Abstract: A silicon nitride-ceramic is composed of a sintered body including silicon nitride and an additive, and has a columnar crystal of .beta. type silicon nitride substantially parallel to one plane. A method for manufacturing a silicon nitride-ceramic comprises the steps of forming first powder including a needle-shaped crystal of .beta. type silicon nitride by mixing the needle-shaped crystal of the .beta. type silicon nitride with second silicon nitride powder mainly of .alpha. type including an additive, or by heating the second silicon nitride powder at temperature 1500.degree. to 1750 .degree. C. in advance; and sintering the first powder at a predetermined temperature under non-oxidation atmosphere.

Abstract: This invention is directed to the production of glass-ceramic articles exhibiting an apparent annealing point in excess of 400.degree. C. and excellent resistance to moisture attack, the articles consisting essentially, in mole percent, of:______________________________________ Li.sub.2 O 5-25 ZnO 35-50 Na.sub.2 O 0-15 Al.sub.2 O.sub.3 0.75-6 K.sub.2 O 0-10 P.sub.2 O.sub.5 29-37. Li.sub.2 O + Na.sub.2 O + K.sub.

Abstract: Disclosed are an adhesive for oxide ceramics, which comprises as its effective ingredient a crystallized glass mainly comprising SiO.sub.2, Al.sub.2 O.sub.3, Li.sub.2 O, MgO and/or ZnO, and TiO.sub.2 and/or ZrO.sub.2, and also a method of bonding oxide ceramics together, which comprises heating oxide ceramics to be bonded together at 1200.degree. to 1600.degree. C. with the adhesive placed between the ceramics.

Abstract: Ion exchangeable glass compositions containing from 50 to 90 mole percent GeO.sub.2, from 5 to 30 mole percent Al.sub.2 O.sub.3, from 3 to 30 mole percent Li.sub.2 O, up to 30 mole percent Na.sub.2 O and up to 30 mole percent K.sub.2 O are provided. In another aspect, minor amounts of anhydrous fluorides and chlorides corresponding to these oxides are added to the glass compositions to aid in water removal. Glass articles formed of the germanate glass compositions of the present invention are readily ion exchangeable when contacted with certain salts. Strengthened germanate glass articles are also provided having an inner tension region and an outer compressive surface layer which provide good mechanical strength for the formed glass article. The strengthened germanate glass articles are made using the ion exchangeable germanate glass compositions of the present invention.

Abstract: An optical glass which is a P.sub.2 O.sub.5 system glass including ingredients selected from two groups of R.sub.2 O.sub.3 ingredients of specific contents have excellent resistivity to devitrification, homogeneity, light transmissivity and chemical durability.

Abstract: A sensitized laser glass which includes a primary lasing dopant and auxiliary dopants which absorb in regions of the flashlamp emission spectrum away from the absorption bans of the primary dopant and transfer the energy absorbed to the primary dopant, thus improving the efficiency and sensitivity of the laser glass. The auxiliary dopant comprises the combination of cerium and chromium as Ce.sub.2 O.sub.3 and Cr.sub.2 O.sub.3 and the primary dopant is a rare earth metal, preferably neodymium or erbium as Nd.sub.2 O.sub.3 or Er.sub.2 O.sub.3. Th auxiliary dopant consists essentially of 0.1 to 5% by weight Ce.sub.2 O.sub.3 and 0.025 to 0.1% by weight Cr.sub.2 O.sub.3, however the preferred concentration of the auxiliary dopant is 2 to 4% by weight Ce.sub.2 O.sub.3 plus 0.03 to 0.07% by weight Cr.sub.2 O.sub.3. The experimental data establishes that such auxiliary dopants are particularly suitable for phosphate laser glasses.

Abstract: The invention relates to a photosensitive and heat-sensitive glass which is composed of 25-70 mol % of Al.sub.2 O.sub.3 and/or Ga.sub.2 O.sub.3, 30-75 mol % of at least one of CaO, BaO, SrO and MgO and 0-40 mol % of an auxiliary component which is at least one of SiO.sub.2, GeO.sub.2, B.sub.2 O.sub.3 and P.sub.2 O.sub.5. The glass is produced by melting a batch mixture of powdery raw materials. By exposure to UV rays the glass colors in yellowish brown, and the color does not fade by termination of the exposure. Bleaching of the colored glass is accomplished by heating for a short time at about 150.degree.-300.degree. C. Coloration and bleaching can be repeated without deterioration. The same glass turns into an opaline foam glass, which presents a very attractive appearance, by heat treatment at a temperature above the softening temperature. This change is irreversible. The foams created in the glass matrix are usually tens of microns in diameter.

Abstract: A phosphate glass ceramic which can be utilized especially as biomaterial in medicine and biology. The object of the invention is to provide a glass ceramic extensively adapted to bone, possessing adjustable biologically active characteristics. Another object of the invention is to produce a glass ceramic free of SiO.sub.2 or low in SiO.sub.2, of high P.sub.2 O.sub.5 and CaO content, possessing adjustable biologically active characteristics. The object is solved, whereby an initial glass of the composition having the mass percentages of Al.sub.2 O.sub.3 3-21, CaO 8-26, R.sub.2 O 10-25, P.sub.2 O.sub.5 43-58, is provided under the condition that R.sub.2 O can contain up to 25% of mass of Na.sub.2 O and up to 18% of mass of K.sub.2 O, and is thermally treated after melting, to provide the new phosphate glass ceramic. The main crystal phases are apatite and aluminiumorthophosphate. The phosphate glass ceramic can contain additions of SiO.sub.2, B.sub.2 O.sub.3, F.sup.-, MgO, FeO, Fe.sub.2 O.sub.3, TiO.sub.2.

Abstract: A staining composition for use in manufacturing artificial tooth, etc. which is composed of Ca and P at their atomic ratio (Ca/P) in a range of from 0.05 to 0.33; and 5 to 28 mol % of Al.sub.2 O.sub.3.

Abstract: Dental materials using calcium phosphate glass-ceramics and having the color tone with high approximation to that of natural teeth. In those dental materials, calcium phosphate composite, nickel oxide and one or more other type of compounds selected from oxides of iron, manganese, cerium, titanium and tungsten, are contained as coloring component. Also, if necessary, Al.sub.2 O.sub.3 and/or SiO.sub.2 is contained as a color assisting agent in that composite. The calcium phosphate glass-ceramic according to this invention consists of the same components as that of natural teeth. Besides, it is possible to adjust the color tone delicately to match with the color tone of each individual`s teeth. Moreover, the coloring components are incorporated in crystals of calcium phosphate. Consequently, they cause no elution during use and are therefore ideal as dental material.

Abstract: Calcium phosphate type crystallizable glass for dental materials, which is composed essentially of from 41 to 49.5 mol % of CaO, from 50 to 58.5 mol % of P.sub.2 O.sub.5 and from 0.5 to 5 mol % of Al.sub.2 O.sub.3, and which has an atomic ratio of calcium to phosphorus (Ca/P) within a range of from 0.35 to 0.49.

Abstract: An optical CuO-bearing, alkali- and alkaline-earth rich phosphate glass with relatively high elongation (at 20.degree.-300.degree. C. from 110.times.10.sup.-7 grd.sup.-1 to 138.times.10.sup.-7 grd.sup.-1) and a transformation range .ltoreq.380.degree. C., with substantially improved transmission in the UV to blue range of the spectrum (UV-transmission at .lambda.=350 nm between .gtoreq.69% and .gtoreq.83%) and a very strong absorption in the red region of the spectrum (IR-absorption at .lambda.=700 nm between .ltoreq.2% and .ltoreq.12%), consisting essentially of the following synthesis/composition, in wt. %: P.sub.2 O.sub.5 65-70%; SiO.sub.2 0-0.75%; B.sub.2 O.sub.3 0-2%; A.sub.2 O.sub.3 2.5-6%; R.sub.2 O (alkali metal oxides) 11-17%; BaO 3-9.5%; CeO.sub.2 0.45-2.0%; CuO 2.55-6.55%; Cl.sup.- 0.15-0.75%; F.sup.- 0.25-1.50%; refining agent 0.10-2.00% with .SIGMA.CeO.sub.2 +Al.sub.2 O.sub.3 +BaO+CuO.gtoreq.8.5 and .SIGMA.R.sub.2 O=F.sup.- +Cl.sup.- .gtoreq.21.

Abstract: There are described a glass composition and a magnetic head containing the same, wherein the glass composition comprises an oxide of an alkali metal or alkaline earth, and at least one non-alkali metal oxide in an amount sufficient to provide a coefficient of thermal expansion of 80-170.times.10.sup.-7 .degree. C..sup.-1, the composition featuring from 5-15 mole % Al.sub.2 O.sub.3 and an amount of a compatible glass former sufficient to insure the Al.sub.2 O.sub.3 is soluble in the composition.

Abstract: A composite material for the controlled release of an active substrate comprises a relatively insoluble, e.g. polymeric, matrix (11) in which a soluble particulate material (12) is dispersed. When the composite is placed in an aqueous medium dissolution of the particulate material substantially increases the water permeability of the matrix. This effect may be used to provide for the controlled release of an active material into the aqueous medium.

Abstract: Phosphate neodymium glass for laser use, consisting of phosphoric anhydride, an oxide of at least one of alkaline metals, and neodymium oxide or a mixture of neodymium oxide and oxide of at least one of the following metals; La, Gd, Lu, Sc, Y, Al, Cr; the ratio between the above-cited components as follows (mol. %):______________________________________ phosphoric anhydride 64-77 oxide of at least one of alkaline metals 26-8 neodymium oxide or a mixture of neodymium 10-15 oxide with an oxide of at least one of the metals: Ln, Gd, Lu, Sc, Y, Al, Cr. ______________________________________The herein-proposed invention is intended for producing active elements for lasers of a wide purpose including thin-film and miniature lasers with generation wavelengths within the ranges 1.06 and 1.34.mu.. Phosphate neodymium glass for laser use of the developed composition can be synthesized in required amounts by a simple method.

Abstract: The chemical durability of alkali phosphate glasses is improved by incorporation of up to 23 weight percent of nitrogen. A typical phosphate glass contains: 10 to 60 mole % of Li.sub.2 O, Na.sub.2 O or K.sub.2 O; 5-40 mole % of BaO or CAO; 0-1 to 10 mole % of Al.sub.2 O.sub.3 ; and 40-70 mole % of P.sub.2 O.sub.5. Nitrides, such as AlN, are the favored additives.

Abstract: An optical glass comprising, in % by weight,18 to 38% P.sub.2 O.sub.5 ;3 to 30% Na.sub.2 O+K.sub.2 O,with the proviso of0 to 30% Na.sub.2 O and0 to 30% K.sub.2 O;8 to 65% PbO;1 to 45% Ta.sub.2 O.sub.5 ;0 to 20% Nb.sub.2 O.sub.5 ;0 to 15% TiO.sub.2 +WO.sub.3 ;0 to 25% BaO+CaO+ZnO+SrO+MgO,with the proviso of0 to 25% BaO,0 to 5% CaO,0 to 25% ZnO,0 to 20% SrO, and0 to 10% MgO;0 to 15% B.sub.2 O.sub.3 ;0 to 3% Li.sub.2 O;0 to 3% Al.sub.2 O.sub.3 ;0 to 3% ZrO.sub.2 ;0 to 3% Y.sub.2 O.sub.3 ;0 to 3% Gd.sub.2 O.sub.3 ; and0 to 3% La.sub.2 O.sub.3.

Abstract: Glasses consisting of 45-55 mol. % P.sub.2 O.sub.5, 15-40 mol. % BaO, 5-15 mol. % Li.sub.2 O, 5-35 mol. % PbO, 0-2 mol. % Al.sub.2 O.sub.3 and 0-6 mol. % F are suitable for the precision pressing of lenses.

Abstract: The present invention is directed to fluorophosphate glasses containing about 3-21.5% Nb.sub.2 O.sub.5 and exhibiting softening points below 500.degree. C. The inventive glasses contemplate two general composition areas in weight percent:______________________________________ P.sub.2 O.sub.5 35-46 P.sub.2 O.sub.5 20-35 Al.sub.2 O.sub.3 3.5-6.5 Li.sub.2 O 0.5-5 Li.sub.2 O 0.8-3.0 Na.sub.2 O 0-10 Na.sub.2 O 3-10 Li.sub.2 O + Na.sub.2 O 0.5-10 Li.sub.2 O + Na.sub.2 O 5-10.5 PbO 0-40 BaO 18-44 Sb.sub.2 O.sub.3 0-25 CaO 0-12 PbO + Sb.sub.2 O.sub.3 20-50 SrO 0-15 BaO 0-20 MgO 0-7 Al.sub.2 O.sub.3 0-5 BaO + CaO + SrO + MgO 28-47 Nb.sub.2 O.sub.5 13-21.5 CaO + SrO + MgO <15 F 1-12 Nb.sub.2 O.sub.5 3-8.5 F 4.

Abstract: A copper phosphate water soluble glass composition. The composition of the glass may be adjusted so as to release copper at a uniform preselected rate and to produce a desired pH in the resultant solution. In one application of the glass copper may be supplied to an animal from an implant formed from a cupric oxide/phosphorus pentoxide glass which also incorporates one or more glass modifying oxides such as alkali metal oxides and alumina, to control the glass solubility. Suitable glasses comprise 5-55 mole % cupric oxide + alkali metal oxides. 45-75 mole % phosphorus pentoxide, and not more than 15 mole % alumina, where the copper oxide concentration is not less than 5 mole %.

Abstract: Mercury thallium fluorophosphate glasses are disclosed that have very low transition temperatures, very high refractive indices and dielectric constants, and are resistant to moisture attack. The glasses are free of alkali metals and substitute thallium chloride in the glass batch as a modifier. The melted glass is largely oxide in nature, but the halogens appear to facilitate melting of these soft glasses.

Abstract: Optical components can be pressed with such a precision that grinding and polishing of the formed components is not necessary, from glasses containing 45-55 wt. % P.sub.2 O.sub.5, 3.5-9 wt. % Al.sub.2 O.sub.3, 5-20 wt. % K.sub.2 O, 0-3 wt. % Li.sub.2 O, 8-15% BaO, 4.5-9 wt. % ZnO, 0-6 wt. % MgO, 0-18 wt. % PbO, 0-1 wt. % SiO.sub.2, 0-3 wt. % B.sub.2 O.sub.3, 0-2 wt. % TiO.sub.2.

Abstract: Fluorophosphate optical glass has the following composition in percent by weight:(a) By metaphosphate raw material conversion:______________________________________ Al(PO.sub.3).sub.3 13.0-39.0 Mg(PO.sub.3).sub.2 0-24.0 Ca(PO.sub.3).sub.2 1.0-20.0 Ba(PO.sub.3).sub.2 5.0-19.0 ______________________________________(The total amount of metaphosphate raw materials is 31-49 percent by weight.)(b) By fluoride raw material conversion: ______________________________________ MgF.sub.2 2.0-13.0 SrF.sub.2 0-20.0 BaF.sub.2 1.0-33.0 AlF.sub.3 0-8.0 YF.sub.3 0-8.0 ______________________________________(The total amount of fluoride raw materials is 19-47 percent by weight.)(c) By oxide raw material conversion: ______________________________________ BaO 10.0-36.0 Y.sub.2 O.sub.3 and/or Yb.sub.2 O.sub.3 1.5-12.0 ZnO 0-6.0 PbO 0-29.0 Nb.sub.2 O.sub.5 0-22.0 ______________________________________(The total amount of oxide raw materials is 20-42 percent by weight.

Abstract: Phosphate glass compositions are described comprising from 8 to 35 wt % P.sub.2 O.sub.5, from 8 to 48 wt % SiO.sub.2 and GeO.sub.2, provided that the GeO content is not more than 6 wt %, from 3 to 18 wt % B.sub.2 O.sub.3, from 16 to 28 wt % Al.sub.2 O.sub.3, and from 8 to 33 wt % CaO, MgO, SrO, and BaO, provided that the sum of the MgO, SrO, and BaO contents is not more than 15 wt %, andwherein the sum of the above-described oxides comprises at least 88 wt % of the total composition and the ratio of the sum of the CaO, MgO, SrO and BaO contents to the P.sub.2 O.sub.5 content ranges from 0.6/1 to 1.

Abstract: Glass objects, lenses in particular, can be pressed with precision from a glass which contains 45-55 mol. % P.sub.2 O.sub.5, 15-40 mol. % BaO, 5-15 mol. % Li.sub.2 O, 5-35 mol. % PbO, 0-2 mol. % Al.sub.2 O.sub.3 and 0-6 mol. % F.

Abstract: Novel self-setting potassium-aluminum-phosphate compositions of matter are prepared by forming an aqueous slurry of a potassium source, an aluminum source and a phosphate source; mixing the slurry for a period of time sufficient to form a reactive, creamy mass having a viscosity of at least 2000 cps; and setting or curing the reactive creamy mass. The product is porous, can be foamed or nonfoamed, adheres well to substrates and when foamed, can be lightweight.

Abstract: A composition of matter for use as a vitreous fertilizer comprising a soluble vitreous constituent comprising the following ingredients: 35 to 55 moles %, P.sub.2 O.sub.5 ; less than 10 moles %, K.sub.2 O; and the balance to 100 moles %, CaO and/or MgO. The balance of the composition, if any, is constituted by optional additions of nutrient proportions of one or more micro-nutrients in plant assimilable form, and/or optional additions of one or more plant-inert filler materials. Such compositions have favorable nutrient release rates. The invention also encompasses compositions of matter adapted for use as a plant fertilizer which comprises soluble vitreous plant nutrient release material in expanded or cellular form, and to methods of plant cultivation using such compositions.

Abstract: A phosphate laser glass in which the optical path length is substantially independent of temperature, or "athermal", particularly under rapid pulsing, and chemically stable, while providing high gain. The base glass composition comprises, in mole percent, 55 to 70% P.sub.2 O.sub.5, 3 to 15% of an alkali metal oxide, preferably Li.sub.2 O plus K.sub.2 O, 20 to 30% BaO and 0.5 to 5% Al.sub.2 O.sub.3. Up to 15% of the BaO may be replaced by CaO, SrO or MgO and part of the Al.sub.2 O.sub.3 may be replaced by Nd.sub.2 O.sub.3. The total Al.sub.2 O.sub.3 plus Nd.sub.2 O.sub.3 is 4 mole percent .+-.1.5%. The laser glass composition also includes a laseable component, preferably Nd.sub.2 O.sub.3 and preferably includes a solarization inhibitor.

Abstract: Sealing materials for making heat-resistant seals in electrical discharge devices comprise a rare earth oxide, such as lanthanum oxide, and boric oxide, preferably together with minor amounts of phosphorus pentoxide, aluminium oxide and magnesium oxide. Preferred compositions comprise 55 to 95% lanthanum or other oxide, 5 to 45% boric oxide and 0 to 5% phosphorus pentoxide, 0 to 5% aluminium oxide and 0 to 5% magnesium oxide. The compositions can be made by mixing the oxides, or appropriate salts, calcining the mixture at up to 1200.degree. C. and crushing it to a powder. They may be used as frits in a slurry or formed into pressed elements such as discs or washers. Sealing can be accomplished by heating the surfaces to be joined, together with the interposed sealing composition, to a temperature between 1100.degree. and 1650.degree. C.

Abstract: A near infrared absorption filter for color television cameras, comprising(a) a base glass comprising, in % by weight based on the weight of the base glass, 50-78% P.sub.2 O.sub.5, 10-50% BaO, 0-7% Al.sub.2 O.sub.3, 0-6% B.sub.2 O.sub.3, 0-5% SiO.sub.2, 0-8% Li.sub.2 O, 0-15% Na.sub.2 O, 0-18% K.sub.2 O, 0-5% MgO, 0-10% CaO, 0-15% SrO, 0-10% ZnO, and 0-10% PbO, and(b) about 0.5 to about 2.5% by weight of CuO based on the weight of the base glass.