Abstract: An acicular alloy base magnetic powder comprising iron and cobalt, which has an average particle long axis size of not larger than 0.25 .mu.m, an axial ratio of from 4 to 8, a cobalt content of from 8 to 50% by weight based on the weight of iron and saturation magnetization of at least 120 emu/g after being kept standing at the temperature of 60.degree. C. and relative humidity of 90% for a week, which has improved corrosion resistance and can provide a magnetic recording medium suitable for recording in the short wavelength range.

Abstract: There is disclosed a process for preparing a resin composition for powder molding, comprising 50 to 97 wt % of a metal or alloy powder and 50 to 3 wt % of a thermoplastic resin having heat resistance and crystallinity, which process comprises dissolving the thermoplastic resin having heat resistance crystallinity in a solvent and at the same time, dispersing therein at least one metal or alloy powder selected from iron, brass, nickel silver, stainless steel and aluminum, having an average particle diameter of not more than 500 .mu.m to thereby prepare a mixture. In addition, there is disclosed a process for producing a powder molded product which comprises cold compressing molding the above resin composition and then heating the molding at a temperature not less than the melting point of the thermoplastic resin. This powder molded product has excellent dimensional stability against heat, chemical resistance, and mechanical strength.

Abstract: This invention relates to a process for producing a rare earth-containing powder comprising crushing a rare earth-containing alloy in a passivating gas at a temperature from ambient temperature to a temperature below the phase transformation temperature of the material.Additionally, this invention relates to a process for producing a rare earth-containing powder compact comprising crushing a rare earth-containing alloy in water, compacting the crushed alloy material, drying the compacted alloy material at a temperature below the phase transformation temperature of the material, and treating the compacted alloy material with a passivating gas at a temperature from ambient temperature to a temperature below the phase transformation temperature of the material.Rare earth-containing alloys suitable for use in producing magnets utilizing the powder metallurgy technique, such as Nd-Fe-B and Sm-Co alloys, can be used.

Abstract: A method for making an isotropic permanent magnet comprises atomizing a melt of a rare earth-transition metal alloy (e.g., an Nd--Fe--B alloy enriched in Nd and B) under conditions to produce protectively coated, rapidly solidified, generally spherical alloy particles wherein a majority of the particles are produced/size classified within a given size fraction (e.g., 5 to 40 microns diameter) exhibiting optimum as-atomized magnetic properties and subjecting the particles to concurrent elevated temperature and elevated isotropic pressure for a time effective to yield a densified, magnetically isotropic magnet compact having enhanced magnetic properties and mechanical properties.

Abstract: This invention relates to a process for producing a rare earth-containing material capable of being formed into a permanent magnet comprising crushing a rare earth-containing alloy and treating the alloy with a passivating gas at a temperature below the phase transformation temperature of the alloy. This invention further relates to a process for producing a rare earth-containing powder comprising crushing a rare earth-containing alloy in a passivating gas at a temperature from ambient temperature to a temperature below the phase transformation temperature of the material. This invention also relates to a process for producing a rare earth-containing powder comprising crushing a rare earth-containing alloy in water, drying the crushed alloy material at a temperature below the phase transformation temperature of the material, and treating the crushed alloy material with a passivating gas at a temperature from the ambient temperature to a temperature below the phase transformation temperature of the material.

Abstract: The magnetic recording medium of the invention has a magnetic layer formed by mixing an iron base metal magnetic powder with a binder, the metal magnetic powder being prepared by furnishing hydrous iron oxide or iron oxide powder as a starting material, applying Zr, Al, and Si compounds or Zr, Al, and Co compounds to the powder surface, and reducing the treated powder in a reducing atmosphere. Improved surface smoothness, a low coefficient of friction, and improved dynamic durability are achievable.

Abstract: The invention relates to a method of obtaining friable and relatively inert TR Fe B type magnetic materials in divided form which lead to magnets having improved corrosion resistance. This method involves treating the material in an atmosphere containing (or capable of containing) hydrogen under the following conditions of absolute pressure (P) and of temperature (T.degree. C.): if P.ltoreq.Pa, 250<T<550; and if P>Pa, 250+100 log (P/Pa)<T<250+100 log (P/Pa) log base 10, Pa being atmospheric pressure. The invention is used for obtaining sintered TR Fe B magnets having improved corrosion resistance.

Abstract: This invention relates to a method for producing surface-treated magnetic power for high record density magnetic recording medium which has excellent dispesibility and high filling density and surface smootheness.This invention provides a method for producing surface-treated magnetic powder characterized by treating magnetic powder with at least one functional group of the epoxy group, carboxyl group, hydroxyl group, thiol group and amino group and with hydrocarbon group having more than eight methylene chains.

Abstract: Acicular, ferromagnetic metal powders essentially consisting of iron are stabilized against oxidation and corrosion by a two-stage reaction of the metal powder with an oxygen-containing inert gas, by a process in which this gas mixture has a water vapor content of from 70 to 95% relative humidity in the second stage and the oxygen content is from 10 to 20%.

Abstract: A magnetic metal powder, having a large specific surface are, a high coercive force, a high dispersibility and an excellent corrosion resistance, is produced by converting an aciculate goethite having a silicon and/or aluminum compound layer formed thereon or an aciculate goethite modified with a metal other than iron into magnetite, forming thereon a nonferrous transition metal compound layer, further forming thereon a silicon or aluminum compound layer, and reducing the coated magnetite to prepare a magnetic metal powder mainly composed of iron and having on the surface thereof a layer containing a nonferrous transition metal element, characterized in that the formation of the silicon and/or aluminum compound layer on the aciculate goethite and/or the formation of the nonferrous transition metal layer on the magnetite are conducted while conducting dispersion by means of a disperser.

Abstract: The magnetic coercivity of magnetically anisotropic powder containing the magnetic phase Nd.sub.2 Fe.sub.14 B, which already has appreciable magnetic coercivity, is enhanced by the method of this invention. The powder is produced by melt spinning an appropriate composition to form amorphous or extremely finely crystalline particles, hot working the particles to produce grains containing the Nd.sub.2 Fe.sub.14 B phase and having dimensions in the range of about 20 to about 500 nonometers, comminuting the worked body to a powder, and then appropriately heating the powder to a temperature of between about 550.degree. C. to about 675.degree. C. followed by a normal cooling in the protective atmosphere of the furnace. The heat-treated powder exhibits magnetic anisotropy and magnetic coercivity of at least about 5,000 Oersteds at room temperature.

Abstract: An (Fe, Co)-B-R tetragonal type magnet having a high corrosion resistance, which has a boundary phase stabilized by Co and Al against corrosion, and which consists essentially of:0.2-3.0 at % Dy and 12-17 at % of the sum of Nd and Dy;5-10 at % B;0.5-13 at % Co;0.5-4 at % Al; andthe balance being at least 65 at % Fe.0.1-1.0 at % of Ti and/or Nb may be present. Alloy powders therefor can be also stabilized.

Abstract: There is disclosed a rare earth permanent magnet composed of a sintered product consisting of R and M where R represents at least one rare earth, and M represents Co or a combination of Co and at least one kind selected from the group consisting of Fe, Ni and Cu, the sintered product being of such a composition that a RM.sub.5 phase and a R.sub.2 M.sub.7 phase occur in the sintered product. The sintered product contains 63 to 65 wt. % of M, and the sintered product has a coercive force iHc of not less than 13,000 Oe. The permanent magnet can have a disk-shape, a ring-shape or a cylindrical shape. A method of heat treatment of the permanent magnet is also disclosed.

Abstract: Disclosed herein are acicular magnetic iron based alloy particles for magnetic recording, containing 1.5 to 10 mol % of B based on Fe (calculated as B) and 1.5 to 10 mol % of Co based on Fe (calculated as Co) in the vicinity of the surfaces of said particles and having a saturation magnetization of not less than 125 emu/g and an S.F.D. value of not more than 0.50, and a process for producing the same.

Abstract: A metal magnetic powder for magnetic recording media consisting essentially of iron is obtained by providing a hydrous needle-like iron oxide powder as a starting material, applying cobalt ions on the surface thereof, and subsequently reducing the resultant powder in a reducing atmosphere. The metal magnetic powder contains cobalt in an amount not less than 6 weight % relative to iron, and the coercive force of the powder is not more than 1600 Oe.

Abstract: A process for producing resin bonded magnet structures is disclosed which includes the steps of: (a) adding a solid epoxy resin of at least one epoxy oligomer and a microcapsule which contains at least one liquid epoxy resin to a melt spun powder of a rare earth element-iron alloy to form a granulated intermediate material, wherein the epoxy oligomer has alcoholic hydroxyl groups in the molecular chain thereof and the solid epoxy resin has a softening temperature (Durran's melting point) of 65.degree. C. to 85.degree. C.; (b) mixing the granulated intermediate material with a powdered curing agent and a lubricant to form a compound; (c) forming a green body of a resin bonded magnet by compressing the compound, and then integrating the green body directly with a supporting member; and (d) curing the solid and liquid epoxy resins in the green body by application of heat to form a rigid structure of the resin bonded magnet integrated with the supporting member.

Abstract: The present invention provides a process for producing magnetic metal powder for magnetic recording using a metal compound mainly composed of a hydrous iron oxide on an iron oxide, characterized in that prior to subjecting the metal compound mainly composed of a hydrous iron oxide or an iron oxide to a reduction treatment, addition of a boron compound and a heat treatment at 350.degree.-750.degree. C. in a gas atmosphere having a water vapor partial pressure of 10 mmHg or higher are carried out. When a heat treatment at 550.degree.-900.degree. C. in a non-reducing atmosphere is carried out in combination with the above heat treatment, the effect of the present invention is further increased.

Abstract: A method for the high volume manufacture of Fe-B-R-T alloy powders without sacrificing the resultant magnetic properties (such as intrinsic magnetic coercivity) of the alloy involves hydrogen decrepitation of vacuum cast or die-upset billets of the alloy. Hydriding is carried out at a partial pressure of hydrogen of between 250 and 760 mm Hg at 100.degree. to 500.degree. C. for 30 minutes to 6 hours or longer, depending upon load size. Dehydriding occurs in a vacuum below 10.sup.-2 mm Hg or in an inert atmosphere possessing a partial pressure of hydrogen below 10.sup.-2 mm Hg. The alloy powder is preferably incorporated in matrix or composite magnets by the addition of a binder prior to pressing and orienting. The binder may set during pressing in a hot die, or by heating after pressing in a cold die.

Abstract: A method for improving the magnetic properties, particulaarly intrinsic coercivity, of particles of a permanent magnet alloy comprising a rare earth element, iron and boron. The method includes subjecting particles to a hydrogen atmosphere for a time at elevated temperature sufficient to hydride the particles. The hydrogen atmosphere is removed while maintaining the particles at the elevated temperature. Thereafter, while maintaining the particles at elevated temperature, the particles are subjected to a vacuum atmosphere for a time at the maintained elevated temperature sufficient to dehydride the particles. Thereafter, while maintaining the particles at the elevated temperature, they are again subjected to a hydrogen atmosphere for a time at the maintained elevated temperature sufficient to hydride the particles. The hydrogen atmosphere is removed while maintaining the particles at the elevated temperature.

Abstract: A method of forming a cylindrical compact for a cylindrical magnet is improved by moving a core pin and a die of a mold at the same time of pressing magnet materials with a pressing punch in the same direction as that of the pressing punch at travelling speed Vc and Vd indicated by following equation:Vc=m.multidot.Vp(0.5.ltoreq.m.ltoreq.1.0)Vd=n.multidot.Vp(0.5.ltoreq.n.ltoreq.1.0)where Vc is the travelling speed of the core pin, Vd is the travelling speed of the die and Vp is the pressing speed of the pressing punch. It is possible to form the thin-walled elongated cylindrical compact by utilizing the frictional force caused between the mold and the magnet materials for forming the compact very effectively in order to obtain a thin walled elongated cylindrical magnet.

Abstract: This invention relates to a process for producing a rare earth-containing material capable of being formed into a permanent magnet comprising crushing a rare earth-containing alloy and treating the alloy with a passivating gas at a temperature below the phase transformation temperature of the alloy. This invention further relates to a process for producing a rare earth-containing powder comprising crushing a rare earth-containing alloy in a passivating gas at a temperature from ambient temperature to a temperature below the phase transformation temperature of the material. This invention also relates to a process for producing a rare earth-containing powder comprising crushing a rare earth-containing alloy in water, drying the crushed alloy material at a temperature below the phase transformation temperature of the material, and treating the crushed alloy material with a passivating gas at a temperature from the ambient temperature to a temperature below the phase transformation temperature of the material.

Abstract: A method of treating ferromagnetic metal powder to achieve a uniform stable oxide coating is provided, comprising:(a) molding ferromagnetic metal powder into granules having a minimum diameter of 0.

Abstract: In a rare earth-iron-boron alloy magnet powder, each individual particle includes a recrystallized grain structure containing a R.sub.2 Fe.sub.14 B intermetallic compound phase as a principal phase thereof, wherein R represents a rare earth element. The intermetallic compound phase are formed of recrystallized grains of a tetragonal crystal structure having an average crystal grain size of 0.05 .mu.m to 50 .mu.m. For producing the above magnet powder, a rear earth-iron-boron alloy material is first prepared. Then, hydrogen is occluded inot the alloy material by holding the material at a temperature of 500.degree. C. to 1,000.degree. C. either in an atmosphere of hydrogen gas or in an atmosphere of hydrogen and inert gases. Subsequently, the alloy material is subjected to dehydrogenation at a temperature of 500.degree. C. to 1,000.degree. C. until the pressure of hydrogen in the atmosphere is decreased to no greater than 1.times.10.sup.-1 torr, and is subjected to cooling.

Abstract: A method for manufacturing permanent magnets from a plurality of thin flakes of a rare earth-Fe-B alloy metal, comprising the steps ofsubjecting the thin flakes to a discharge electric field, the thin flakes being comprised of an R-Fe-B alloy metal; and R-Fe-B-M alloy metal; an R-Fe(Co)-B alloy metal comprising 11 to 18 atom % R, 4 to 11 atom % B, 30 atom % Co, the balance being Fe; and/or an R-Fe(Co)-M-B alloy metal,generating Joule heat on the contacting interfaces of the thin flakes by applying pressure to the gathered body of thin flakes and by supplying a current thereto, andbonding the gathered body integrally by making the thin flakes deform plastically in a warm state.R is one or more rare earth elements and M is one or more members selected from the group consisting of Si, Al, Nb, Zr, Hf, Mo, Ga, P and C. The thin flakes are in a nonequilibrium state such that the R.sub.2 Fe.sub.14 B phases and amorphous phases are coexistent.

Abstract: A the magnetically anisotropic magnetic powder having an average particle size of 1-1000 .mu.m and made from a magnetically anisotropic R-TM-B-Ga or R-TM-B-Ga-M alloy having an average crystal grain size of 0.01-0.5 .mu.m, wherein R represents one or more rare earth elements including Y, TM represents Fe which may be partially substituted by Co, B boron, Ga gallium, and M one or more elements selected from the group consisting of Nb, W, V, Ta, Mo, Si, Al, Zr, Hf, P, C and Zn. This is useful for anisotropic resin-bonded magnet with high magnetic properties.

Abstract: This invention describes a practice for the hot pressing and/or hot working of rare earth element-containing alloy powders using open-to-the-air presses. The rare earth-containing powder is pressed into a compact at ambient temperatures using a solid lubricant only on the die wall. This compact is then hot pressed in an open air press utilizing a heated die flooded with argon.

Abstract: A process for the preparation of ferromagnetic metallic particles for magnetic recording which comprises(I) a step of preparing a slurry of acicular iron oxide hydrate containing nickel and, if necessary, manganese,(II) a step of coating the surface of the above iron oxide hydrate with aluminum-containing iron oxide hydrate, thus giving a slurry containing the coated iron oxide hydrate and free aluminate ions,(III) a step of depositing aluminum and phosphorus and/or silicon on the outside surface of the aluminum-containing iron oxide hydrate, thereby giving a slurry of the iron oxide hydrate thus treated,(IV) a step of subjecting the slurry to washing, drying and dehydrating, reducing the obtained particles, and forming an oxide layer on the surface of the reduced particles.

Abstract: A process for preparing by a reduction/diffusion method rare earth-iron-boron alloy powders useful in permanent magnets. The process generates rare earth-iron-boron alloy powders having large and uniform particle sizes with minimal contamination. The process entails the use of a seed alloy among the starting materials, the seed alloy having substantially the same composition as the rare earth-iron-boron alloy to be prepared.

Abstract: Disclosed are (1) methods for treating ferromagnetic metal powders which comprise synthesizing the ferromagnetic metal powders, and then exposing the ferromagnetic metal powders to plasma in an oxygen atmosphere, and (2) magnetic recording media comprising non-magnetic supports and magnetic layers formed thereon, the magnetic layers being mainly composed of ferromagnetic metal powders and binder resins, in which the ferromagnetic metal powders are treated by the methods described in (1). The ferromagnetic metal powders obtained by the above methods are excellent in oxidation stability, and the magnetic recording media using the above ferromagnetic metal powders are excellent in storage stability.

Abstract: Methods of doubly coating iron particles. The methods comprise treating the iron particles with phosphoric acid to form a layer of hydrated iron phosphate at the surfaces of the iron particles. The particles are heated in an inert atmosphere at a temperature and for a time sufficient to convert the hydrated layer to an iron phosphate layer. The particles are then coated with a termoplastic material to provide a coating of thermoplastic material substantially uniformly circumferentially surrounding the iron phosphate layer. Doubly-coated iron particles provided in accordance with this invention are generally useful for forming magnetic components and cores for use in high frequency switching applications.

Abstract: A rare earth permanent magnet of a composition, Ce(CO.sub.1-x-y-a Fe.sub.x Cu.sub.y M.sub.a).sub.z, where a, x, y, and z are: 0.005<1<0.10; 0.20<x<0.40; 0.10<y<0.30; 4.8<z<6.0; and M is zirconium, titanium, nickel, and/or manganese. A method for manufacturing the magnet is disclosed comprising the steps of: applying a first solid solution heat treatment to an alloy ingot having the above composition at temperatures from 900.degree. to 1100.degree. C. for 10 minutes to 100 hours; pulverizing the alloy ingot; obtaining a magnet body from this pulverized alloy by the powder metallurgy method; sintering the magnet body; applying a second solid solution heat treatment to the sintered magnet body at 900.degree.-100.degree. C. for 10 minutes to 100 hours; and applying aging heat treatment to the sintered magnet.

Abstract: A process for the continuous production of cobalt-modified magnetic iron oxide. This process comprises carrying out a batchwise preliminary cobalt treatment by adding a magnetic iron oxide powder to an alkaline solution followed by the addition of a cobalt salt to cover the magnetic iron oxide powder with cobalt. A cobalt modification reaction is carried out continuously by passing the solution containing the preliminary cobalt-treated magnetic iron oxide powder under heat and pressure through a flow-type reaction vessel.

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, which is formed on the silicon compound layer.

Abstract: A method is provided for comminuting and mechanically magnetically orienting particles of hot worked rare earth-transition metal-boron alloy to make bonded anistropic magnets. The method involves comminuting a hot-worked body of the alloy to form platelet shaped particles, and applying pressure to the particles in a die in the absence of an external magnetic field.

Abstract: A process for fabricating high strength Sm.sub.2 TM.sub.17 (TM=transition metal) magnets is disclosed. An alloy is crushed and pulverized to a very fine powder. The powder is aligned in a magnetic field, cold pressed to substantially immobilize the powder particles and then compacted by hot isostatic pressing. The material is either homogenized at this time or prior to crushing. Thereafter, the powder is optimized by an aging heat treatment which includes isothermal exposure followed by controlled cooling. When aging is complete, the compact is magnetized.

Abstract: A method and apparatus for packing a permanent magnet powder wherein a solenoid coil is provided near the opening of a cylindrical molding space of a mold in such a manner that the direction of the central axis of the solenoid coil substantially coincides with the central axis of the molding space, and an alternating current magnetic field is applied, so that a permanent magnet powder above the opening is packed into the molding space. A magnetic pole may be provided in the center of the solenoid coil. The method of the present invention can be applied to not only a powder for a sintered magnet but also a powder for a bonded magnet.

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: Composite magnetic compacts having good conductivity and excellent mechanical and magnetic properties and their forming methods. The composite magnetic compacts are basically made by forming mixtures consisting essentially of 1 to 50 percent by weight of a magnetic powder and the remaining percentage of a powder of superplastic Zn-22Al alloy. A drop in the strength of the compacts that occurs when the mixing percentage of the magnetic powder increases is made up for by the impregration of plastic in the compacts or the simpler addition of a plastic powder to the mixture of the powders of magnetic material and superplastic Zn-22Al alloy. The forming methods of the composite magnetic compacts are carried out at different temperatures and under different conditions depending on the composition of the powder mixtures and so on.

Abstract: A method for producing permanent magnet alloy particles suitable for use in producing bonded permanent magnets. A melt or molten mass of a permanent magnet alloy having at least one rare earth element, at least one transition element, preferably iron, and boron is produced. The melt is inert gas atomized to form spherical particles within the size range of 1 to 1000 microns. The particles are heat treated in a nonoxidizing atmosphere for a time at temperature to significantly increase the intrinsic coercivity of the particles without sintering the particles to substantially full density. Thereafter, the particles are separated to produce a discrete particle mass. The particles during heat treatment may be maintained in motion to prevent sintering thereof.

Abstract: A high energy rare earth-ferromagnetic metal permanent magnet is disclosed which is characterized by improved intrinsic coercivity and is made by forming a particulate mixture of a permanent magnet alloy comprising one or more rare earth elements and one or more ferromagnetic metals and forming a second particulate mixture of a sintering alloy consisting essentially of 92-98 wt. % of one or more rare earth elements selected from the class consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and mixtures of two or more of such rare earth elements, and 2-8 wt. % of one or more alloying metals selected from the class consisting of Al, Nb, Zr, V, Ta, Mo, and mixtures of two or more of such metals. The permanent magnet alloy particles and sintering aid alloy are mixed together and magnetically oriented by immersing the mixture in an axially aligned magnetic field while cold pressing the mixture.

Abstract: Disclosed are a method of and a device for manufacturing Nd-Fe-B alloy magnet materials, and in particular, for manufacturing an integral, columnar-ring-shaped Nd-Fe-B magnet which is multi-pole-magnetized along the circumference thereof and which is used as the rotor magnet of a high-efficiency stepping motor. According to the method, a green compact or a densified compact is first prepared from a selected flake or a powder material composed of amorphous and/or fine-crystallized particles obtained through rapid quenching of the molten alloy. It is then provided with magnetic anisotropy through plastic deformation effected radially inwardly along substantially the entire periphery of the compact initially deformed to receive a mandrel-core, and maintained at a temperature of 600 to 850 degrees C. Subsequently, the deformed body is magnetized with the desired radial or polar magnetization pattern.

Abstract: A method of concurrently compacting and bonding a plurality of solid particles together including combining particles with a thermobonding agent, placing the particle-agent combination in a die having a desired shape, and applying compaction pressure to the particles while concurrently applying sufficient ultrasonic energy to the particles to densify the particles and thermally activate the thermobonding agent.

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

Abstract: A method of making high energy Nd-Fe-B magnets having a mass less than 30 grams wherein an alloy of said materials having a grain size less than that desired in the finished magnet is first prepared and subsequently hot worked to the desired configuration with increased magnetic properties and density by introducing into a cavity formed by a die and punch a Nd-Fe-B alloy powder having a particle size of from 45 .mu.m to 250 .mu.m and a grain size of from 100 to 1500 angstroms, compressing the powder at a temperature of from about 550.degree. C. to 750.degree. C. under a die-punch pressure of at least 10 kpsi under a vacuum of less than 200 millitorr to achieve a permanent magnet having a remanence of at least 7 kilogauss.

Abstract: A powder of a rare earth oxide, or a powder of a rare earth oxide and a rare earth metal is mixed with a powder containing iron, a powder containing boron and at least one material selected from among an alkali metal, an alkaline earth metal and a hydrogenated product thereof. The mixture is heated at a temperature of 900.degree. C. to 1200.degree. C. in a non-oxidizing atmosphere, subjected to wet treatment, and heated again at a temperature of 650.degree. C. to 1100.degree. C., whereby an alloy powder is obtained. Alternatively, the mixture is heated at a temperature of 900.degree. C. to 1200.degree. C., crushed into coarse particles, heated again at a temperature of 650.degree. C. to 1100.degree. C. and subjected to wet treatment. The powder is pulverized into a finer powder having an average particle diameter of 1 to 10 microns. The powder is used for making a magnet with a resin.

Abstract: To indicate the origin of manufacture of the components of a roofing system, magnetically permeable particles are incorporated into the components. The particles are preferably loaded into the lap sealant and adhesive used to form field splices. Thus loaded, the lap sealant and/or adhesive has magnetically permeable properties or characteristics which are electromagnetically detectable through and beyond one layer of rubber sheeting. Detection of these particles provides an indication of origin of the material.

Abstract: A method for treating rare earth permanent magnetic material is disclosed. The treatment includes soaking ribbon rare earth permanent magnetic material consisting essentially of grains of the tetragonal crystal phase RE.sub.2 TM.sub.14 B where RE is neodymium and/or praseodymium or mixtures thereof with other rare earth elements and TM is iron or mixtures of iron and cobalt, cobalt in a soaking solution of either distilled water or phosphoric acid and manganese phosphate solution, draining off the soaking solution, rinsing with distilled water while agitating to separate and remove fine powdered magnetic material, and washing and drying the remaining powder or ribbons. The treated material is taken to substantial dryness before the material is incorporated into a permanent magnet.

Abstract: Ferromagnetic metal particles of substantially iron are prepared by starting from an acicular .alpha.-FeOOH, applying a shape-stabilizing finish to the particle surface, heating at 500.degree.-850.degree. C. and subsequently reducing with gaseous reducing agents at 200.degree.-500.degree. C. to the metal, and starting .alpha.-FeOOH being prepared in the presence of zinc and phosphate ions.

Abstract: A metal-metal matrix composite magnet including a magnetic material such as a neodymium-iron-boron magnetic phase bonded by a metal matrix, preferably copper an a method of making the magnet which involves plating a thin metal layer, for example, a layer having a thickness of less than 1000 angstrom average, from a magnetic phase, pressing the powder, with or without magnetic alignment, into the desired shape and then sintering the pressed powder at a temperature below about 400.degree. C.

Abstract: Production of a bonded magnet from a composition of a cross-linkable organic material and a particulate magnetic material by(1) placing in a mold a shaped composition in which the particles of magnetic material are optionally aligned and demagnetized,(2) rotating the mold about an axis thereof,(3) cross-linking the organic material in the shaped composition while rotating the mold,(4) recovering from the mold a shaped article, and(5) optionally remagnetizing the particles.