Abstract: An aluminum nitride sintered body is mainly composed of aluminum nitride, contains 0.01 to 1.0 percent by weight of a rare earth element and 0.001 to 0.5 percent by weight of oxygen, and has thermal conductivity of at least 180 W/mK. According to a method of manufacturing such an aluminum nitride sintered body, aluminum nitride powder (201) is first prepared. At least one compound (203) containing a rare earth element is added to the aluminum nitride powder (201) to contain 0.01 to 1.0 percent by weight, in rare earth element conversion, of the compound, to be homogeneously mixed with each other. A formed body obtained by forming such mixed powder is sintered in a non-oxidizing atmosphere containing nitrogen at a temperature of 1500 to 2200.degree. C.

Abstract: A defined and delaminated kaolin composition exhibiting high opacity is produced by defining and delaminating a base kaolin clay so as to reduce its colloidal content. The defined and delaminated kaolin composition may also be treated with hexamethylenediamine and aluminum sulfate to further enhance opacity. Whether treated or untreated, the defined and delaminated kaolin composition functions superiorly in paper coating formulations, alone or blended with known coating clays, improving the opacity, print gloss, sheet gloss and printability of paper sheet coated therewith.

Abstract: The invention provides a conductor comprising a reaction-sintered body of a conductive nitride produced from a powder of at least one metal selected from Ti, Zr, V, Nb, Ta, Cr, Ce, Co, Mn, Hf, W, Mo, Fe, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Yb, Lu, Th and Ni, and a process for producing such conductor by heating a molding containing a metal powder in a nitriding gaseous atmosphere containing no CO gas.

Abstract: A method for producing a self-supporting ceramic composite structure comprising a ceramic matrix embedding a filler, includes oxidizing a parent metal to form a polycrystalline material comprising the oxidation reaction product of the parent metal and, optionally, one or more metallic constituents. The method includes heating the parent metal to provide a source of molten parent metal and a reservoir of molten metal which is in communication with the parent metal and contacting the molten parent metal with a permeable bedding of filler. The molten parent metal reacts with the oxidant to form the oxidation reaction product and is replenished by the reservoir as the reacting continues for a time sufficient to grow the oxidation reaction product to a desired extent and thereby embed at least a portion of the bedding of filler within the oxidation reaction product to form the ceramic composite structure.

Abstract: The invention relates to novel polysilazanes, the preparation thereof, the further processing thereof to form silicon nitride-containing ceramic material, and this material itself. In order to prepare the polysilazanes, dialkylaminoorganyldichlorosilanes of the formula RSiCL.sub.2 --NR'R' are reacted with ammonia. The polysilazanes can then be pyrolyzed to form silicon nitride-containing ceramic material. The polysilazanes according to the invention dissolve in customary aprotic solvents.

Abstract: This invention relates to a method of producing enhanced strength portland cements. Under the process of this invention, certain portland cements, in particular those containing at least 4% C.sub.4 AF and up to 0.2% of a strength enhancing additive comprising triisopropanolamine, exhibit a marked increase in 7 and 28 day compressive strength. The triisopropanolamine strength enhancing additive may be admixed with cement powder or may be interground as a grinding aid with cement clinker during finish milling.

Abstract: An aqueous magnetic fluid composition comprising water as a dispersion medium and fine ferromagnetic particles as a dispersed phase, in which a coupling agent having a hydrophilic group and at least one hydrolyzable group is chemically bonded by way of the reaction product of the hydrolyzable group to the surface of the fine ferromagnetic particles. The magnetic fluid composition is prepared by way of obtaining an intermediate medium by chemically bonding the coupling agent by way of the hydrolysis product to the fine particles and separating fine particles of poor dispersibility and evaporating the composite product of the hydrolysis and at least a portion of water.

Abstract: A composition for use in manufacturing fire and heat resistant components, typically by moulding, comprises a mixture of foamed filler, a liquid binder and one or more frits. The composition may itself be moulded to form such components or may be included in other moulding systems to impart fire and heat resistant properties to a moulding.

Abstract: A body of sintered silicon nitride contains new non-glassy phases which produce significant X-ray diffraction peaks at 2-theta diffraction angles corresponding to d-spacings of about 2.86 Angstroms and 3.59 Angstroms and process for making same, which process includes (a) comminuting a slurry of a silicon-containing powder, water, about 0.1 to 5 volume percent of Fe.sub.2 O.sub.3, about 0.1 to 5 volume percent Al.sub.2 O.sub.3, and about 0.5 to 10 volume percent CeO.sub.2, wherein all volume percents are based on the volume of the resultant silicon nitride, the composition of the slurry being such that about a 4 to 12 volume percent liquid phase is achieved during sintering; (b) reducing the water content of the reacted slurry to form a dry mass; (c) nitriding the dry mass by exposure to a nitriding gas at an elevated temperature to form silicon nitride; and (d) sintering the silicon nitride at about 1450.degree.-2100.degree. C.

Abstract: A fiber-reinforced ceramic composite material reinforced by particle dispersion with improved fracture toughness comprised of a mullite matrix, and fibers and same or different kind of ceramic fine particles both dispersed within the mullite matrix is produced by a method comprising: dispersing mullite particles forming a matrix in a solution dissolving an organometallic macromolecular substance to prepare an impregnating solution, continuously passing fibers through said impregnating solution to uniformly impregnate the fibers with said impregnating solution, laminating said fibers to provide a laminated body, converting the organometallic macromolecular substance within said laminated body into a nonmeltable state, and performing sintering (or press sintering) of said laminated body in an inert gas and/or nitrogen gas. By press sintering K.sub.Ic of 10 MN/m.sub.3/2 or more is achieved.

Abstract: Lightweight, low density magnesia-based tundish refractory compositions containing from 0.01 to 2.00 weight percent styrofoam beads and up to 5.0 weight percent paper fiber are disclosed. The compositions have excellent rapid heating, thermal insulative, vertical adhesion and deskullability properties. The compositions are useful as a lining applied over the permanent lining of a tundish, such as is used in continuous molten metal casting processes.

Abstract: A tractable ceramic precursor and method for producing the same, capable of being formed into useful shapes at low temperatures and thereafter capable of transformation into high-temperature superconducting ceramics is provided. The method consists of preparing one or more organometallic compounds selected from organometallic clusters and organometallic polymers and combining them in the proper stoichiometric ratio to form a tractable ceramic precursor having rheological/viscoelastic properties suitable for forming useful shapes and having metal elements in suitable proportions to form high-temperature superconducting ceramics.

Abstract: This invention provides for a porous dielectric composition comprising at least one crystallized glass, at least one non-crystallized glass, and at least one Group IIA metal silicate, the porosity of said composition ranging from about 2% to about 50% by volume open space, the average diameter of the pore spaces in said composition ranging from about 1 to about 30 micrometers. The invention also provides for dielectric pastes and dieletric tapes for providing these dielectric compositions. The invention also provides for a process for making these dielectric compositions. These dielectric compositions are useful in making multilayered circuits, thick film circuits and other electronic components.

Abstract: A low-temperature curable composition is provided which is based upon a polyaromatic aldehyde group-containing compound and a ketiminized polyamino compound. These compositions display good stability, extended potlife, and a good balance of physical and mechanical properties making them suitable for a wide variety of coating, impregnating, sealing and bonding application.

Abstract: In the production of silicon carbide, a starting composition comprising silicon dioxide powder and a carbonaceous substance and having a bulk density of 0.2 to 2.0 g/cm.sup.3 is used, wherein the silicon dioxide is covered with the carbonaceous substance and uniformly dispersed therein. The starting composition is produced by forming a kneaded mixture of silicon dioxide and high molecular weight organic compound, heating the kneaded mixture to conduct carbonization and thereby form a composite body and then granulating the composite body into 3 to 25 mm sized granules.

Abstract: A method for rendering toxic waste harmless by mixing water, at least ground, granulated blast furnace slag as reagent and said waste to form a transportable fluid slurry which can be allowed to harden to a hard, rock-like material. The toxic waste appropriately consists of substances which do not react with the reagent. A hardening activator can be added to the slurry at an arbitrary point in time. The solids content of the slurry, based on water-insoluble substances, is preferably at least 50%.

Abstract: The invention relates to novel polymeric hydridosilazanes, processes for their preparation and their use for the preparation of ceramic material containing silicon nitride. To prepare the polymeric hydridosilazanes, polymeric hydridochlorosilazanes are reacted with NH.sub.3. To prepare the ceramic material containing silicon nitride, the polymeric hydridosilazanes are then pyrolyzed.

Abstract: A composition which comprises a solvent extract of peat or a pyrolysis product of peat or a montan wax and petroleum bitumen of the paving grade type.

Abstract: An improved solder/polymer fluxless composite paste interconnection material having a low reflow temperature to form electrical contacts having good bonding strength and low contact resistance. The present pastes comprise a major proportion of a meltable metal alloy powder filler, free of noble metals and preferably free of lead, a minor proportion of a solution of a temperature-stable thermoplastic polymer having a softening temperature above the melting temperature of the metal powder filler in a volatile solvent which evaporates during reflow, and a minor proportion of a fluxing agent having a boiling point lower than the reflow temperature of the composition and higher than the melting point of the eutectic alloy powder filler. An oxide-free, partially coalesced metal alloy connection is obtained, which is polymer strengthened and reworkable at a low reflow temperature, per se, or in the presence of polymer solvent.

Abstract: A process for preparing a nitridable silicon-containing material, which process includes (a) comminuting a slurry of silicon powder, water, at least one densification aid, including Al.sub.2 O.sub.3, and another densification aid, the comminuting performed to cause substantial chemical reaction between the silicon and the water; and (b) reducing the water content of the reacted slurry to form a dry mass. In another embodiment, at least one nitriding agent may be added to aid any nitridation which may be performed.