide functional groups, poly(vinyl amine), poly(vinyl formamide) or a copolymer of vinyl alcohol and vinyl amine. The binder is combined with an aqueous solution containing a ceramic powder to make a slurry, and the slurry is subsequently spray dried, pressed and heated to make a ceramic.

Abstract: A process for the preparation of optical materials from silicon nitride by pyrolysis of polymeric silazanes, by pressing the pulverulent polymeric silazanes to give moldings before the pyrolysis or first dissolving the polymeric silazanes in an organic solvent, drawing fibers from this solution and pyrolyzing these fibers after evaporation of the solvent, or by melting polymeric silazanes, casting, injection-molding or extruding this melt to give moldings and subsequently pyrolyzing the moldings. An oxidic coating is produced on the silicon nitride molding in an oxygen-containing atmosphere during or after the pyrolysis. The pyrolysis can be carried out at 800.degree.-1000.degree. C. in an atmosphere containing ammonia or an ammonia/inert gas mixture.

Abstract: The distributed index of refraction type optical element consists of an element composing a glass forming oxide and a cation composing a glass modifying oxide, and has therein a distributed index of refraction imparted by a gradient of density of the element and a distributed index of refraction imparted by a gradient of density of the cation which are completely independent of each other. This optical element permits controlling chromatic aberration in various ways and has various favorable optical characteristics. The method of making the optical element comprises a first step for imparting a first distributed index of refraction to a glass body material by forming a gradient of density of the element and a second step for imparting a second distributed index of refraction to the glass body material by forming a gradient of density of the cation.

Abstract: A titanium tetrahalide is reacted with a disilazane to prepare a titanium containing organometallic precursor, which is thereafter mixed with a refractory material powder and pyrolyzed to form a titanium nitride-containing refractory material composite containing crystalline titanium nitride.

Abstract: An improved double-layered ceramic heater, which is used for heating a semiconductor silicon wafer mounted thereon in the processing of semiconductor devices, is proposed to be freed from the problems in the prior art ceramic heaters in respects of service life and contamination of silicon wafers mounted thereon. Different from conventional ceramic heaters having a ceramic substrate plate of, for example, boron nitride provided with a heater element layer of a metal foil, the inventive ceramic heater has a substrate plate of silicon nitride and a heater element layer of graphite is formed thereon by the CVD method so that the ceramic heater is not responsible for contamination of semiconductor silicon by virtue of absence of any element which can be a disturbing dopant of the semiconductor. The problem of contamination with carbon can be solved by further providing a coating layer of silicon nitride by the CVD method.

Abstract: Improved gunnable plastic refractory compositions consist of a mass of friable clusters of granular material which has a moisture content of from about 4% to about 10% by weight of the total composition and contains from about 0.05% to about 0.5% by weight (added), preferably 0.1% to 0.3%, of a hydrocolloid selected from the class consisting of a polysaccharide ether and xanthan gum and from about 0.05% to about 1.0% by weight (added), preferably 0.15% to about 0.50%, carbon.

Abstract: A cubic boron nitride sintered compact is produced by adding to atmospheric pressure type boron nitride, a cubic boron nitride synthetic catalyst and 0.01 to 5.0 percent by weight of a hydroxide of an alkaline earth metal to form a mixture. Then, the mixture is subjected to a high temperature/high pressure treatment under a thermodynamically stable pressure condition for cubic boron nitride, whereby the atmospheric pressure type boron nitride is converted to cubic boron nitride under the action of the cubic boron nitride synthetic catalyst. The cubic boron nitride sintered compact thus obtained contains 0.01 to 5.0 percent by weight of an oxide of the alkaline earth metal only in triple points between the cubic boron nitride grains. The cubic boron nitride grains are densely bonded with each other.

Abstract: For the preparation of high purity glass powder having a mean particle size of .ltoreq.10 .mu.m, glass powder having a larger particle size up to 300 .mu.m is ground to the desired particle size in a stirred mill with glass grinding elements in the presence of a grinding liquid comprising water or preferably a mixture of at least 50% by weight of water and at least one water-soluble, oxygen-containing organic compound having 1 to 5 carbon atoms in the molecule, e.g., tert.-butyl alcohol; the ground slurry is then frozen, and the solvent is subsequently removed from the frozen slurry by freeze-drying. A resultant glass powder with a mean particle size d.sub.50 of 0.5 to 2 .mu.m is particularly suitable as a filler for synthetic resins in the dental sector.

Abstract: A process is disclosed for the production of high purity mullites. The process involves reacting a mixture of aluminum alkoxide and silicon alkoxide with an atomic ratio (weight) of Al/Si in the range of 2-7 in an aromatic hydrocarbon solvent at a temperature of 200.degree.-350.degree. C. and calcining the resulting reaction product at a temperature above 900.degree. C. The mullite product obtained finds wide application as a high temperature service structural material such as for automotive engines and turbines as well as a support for combustion catalyst.

Abstract: Inorganic fibers which have a silicon extraction of greater than about 0.02 wt % Si/day in physiological saline solutions. The fiber contains SiO.sub.2, MgO, CaO, and at least one of Al.sub.2 O.sub.3, ZrO.sub.2, TiO.sub.2, B.sub.2 O.sub.3, iron oxides, or mixtures thereof. Also disclosed are inorganic fibers which have diameters of less than 3.5 microns and which pass the ASTM E-119 two hour fire test when processed into a fiber blanket having a bulk density in the range of about 1.5 to 3 pcf.

Abstract: The present invention broadly relates to novel aluminum nitride matrix ceramic composite bodies for use as refractory materials and methods for making the same. The refractory materials are useful in environments which are corrosive, erosive, abrasive and/or which generate thermal shock. Such environments include furnaces, and associated apparatus which house or contact molten masses including, for example, molten metals, molten glasses, etc. The preferred method for making the aluminum nitride matrix ceramic composites comprises a directed oxidation of molten metal.

Abstract: Proposed is a novel composite material consisting of carbon as the matrix phase and particles of silicon carbide having an acicular or needle-like particle configuration uniformly and isotropically dispersed in the matrix phase as the reinforcing dispersed phase, in which the needle-like silicon carbide particles are formed by the in situ crystal growth from particles of .beta.-silicon carbide in a shaped body of a powder blend consisting of particles of carbon and the powder of .beta.-silicon carbide with further admixture of boron or a boron compound which promotes crystal growth of silicon carbide to have an acicular particle configuration.

Abstract: The ceramic composites consisting of sintered alumina comprising a polycrystalline alumina matrix having a grain size of from 0.5 to 10 .mu.m, and fine particles of TiB.sub.2 2 .mu.m or less in diameter being dispersed in the alumina grains, the composite alumina ceramic containing from 15 to 40% by volume of TiB.sub.2 ; or a ceramic composites comprising a polycrystalline alumina matrix as above, fine particles of TiB.sub.2, and fine particles of SiC, the fine particles of TiB.sub.2 and SiC being each 2 .mu.m or less in diameter and being dispersed in the alumina grains, the ceramic composites containing from 5 to 30% by volume of TiB.sub.2 and from 5 to 30% by volume of SiC.

Abstract: A storable cement-mortar dry mix, which comprises the components cement, aggregate, reaction resin and hardener in a single mixture, wherein the hardener is present as the reaction product of the hardener with an organic acid or a functional derivative thereof.

Abstract: A method of manufacturing metal alloys to obtain a homogeneous powder made up of oxides of the metals and applications thereof to the manufacture of semiconductors and superconductors comprises, after placing the various metals selected in a crucible, melting the metals in a neutral or reducing atmosphere while stirring the liquid to homogenize it, recovering the liquid alloy, spraying the alloy obtained to form homogeneous powder particles of determined particle size, and oxidizing the particles. It applies to the manufacture of zinc oxide-based varistor type semiconductor ceramics and to the manufacture of superconductor products or positive or negative temperature coefficient thermistors.

Abstract: Ultra-high-strength refractory silicon carbide fiber having a decomposition temperature of not less than about 1800K, a breaking strength of not less than about 5 GPa, and a modulus of elasticity of not less than about 300 GPa is disclosed, which is obtained by irradiating a precursor comprising organosilicon compound fiber with an ionizing radiation in a mixed carrier gas comprising a reactive gas and a first inert gas to render the precursor infusible and calcining the irradiated precursor in a second inert gas. Irradiation damage can be minimized, and no oxygen is incorporated into the fiber.

Abstract: Disclosed is a process for preparing sintered polycrystalline CBN/ceramic conjoint masses in an HP/HT process which comprises subjecting a mixture of GBN and one or more of a ceramic material or metal which reacts with BN to form a ceramic material, to HP/HT conditions for inducing conversion of said GBN to CBN, inducing conversion of any of said metal to its corresponding metal ceramic, and forming said CBN/ceramic conjoint mass.

Abstract: An infrared and ultraviolet radiation absorbing glass suitable for use in building and vehicle windows, which comprises, on a weight basis, 68-72% of SiO.sub.2, 1.6-3.0% of Al.sub.2 O.sub.3, 8.5-11.0% of CaO, 2.0-4.2% of MgO, 12.0-16.0% of Na.sub.2 O, 0.5-3.0% of K.sub.2 O, 0.03-0.30% of SO.sub.3, 0.58-0.80% of total iron expressed as Fe.sub.2 O.sub.3, 0.1-0.7% of CeO.sub.2, 0.1-0.4% of TiO.sub.2 and 5-350 ppm of MnO. In the glass the ratio of ferrous iron to ferric iron is in the range from 0.50 to 0.70. The glass has a greenish tint and is well balanced in visible light transmittance, infrared radiation absorption and ultraviolet radiation absorption, and a sheet of the glass can be easily tempered by a conventional method.

Abstract: A blue glass composition is disclosed. This blue glass composition is based on a standard formulation for soda/lime silica glass, except that neither the basic glass composition nor the coloring components therefor contains nickel. The blue glass color is developed by using coloring components consisting essentially of 0.3-0.6% Fe.sub.2 O.sub.3, 0.004-0.008% .[.Co.sub.3 O.sub.4 .]. .Iadd.Co, .Iaddend.and is a neutral blue having a dominant wavelength of 482 nm.+-.1 nm, color purity of 13%.+-.1% and transmission (T) equal to at least 54%.+-.1% using Illuminant C (corrected to 0.25 inch glass thickness).

Abstract: A blue glass composition comprises conventional soda-lime-silica glass ingredients and specific amounts of Fe.sub.2 O.sub.3, Co.sub.3 O.sub.4, NiO, and optionally Se, resulting in an Illuminant C transmittance of 54%.+-.3% at one quarter inch thickness, a dominant wavelength of 482 nm.+-.1 nm, and a color purity of 13%.+-.1%.