Abstract: A method for the manufacture of cobalt-rare earth permanent magnets formed of consolidated particles thereof, for installation within electromagnetic devices such as induction watthour meters, and the product thereof. The method includes the magnetization of the consolidated cobalt-rare earth to substantial saturation in a predetermined polarity, the demagnetization and installation of the cobalt-rare earth permanent magnet while in a demagnetized state in an electromagnetic device, then its remagnetization in situ within the device to substantial saturation in a magnetizing field of the same predetermined polarity.

Abstract: Ferromagnetic metal or alloy particles are prepared by reducing ferromagnetic metal ions in the solution with a reducing agent to obtain a slurry of ferromagnetic metal or alloy particles and separating the particles by attracting the particles on a magnetic drum which is rotated under contacting with the slurry, and washing the particles and separating the particles from the magnetic drum.

Abstract: A permanent magnetic material, predominantly containing cerium misch-metal (CeMM) and cobalt, characterized by the composition:(CeMM.sub.1-x RE.sub.x).sub.1 -y Sm.sub.y Co.sub.5.+-.0.2Wherein0<x<0.5; 0.ltoreq.y.ltoreq.0.25,Re comprises at least one of the rare earths, cerium, lanthanum, neodymium and praseodymium, and the cerium misch-metal approximately possesses the compositionCe.sub.60 La.sub..beta. Nd.sub..gamma. Pr.sub..delta.,Wherein0.45<.alpha.<0.550.20<.beta.<0.400.05<.gamma.<0.150.00<.delta.<0.05And.alpha.+.beta.+.gamma.+.delta..perspectiveto.1.

Abstract: A permanent magnet consists of a rare earth element (RE) or a mixture thereof, cobalt, iron and a transition metal (TM) selected from the group consisting of chromium, manganese, titanium, tungsten, molybdenum, and mixtures thereof; wherein for each two moles of the rare earth elements there are 14-19 moles of all other elements.

Abstract: A process is provided for improving magnetic properties of certain glassy metal alloys which comprises immersing toroidally wound cores of glassy metal alloy filaments in a thermally stable, nonferromagnetic, electrically inert and chemically unreactive liquid, maintaining the liquid at a temperature of between about 310.degree. and 350.degree. C for about 3/4 to 8 hrs., depending on the temperature selected, and cooling the filament to about 25.degree. C at a rate not greater than about 30.degree. C/min. through its Curie temperature. Optionally, a magnetic field of about 1 to 10 Oe may be applied circumferentially around the cores during cooling through the Curie temperature to further improve the magnetic properties of the glassy metal alloy.

Abstract: In a preferred embodiment thin layers of rare earth metal-cobalt powder comprising an outer layer of RCo.sub.5 and a discrete transitional layer of R.sub.2 Co.sub.17 are compressed against an adjacent thicker layer of iron powder to form a laminated green compact, with the rare earth-cobalt powdered material being magnetically aligned. The green laminate body is then sintered to densify the rare earth-cobalt material layer to a body wherein the pores are substantially noninterconnecting. The laminate structure is then magnetized. By this method a strong rare earth-cobalt (RCo.sub.5) permanent magnet body is produced in which the rare earth-cobalt layer may be very thin (of the order of 1 to 2 millimeters) but of relatively large surface area and supported by a strong iron layer so as to be durable in handling, manufacturing and use.It is possible to press an RCo.sub.5 layer directly onto a powdered iron layer when the oxygen content of the iron is suitably low. The method will also produce an R.sub.2 Co.sub.

Abstract: Alloy compositions based on ternary alloys of the chromium-cobalt-iron system modified by addition of zirconium molybdenum, niobium, vanadium, titanium, and/or aluminum, are found to manifest improved formability. Exemplary compositions are magnetic and evidence coercivities of 350-550 Oe., remanent magnetizations of from 10,000 - 7,500 Gauss, and maximum energy products in excess of one million. Improvement in formability may take the form of room temperature stamping, sometimes in air, to final configurations including curvatures of radius equal to thickness. Novel compositions particularly desirable from such standpoint necessarily contain zirconium together with aluminum, niobium, and/or titanium.

Abstract: The coercive force of pulverized selected rare earth-cobalt alloys is increased or maintained at least at its initial value by depositing tin on the surface of the alloy particles and subjecting the particles to a heat treatment so as to cause diffusion of the tin into the particle structure.Permanent magnets formed from tin enriched rare earth-cobalt alloy particles are also disclosed.

Abstract: Ferromagnetic powders comprising cobalt and/or nickel are produced by reducing cobalt and/or nickel salts in an aqueous solution containing hypophosphite ions while applying a magnetic field.

Abstract: The disclosed magnetic devices, including a magnetically coupled conducting path, incorporate amorphous, low magnetostriction alloys of the general formula (Co.sub.a Fe.sub.b T.sub.c).sub.i X.sub.j, the "metallic" constituents thereof being within the parenthetical expression. T, in the formulation, is selected from among Ni, Cr, Mn, V, Ti, Mo, W, Nb, Zr, Pd, Pt, Cu, Ag and Au, X being at least one "glass former" selected from among P, Si, B, C, As, Ge, Al, Ga, In, Sb, Bi and Sn. The "metallic" constituents comprise from 70-90 atomic percent of the alloy with cobalt being present in an amount of at least 70 atomic percent of the "metallic" constituents. The described material is prepared by rapid cooling from the liquid, directly to the shape needed for fabrication of the device (e.g., tape to be wound to form an inductor core).

Abstract: Through the practice of this invention there is achieved control of the vibrational frequency of an electromechanical oscillator. This is achieved by utilizing the change in Young's modulus of elasticity which occurs for certain materials with applied magnetic field, known as the .DELTA.E-effect. By selective annealing in the presence of specially directed magnetic field, the .DELTA.E-effect is selectively altered along specific directions in the vibrational member. Additionally, by control of the .DELTA.E-effect of a sonic delay line, there is achieved control of the delay time for an acoustic pulse propagating therein.

Abstract: A method for increasing the magnetic permeability of a magnetic alloy having an easy axis and a hard axis which comprises subjecting a body of the magnetic alloy to a magnetic field of at least about 40 Gauss oriented in the direction of the hard axis while the body is maintained at a temperature at or above that required to deposit the alloy on a substrate.

Abstract: A method is described for producing permanent magnets, in accordance with which magnetic material in finely divided or powdered form, comprising an alloy of a rare earth metal and cobalt, is first premagnetized by subjecting it to a high-intensity magnetic field to magnetize the individual particles thereof, the particles are then introduced into a hardenable resinous material and caused to be distributed substantially uniformly throughout at least a region of said resinous material. While said particles are being introduced into and distributed throughout said resinous material, they are subjected to a magnetic field to align them magnetically. The resinous material is then hardened to form a body thereof in which said particles are maintained in magnetic alignment to form an effective permanent magnet structure. In preferred forms of the invention, fibrous material and/or fiberglass cloth or mat may be embedded in the matrix to enhance its strength.

Abstract: A rotor containing rare earth magnet material which can be assembled, machined and then magnetized. A stack of laminations is built up, pieces of virgin rare earth magnet material are inserted in the slots provided therefor in the laminations, the laminations with the rare earth magnet material are cast with aluminum, the cast rotor is machined and the rare earth magnet material is then magnetized. The strength of the rare earth magnets in the rotor may be adjusted after magnetization thereof.

Abstract: A method of making an integral toroidal magnet comprising the steps of compacting suitable magnetic powder material into a toroidal shape while subjecting it to a particle aligning magnetic field, hot pressing the compacted powder toroid in a confining die at a temperature and pressure sufficient to cause shrinkage of the toroid in the axial direction and provide a packing density greater than 93% of the theoretical maximum value and substantially unidimensional shrinkage, heat treating the toroid at a temperature sufficiently higher than the hot pressing temperature to achieve an enhanced crystallographic alignment equivalent to the alignment obtained by sintering, annealing the toroid at a temperature sufficiently lower than the heat treating temperature to provide a magnetic coercivity similar to the coercivity achieved by annealing after sintering, and magnetizing the heat treated toroid in the direction of crystallographic alignment.

Abstract: The permanent magnet of a magnetic structure is formed of isotropic magnetic material, and is magnetized along the path that the flux follows during use of the magnetic structure to increase the efficiency of the magnetic structure in use. The magnetic structure, which may be the annular magnetic structure of an electrodynamic loudspeaker, includes a cylindrical permanent magnet and an annular cup-like return path element connected to the magnet at one end thereof and forming an air gap with the magnet at the opposite end. Apparatus is provided for magnetizing the permanent magnet having an annular portion which may extend into the air gap of the speaker magnetic structure, to provide curved magnetic lines in the permanent magnet in substantially the path of the operating flux to the air gap.

Abstract: A ferromagnetic powder which contains at least Fe--B or Fe--Co--B with the surface of the powder having thereon a layer of Cr or a layer mainly consisting of Cr and a method of preparing the ferromagnetic powder comprising reducing a metal salt capable of forming a ferromagnetic powder containing at least Fe or Fe-Co in an aqueous solution thereof with one or more borohydride compounds or derivatives thereof and after the reduction is initiated adding an aqueous solution containing Cr ion or an anion containing Cr.

Abstract: In accordance with a preferred embodiment of this invention, ferromagnetic, polycrystalline, iron-based materials are subjected to an alternating magnetic field at low temperatures. This treatment provides improved mechanical properties and resistance to corrosive attack. It is believed that this improvement is due to a modification in the dislocation density and distribution in the material. More specifically, it is believed that this method causes a significant reduction in the dislocation density and thereby produces a more perfect crystalline lattice structure.

Abstract: A method of producing metal parts having magnetic and non-magnetic portions comprising heat treating an integral workpiece made of a metal capable of acquiring a magnetic structure in the course of aging and of losing the magnetic structure after high temperature tempering. The portions intended for producing the magnetic structure are heated to a temperature of 450.degree. to 980.degree.C, soaked until the magnetic structure is formed and then cooled, and the portions intended for producing a non-magnetic structure are heated to a temperature of between 1000.degree.C and the melting point of the metal so that its integrity is retained and then cooled at a rate that prevents the formation of the magnetic structure.

Abstract: The problem of characterizing metallic magnetic particles as suitable or unsuitable for use in a high density magnetic recording media is believed to have been solved by use of a figure of merit designated as "W/H.sub.c ", and defined herein.It has been found that metallic magnetic particles which exhibit a W/H.sub.c of about 1.2 or less offer the most desirable magnetic recording characteristics for high density magnetic recording media. With this characterization technique available, it has been determined that most quantities of metallic magnetic cobalt-phosphorus particles produced by chemical reduction have W/H.sub.c 's greater than 1.2, and are unsuitable for use in high density magnetic recording media. Using W/H.sub.c, it has been possible to recognize those metallic particles which are suitable for use in high density recording media, and to engage in experimentation to determine what methods of manufacturing are required for the production of suitable high density recording particles.

Abstract: A spinodal decomposition-type hard or semi-hard magnetic alloy consisting by weight essentially of 3 to 20 % cobalt, 10 to 40 % chromium, 0.2 to 5 % one or both of niobium and tantalum, 0 to 5 % aluminum and the balance of iron. When aluminum is to be incorporated, its lower limit should be 0.5 %.

Abstract: Carbonyl iron powder core (dust core) materials whose rate of change of magnetic permeability with temperature are preselected, are produced by a process which includes the mixing together of powders from two source batches. These source batches produce core materials whose temperature coefficients, Y and Z, lie on either side of the desired temperature coefficient, X. The fraction, A, of the Y powder is selected in accordance with the formula:A = 0.7 [(X-Y)/(Z-Y)] + 0.15; 0.15 .ltoreq. A .ltoreq. 0.85.exemplary core materials incorporate a phosphate insulator and a phenolic binder.

Abstract: A magnetic recording medium for high density recording comprising a support having thereon a magnetic recording layer comprising a ferromagnetic metal powder of the Fe-Co-Cr-B system and having a coercive force of about 700 to 500 oersteds in the oriented direction of the magnetic substance and a residual magnetic flux density of about 1500 gausses or more, the residual magnetic flux density of which after storage for 160 hours under the conditions of a temperature of 60.degree.C and 90%RH is 85% or more of the initial value thereof before storage under these conditions in a binder. The magnetic recording medium is especially suitable for high density recording, having sufficient sensitivity and excellent resistance.

Abstract: Magnets are produced by dissolving in a solvent organic polymer which is a binder for magnetic powder, adding a magnetic powder to the solution, then adding to the solution a vehicle in which the polymer is insoluble. The vehicle is added until the polymer has precipitated onto the magnetic particles. These coated particles are then dried and hot pressed within an orienting magnetic field to produce the magnet.

Abstract: For forced ageing of a commutator intended for a rotary electrical machine while the commutator is being rotated, heat is being supplied to it by a coil for generating a high frequency magnetic field arranged outside the commutator in such a way that the field is directed substantially perpendicular to the commutator surface, the coil being supplied with a current of a frequency of at least 1,000 Hz.