Abstract: A process for producing unagglomerated single crystals of aluminum nitride having a size of at least 10 microns suitable for the reinforcement of metal and ceramic matrix composite materials. The process involves reacting alumina (or a precursor) with carbon under an atmosphere of nitrogen (or a precursor such as ammonia or an amine) at a temperature in the range of 1800.degree.-1950.degree. C. in the presence of an alkaki metal oxide (or precursor such as a carbonate) as a crystal growth promoter or catalyst. The alkali metal oxide is present in an amount required for the formation of crystals of the required size, preferably in the range of 10-60 microns. Particularly desirable crystals are produced if electrostatic precipitator dust is used as a source of the alumina, if petroleum coke or calcined anthracite coal is used as a source of the carbon and if the reaction is carried out in the presence of a porosity enhancer for the reaction mass, especially short cellulose fibres.

Abstract: An improved thickening agent suitable for paper coating applications is a fluid suspension of 35 to 55 parts CMC or similar water soluble polymer in 40 to 55 parts fatty acid with 1 to 5 parts clay and up to 20 parts emulsifier. Handling convenience and thickening performance are improved.

Abstract: A crystalline composition having an X-ray diffraction pattern essentially the same as the high cristobalite form of silica comprising SiO.sub.2, Al.sub.2 O.sub.3 and a metal oxide (Me.sub.x O) in which Me is selected from Na, Ca, Sr and mixtures thereof.

Abstract: Disclosed is a sintered silicon carbide body with a high thermal conductivity which has a thermal conductivity of not less than 150 W/m.multidot.K, which is produced by(a) mixing(1) a first silicon carbide powder having a mean grain size of from 0.1 to 10 .mu.m with(2) a second silicon carbide powder having a mean grain size of not greater than 0.1 .mu.m prepared by(2-1) introducing a starting gas composed of a silane compound or silicon halide and a hydrocarbon into a plasma of a non-oxidative atmosphere, and(2-2) conducting gas phase reaction between the silane compound or silicon halide and the hydrocarbon while controlling the pressure of the reaction system within the range of from less than 1 atom to 0.1 torr, and(3) optionally, a carbon powder which is required for reducing oxides contained in both the first and second silicon carbide powders,(b) optioanlly reducing the oxides with the carbon, and(c) heating the resulting mixture for sintering. Also, processes of producing the same are disclosed.

Abstract: A coating composition for forming an inorganic film on a glass, ceramic metal or plastic surface is obtained by hydrolyzing and condensing a metal alkoxide of the general formula:M(OR).sub.nwherein M represents a metal atom, R represents an alkyl group having 1 to 5 carbon atoms, and n represents the valence number of M in an organic solvent in the presence of an aluminum salt; and adding a deposition inhibitor which prevents the separation of the aluminum salt when a film is formed. A process for preparing the composition is also disclosed.

Abstract: Prepare a self-reinforced silicon nitride ceramic body of high fracture toughness by hot-pressing a powder mixture containing silicon nitride and three other components under conditions such that densification and the in situ formation of .beta.-silicon nitride whiskers having a high aspect ratio occur. The other components are silicon dioxide as a densification aid, a conversion aid such as yttrium oxide and a compound, such as calcium oxide, which enhances growth of .beta.-silicon nitride whiskers. The resultant silicon nitride ceramic has a .beta.-silicon nitride cyrstalline phase, at least 20 volume percent of which is in the form of whiskers or elongated grains having an average aspect ratio of at least about 2.5, and a glassy second phase. The glassy phase contains the silicon dioxide, the conversion aid and the compound which enhances growth of .beta.-silicon nitride whiskers. The glassy phase may also include a minor amount of aluminum nitride or boron nitride.

Abstract: A ceramic-making composition comprising at least one starting powder selected from the group consisting of powders of metals, powders of metal oxides, powders of metal carbides, powders of metal nitrides and powders of metal borides, and a synthetic resin binder. To enhance plastic moldability such as injection moldability and extrusion moldability and facilitate dewaxing, a polyalkylene carbonate is used as the synthetic resin binder.

Abstract: Inks comprising, by weight, from about 4% to about 10% formamide, from about 1% to about 10% dye, and the balance water when printed on paper from an ink-jet printer have improved resistance to bleed, especially when printed at a rate up to about 3.7 kHz.

Abstract: A powdered admixture of a metal and its boron, carbon, nitrogen or silicon derivative is, when subjected to densification conditions, partially reacted and converted to a hard, wear resistant material. Such a material, when formed from an admixture of tungsten carbide and tungsten, contains tungsten monocarbide and (di-tungsten) carbide. Other choices of metal and metal derivatives produce at least one compound having a stoichiometry which differs from that of starting metal derivative. Articles formed from this material can be useful as, for example, nozzles in abrasive or nonabrasive waterjet cutting machines and various parts of wire drawing apparatus.

Abstract: Disclosed is a high-strength alumina sintered body which consists of 1 to 30% by weight, based on Al.sub.2 O.sub.3 and ZrO.sub.2, of ZrO.sub.2 and 99 to 70% by weight, based on Al.sub.2 O.sub.3 and ZrO.sub.2, of Al.sub.2 O.sub.3, and unavoidable impurities, said sintered body having a peak based on ZrO.sub.2 at a position of a wave body having a peak based on ZrO.sub.2 at a position of a wave number of 600.+-.10 cm.sup.-1 in a measurement chart of the laser Raman spectrum analysis. This sintered body has a high flexural strength and a high breaking toughness in combination.

Abstract: Low-expansion devitrifying glass compositions exhibiting a negative-slope temperature coefficient of expansion over a temperature range from about 125.degree. C. to about 500.degree. C. are useful for the fabrication of thick film copper via-fill inks for multilayer printed-circuit boards.

Abstract: A coated abrasive product comprising a backing bearing on at least one major surface thereof a make coat, a multiplicity of erodable agglomerates comprising a resinous binder and at least one inorganic filler material adhered to said make coat, a multiplicity of individual premium abrasive grains adhered to said make coat and disposed between said erodable agglomerates, a multiplicity of individual premium abrasive grains overlying said erodable agglomerates, and a size coat overlying said individual premium abrasive grains, said erodable agglomerates, and said make coat. The coated abrasive products of this invention abrade faster and endure longer than coated abrasive products using individual conventional abrasive grains in place of erodable agglomerates.

Abstract: Macromonomeric (meth-)acrylate esters, having fluoroalkyl groups are disclosed. The esters have the general formula ##STR1## wherein R.sup.1 is the same or different and represents a hydrogen or fluorine groupR.sup.2 is the same or different and represents a hydrogen or methyl group,a has a value of 0, 1, 2, 3 or 4,c has a value of 2, 3 or 4,b has an average value of 2 to 30n has an average value of 4 to 12 andm has an average value of 3 to 14.The products can be used in dentistry, preferably as relining material for dental prostheses. The esters have a lower solubility and a higher mechanical strength when cured and adhere to already cured poly(methyl methacrylate).

Abstract: The present invention discloses a process for producing a formed carbon products which comprises the steps of mixing a pitch or a pitch precursor and at least one kind of polymer becoming compatible with the pitch or the pitch precursor by heat-treating and having an aromatic ring and at least one sulfur, oxygen or nitrogen atom in its repeating unit; of heat-treating the mixture to convert it to a raw material pitch and thereafter of at least forming, infusibilizing and carbonizing and which succeeded to simplify a production apparatus and to reduce an energy comsumption by reducing an infusibilizing time without deteriorating physical properties of the carbon products.

Abstract: An electronic package comprising dielectric layers including a densified aluminum nitride (AlN) base layer and at least one densified AlN-borosilicate glass composite layer bonded thereto is described. Any of the dielectric layers may be metallized with conductive circuit patterns and can contain conductive vias. Production of this package is accomplished by hot pressing a greenware laminate comprising a densified base (e.g., AlN); at least one green sinterable sheet (e.g., AlN-borosilicate glass composite); and a green sheet of non-sinterable material (e.g., boron nitride [BN]). The respective green sheets comprise homogeneous mixtures of the ceramic powders and a binder, e.g., polyethylene. The polyethylene is burnt off during the hot press operation. Residual BN is removed by brushing and/or grit blasting, leaving the finished electronic package, all ceramic elements of which are densified. The package provides superior thermal conductivity, strength, dielectric properties, and silicon-compatibility.

Abstract: An improved abrasive product such as a grinding wheel is disclosed. The abrasive product contains an active filler mixture of tin, FeS.sub.2, and K.sub.2 SO.sub.4, which mixture improves the grinding quality and versatility of the abrasive product.

Abstract: Sinterable raw material product for ceramics based on aluminum titanate, consisting essentially of particles having a core/shell structure with a core of an oxide, oxide hydrate or hydroxide of ether of aluminum or titanium on which are precipitated, as a shell, sparingly soluble compounds of the other aluminum or titanium not used as the core matrial, with the molar ratio of titanium to aluminum of from 1:0.1 to 1:30, which in addition to the precipitated compounds of aluminum or titanium contains additional sparingly soluble compounds of elements in a quantity of from 0.1 to 65% by weight, calculated as oxide of the element and based on the total quantity are useful in fabricating sintered bodies for high temperature environments which include internal combustion engine parts, tubes for transporting liquid metals, catalysts carriers and so forth.

Abstract: A ceramic cutting insert including whiskers for chip forming machining of steel and having improved mechanical, thermal and wear properties. The insert comprises an oxide based matrix and 5-50% by volume, preferably 10-40% by volume, of homogeneously dispersed whiskers of a solid solution of nitride and oxide of aluminum, preferably of the cubic aluminum oxynitride spinel (AlON). A part of the whiskers constituent may be replaced by whiskers of silicon carbide. The properties of the composite material can be further modified by coating the whisker material with thin layers. The whisker reinforced cutting material shows an improved toughness behavior compared to non-whisker containing ceramic materials.

Abstract: Fiber-reinforced ceramic matrix composite products are made by providing inorganic fiber reinforcement materials with pyrolytic carbon coatings, combining the carbon-coated fibers with a selected ceramic matrix material to make a composite preform, and consolidating the preform with heat and pressure to form the fiber-reinforced composite. Preferably, the peak consolidation temperature of the composite is moderated, with the retained pyrolytic carbon coating acting to preserve tough fracture behavior in the composite product notwithstanding the absence of the conventional graphitic fiber interface layer therefrom.

Abstract: A process for producing a dielectric ceramic comprising a firing step comprises the substeps of heating a calcined product rapidly up to a temperature of from 1,500.degree. to 1,700.degree. C. and thereafter sintering the product at the temperature, and heating the product thus heat-treated through said first heat-treating substep at about 1,200.degree. C. to 1,600.degree. C. for not less than 10 minutes. It is possible to prepare a dielectric ceramic with a desired temperature properties of the resonant frequency.