Abstract: A dielectric ceramic composition for high-frequency applications comprising a composite oxide containing at least Ba, Zn and W as metal elements. When the composition formula of the composite oxide is expressed in the form of molar ratios of the metal oxides, the molar ratios of the metal oxides lie within particular ranges. The ceramic composition exhibits a high dielectric constant and a large Q-value in high-frequency regions.

Abstract: Novel aluminum phosphates, in particular amorphous aluminum phosphate powders having a BET specific surface no greater than 25 m.sup.2 /g, well suited as binders/hardeners or for the production of ceramic shaped articles, are prepared by reacting at least one aluminum compound, e.g., an aluminum oxide, hydroxide or oxyhydroxide, with phosphoric acid or an aluminum phosphate, e.g., an acid aluminum orthophosphate, in a liquid reaction medium devoid of inorganic acid anions other than of phosphoric acid, and then spray- or freeze-drying the suspension thus obtained.

Abstract: The present invention relates to a material for the purification of fluids. More particularly, the present invention relates to a material for flocculating and separating organic substances or surface active agents contained in waste water.

Abstract: A method for the preparation of a carbonated hydroxyapatite composition which has a density of at least 95% of the theoretical density, which method comprises sintering at substantially atmosphere pressure a green carbonated hydroxyapatite composition containing up to 20% by weight of CO.sub.3.sup.2- ions and having a green density of from 25 to 60% of the theoretical density at a temperature in the range of from 750.degree. to 1450.degree. C. in carbon dioxide containing from 0.001 to 0.10 grams of water per liter of gas, the sintering temperature being selected within the above range and the green composition being sintered for a period of time sufficient to cause the green composition to densify to at least 95% of the theoretical density.

Abstract: A slurry for joining metallic or ceramic surfaces or for coating metallic or ceramic and refractory surfaces, comprising a liquid suspending medium and at least two constituents in particulate form suspended in the medium, the constituents being so selected and proportioned as to undergo combustion synthesis when ignited. A method for coating or joining metallic or ceramic surfaces comprises applying such a slurry to a surface to be coated or to surfaces to be joined, and igniting the slurry to cause combustion synthesis.

Abstract: A method for producing a high solids content, low viscosity ceramic slurry composition comprises turbomilling a dispersion of a ceramic powder in a liquid to form a slurry having a viscosity less than 100 centipoise and a solids content equal to or greater than 48 volume percent.

Abstract: Ceramic materials which exhibit stability in severely-corrosive environments having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200.degree.-550.degree. C. or organic salt (including SO.sub.2 and SO.sub.2 Cl.sub.2) at temperatures of 25.degree.-200.degree. C. These sulfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components.

Abstract: An apparatus provides high temperature and short residence time conditions for the production of nanoscale ceramic powders. The apparatus includes a confinement structure having a multiple inclined surfaces for confining flame located between the surfaces so as to define a flame zone. A burner system employs one or more burners to provide flame to the flame zone. Each burner is located in the flame zone in close proximity to at least one of the inclined surfaces. A delivery system disposed adjacent the flame zone delivers an aerosol, comprising an organic or carbonaceous carrier material and a ceramic precursor, to the flame zone to expose the aerosol to a temperature sufficient to induce combustion of the carrier material and vaporization and nucleation, or diffusion and oxidation, of the ceramic precursor to form pure, crystalline, narrow size distribution, nanophase ceramic particles.

Abstract: Brazed structures are disassembled with little or no physical damage to the components by coating the brazed joints with a powdered wicking agent, preferably mixed with a fugitive liquid binder to form an adherent slurry, then heating the joint to allow the brazing alloy to melt and be drawn into the powdered wicking agent by capillary action. After cooling, the powder and braze alloy are mixed together to form a loosely consolidated mass which can be readily removed by mechanical and/or chemical means so that the components can then be separated for repair or reuse.

Abstract: Aggregates, matrices, and composites exhibiting enhanced structural characteristics, together with methods and apparatuses for their manufacture, are disclosed. Many of these embodiments rely on three dimensional reticulation to enhance material property features, such as fracture toughness and resistance to thermal shock.

Abstract: A process for the preparation of a hydroxyapatite, which is suitable as a tooth-cleaning substance, by precipitation from aqueous phosphoric acid and calcium hydroxide solution, in which a calcium-doped phosphoric acid solution is fed to an intensive mixer with a suspension of calcium hydroxide/oxide in a molar ratio of Ca:P=1.667 corresponding to the hydroxyapatite of and reacted there at precipitation temperatures of 60.degree.-100.degree. C., preferably 80.degree.-90.degree. C. and a pH of 4-8, preferably of 6.5-7.5. Also disclosed in a tooth-cleaning substance containing the hydroxyapatite.

Abstract: The present invention relates to a material for the purification of fluids. More particularly, the present invention relates to a material for flocculating and separating organic substances or surface active agents contained in waste water.

Abstract: Polymers of 2,2-disubstituted-3-hydroxypropionic acid, e.g., polymers of .beta.-propiolactone, are employed in ceramic compositions as binders or dispersing agents.

Abstract: Submicron sized ceramic particles are produced by combining a ceramic precursor with an organic or carbonaceous carrier material, and exposing droplets of the mixture to a temperature sufficient to cause combustion of the organic material and subsequent vaporization and nucleation, or diffusion and oxidation, of the ceramic precursor to form pure, crystalline, uniform nanophase ceramic particles.

Abstract: This invention offers a unique method to fabricate unique, straight, curved, or coiled tubes as small as 5 nanometers in diameter with wall thicknesses starting at about 1 nanometer. These tubes can be made from many materials such as polymers, ceramics and metals that can be applied to a surface of carbon, glass, or other tube forming fibers and then made to withstand the environment used to remove the fiber.

Abstract: A feed material which is a mixture of chemically reduced lunar ilmenite and lunar agglutinates having a particle size in the range of 20-200 microns produced by hydrogen reduction in a fine particulate state is compacted into a shape and sintered to produce structural, radiation shielding construction blocks or bricks.

Abstract: A calcium tertiary phosphate is used as a carrier, and the carrier is caused to carry silver and zinc. The result is an antibacterial ceramic exhibiting an ultra high degree of whiteness and suppressed discoloration. This material may be heat fired at a temperature above 960.degree. C. to obtain a further improvement.

Abstract: The materials for living hard tissue replacements of the present invention comprise a ceramic material which contain Cao and SiO.sub.2 as essential components, and MgO as an optional components, are substantially free from calcium phosphate and are capable of forming a compound based on calcium phosphate by contact with an aqueous solution containing phosphorus, and show high biological affinity.

Abstract: A superhard form of boron suboxide comprises at least about 95% by weight B.sub.6 O and has a KNH.sub.100 value of at least about 3800 kg/mm.sup.2. In a preferred embodiment, the boron suboxide has an average grain size of about 0.1-40 microns. A method for forming the superhard boron suboxide comprises mixing boron oxide (B.sub.2 O.sub.3) and boron powder and subjecting the mixture to a temperature of 1500.degree. C. to about 2,200.degree. C. and a pressure sufficient to produce the superhard boron suboxide. The superhard boron suboxide may be made by this method with or without a sintering aid being present in the mixture of boron and boron oxide.

Abstract: Ceramic abrasive grits are formed by an impregnation process that involves preparing an alumina hydrate sol, drying the sol to form a porous solid, crushing the solid to produce particles, calcining the dried particles, preparing a mixture of an additive metal oxide or its precursor in a liquid vehicle, impregnating the mixture into the calcined particles, drying the impregnated particles, calcining the dried impregnated particles, and firing the particles to produce ceramic abrasive grits. The concentration of the modifying additive metal is greater at or near the surface of the grit than at the interior of the grit.

Abstract: The present invention relates to a method to manufacture a composite ceramic material having a high strength combined with bioactive properties, when the material is used as a dental or orthopedic implant, which includes preparing a powder mixture, mainly comprising partly a first powder, which in its used chemical state will constitute a bioinert matrix in the finished material , and partly a second powder, mainly comprising a calcium phosphate-based material. The invention is characterized in that said first powder comprises at least one of the oxides belonging to the group consisting of titanium dioxide (TiO.sub.2), zirconium oxide (ZrO.sub.2) and aluminum oxide (Al.sub.2 O.sub.

Abstract: A new surgical cement is disclosed. This surgical cement comprises a hardened cement formed from a mixture comprising a cementing component selected from the group consisting of calcium components having a solubility in water at 25.degree. C. in the range of about 0.5 .times. 10.sup.-2 M to about 20 .times. 10.sup.-2 M and mixtures thereof; a setting component selected from the group consisting of water soluble salts of polyfunctional carboxylic acids containing 2 to about 10 carbon atoms, water soluble dibasic phosphate salts and mixtures thereof; and water in an amount effective to form a paste from the mixture which paste hardens into said hardened cement which is biocompatible.

Abstract: A composition for forming a calcium phosphate type setting material comprising(1) powder comprising at least one of .alpha.-tricalcium phosphate and tetracalcium phosphate; and(2) a setting solution comprising an aqueous acidic solution having dissolved therein at least one polysaccharide selected from the group consisting of carboxymethyl chitin, glycol chitin, pullulan, high methoxy-pectin and chitosan in such an amount that the setting solution has a viscosity of 70 cp or more, anda process for producing a calcium phosphate type setting material using such a composition.

Abstract: Ceramic compositions comprising a distillable binder, shaped articles formed therefrom and a method for making said compositions and for forming the shaped articles.

Abstract: The invention relates to a method of preparing sintered shapes, comprising the steps of forming a green body from a mixture comprising (A) a major amount of at least one inorganic powder with (B) at least one reaction product of an amine other than an alkanolamine with a hydrocarbyl-substituted carboxylic acylating agent or alkylalkyleneglycolacetic acylating agent; provided the reaction product is other than an alkylene oxide treated fatty monocarboxylic amide and provided that when the hydrocarbyl-substituted carboxylic acylating agent is a nonaromatic acylating agent, then the hydrocarbyl group is other than hydrocarbyl groups having an average of about 55 to about 110 carbon atoms; and sintering the body. Sintered shapes made from the methods of the present invention have relatively high fired densities and small uniform grain sizes; and low porosity. The reaction products of the present invention help disperse the inorganic powder.

Abstract: A process for producing beryllium oxide (BeO) from beryllium hydroxide (Be(OH).sub.2) in a single reactive step. Beryllium hydroxide powder is mixed with a calcination additive containing Mg and/or Ca and calcined at 1000.degree.-1300.degree. C. The resultant oxide pow-der is characterized by low fluorine content (<100 ppm), low surface area (<1.5 m.sup.2 /g) and a controlled particle size of 2 .mu.m to 25 .mu.m.

Abstract: A calcium phosphate ceramic such as hydroxyapatite or calcium tertiary phosphate or calcium carbonate is used as a carrier, and the carrier is caused to carry silicon in addition to silver, or silicon and zinc in addition to silver. The result is an antibacterial ceramic exhibiting an ultra high degree of whiteness and suppressed discoloration. This ceramic material may be heat-fired at a temperature above 960.degree. C. to obtain a further improvement.

Abstract: The present invention relates to a material for the purification of fluids. More particularly, the present invention relates to a material for flocculating and separating organic substances or surface active agents contained in waste water.

Abstract: Guanidine oxalate is used as a precipitating agent in the coprecipitation of multicomponent oxide powder precursors. A solution of a soluble inorganic salt is combined with a solution of guanidine oxalate. A resultant metal oxalate is precipitated from the solution and can thereafter be subjected to heat to convert the metal oxalate into a multicomponent ceramic powder.

Abstract: A voltage non-linear resistor element mainly including ZnO, substantially free from internal defects, exhibiting an excellent current impulse withstand capability, can be manufactured by a process wherein an SiC inclusion in the starting ZnO powder is restricted to at most 10 ppm, preferably at most 0.1 ppm, by weight, whereby formation of closed pores in the element is prevented, which is otherwise caused by decomposition of considerable amount of SiC during firing. The starting ZnO powder has an average particle diameter (R) of 0.1-2.0 .mu.m, preferably 0.3-0.8 .mu.m, a particle size distribution within the range of between 0.5R and 2R, of at least 70%, preferably 80%, by weight, needle-like crystals of at most 20%, preferably at most 10%, by weight, and an SiC content as an impurity of at most 10 ppm, preferably at most 0.1 ppm, by weight.

Abstract: A non-magnetic substrate for use in a magnetic head, consists of the basic composition consisting of CoO and NiO or NiO, and (a) from 0.1 to 7% by weight of ZrO.sub.2 and HfO.sub.2 based on 100% of the basic composition, or (b) from 0.1 to 7% by weight of ZrO.sub.2, and from 0.1 to 2% by weight of Al.sub.2 O.sub.3. Cracking of the magnetic-layer structure is prevented.

Abstract: This present invention comprises a composition for cleaning unfired ceramic, porcelain and stoneware comprising a major amount of organic polar solvent, a small amount of glycerin and optionally minor amounts of dye and fragrance. The method of processing those materials without the risk associated with fine crystalline silica becoming air-borne is also described.

Abstract: A calcium phosphate type glass-ceramic which comprises from 64 to 72% by weight of phosphorus oxide in terms of P.sub.2 O.sub.5, from 13 to 20% by weight of calcium oxide in terms of CaO, from 6 to 13% by weight of strontium oxide in terms of SrO, and from 3 to 15% by weight in total of at least one member selected from the group consisting of aluminum oxide, cerium oxide and lanthanum oxide respectively in terms of Al.sub.2 O.sub.3, Ce.sub.2 O.sub.3 and La.sub.2 O.sub.3, a molar ratio of (CaO+SrO)/P.sub.2 O.sub.5 being 0.78-0.86.

Abstract: An electroconductive zinc oxide sintered body composed of sintered particles fusion-bonded in the grain boundaries thereof; which has a sintered density of from 5 to 5.5 g/cm.sup.3 ; and which does not substantially contain closed cells isolated from the outside in the interior of the sintered body. The electroconductive zinc oxide sintered body is prepared by sintering a mixture of an oxide of an element having a positive valency of at least 3 and zinc oxide in the presence of water at a temperature of at least 1,300.degree. C. The electroconductive zinc oxide sintered body is used as a sputtering target for the preparation of a low resistance, transparent electroconductive film.

Abstract: The invention provides a process for producing high phase purity ceramic materials through the utilization of organic gelling agents. The process comprises the following steps: (a) dissolving stoichiometric amounts of metal salts in a solvent to form a solution; (b) heating the solution to a temperature sufficient to dissolve the gelling agent; (c) dissolving from about 0.1 to about 50 weight percent of an organic gelling agent into the heated solution; (d) cooling the solution to form a gel; (e) drying the gel to form a xerogel precursor; and (f) subjecting the xerogel precursor to a calcination process to produce a high phase purity ceramic material.

Abstract: A titanium oxide film consists of a mixture of titanium monoxide (TiO), titanium dioxide (TiO.sub.2), titanium trioxide (Ti.sub.2 O.sub.3), titanium pentoxide (Ti.sub.3 O.sub.5) and other titanium oxides which are expressed as Ti.sub.n O.sub.2n-1 is an integer from 4 to 10. Average content of oxygen in the film is from 51 to 59 atom percent.

Abstract: New surgical cements for use in medical applications such as orthopedic and maxillofacial surgeries and dental applications are disclosed. These surgical cements comprise a hardened cement formed from a mixture comprising a cementing component selected from the group consisting of ceramics having the formulaw(RO)--x(R.sub.2 O)--y(P.sub.2 O.sub.5)--z(X)wherein RO is selected from the group consisting of CaO and mixtures of CaO and MgO, R.sub.2 O is selected from the group consisting of alkali metal oxides and mixtures thereof, X is selected from the group consisting of SO.sub.4 and Cl, and w, x, y and z are the mole fractions of the respective constituents in the ceramic, when X is SO.sub.4, w is in the range of about 0.25 to about 0.5, x is in the range of about 0.05 to about 0.4, y is in the range of about 0.05 to about 0.25 and z is in the range of about 0.01 to about 0.25, and when X is Cl, w is in the range of about 0.25 to about 0.5, x is in the range of about 0.05 to about 0.

Abstract: A flywheel having superconductor bearings has a lower drag to lift ratio that translates to an improvement of a factor of ten in the rotational decay rate. The lower drag results from the lower dissipation of melt-processed YBCO, improved uniformity of the permanent magnet portion of the bearings, operation in a different range of vacuum pressure from that taught by the art, and greater separation distance from the rotating members of conductive materials.

Abstract: A process for producing a sintered apatite article having a porous surface by contacting a dense sintered apatite article with an acidic buffer solution, provided that the acidic buffer solution does not contain phosphoric acid.

Abstract: An oxide ceramic superconductor can be obtained if the oxides of bismuth, strontium, calcium and copper are mixed, the atomic ratios of the metals corresponding to a high-temperature superconductor, the mixture is mixed with an alkaline earth metal indate powder of the formula (Sr,Ca)In.sub.2 O.sub.4 and the mixture is heated for a prolonged period in the presence of oxygen. The presence of the indate promotes the development of a phase having a critical temperature of 110K.

Abstract: Microspherical sintered bodies of hydroxyapatite are prepared according to a new specific process wherein a suspension having hydroxyapatite microparticles dispersed in water or an organic solvent or a mixture of water and an organic solvent compatible therewith is atomized into a heating zone maintained above 500.degree. C. whereby spherical agglomerates of hydroxyapatite microparticles formed by drying and solidification of microdroplets of the suspension are sintered while the agglomerates are suspended in the heating zone. Microspherical sintered bodies of hydroxyapatite thus obtained, which may be modified by an optical heat treatment to adjust the surface area of the sintered body and growth of crystals therein, are useful in various fields of industry, for example, as a sorption agent in chromatographic separation.

Abstract: Non-whiteware ceramic articles having an increased green strength are prepared from slip compositions containing a polyalkylene polyamine as an additive or a mixture of a polyalkylene polyamine and binder as an additive. An example of such an additive is tetraethylenepentamine or a mixture of tetraethylenepentamine and a styrene butadiene latex.

Abstract: Calcium phosphate series compound ceramics are provided in which heat-resistant inorganic short fibers such as flawless SiC or Si.sub.3 N.sub.4 are three-dimensionally dispersed in a matrix composed of calcium phosphate series compound and entangled with each other to form a high strength shaped body as well as a method of producing the same. Also, a high density silicon carbide ceramic is provided in which biological glass is impregnated and filled in a porous shaped body. These composite ceramics have high strength and high toughness and are suitable as a heat-resistant structural material or a material for bio hard texture.

Abstract: A laser ablation method for forming a fluorinated superconducting Y-Ba-Cu-O thin film on a sapphire substrate is disclosed, which comprises the steps of: (1) depositing a barrier layer of BaAl.sub.2 O.sub.4 on the sapphire substrate; (2) placing the coated substrate and a tagret in a deposition chamber, said target including fluorine, barium, yttrium, copper and oxygen; (3) providing a background atmosphere including at least partial pressure of O.sub.2 within the chamber; (4) heating the coated substrate to a temperature above ambient; (5) laser-ablating the target material onto the heated substrate while controlling the partial pressure of O.sub.2 in said background atmosphere and the temperature of said heated substrate so that the as-deposited thin film on said substrate is superconductive.

Abstract: A method of preparing dense ceramic product is described, wherein a coagulated network of ceramic powder particles in water is formed and then treated to increase the volume fraction of particles, thereby forming a water-saturated powder compact. The compact is formed into a desired shape and fired to provide the dense ceramic product. A coagulated network may advantageously be formed by mixing a ceramic powder with water at a pH that produces a net surface charge, to form a dispersed slurry and adding a sufficient amount of salt to the dispersed slurry to cause particles within the slurry to form the coagulated network.

Abstract: A disinfectant bio-ceramic material which can be easily manufactured, has a stable disinfectant property, catches heavy metals which are harmful to human body, and radiates far infra-red rays with a positive influence on living things.Examples of the base materials used are compounds containing alkaline earth metal and phosphorus such as granulated bone, keel (fossils of vertebrate animals), artificial spatite, phosphate calcium ore, TCP (tricalcium phosphate),Mg3 (PO.sub.4).sub.2.5H.sub.2 O MgO.3SiO.sub.2.xH.sub.2 O and Sr(C.sub.3 H.sub.5 OH).sub.2.3H.sub.2 O in which compounds containing calcium and phosphorus are most preferable. With these base materials, by reacting metals with disinfectant and harmless property such as silver, copper, or zinc, a disinfectant bio-ceramic material is obtained.

Abstract: The invention relates to a process for producing a sintered body of calcium carbonate without permitting thermal decomposition of calcium carbonate during sintering, and to the sintered body. A powder material primarily comprising calcium carbonate is subjected to a cold powder pressing process to prepare a green compact, which is then heated in a high-pressure gas atmosphere consisting essentially of an inert gas at a temperature t.degree. C. of900.ltoreq.t<1200and at a high gas pressure P kgf/cm.sup.

Abstract: A composition for forming a calcium phosphate type setting material comprising(1) powder comprising at least one of .alpha.-tricalcium phosphate and tetracalcium phosphate; and(2) a setting solution comprising an aqueous acidic solution having dissolved therein at least one polysaccharide selected from the group consisting of carboxymethyl chitin, glycol chitin, pullalan, high methoxy-pectin and chitosan in such an amount that the setting solution has a viscosity of 70 cp or more, anda process for producing a calcium phosphate type setting material using such a composition.

Abstract: This invention relates to a process for preparing a lithium containing ceramic article. The process provides a ceramic article that is substantially crack free and has as its principal crystalline phase a beta-eucryptite phase, a beta-spodumene phase, or a mixture thereof. The process comprises calcining a powder of a lithium-exchanged zeolite up to its collapse temperature for a time sufficient to collapse the zeolite framework and provide an amorphous powder. The amorphous powder is now formed into a shaped article and sintered at a temperature of about 700.degree. to about 1150.degree. C. for a time of about 1 to about 12 hours. The zeolites which can be used are those having a SiO.sub.2 Al.sub.2 O.sub.3 ratio of about 2 to about 8.5 and include zeolite B, zeolite ZK-19, zeolite W, phillipsite, hormotome, gismondine and mixtures thereof and have a sodium content less than about 1 weight percent. It is preferred that the lithium-exchanged zeolite have an average particle size of less than about 10 microns.

Abstract: Ceramic abrasive grits are formed by an impregnation process that involves preparing an alumina hydrate sol, drying the sol to form a porous solid, crushing the solid to produce particles, calcining the dried particles, preparing a mixture of an additive metal oxide or its precursor in a liquid vehicle, impregnating the mixture into the calcined particles, drying the impregnated particles, calcining the dried impregnated particles, and firing the particles to produce ceramic abrasive grits. The concentration of the modifying additive metal is greater at or near the surface of the grit than at the interior of the grit.