Abstract: Particles of Cu-containing metal having a particle size of 0.5-20 .mu.m in largest dimension bearing a thin, substantially continuous coating of at least one metal oxide having a free energy of formation more negative than -98 kcal/mole and method of making them. The metal oxide-coated particles have improved sintering and shrinking properties which closely match those of green ceramic tape.

Abstract: A process for the production of depleted uranium metal particles comprising heating depleted uranium metal to red heat, rapidly chilling the heated metal, grinding the resulting brittlized metal to form powder size particles, annealing the particles and coating the particles with silver, copper, or lead, wherein the grinding and annealing are carried out in an inert argon atmosphere. The invention also contemplates the resulting depleted uranium metal powder, compositions containing the same as well as the liners for shaped charges formed therefrom.

Abstract: Novel constituent materials for gas sensors detecting gaseous impurities in air contain metal oxides and catalyst additives. The materials are prepared by mixing a colloidal solution A of an oxide or a hydroxide of at least one metal selected from the groups Ib, IIa, IIb, IIIa, IIIb, IVa, IVb, Va, Vb, VIa, VIb, VIIb, VIII and the lanthanides and actinides of the periodic system with a solution B containing a salt or a complex compound of at least one metal selected from the group: lanthanum, chromium, manganese, iron, cobalt, nickel, copper, ruthenium, iridium, palladium, platinum, rhodium, osmium, silver, gold, antimony, bismuth, thorium, and irradiating the mixture thus obtained with light of the visible and ultraviolet spectral region in order to photochemically deposit the metal in finely distributed form on the metal oxide or metal hydroxide, respectively.

Abstract: Gold, silver or palladium can be deposited by photoredox reaction on semiconductor oxide powders by irradiating a suspension of semiconductor oxide powder in the presence of oxygen, CO.sub.2 or mixtures thereof, of an oxidizable system which protects the semiconductor from photocorrosion, and of a salt or complex of copper, lead, mercury, tin, gold, silver or palladium.

Abstract: Dental alloy particles having a coating of a silver-tin alloy are prepared by a process comprising codepositing silver and tin from a cyanide based plating solution containing silver and tin ions on a particulate metal substrate having a particle size sufficient to allow integral bonding between the alloy layer and the particulate substrate.

Abstract: Improved granular abrasive material comprises silicon carbide particles at least partially coated with an integral, durable surface layer of a hard refractory material comprising metal nitride or carbide. Hard refractory materials which provide a useful coating include, for example, silicon nitride or carbide, titanium nitride or carbide, sialon, and others. The surface layer is preferably provided by chemical vapor deposition, most preferably utilizing a fluidized bed. The improved granular abrasive material is particularly useful in various abrasive products such as coated abrasive products, nonwoven abrasive products and abrasive grinding wheels.

Abstract: A process is provided for coating the particle surfaces of a phosphor-containing magnetic iron oxide powder with a cobalt compound after subjecting said powder to an activation treatment with an aqueous alkaline and/or acidic medium. The cobalt-containing magnetic iron oxide powder obtained according to this process has excellent coercivity and thermal stability, and the magnetic tape produced by using said powder has not only high coercivity but also excellent squareness, orientability and remanent induction.

Abstract: A metal-clad laminate having special utility in the production of high resolution printed circuit patterns and preparation of the laminate are described. The laminate preferably comprises a resin-bonded, glass-reinforced substrate, a layer of coupling agent covering and bonded to a major surface of the substrate, a layer of ultra-thin copper adjacent the layer of coupling agent, and a composite bonding layer disposed between the copper layer and the layer of coupling agent. The composite bonding layer comprises copper alloyed with at least one non-copper metal and oxide material of the non-copper metal.

Abstract: A process for improving the compressive strength of iron ore agglomerates, such as pellets or briquettes, used as a feed to an iron blast furnace, in which the particulate iron ore is treated, either before or after agglomeration with sufficient liquid or gaseous iron pentacarbonyl to provide about 2-5% carbonyl iron on the surfaces of the iron ore particles, following decomposition of the iron pentacarbonyl by heating, and induration of the pellets or briquettes.

Abstract: A process for preparing a silver-plated coral sand useful as a bacteriological inhibitor for drinking water is provided. The process comprises (1) heating desalted coral sand in an inert gas under reduced pressure; (2) thoroughly washing the resulting activated coral sand with water; (3) soaking the so washed coral sand in a silver-ammonia complex solution with heating under reduced pressure, adding a trace amount of glucose as a reducing agent to the complex solution, maintaining the soaked state to thereby effect plating the coral sand with silver; (4) evaporating the silver-plate coral sand to dryness with heating under reduced pressure; (5) thoroughly washing the silver-plated coral sand with water, and (6) then drying the silver-plated coral sand.

Abstract: A particle suitable for use as an electrode material comprising a substrate at least partially coated with an admixture of a hydrophobic material and an electrochemically active, electrically conductive catalyst.The invention includes a method for producing the coated particles.

Abstract: A process for the preparation of precious metal-coated particles which comprises adding a reducing agent to an aqueous suspension containing:(A) homogeneously suspended core material particles;(B) homogeneously suspended precious metal salt particles; and(C) dissolved precious metal ionsin an aqueous acidic medium having little dissolving capacity for the core material to produce precious metal-coated particles through gelling state, and recovering the produced precious metal-coated particles.The invention also provides alternate processes (1) wherein the precious metal salt is in a solution and (2) wherein the components are in a chelated gelling mixture which also uses an alkali agent, which also produce the precious metal-coated particles via the gelling state.

Abstract: In a composite material of metal and ceramic, the excellent properties of metal and ceramic are combined, so that, when the composite material is flame sprayed, a flame sprayed coating having good mechanical strength and heat- corrosion- and wear-resistance can be obtained. Conventional composite material, in which metal and ceramic are merely mixed or mechanically bonded with one another, cannot provide a plasma sprayed coating having a high bonding strength to the substrate. The present invention improves the plasma spraying composite material by means of a chemical bond between the metal and ceramic parts. The chemical bond may be a compound-or solid solution formation between these parts. The core of the composite material is ZrO.sub.2 and the coating is a metal, metallic compound or combination thereof.

Abstract: A liquid or powder material can be dispersed by the application of electrostatic fields. The phenomena, referred to as "electrodispersion" is the dispersion by an intense electric field of part of a static bed of liquid or powder into a stable cloud of rapidly moving particles, and the maintenance of a dynamic equilibrium between the static and dispersed phases. The density of the dispersed cloud of particles varies with a number of factors, including the field strength and the nature of the powder. The electrodeposition effect is employed to produce a uniform and durable coating of controlled thickness on the individual particles, by the generation of a vapor of the desired coating--typically a metal or semiconductor material--and allowing the vapor to permeate the dispersed particles. The electric field ensures that only the particles are coated, and the dispersed particles, having the same charge, repel each other, avoiding agglomeration.

Abstract: A metallic powder having a core of silver and an outer layer of platinum wherein the silver is from about 90 to about 99.5% by weight of the total composition. A process for producing such a powder comprising forming a first aqueous slurry of silver powder, an appropriate amount of lignosulfonate ammonia and water, forming a second slurry of platinum as a platinum-ammonium complex dispersed in a water soluble alkanol, mixing the first and second slurry, adjusting the pH of the mixture to a range of from about 8 to about 10, adding an appropriate amount of hydrazine to the mixture maintaining the resultant slurry at about 40.degree. C. to 60.degree. C. for an appropriate time to coat the platinum onto the silver, then separating the platinum-coated silver powder from the remainder of the slurry.

Abstract: Iron-containing refractory balls, in a retorting process for oil shale, permit effective magnetic separation of the balls from the spent shale. These ceramic balls can be made by a process such as admixing powdered alumina and water to form an extrudable mixture, extruding to form cylinders, reshaping cylinders into balls, overcoating with iron particles, further overcoating with alumina, and firing.

Abstract: An improved metal coated abrasive is prepared with a controlled, rough textured surface, which surface has improved adherence to resinous materials when said coated abrasives are incorporated into resin bonded tools. Disclosed is a process for achieving this rough texture through a modification to the known electroless or autocatalytic techniques for coating abrasives with metals such as copper and nickel. The improvement comprises: interrupting the electroless coating process by passivating the surface one or more times; and then reactivating the passivated surface each time with a catalytic material whereby an array of preferential sites for metal deposition is obtained; and resuming normal electroless coating.

Abstract: A flame spray powder comprising particles with a central core of a material selected from the group consisting of zirconium oxide, magnesium oxide, hafnium oxide, cerium oxide, yttrium oxide and combinations thereof. The core then has discrete aluminum particles in a binder deposited therein to form the flame spray powder which may be flame sprayed produce an abradable and erosion resistant coating.

Abstract: Processes are described for coating a particulate silver material such as sand or diatomaceous earth with metallic silver for sterilizing water and the like, the objective being to produce a highly adherent, thin layer of silver on the diatom surfaces. One method comprises mixing the filter particles with a silver compound in solution, then reducing the silver to elemental form on the particle surfaces by chemical, optical, or gaseous means with or without the addition of heat. Another method comprises sputtering elemental silver on to the diatom particle surfaces in a partial vacuum or inert atmosphere.

Abstract: Disclosed is an improved method for applying a coating of elemental silver on the exterior surfaces of diamond particles wherein an ammoniacal silver solution is mixed with the reducing solution and the diamond particles contacted with said mixture. The improvement of the present invention comprises agitating the ammoniacal silver solution containing said diamond particles sufficiently to suspend the particles therein and adding the reducing solution to the agitated ammoniacal solution at a metered rate adequate to produce a continuous grainy elemental silver coating on the diamond particles. A typical reducing solution is aqueous invert sugar.

Abstract: The invention provides a method of metal coating diamond or cubic boron nitride particles, the metal being capable of forming a chemical bond with the particles, including the steps of providing a mass of metal for the coating in powdered form in contact with the particles, heat treating the metal powder and the particles at a temperature below the melting point of the metal to deposit a layer of metal on the particles, and recovering the particles as discrete, metal coated particles, the heat treatment taking place in a non-oxidizing atmosphere and being chosen to allow chemical bond formation between the particles and the coating.

Abstract: A color developer for use in a pressure- or heat-sensitive record material comprises a particulate amorphous hydrated silica/hydrated alumina composite in which the hydrated silica and hydrated alumina are chemically bound, in which hydrated silica predominates, in which the mean alumina content on a dried weight basis is at least 7.5%, based on the total weight of silica and alumina, and in which the surface area is below 300 m.sup.2 g.sup.-1. The composite may be metal-modified.

Abstract: Very smooth polymeric coatings or films graded in atomic number and density can readily be formed by first preparing the coating or film from the desired monomeric material and then contacting it with a fluid containing a metal or a mixture of metals for a time sufficient for such metal or metals to sorb and diffuse into the coating or film. Metal resinate solutions are particularly advantageous for this purpose. A metallic coating can in turn be produced on the metal-loaded film or coating by exposing it to a low pressure plasma of air, oxygen, or nitrous oxide. The process permits a metallic coating to be formed on a heat sensitive substrate without the use of elevated temperatures.

Abstract: Contact electrodes on a semiconductor device (50) such as a photovoltaic solar cell is formed by screening through a mask (38) onto a surface (40) a pattern of ink containing a dispersion of lower melting, sinterable metal (tin) coated base metal (copper) particles dispersed in a liquid vehicle including a vaporizable binder polymer and a fluorocarbon polymer. On firing the screen coated device (46) in an oven (48) the binder polymer is vaporized, the fluorocarbon vapors etch the surface and the coated metal particles sinter without being oxidized to form an adherent, coherent, contact electrode (53).

Abstract: A method for the preparation of magnetic particulate matter coated with a protective layer of chromium(III) hydroxide, oxyhydroxide or oxide, optionally crosslinked with polyacrylic acid, which process comprises a first step of depositing a hydrogel of chromium(III) hydroxide onto magnetic material in a desired particulate form, a second step of heating to form chromium(III) hydroxide, oxyhydroxide or oxide, and a third optional step, which may precede or follow the said second step, of crosslinking with polyacrylic acid. The coated protected magnetic particles are useful for the preparation of composite magnetic polymeric particles for use in processes involving ion exchange, filtration and adsorption.

Abstract: A method for producing boundary layer semiconductor ceramic capacitors comprises firing shaped bodies of a semiconductor ceramic material in a neutral or reducing atmosphere, heat-treating the resultant semiconductor ceramic bodies to insulatorize crystal grain boundaries of the semiconductor ceramics, and providing opposite electrodes on surfaces of the heat-treated semiconductor ceramic bodies and is characterized in that said heat-treating is carried out by heating the semiconductor ceramic bodies together with power of an insulatorizing agent with stirring in a neutral or oxidizing atmosphere at a temperature ranging from 950.degree. to 1300.degree. C. As a semiconductor ceramic material, there may be used semiconductor ceramics of a barium titanate system, or of a strontium titanate system, or a complex semiconductor ceramic mainly comprising barium titanate or calcium titanate and strontium titanate.

Abstract: A composite powder sprayable by thermal spraying onto a substrate to form an abradable seal coating, is composed of particles each having a core of non-metallic solid material surrounded by a layer of nickel-chromium-aluminum alloy containing from about 4 to about 8% and from about 2 to about 6% aluminum.

Abstract: Methods and apparatus for manufacturng rapidly cooled powder particles is disclosed. Concepts discussed include both convection cooling and conduction cooling of molten material from which the particles are fabricated.By one effective technique of the present invention, seed particles are dropped across the path of a molten droplet stream causing impact and solidification of the molten droplets on the seed particles. Particles of increased size which are formed of conductively quenched material result.

Abstract: Silver coated particles having high concentrations of metallic silver are produced which are useful in forming alloys with metals such as mercury. The process comprises admixing carrier particles with an aqueous solution of a silver salt to form a slurry. A hydrazine compound is added to the slurry to precipitate metallic silver on the carrier particles in a medium which becomes increasingly acidic. Silver coated particles having a metallic silver content up to 90 percent by weight of the coated particle can be produced in a single impregnation under conditions which prevent the formation of explosive by-products such as silver nitride. The silver coated particles are particularly suitable for the recovery of metals such as mercury from fluids.

Abstract: Powder is coated with valve-metal by rotating it in a drum 15 so that it is presented to valve-metal vapor derived by evaporation of a source of valve-metal. In the case of coating with aluminum, the vapor may be produced by directing aluminum wire 10 on to a heater 11, and oxygen or air is admitted to control agglomerate formation. Aluminum and tantalum coating are both described using electron beam evaporators.

Abstract: A process for coating a particulate insulating material, e.g. alumina, with a uniform layer of a valve metal. The particles are exposed to a gaseous nitrogen compound, or to nitrogen gas together with hydrogen and a volatile halide of the valve metal. It is thought that nitrogen provides nucleation of the surface for subsequent metal deposition. The coated powder may be used in the fabrication of electrolytic capacitor anodes.

Abstract: A powder suitable for flame spraying which is a composition of an admixture of particles, 20-40% by volume of the particles being an alloy such as a nickel base alloy or cobalt base alloy, each containing aluminium and chromium and the balance of the composition are hollow glass particles, each hollow glass particle being coated with a nickel base alloy or cobalt base alloy, each containing aluminium and chromium. The powder, when flame sprayed, is effective as a thermal barrier which is resistant to thermal shock and oxidation.

Abstract: A photoconductive material for electrophotography is composed of photoconductive cadmium sulfide particles provided with a hydroxide, oxide or sulfide of a metal element or semiconductive element on the particle surface. The photoconductive material dispersed in a binder resin can be used as a photoconductive layer for an electrophotographic photosensitive member.

Abstract: Composite powder coated with a noble metal is produced by adding a powder of a metal or alloy baser than the noble metal to a powder of a metallic sulfide, carbon, activated charcoal, metallic carbide, or metallic oxide, and then adding to the resulting mixture a solution containing the noble metal with stirring. The particles of the composite powder are coated with the noble metal that results from a cementation reaction.

Abstract: A multilayer-coated composite powder is produced by a first step of treating a core powder to be coated with first metallic ions and a metallic powder for reducing the first ions and thereby forming a single-layer coated powder, and a second step of treating the single-layer-coated powder with either only second metallic ions other than the first metallic ions or the second ions in the presence of a metallic powder for reducing the second ions. Where necessary, the second step is repeated the number of times required for forming a predetermined number of coating layers.

Abstract: A powder suitable for flame spraying comprising particles of an alumino silicate glass, each of the particles being hollow and coated with an alloy containing, by weight, 80% nickel, 2.5% aluminium, 15.7% chromium and 1.8% silicon. The resultant coating is particularly suitable for use as a thermal barrier.

Abstract: A composite powder sprayable by thermal spraying onto a substrate to form an abradable seal coating with suitable strength and erosion resistance. Each powder particle has a core of non-metallic solid material surrounded by a layer of metallic material selected from the group consisting of nickel and nickel alloys. At least about 95% of the particles have a size less than about 150 microns, at least about 50 to about 90% of the particles have a size greater than about 75 microns, and less than about 10% of the particles have a size less than about 45 microns.

Abstract: Improved catalytic fillers result from the use of hydrazine to render reducible metal salts absorbed on filler material surfaces catalytic to the deposition of electroless metal. Use of such catalytic fillers in forming insulated articles in which holes are made lead to improved electroless metallization of the barrels of such holes.

Abstract: An electrically conductive composition and method for making same is disclosed. The composition includes a uniform mixture of electrically conductive particles comprising pyrolytic carbon doped or coated with a component taken from Group III-VIII elements of the Periodic Table and a curable, non-conducting polymer binder.

Abstract: Electrostatographic carrier materials having low bulk densities and high magnetic permeabilities are obtained by impregnating low density porous silicaceous particles with a magnetic or magnetically-attractable transition metal or metal oxide thereof. The low density magnetic composite carrier particles are prepared by the thermal decomposition of transition metal carbonyls in the presence of the silicaceous particles with a suitable suspending medium. Air and moisture are excluded from the reaction vessel and the contents are heated with agitation so that the carbonyl boils and the mixture is refluxed until the temperature rises to that of the suspending medium whereupon impregnation of the silicaceous particles with elemental metal and/or metal oxide is complete. The mixture is cooled, the beads washed, air-dried, and recovered. When mixed with toner particles the aforementioned carrier materials experience significantly reduced toner impaction levels.

Abstract: A method of producing ferromagnetic metal powder comprises the steps of dipping an iron compound powder in a solution in which an aluminum compound and/or a titanium compound is dissolved, removing solvent from the iron compound powder, reducing the iron compound powder in a reducing atmosphere at an elevated temperature and forming oxide layers on whole surfaces of the individual particles of the iron powder. Ferromagnetic iron powder produced according to this method has both a high coercive force and a high remanence ratio.

Abstract: A double-metal-coated metal sulfide powder comprises particles of a metal sulfide, a layer of a platinum group metal coating formed thereon, and an outer coating layer of a metal or alloy which contains at least one of iron, copper, nickel, and cobalt. The powder is obtained by forming a platinum group metal layer on metal sulfide particles by thermal decomposition of a plating composition which includes at least one platinum-metal compound containing a radical selected from the class consisting of NO, NO.sub.2, NO.sub.3, and NOCl and then forming a layer of at least one metal selected from the group consisting of iron, copper, nickel, and cobalt by the cementation reaction.

Abstract: A method for plating a powder with a metal by substitution, which comprises adding a crystalline powder of a metal chloride hydrate after and/or during mixing a powder to be plated and a reducing metal powder, and after the initiation of the reaction, adding water and/or hydrochloric acid.

Abstract: Graphite particles as small as 38 microns are cleaned, dried and chemically plated with copper or silver. One or multiple chemical platings may be carried out to provide a uniform and thick metal coating. The plated powders are dried and then molded into a desired shape under heavy pressure in a hydraulic press or the like after which the molded shape is sintered under a hydrogen atmosphere for the subsequent fabrication into monolithic or multi-elemental brushes for high-current collectors.

Abstract: Electrostatographic carrier materials having low bulk densities and high magnetic permeabilities are obtained by impregnating low density imbibitive polymer particles with magnetic or magnetically attractable metal, or metal oxide. The low density magnetic composite carrier particles are prepared by the solution phase thermal decomposition of transition metal carbonyls in the presence of the polymer particles with a suitable suspending medium. Air and moisture are excluded from the reaction vessel and the contents are heated with stirring so that the carbonyl boils and the mixture is refluxed until the temperature rises to that of the suspending medium whereupon the polymer particles are impregnated within their pores with elemental metal. The mixture is cooled, the beads washed, air dried, and recovered.

Abstract: An improved circuit board comprising a substrate having electrical conductor runs resistant to the formation of electrically non-conductive localized areas carried thereon. Such a circuit board is particularly adapted to use with a flash lamp array having a plurality of flash lamps and sequencing electrical circuitry for sequentially flashing the lamps. The sequencing electrical circuitry is formed in part by the conductor runs. The conductor runs comprise an organic polymer binder for attachment of the conductor runs to the substrate and silver-coated vitreous bead-like particles with a triazole-silver water-insoluble reaction product comprising the surface of the bead-like particles. The triazole-silver reaction product prevents the formation of non-conductive localized areas in the conductor runs.

Abstract: Metal sulfide powder coated with copper is produced by mixing powder of a metal and/or an alloy baser than copper with powder of a metal sulfide, and then adding an acidic solution containing copper ions to the resulting mixture with stirring. The metal sulfide particles are coated with metallic copper that results from a cementation reaction. Where the metal sulfide powder contains too coarse or fine particles, it is ground, granulated, and sized before the mixing.

Abstract: This invention relates to a novel composite pigment and method for its manufacture which comprises a finely-divided inert pigment as a core which has deposited on its surface a non-photoconductive grade of zinc oxide, the weight ratio of zinc oxide ranging from about 30% to about 80% of the total weight of the composite pigment and the composite pigment characterized by a specific surface in excess of about 10 square meters/gram. In rubber compounding, the composite pigment reduces the cost of the zinc essential to produce quality products and the composite pigment because it is itself photoconductive is of utility in photoconductive end uses.

Abstract: A magnetic iron oxide having a large coercive force and an improved squareness ratio prepared by coating the surface of needle-like particles of magnetic iron oxide with a cobalt compound, placing the coated iron oxide particles in a unidirectionally oriented magnetic field thereby orienting the particles in the direction of the magnetic field, and heat-treating the needle-like particles in this state with the application of an external magnetic field, or heat-treating the needle-like particles in a magnetized state.

Abstract: A positive active material for electric primary cells, such as are used in electronic watches, is formed from a powder composed at least partially of grains having cores of silver peroxide completely surrounded by a layer of monovalent silver oxide and covered with a thin surface layer of metallic silver. The remainder of the powder, if any, comprises monovalent silver oxide grains, also covered with a thin surface layer of metallic silver. A process for making the material includes adding a reducing agent such as hydrazine to a powder having grains of less than 50 microns in diameter of essentially pure silver peroxide and reducing the silver peroxide to the point at which a thin layer of metallic silver forms on the surface of each powder grain. This point can be detected by a substantial reduction in electrical resistivity of the powder and occurs when approximately one-half of the original powder remains as silver peroxide.