Abstract: A ferromagnetic metal powder comprises a ferromagnetic metal particle composed mainly of iron, a silicon compound layer formed on the surface of the ferromagnetic metal particle in such an amount that the amount of silicon is 0.1 to 1% by weight based on iron in the ferromagnetic metal particle, and a layer containing a nonferrous transition metal element compound in an amount of from 2 to 15% by weight based on the weight of iron in said ferromagnetic particle which is formed on the silicon compound layer.

Abstract: The present invention relates to the preparation of permanent magnet materials of the Iron-Boron-Rare Earth type.

Abstract: A process for producing a ferromagnetic metal powder composed mainly of iron and having an oxidized coating and a superior dispersibility is provided, which process comprises feeding granules of a ferromagnetic metal powder composed mainly of iron and impregnated with an organic solvent into a horizontal, cylindrical, rotating type reactor having scraping plates fixed onto the inner wall thereof in parallel to the generating line thereof, passing an oxygen-containing gas through the reactor while rotating the reactor and keeping the inside temperature thereof at 10.degree. to 80.degree. C. to vaporize off the solvent and dry the granules, and then continuously or stepwise raising the temperature of the resulting material on heating while passing an oxygen-containing gas through the inside of the reactor.

Abstract: In production of rare earth type magnet, addition of Nd to Fe-Gd-metalloid base containing 2 or more of B, Si, and P, combined with solidification of molten alloy by abrupt cooling assures large coercive force and high susceptibility of the product.

Abstract: A method to produce rare earth (RE), iron, boron type anisotropic permanently magnetic material includes forming magnetically isotropic coarse powder particles of melt-spun alloy with a very fine grain RE.sub.2 FE.sub.14 B phase. The particles are mixed with inert particles of a size and of a weight percentage of the mixture to separate the powder particles for preventing hot work bonding therebetween. The mixture is hot pressed to cause the magnetically isotropic particles to be compressed in a direction parallel to the press direction so as to strain the particles to cause crystallites to be oriented along a crystallographically preferred magnetic axis resulting in particles of anisotropic permanently magnetic material.

Abstract: Permanent magnets are prepared by a method comprising mixing a particulate rare earth-iron-boron alloy with particulate aluminum, aligning the magnetic domains of the mixture, compacting the align mixture to form a shape, and sintering the compacted shape.

Abstract: A method and apparatus for producing rare earth (RE), iron, boron type anisotropic magnetic material includes process steps of forming dense substantially magnetically isotropic coarse powder particles of melt spun alloy with a very fine grain RE.sub.2 Fe.sub.14 B phase; heating such particles (e.g. by plasma spraying) and directing them against hot working rolls at the entrance thereof; and hot deforming the particles while in a plastic state between surfaces of the hot working rolls so as to cause crystallites in the particles to be oriented along a crystallographically preferred magnetic axis. The particles are cooled and ejected from the rolls as individual anisotropic permanently magnetic flakes. Apparatus including a feed hopper with a carrier tube pressurized to direct isotropic particles to the arc of a plasma spray torch. The torch softens the particles and sprays them in a spatter pattern.

Abstract: A rare earth-iron permanent magnet is comprised of compacted Re-B-R type alloy particles in which R represents at least one element selected from rare earth elements and yttrium. The magnet has a sealing agent filling voids between the compacted Fe-B-R type alloy particles and a coating layer formed on outer surfaces thereof. The coating layer is formed by coating the surfaces wrought in a desired magnet shape.

Abstract: Permanent magnets are manufactured by grinding a magnetic phase having the composition RE.sub.2 (Fe, Co).sub.14 B with a non-magnetic phase, orienting it magnetically, densifying and then sintering it. The non-magnetic phase may be a hydride of either a rare earth metal or alloy thereof. The second phase must have a melting point lower than the magnetic phase.

Abstract: A permanent-magnet material of a metal/metal/metalloid system is produced in which at least one starting component of the metals in powder form is mixed together with a component in powder form of elemental boron, or a boron compound or alloy, is optionally compacted, and finally subjected to an annealing treatment for forming the permanent-magnet material. In order that a powder of this material system is produced with an extremely fine microstructure, the powder mixture of the starting components is first subjected to a milling process in the manner of mechanical alloying whereby a mixture powder of the at least one metallic starting component with embedded or adsorbed fine particles of the boron component is formed.

Abstract: Magnetically anisotropic powder having high coercivity and containing the magnetic phase Nd.sub.2 Fe.sub.14 B is produced by melt spinning a composition of these elements to form amorphous or extremely finely crystalline particles which are hot worked to produce grains containing the above phase and having dimensions in the range of about 20 to 500 nanometers. When the hot worked body is comminuted to powder, the resultant particles are magnetically anisotropic and have appreciable coercivity at room temperature.

Abstract: Permanent magnets are prepared by a method comprising mixing a particulate rare earth-iron-boron alloy with a particulate additive metal powder, compacting the aligned mixture to form a shape, and heating the compacted shape at a temperature at least 150.degree. C. less than the sintering temperature of a rare earth-iron-boron alloy and usually in the range from about 700.degree. C. to less than 850.degree. C.

Abstract: A method of making a bonded permanent magnet including the steps of dissolving, in a solvent, an uncured epoxy resin having an incorporated catalyst which is inactive at a temperature of about 120.degree. F. Particles of a rapidly quenched rare earth-iron-boron alloy are added to the epoxy resin solution. The solution with the particles are mixed at a temperature of about 120.degree. F. until the solvent is removed and the magnetic particles are substantially uniformly coated with the resin. The epoxy coated particles are then cold-pressed into a compact to form a magnet and the epoxy compact is then cured by heating.

Abstract: The permanent magnet which is excellent in moldability, capable of maintaining the dimensional stability and magnetic properties during manufacturing steps, and having good dimensional stability at high temperature, water proofness, oil resistance and solvent resistance, can be constituted by a shaped substance containing, as major ingredients, rare-earth magnet powder and, as binder materials which has been cured and the process for producing the same.

Abstract: A permanent magnetic alloy essentially consists of 10 to 40% by weight of R, 0.1 to 8% by weight of boron, 50 to 300 ppm by weight of oxygen and the balance of iron, where R is at least one component selected from the group consisting of yttrium and the rare-earth elements.An alloy having this composition has a high coercive force .sub.I H.sub.C and a high residual magnetic flux density and therefore has a high maximum energy product.

Abstract: This invention relates to a stabilized ferromagnetic metal pigment which is produced by treating metal particles with a passivating reaction product comprising a silane-modified phosphate. The treated pigment is employed in the preparation of a magnetic recording medium which is resistant to storage at elevated temperature and humidity.

Abstract: Fine cobalt or nickel powder is produced by hydrogen reduction of a sulfate solution in the presence of a base and a strong reductant such as a metal borohydride wherein the base is added stagewise to the solution with the initial addition of base being sufficient to insure an essentially neutral pH at the time of reductant addition.

Abstract: A metal part, which may be an amorphous metal, is formed from an intermediate product comprised of at least two alloy components in powder form which have been compacted and optionally deformed such as by hammering or extrusion. The intermediate part is transformed into the metal part by a diffusion reaction. The intermediate product is produced by milling the at least two starting alloy components to form a mixture powder of particles having a predominantly layer-like structure comprising the starting alloy components. At least one of the starting alloy components is magnetic. After milling, the produced mixture powder is subjected to a magnetic field which aligns the still mobile powder particles. Thereafter, the final compacting and possible deformation takes place.

Abstract: A sintered magnet of Fe-B-rare earth alloy having an axis of easy magnetization oriented at an angle to a major axis can be directly produced from the alloy material by (a) press molding the material in an applied magnetic field into a compact of the dimensions determined by taking into account factors of shrinkage expected in X, Y and Z directions, and (b) sintering the compact.

Abstract: A process for preparing a porous metal plate is disclosed which is adapted to use short metal fiber to prepare the plate. The process is capable of providing a porous metal plate which has increased bending strength and porosity, of which the porosity and thickness are controlled as desired and which has a wide and lengthy shape. The so-formed porous metal plate is capable of being extensively utilized, for example, not only as a filter and a sound absorption material but for a fuel cell, a catalyst and the like. It is formed by applying adhesive onto a surface of a substrate, and embedding short metal fibers in the adhesive. The composite thus formed is then pressed, to push over the short metal fibers, and the composite is then sintered. The substrate is a material which is capable of being burned out, or is a metal net, or is a release paper, so that the final plate will be porous throughout.

Abstract: Finely divided mineral ore is pelletized using a soluble synthetic polymer. Preferably the polymer is in the form of beads made by reverse phase polymerization and all having a size of below 300 .mu.m. When the ore gives a pH in water of below 8 the soluble polymer is preferably cationic.

Abstract: A method of forming a magnetic material. The magnetic material is a solid mass of grains, and has magnetic parameters characterized by: (1) a maximum magnetic energy product, (BH).sub.max, greater than 15 megagaussoersteds; and (2) a remanence greater than 9 kilogauss. The magnetic material is prepared by a two step solidification, heat treatment process. The solidification process is carried out by: (a) providing a molten precursor alloy; (b) atomizing the molten alloy through nozzle means to form individual droplets of the molten alloy; and (c) quenching the droplets of the molten alloy to form solid particles of the alloy. The solid particles have a morphology characterized as being one or more of (i) amorphous; (ii) microcrystalline; or (iii) polycrystalline. The grains within the solid have, at this stage of the process, an average grain characteristic dimension less than that of the heat treated magnetic material.

Abstract: A method of forming a magnetic material. The magnetic material is a solid mass of grains, and has magnetic parameters characterized by : (1) a maximum magnetic energy product, (BH).sub.max, greater than 15 megagaussoersteds; and (2) a remanence greater than 9 kilogauss. The magnetic material is prepared by a two step solidification, heat treatment process. The solidification process is carried out by controlled vaporization of precursor elements of the alloy into an inert atmosphere, with subsequent controlled vapor phase condensation. This may be accomplished by vaporizing a precursor type alloy in a plasma torch, such as an argon torch, a hydrogen torch, or other electro-arc torch to form a particulate fine grain alloy. The resulting product of this alternative method is a particulate fine grain alloy. The solid particles have a morphology characterized as being one or more of (i) amorphous; (ii) microcrystalline; or (iii) polycrystalline.

Abstract: Finely particulate iron ore is pelletized using finely particulate, free flowing, anionic water soluble synthetic polymer having intrinsic viscosity of from 3 to 16 as binder.

Abstract: Permanent magnet materials of the Fe-B-R type are produced by:preparing a metallic powder having a mean particle size of 0.3-80 microns and a composition of 8-30 at % R, 2-28 at % B, and the balance Fe,compacting, andsintering, at a temperature of 900-1200 degrees C. Co up to 50 at % may be present. Additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf) may be present. The process is applicable for anisotropic and isotropic magnet materials.

Abstract: Magnetic powder protected from subsequent oxidation and deterioration can be obtained by effecting contact of starting magnetic powder, which is formed of an intermetallic compound containing a rare-earth metal and an iron-group metal as principal components thereof, with a phosphorus compound containing at least one active proton having a pKa of 4 or smaller and exposure of the starting magnetic powder to an oxygen-containing atmosphere in an arbitrary order or simultaneously. Production of a plastic magnet with the magnetic powder of this invention allows to avoid danger and deterioration in magnetic characteristics of the resulting product due to oxidation of the magnetic powder even if exposed to elevated temperatures during its production or use.

Abstract: Ferrimagnetic particles which are useful as magnetic material for magnetic recording media and consist of a core of a magnetic material exhibiting multiaxial anisotropy and a coating which surrounds the core and is composed of a magnetic material possessing uniaxial anisotropy, and a process for their preparation.

Abstract: A metallic magnetic powder treated with an alkyl group-containing dicarboxylic acid so that the acid is deposited on the particle surfaces. The amount of the acid so deposited ranges from 0.5 to 5% on the basis of the weight of the starting powder.

Abstract: A forms set comprising a pair of covers and a set of blanks held therebetween. One or both of the covers have magnetic material therein which is magnetized so that the covers are held closed by the magnetic attraction therebetween. Also, one or both of the external surfaces of the set of blanks has a portion thereof made of magnetic material which is magnetically attracted by the one or more magnetized covers. The non-magnetic portion of the external surfaces enables the magnetic force to travel between the covers. In an alternative embodiment, the external surface is placed in a pouch disposed in the inside of the cover. The magnetic holding of the covers enables easy replacement of the set of blanks or one or more of the blanks therein.

Abstract: Magnetic powders have a thin film of a nitrogen- or sulfur-containing organic polymer synthesized on the individual particles by plasma polymerization. The film is not more than 100 .ANG. in thickness.

Abstract: Cobalt-free ferromagnetic particles are disclosed. The particles are comprised of ferromagnetic metal inner cores and an outer oxidized layer. The particles have a saturation magnetization of 60 to 100 emu/g and a coercive force of 500 Oe or more. The outer layer provides a means for stabilizing the magnetic characteristics of the particles at temperatures not higher than 80.degree. C. in air. The particles are produced by gradually oxidizing ferromagnetic metal particles containing no cobalt in oxygen-containing gas such that the surface-oxidized metal particles have a saturation magnetization of 60 to 100 emu/g. The particles provided have good magnetic characteristics which are maintained with the passage of time even when the particles are subjected to adverse temperature and humidity conditions.

Abstract: A compacted powdered iron core utilizes iron powder in the 0.002 to 0.006 mean particle size range which is firt coated with an alkali metal silicate and then overcoated with a silicone resin polymer. The treated powder is compressed to approximately 94% of theoretical density and then annealed at approximately 600.degree. C. This results in a core component characterized by overall core losses as low as in conventional laminated cores in A.C. operation.

Abstract: Permanent magnet materials of the Fe-B-R type are produced by:preparing a metallic powder having a mean particle size of 0.3-80 microns and a composition of 8-30 at % R, 2-28 at % B, and the balance Fe,compacting, andsintering, at a temperature of 900-1200 degrees C.Co up to 50 at % may be present. Additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf) may be present. The process is applicable for anisotropic and isotropic magnet materials.

Abstract: A magnetic field sensing device for sensing low levels of magnetic intensity is composed of a ribbon-shaped strip of amorphous magnetic material having at least one twist along the length thereof between the ends of the strip. Subsequent to imparting the desired number of twists to the strip, the strip is supported in the twisted condition. The device is capable of generating a pulse in response to the presence of an external magnetic field similar to the Wiegand wire effect.

Abstract: The aforementioned invention comprises an iron based powder mixture with up to 8% silicon, addition of which is in the form of ferrosilicon with a silicon content of approximately 50% and a particle size mainly less than 150 .mu.m.

Abstract: A powder for a magnetic recording medium comprising a plurality of magnetic particles and a coating covering the surfaces of the magnetic particles. The coating is a residue resulting from the thermal decomposition of an organic material. The powder is manufactured by applying one or more organic materials to the surfaces of a plurality of magnetic particles by dispersing the magnetic particles in a solution containing the organic material. The magnetic particles, having the organic material as a coating, are separated from the solution, and the magnetic particles are heated to a temperature at which the organic material decomposes.

Abstract: A process for producing a ferromagnetic metal powder comprising treating acicular iron oxyhydroxide or an acicular metal oxyhydroxide composed mainly of iron with a silicon compound, dehydrating the treated material by heating the material in a non-reducing atmosphere to produce iron oxide particles or metal oxide particles composed mainly of iron, and reducing the resulting iron oxide particles or metal oxide particles composed mainly of iron by heating in a reducing atmosphere to produce iron powder or a metal powder composed mainly of iron, which is characterized in that the dehydration by heating in a non-reducing atmosphere is carried out at a temperature of from 300.degree. to 800.degree. C. and the iron oxide particles or the metal oxide particles composed mainly of iron are treated with a silicon compound prior to reduction by the heating in a reducing atmosphere.

Abstract: A method for producing iron-silicon alloy articles having an improved combination of hot workability and electrical properties; the method comprises taking a molten alloy mass of an iron-silicon alloy from which the article is to be made and gas atomizing it to form alloy particles which are quickly cooled to solidification temperature. These alloy particles are then hot isostatically pressed to form a substantially fully dense article. The fully dense article is then hot rolled to sheet form suitable for example for use as laminates in the manufacture of transformer cores.

Abstract: A method for producing magnets from powdered magnetic alloy, and magnets having improved remanence and good coercive force; the method comprises aligning a particle charge of magnet alloy within a container, which aligning may be achieved by use of a pulsating magnetic field; consolidating the charge after alignment to a density in excess of 95% of theoretical density by cold or hot isostatic pressing, or a combination thereof.

Abstract: A method is disclosed for producing iron or iron alloy particles. A metal or metal alloy strip having fine particles of iron or alloy distributed throughout is provided. The metal strip is selectively dissolved without substantial dissolving of the iron or iron alloy particles in order to recover the particles.

Abstract: Disclosed is an magnetic core comprising a molded product made of an iron powder and/or an iron alloy magnetic powder having a mean particle size of 10 to 100 .mu.m, and 1.5 to 40%, as a total amount in terms of volume ratio, of an insulating binder resin and an insulating inorganic compound powder. Also disclosed is a useful method of producing the magnetic core.

Abstract: An iron powder developer carrier for electrophotography having at least the outer surface thereof coated with iron oxide. The iron oxide has a particle size of 50 to 200.mu., an apparent density of 1.5 to 2.5 g/cm.sup.3 and a specific surface area of 0.01 to 0.3 m.sup.2 /g.A process for the preparation of iron powder developer carriers for electrophotography, which comprises the steps of subjecting a starting iron powder to a primary calcination treatment in an inert gas atmosphere without using a binder, pulverizing and classifying said calcination product to prepare an intermediate iron powder, reducing the intermediate iron powder in a reducing atmosphere and washing the intermediate iron powder, and subjecting the intermediate iron powder to an oxidizing calcination treatment.

Abstract: Disclosed herein is acicular ferromagnetic alloy particles for magnetic recording, containing Si, Cr, Ni and P and optionally Mg impregnated with phosphorus compound and silicon compound and process for producing the same.

Abstract: Improved acicular fine particles of ferromagnetic metal having superior powder characteristics and tape characteristics are provided, which fine particles are prepared by adding to an aqueous suspension of acicular iron oxide or oxyhydroxide, a solution of a different kind and non-alkali metal salt of an organic acid in place of conventional inorganic acids, followed by making the mixture basic and heat reduction.

Abstract: Ferromagnetic Fe-Ni alloy powders having the combination of a coercive force of 550-900 Oe (oersted) and a saturation flux density of 90-170 emu/g are provided by applying a nickel compound in a liquid to a particulate, oxygen-containing iron compound having an average particle length of 0.5-5 .mu.m and an average particle width of 0.02-0.5 .mu.m, and then drying and reducing the treated material to produce a metallic powder. The ferromagnetic powders are suitable for production of magnetic recording media because of the balanced magnetic properties.

Abstract: A method is proposed for manufacturing a semiconductor device, which comprises forming groove(s) having a vertical wall in a semiconductor substrate; doping the same type of impurity as that of the substrate at a dose of not less than 1.times.10.sup.14 cm.sup.-2 or the opposite type of impurity to that of the substrate in said groove(s) to form an impurity region; filling the groove(s) with an insulating material to form a field region. A semiconductor device having an impurity region of the same conductivity type as that of the semiconductor substrate under a buried field region and of a sheet resistance .rho.s=50 ohms/.quadrature. is also proposed.

Abstract: A method for preparing ferromagnetic metal particles is disclosed. The method involves dehydrating oxyhydroxide particles comprised mainly of iron in a nonreducing gas under heating at a temperature of not more than 500.degree. C. to form oxide particles, providing silicon compounds on the surface of oxide particles, and reducing the oxide particles in a reducing gas under heating. The ferromagnetic metal particles provided have good acicular shape and a large specific surface area.

Abstract: A one-component magnetic dry developer for use in development of positively charged images and transfer of developed images, comprises particles of a composition comprising a vinyl aromatic polymer, an aliphatic carboxylic acid having at least 14 carbon atoms, inclusive of the carbon atom of the carboxyl group, per carboxyl group or its metal salt and a finely divided magnetic material having a coercive force not larger than 120 Oe and a bulk density of at least 0.45 g/ml.This magnetic developer provides an excellent transferred image having high image density and image sharpness on a plain paper as a transfer sheet without fogging or broadening of the contour of the image.

Abstract: Ferromagnetic metal particles are disclosed, which have a silane compound on the surface thereof. The silane compound is represented by the formula:R.sub.n --Si--(OR').sub.4-nwherein R and R' each represent an alkyl group and n represents 2 or 3. The ferromagnetic metal particles have excellent oxidation stability and corrosion resistance. Furthermore, the ferromagnetic metal particles have good dispersibility within a binder when used in connection with producing a magnetic recording medium.

Abstract: Spherical agglomerates of surface-stabilized primary particles substantially consisting of iron, having a BET surface of about 5 to 50 m.sup.2 /g, measured on the agglomerate, in non-pyrophoric form and having a bulk density of about 0.5 to 2.0 kg/l and an agglomerate diameter of about 0.5 to 10 mm are produced by(a) reducing in dry phase particles consisting essentially of iron oxide,(b) intensively dispersing the particles in liquid phase,(c) coating the particles with an inorganic and/or organic coating optionally containing corrosion inhibitors,(d) separating the particles from the liquid phase by evaporating the volatile components with a continuously rotating and simultaneously tumbling movement, and(e) subjecting the resulting granulates to a thermal treatment. The particles are especially useful for the production of magnetic recording media.