Abstract: This invention relates to the production of improved high density nitrogen based ceramics by liquid-phase densification of silicon nitride or a compound of silicon-nitrogen-oxygen-metal, e.g. a sialon. In the process and compositions of the invention minor amounts of finely divided silicon are employed together with the conventional liquid phase producing additives to enhance the densification of the resultant ceramic.

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

Abstract: A ceramic composed of 1 to 15 percent of glass and 99 to 85 percent of a mixture of particulates is disclosed. The glass, present as a vitreous phase bonding the particulates into a dense, gas impervious structure, contains 45 to 80 percent of SiO.sub.2, 8 to 65 percent of CaO and MgO and not more than 15 percent of Al.sub.2 O.sub.3. The particulates, which are finer than 15 microns in ultimate particle size, include Al.sub.2 O.sub.3 and at least one of ZrO.sub.2, HfO.sub.2 and solid solutions of the two. The ceramics are subject to microcracking, which can be cured by refiring, or prevented by including particulate Y.sub.2 O.sub.3 as a stabilizer.

Abstract: The components, of a microwave circuit, such as a filter, and a solid oscillator, etc. consists of a dielectric ceramic composition. A known BaO-TiO.sub.2 compound exhibits properties which make it suitable for use as the components of a microwave circuit but the resonance frequency linearity and the resonance frequency temperature coefficient are not excellent. The dielectric ceramic composition of the present invention is expressed by the formula of BaO.x{(1-y)TiO.sub.2.ySnO.sub.2 }, wherein x is 4.4 moles and y is from 0.06 to 0.09 mole, and has a mixed crystal structure of Ba(Ti.Sn).sub.4 O.sub.9 and Ba.sub.2 (Ti.Sn).sub.9 O.sub.20.

Abstract: Sialon-base ceramic materials having both high hardness and good sinterability and can show excellent wear resistance when used in cutting tools and other wear-resisting tools. A Sialon-base ceramic material according to the invention has main components consisting of .beta.-Sialon expressed by a chemical formula Si.sub.6-z Al.sub.z O.sub.z N.sub.8-z, z being larger than 0 but not more than 4.3, and .alpha.-Sialon expressed by a chemical formula M.sub.x (Si, Al).sub.12 (O,N).sub.16, x being larger than 0 but not more than 2, M representing at least one selected from the group consisting of Li, Na, Ca, Mg, Y, and any rare earth element, the ratio of the .alpha.-Sialon/the .beta.-Sialon being within a range from 25/75 to 95/5 in volume.

Abstract: This invention relates to implantable porous prostheses for use as bone or hard tissue replacements anywhere in the body. The porous implants comprise loose, individual polymeric particles of a specified size, coated with a hydrophilic material and barium sulfate particles. The prostheses are biologically compatible in the body and promote bone and tissue ingrowth and attachment. This invention also relates to a method for producing the novel prosthetic devices disclosed herein.

Abstract: A process for producing a polycrystalline aluminum nitride ceramic body having a composition defined and encompassed by line ABCDEFA but not including lines CD and EF of FIG. 1, a porosity of less than about 10% by volume of said body and a thermal conductivity greater than 1.0 W/cm.multidot.K at 22.degree. C. which comprises forming a mixture comprised of aluminum nitride powder and an yttrium additive selected from the group consisting of yttrium, yttrium hydride, yttrium nitride and mixtures thereof, said aluminum nitride and yttrium additive having a predetermined oxygen content, said mixture having a composition wherein the equivalent % of yttrium, aluminum, nitrogen and oxygen is defined and encompassed by line ABCDEFA but not including lines CD and EF in FIG. 1, shaping said mixture into a compact and sintering said compact at a temperature ranging from about 1850.degree. C. to about 2170.degree. C.

Abstract: A method for manufacturing the insulating layers of a glass multilayer wiring board from a mixture of (1) 30-90 wt. % of a borosilicate glass consisting of 55-75 wt. % of SiO.sub.2, 13-25 wt. % of B.sub.2 O.sub.3, 5-13 wt. % of Al.sub.2 O.sub.3, each 1-5 wt. % of PbO, MgO, and BaO, and each 1-2 wt. % of Na.sub.2 O and K.sub.2 O and (2) 70-10 wt. % of a silica glass, is provided.

Abstract: A process is disclosed for preparing R.sub.3 SiNH-containing hydrosilazane polymer by contacting and reacting trichlorosilane with a disilazane (R.sub.3 Si).sub.2 NH where R is vinyl, hydrogen, phenyl, or alkyl radicals containing 1 to 3 carbon atoms. These hydrosilazane polymers are useful, when fired at high temperatures, in the formation of silicon nitride and silicon nitride-containing ceramic materials.

Abstract: Uniform-size, high-purity, spherical oxide powders are formed by hydrolysis of alkoxide precursors in dilute alcoholic solutions. Under controlled conditions (concentrations of 0.03 to 0.2 M alkoxide and 0.2 to 1.5 M water, for example) oxide particles on the order of about 0.05 to 0.7 micron can be produced. Methods of doping such powders and forming sinterable compacts are also disclosed.

Abstract: A spray powder for the manufacture of wear resistant and temperature resistant coatings, the powder comprising 50 to 90 weight percent aluminum oxide (Al.sub.2 O.sub.3) and 5 to 40 weight percent titanium dioxide (TiO.sub.2) with additives in the form of 5 to 30 weight percent lanthanum oxide (La.sub.2 O.sub.3) and/or niobium oxide (Nb.sub.2 O.sub.5), possibly together with 30 weight percent calcium carbonate (CaCO.sub.3).

Abstract: A zirconium oxide sintered body for an oxygen concentration sensor is produced by mixing 87.5 to 91.0% by weight of zirconium oxide powder, 8.5 to 12.3% by weight of yttrium oxide powder, 0.5% by weight or less of silicon oxide and 0.2 to 1.0% by weight of aluminum oxide, drying the resulting mixture, followed by sintering so as to make the cubic phase content in crystal phase of the resulting sintered body at ordinary temperatures 95% by weight or more. Said zirconium oxide sintered body is excellent in mechanical strength, thermal shock and ionic conductivity and can be used stably for a long period of time.

Abstract: A glass composition for covering a semiconductor element. The glass composition has excellent resistance to chemicals and excellent electric characteristics. The glass composition includes 3 to 8% by weight of Al.sub.2 O.sub.3, 35 to 45% by weight of SiO.sub.2, 10 to 30% by weight of ZnO, 5 to 30% by weight of PbO, 1 to 10% by weight of B.sub.2 O.sub.3, and more than 5% but not exceeding 20% by weight of an alkaline earth metal oxide selected from the group consisting of MgO, CaO, SrO and BaO, where the maximum contents of MgO, CaO, SrO and BaO are 7% by weight, 3% by weight, 7% by weight, and 15% by weight, respectively.

Abstract: Thin, flaky graphite-containing refractories are obtained by refining and processing naturally occurring minerals and possess a specific size of the extent of the surface of a flaky layer and a specific thickness of a flake. Such flaky graphite-containing refractories exhibit high endurance and are effective as lining materials particularly for steel making furnaces.

Abstract: The invention is directed to a barium borosilicate glass which is free of Bi, Cd and Pb. The glass, which also contains small amounts of NiO, is especially useful as a binder for thick film resistor compositions to be used for making low end resistors.

Abstract: A process for preparing a particulate ceramic material comprising the steps of:(a) adding carbon dioxide or an aqueous solution of a soluble carbonate to first aqueous solution of a nitrate or chloride of Ba, Sr, Ca or Mg in a first vessel to adjust the pH of said first aqueous solution to between 7 and 10 thereby forming a carbonate precipitate;(b) adding an aqueous solution of a soluble hydroxide to a second aqueous solution of a nitrate or chloride of Ti, Zr, Sn or Pb in a second vessel to adjust the pH of said second aqueous solution to between 7 and 10 thereby forming a hydroxide precipitate;(c) combining slurries containing the precipitates formed in said first and second vessels;(d) mixing the combined slurries;(e) passing the slurries through a filter;(f) washing the filter cake with water;(g) drying the filter cake to form a powder;(h) calcining the dried powder; and(i) grinding the calcined powder.

Abstract: Glass frit compositions are shown that are lead-free, cadmium-free, and zinc-free, the compositions having improved chemical resistance, especially acid resistance (acetic acid) of a loss of generally less than about 1.9% by weight. The compositions contain B.sub.2 O.sub.3, SiO.sub.2, ZrO.sub.2 and rare earth oxides, the weight ratio of ZrO.sub.2 to rare earth oxides being critical and being about 1/1 to 1.4/1.

Abstract: Novel halide glass-forming compositions in the CdF.sub.2 -AlF.sub.3 -PbF.sub.2 and CdF.sub.2 -AlF.sub.3 -PbF.sub.2 -LiF composition fields are disclosed which exhibit unusual glass stability. The constituents of these glasses are potentially vapor transportable, so that very pure glass articles exhibiting excellent infrared transparency can be envisioned.

Abstract: A sealing composition suitable for sealing alumina packages for integrated circuits at a temperature below about 450.degree. C. for a short time of about 10 minutes. The composition is a mixture of 50-80 wt. % vitreous solder glass powder of PbO-B.sub.2 O.sub.3 system having a deformation point of 350.degree. C. or less, 1-35 wt. % first ceramic powder and 1-45 wt. % second ceramic powder. The total amount of the first and second ceramic powders is 20-50 wt. %. The first ceramic comprises 68-75 wt. % ZnO, 23-28 wt. % SiO.sub.2 and 0-8 wt. % Al.sub.2 O.sub.3, and the second ceramic comprises 98-99.9 wt. % SnO.sub.2 and 0.1-2 wt. % ZnO.

Abstract: The invention is directed to a barium borosilicate glass which is free of Bi, Cd and Pb. The glass, which also contains small amounts of CoO, is especially useful as a binder for thick film resistor compositions to be used for making high-end resistors.