Abstract: Corrosion-resistant rare earth magnets and a method for their manufacture, said magnets containing at least one rare earth element in an amount of 5 to 40 weight %, Fe in an amount of 50 to 90 weight %, Co in an amount of 0 to 15 wt %, B in an amount of 0.2 to 8 weight %, and at least one additive selected from Ni, Nb, Al, Ti, Zr, Cr, V, Mn, Mo, Si, Sn, Ga, Cu, and Zn in an amount of 0 to 8 weight %. The method comprises the steps of: (i) pretreating the surfaces of the magnet after sintering it; (ii) activating the surfaces thereof; and (iii) coating the surfaces thereof with at least one layer of Ni-containing film by electroplating. The activating may be carried out by treating the surfaces with a soap or a surface active agent. The activated surfaces may be subjected to ultrasonic vibrations in water to remove foreign substances before electroplating.

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 process and apparatus for producing articles for magnetic use consisting of a metal alloy in the form of a continuous strip (3) from which the articles (33) are cut out, the alloy being subjected to a heat treatment comprising at least one annealing operation carried out in the presence of a magnetic field. The annealing operation is divided into at least two successive phases, respectively a first, initiating phase in the presence of a magnetic field, carried out on the alloy in the form of a continuous strip (3) as it unwinds, and a second phase of ageing carried out on the separated articles (33) obtained from the strip (3) which has undergone the first phase. The invention enables the production of articles, in particular, for the electrotechnical industry.

Abstract: To obtain an anticorrosive Fe-B-R type permanent magnet; in particular, to reduce deterioration rate of the initial magnetic properties below 10% after the magnet has been kept at 80.degree. C. in 90% relative humidity for 500 hours, the surface of the sintered permanent magnet is coated with metallic coating film layers of at least one noble metal layer and at least one base metal layer disposed on the noble metal layer. Diffusion heat treatment further improves the adhesiveness of the coating film layers.

Abstract: This invention concerns a heat treatment method for rare earth type permanent magnets which are primarily of the Nd-Fe-B type. With regard to these permanent magnets, which oxidize rather easily in the air, the alloy is crushed, and either compression formed in a magnetic a non-magnetic field, sintered at 900.degree. to 1,200.degree. C., and then machined into the shape desired, and then solution treated in an atmosphere of oxygen and/or nitrogen at a temperature of 900.degree. to 1,200.degree. C., and then aged at 300.degree. to 900.degree. C. in order that an oxide and/or nitride protective layer of 0.001 to 10 .mu. be formed on the surface of the permanent magnet to prevent corrosion and in order to relieve machining strain.

Abstract: A process for manufacturing a rare earth-iron-boron alloy permanent magnet by, after sintering, keeping the sintered alloy at temperatures of 750.degree.-1000.degree. C. for 0.2-5 hours, slowly cooling it at a cooling rate of 0.3.degree.-5.degree. C./min. to temperatures between room temperature and 600.degree. C.; annealing it at temperatures of 550.degree.-700.degree. C. for 0.2-3 hours, and rapidly cooling it at a cooling rate of 20.degree.-400.degree. C./min. The permanent magnet contains a matrix, a B-rich phase and a Nd-rich phase. In grain boundaries of the matrix phases covered by bcc phases, thin, fine plates of the bcc phases projecting into the matrix phases are once increased by the first heat treatment and slow cooling and then eliminated by the annealing.

Abstract: A heat-treatment process for producing rare earth-cobalt permanent magnets having relatively high and reproducible magnetic properties wherein one or more controlled cooling rates are applied in temperatures ranging from a sintering temperature and the isothermal annealing temperature. The controlled cooling rates are preferably divided into two steps. In the first step, the cooling rate is preferably greater than 10.degree. C./min. In the second step, the cooling rate is preferably less than 10.degree. C./min. and is ideally in the range of 2.degree.-4.degree. C./min. By the heat-treatment process of this invention, a permanent magnet having a high intrinsic coercivity of more than 20 kOe, a maximum energy product of greater than 19 MGOe, and a coercivity of greater than 8.1 kOe can be reproducibly obtained.

Abstract: The disclosed permanent magnet has a coercive force of larger than 500 Oe, a residual magnetic flux density of larger than 5 kG, and a maximum energy product of larger than 2 MGOe, and it consisting essentially of 48.about.66.9 Atm % of iron, 33.about.47 Atm % of platinum, and 0.1.about.10 Atm % of niobium. It includes a crystal structure of an incomplete single .gamma.1 phase of a face-centered tetragonal system due to either the composition thereof or heat treatment applied thereto. The permanent magnet are made by heating an alloy of the above main composition at 900.degree..about.1,400.degree. for one minute to ten hours and quenching the alloy at a high speed of faster than 30.degree. C./minute but slower than 2,000.degree. C./sec.

Abstract: A process for producing permanent magnet materials, which comprises the steps of:forming an alloy powder having a mean particle size of 0.3-80 microns and composed of, in atomic percentage, 8-30% R (provided that R is at least one of rare earth elements including Y), 2-28% B, and the balance being Fe and inevitable impurities,sintering the formed body at a temperature of 900.degree.-1200.degree. C.,subjecting the sintered body to a primary heat treatment at a temperature of 750.degree.-1000.degree. C.,then cooling the resultant body to a temperature of no higher than 680.degree. C. at a cooling rate of 3.degree.-2000.degree. C./min, andfurther subjecting the thus cooled body to a secondary heat treatment at a temperature of 480.degree.-700.degree. C.35 MGOe, 40 MGOe or higher energy product can be obtained with specific compositions.

Abstract: A process for producing an Sm.sub.2 Co.sub.17 alloy suitable for use as a permanent magnet, the alloy also containing iron, copper and zirconium or a similar group IVB or VB transition metal, and optionally praseodymium in partial replacement of the samarium.

Abstract: A fully self-aligned polycrystalline silicon emitter bipolar transistor. Self-alignment of the p.sup.+ base contact (12) is achieved by using oxidized sidewalls (8) (sidewall spacers) of the emitter mesa (7) as part of the p.sup.+ base contact implantation mask. Collector contact (13) alignment can be achieved using oxidized sidewalls (17) of polycrystalline silicon alignment mesas (14) defined in the same polysilicon as the emitter mesa (7) but deposited on oxide (2) rather than the implanted base region (5).

Abstract: A permanent-magnet material having a composition represented by the following formula;R(Co.sub.1-X-Y-.alpha.-.beta. Fe.sub.X Cu.sub.Y M.sub..alpha. M'.sub.62)A(wherein X, Y, .alpha., .beta., and A respectively represent the following numbers:0.01.ltoreq.X, 0.02.ltoreq.Y.ltoreq.0.25, 0.001.ltoreq..alpha..ltoreq.0.15,0.0001.ltoreq..beta..ltoreq.0.001, and 6.0.ltoreq.A.ltoreq.8.3,providing that the amount of Fe to be added should be less than 15% by weight, based on the total amount of the composition, and R, M, and M' respectively represent the following constituents:R: At least one element selected from the group of rare earth elements,M: At least one element selected from the group consisting of Ti, Zr, Hf, Nb, V, and Ta, andM': B or B+Si),is disclosed.

Abstract: In production of a permanent magnet by forming a roll of an elongated magnetic metal strap, a strap made from a spinodal decomposition type magnetic alloy is subjected, at least before formation into a roll, to age-hardening under concurrent magnetization in order to obtain a magnet having significant radial magnetic anisotropy well suited for use in sound systems such as loudspeakers.

Abstract: In production of a shadow mask for a color cathode ray tube from spinodal decomposition type magnet alloys, application of two staged agings before shaping successfully avoids thermal deformation of the product.

Abstract: An alloy is proposed for use in making permanent magnets. The alloy has the following composition by weight:______________________________________ Chromium 22.5 to 25.5% Cobalt 15.0 to 17.5% Molybdenum 2.0 to 4.0% Silicon 0.1 to 0.8% Oxygen less than 0.10% Effective carbon less than 0.06% Remainder iron and unavoidable impurities, ______________________________________where effective carbon is defined as carbon content plus 0.86 times nitrogen content.In a method of manufacturing permanent magnets, a workpiece is made of the alloy, for example by suction or extrusion casting, and the workpiece is subjected to a heat treatment comprising:(a) a homogenizing annealing for 15 minutes to 3 hours at 1230.degree. C. to 1280.degree. C., followed by quenching in water or oil; and(b) a thermo-magnetic treatment for 10 to 30 minutes at 720.degree. C. to 740.degree. C., followed by the application for 10 to 120 minutes in a preferred axial direction of a magnetic field of 80 to 240 kA/m at a temperature of 630.degree. C.

Abstract: Apparatus and method for forming radial orientation rare earth-transition metal magnets in continuous arc rings by hot isostatic pressing. A method includes the steps of compacting rare earth-transition metal powders having a particle size up to 40 microns into radially oriented rings in a mold provided with a radially aligning field, stacking a plurality of compacted radially oriented rings within an annular cavity within a sealed, evacuated cannister to form a cylinder of a predetermined height, subjecting the cannister to temperatures in the range of 900.degree. to 1150.degree. C. under a gas pressure of 15 kpsi to densify the compacts, and cooling the cannister and the compacts to room temperature.

Abstract: The permanet magnet composed of a rare earth element, e.g. samarium, and cobalt together with iron, copper and some other additive elements and prepared according to the inventive method has a high coercive force and excellent squareness of the magnetic hysteresis loop despite the relatively low content of copper which has been considered to be indispensable for obtaining a high coercive force. The characteristic feature of the inventive method consists in the aging treatment of the sintered body of the alloy powder of a specified composition undertaken in two or more steps, each being carried out by continuously cooling the sintered body within a specified temperature range at a specified cooling velocity.

Abstract: The disclosed permanent magnet consists of an iron-palladium alloy consisting of 25 to 40 atomic % of palladium, and the remainder of iron with less than 0.5 atomic % of impurities or an iron-palladium-silver alloy consisting of 19.5 atomic % of palladium, 0.1 to 27.5 atomic % of silver and the remainder of iron with less than 0.5 atomic % of impurities and having a crystalline structure with fine dispersion of .alpha.+.gamma..sub.1 phase in a matrix, so that the permanent magnet has a coercive force of higher than 500 Oe, a residual magnetic flux density of larger than 6 kG, and a maximum energy product of larger than 2 MG.Oe. The disclosed method of producing the aforementioned permanent magnet comprises steps of homogenizing solid solution treatment at a temperature depending on the specific alloy composition, cooling, and tempering at a suitable temperature so as to generate the aforementioned crystalline structure.

Abstract: Fe--Cr--Co alloys have found application in the manufacture of permanent magnets on account of magnetic properties such as, high coercive force, remanent magnetization, and energy product. A method is disclosed for producing magnetic articles comprising Fe, Cr, and Co from powders comprising elemental or pre-alloyed particles. A powder is mixed with an essentially noncarbonizing organic binder, compressed, heated to remove binder, sintered, and aged. Heating results in essentially complete removal of binder prior to sintering.Magnetic bodies produced according to the disclosed method typically comprise less than 1 weight percent of undesirable nonmagnetic phases and have a maximum energy product of at least 1 million gauss oersted.

Abstract: Magnetically actuated devices such as, e.g., switches and synchronizers typically comprise a magnetically semihard component having a square B-H hysteresis loop and high remanent induction. Among known alloys having such properties are Co-Fe-V, Co-Fe-Nb, and Co-Fe-Ni-Al-Ti alloys which, however, contain undesirably large amounts of cobalt.According to the invention, devices are equipped with a magnetically semihard, high-remanence Fe-Cr-Mo alloy which comprises Cr in a preferred amount in the range of 6-26 weight percent and Mo in a preferred amount in the range of 1-12 weight percent. Preparation of alloys of the invention may be by a treatment of annealing, deformation, and aging.Magnets made from alloys of the invention may be shaped, e.g., by cold drawing, rolling, bending, or flattening and may be used in devices such as, e.g., electrical contact switches, hysteresis motors, and other magnetically actuated devices.

Abstract: The disclosed permanent magnet has a coercive force of 500 Oe or more, a idual magnetic flux density of 5 kG or more, and a maximum energy product of 2 MG. Oe or more. The magnet alloy consists essentially of platinum and iron, and has an initial state of homogeneous dispersion of .gamma..sub.1 phase of face-centered tetragonal type in a .gamma. phase matrix of face-centered cubic type. To produce the magnet, the alloy is heated at 900.degree. to 1,400.degree. C. for 1 minute to 100 hours for homogenizing solid solution treatment, and quenched in water or in air at a rate of 30.degree. C./minute to 2,000.degree. C./second.

Abstract: To provide for an inexpensive magnet alloy, isotropic and nearly isotropic permanent magnet properties are developed in Fe-Mo-Ni alloys. Manufacture may be by a method which comprises steps of annealing, optional deforming by a limited amount, and aging.Typical magnetic properties of alloys of the invention are a coercive force in the range of 50-500 oersted, a magnetic remanence in the range of 7000-14000 gauss, and a magnetic squareness ratio of less than 0.9. Alloys of the invention are highly ductile even after plastic deformation, they are readily bonded to aluminum supports (as used, e.g., in the manufacture of twistor memories), and they are readily etched by etchants which leave aluminum unaffected.

Abstract: This invention relates to a process for manufacturing R.sub.2 Co.sub.17 system permanent magnet alloys of rare earth(R)-cobalt(Co) intermetallic compounds. Sm.sub.2 Co.sub.17 alloy, in which R is samarium (Sm) with respect to intermetallic compounds whose stoichiometric composition is R.sub.2 Co.sub.17, possesses high saturation magnetization and high Curie temperature making it possible to obtain a high energy product. However, its permanent magnetization has not been practiced much at all because coercive force could not be obtained. This invention practices heat aging for 0.5-200 hours at 700.degree.-800.degree. C. in the heat treatment process of the sintered material of R.sub.2 (Co,Fe,M).sub.17 system (M is one or more than one elements of Ti, Cr, Mn, Ni, Cu, Zr, Nb, Hf, Ta, and W) and the coercive force is increased by carrying out this process in a magnetic field to achieve permanent magnetization.

Abstract: A method of making a hard or semihard magnetic alloy which involves initially forming a body of a spinodally decomposable alloy composition of iron-chromium-cobalt base by casting an admixture of 3 to 30% by weight cobalt, 10 to 40% by weight chromium, 0.1 to 15% by weight vanadium and the balance iron. The body is then solution treated at an elevated temperature and for a period sufficient to produce a homogeneous single .alpha.-phase structure in the body and the solution-treated body is tempered at a reduced temperature and for a time period sufficient to spinodally decompose therein the single .alpha.-phase structure into a composition-modulated, phase-separated structure consisting of an .alpha..sub.1 phase which is magnetic and an .alpha..sub.2 phase which is nonmagnetic, said phase-separated structure forming the magnetic alloy.

Abstract: A magnetic alloy of the Fe-Cr-Co type having superior magnetic properties compared to those of the conventional magnetic alloys of this kind and consisting essentially of, by weight, 5 to 30% Co, 0.15 to 35% Cr, 0.1 to 10% Ti, 0.1 to 10% V, 0.1 to 5% of one element selected from the group consisting of W, Mo, Zr and Ta, and the balance being Fe.

Abstract: A method of producing an anisotropic magnet alloy containing iron, chromium and cobalt as the major constituents. The method has a step of aging treatment of the alloy in a magnetic field for permanentally magnetizing the alloy. The aging treatment in the magnetic field is conducted by at first treating the alloy at a temperature below the two-phase separation temperature of the alloy, under application of the magnetic field, thereby to form an anisotropic two-phase separated microstructure, and cooling the alloy continuously at a rate which is not so great, while maintaining the application of the magnetic field, thereby to make the two separated phases approach the equilibrium structures at lower temperature. By so doing, the undesirable disorder of anisotropy is avoided because the magnetic field is maintained to order the two-phase separated microstructure even if a new two-phase separated microstructure is formed during the cooling.

Abstract: Disclosed is the addition of at least two elements of Nb, V, Ta and Zr to the ternary alloy of R (rare earth)-Co-Cu for permanent magnet materials, to thereby provide the permanent magnets with increased coercive force, residual magnetization and energy product. The additional elements enable employment of such Cu and Fe contents of the alloy as less than 10% and more than 6%, respectively. These percentages were avoided in the prior art to prevent the reduction of Br and Hc, respectively.

Abstract: Disclosed is the addition of Nb, V, Ta or Zr to the ternary alloy of R (rare earth)-Co-Cu for permanent magnet materials, to thereby provide the permanent magnets with increased coercive force, residual magnetization and energy product. The additional elements enables employment of such Cu and Fe contents of the alloy as less than 10% and more than 6%, respectively. These percentages were avoided in the prior art to prevent the reduction of Br and Hc, respectively.

Abstract: Fe/Cr/Co alloys of this invention which are provided with both a good workability and maximum energy product of 2.0 MGOe or more, consist of 17 to 45% by weight of chromium, 3 to 14.9% by weight of cobalt and the remainder being essentially of iron, which also attribute to the method of producing improved Fe/Cr/Co permanent alloy products usable with good efficiency on an industrial scale and make the best possible use of the advantageous characteristics particular to the component compositions of the alloys. This method contains the aging in a magnetic field and preferably comprises at least the step of aging in a magnetic field the alloy material in a predetermined temperature range and the secondary aging treatment step of cooling continuously and gradually the alloy material through a predetermined temperature range.

Abstract: A method is disclosed for making a metallic body having desirable magnetic properties. The metallic body is made from an alloy which contains Fe, Cr, and Co and which may also contain one or several additional ferrite forming elements such as, e.g., Zr, Mo, V, Nb, Ta, Ti, Al, Si, or W. According to the disclosed method the alloy is cooled at a rate of at least 60 degrees C. per hour from an initial temperature at which the alloy is in an essentially single phase alpha state to a second temperature which is in a vicinity of 600 degrees C. Subsequently, the alloy is cooled at a second, slower rate to a third temperature which is in the vicinity of 525 degrees C.The disclosed method allows for a relatively broad range of initial temperatures, is relatively insensitive to compositional variations of the alloy, and permits simple reclamation of suboptimally treated parts. As a consequence, the method is particularly suited for large scale industrial production of permanent magnets as may be used, e.g.

Abstract: A copper-hardened permanent-magnet alloy consisting of cobalt, copper and at least one of the rare-earth metals (RE) with atomic number 57 - 71, is characterized by a coarse-grained matrix of the composition Re (Co.sub.1-y Cu.sub.y).sub.6+X, wherein 0.ltoreq.X.ltoreq.1 and 0.15<y<0.35.

Abstract: A permanent-magnet material containing samarium, cobalt, copper and iron, has the composition Sm(Co.sub.1-x-y- Fe.sub.x Cu.sub.y).sub.z, wherein 0 < x < 0.2, 0.1 < y < 0.3 and 6.5 < z < 7.5.

Abstract: Highly active catalysts, suitable for use in hydrogenation and other reactions, are prepared from an alloy of one or more of the Group VIII transition metals with yttrium or a rare earth metal. The alloy is ground to the desired particle size and is thereafter reacted with a gas containing carbon monoxide and hydrogen to form an intimate physical admixture of the Group VIII metal or its corresponding carbide with the oxide of yttrium or the rare earth metal.

Abstract: Permanent magnets are disclosed having a very high coercive force and a very great maximum energy product, and consisting essentially of a rare earth-cobalt based alloy. The alloy is expressed by the formula Sm.sub.1.sub.-u Ce.sub.u (Co.sub.1.sub.-v.sub.-w.sub.-x Cu.sub.v Fe.sub.w Mn.sub.x).sub.z where 0.ltoreq.u.ltoreq.0.20, 0.08.ltoreq.v.ltoreq.0.20, 0.ltoreq.w.ltoreq.0.08, 0.01.ltoreq.x.ltoreq.0.15 and 6.0.ltoreq.z.ltoreq.7.8, preferably 7.2.ltoreq.z.ltoreq.7.8. By using these alloys, the magnetic properties of the resultant permanent magnets are superiorly affected, and the magnet-preparing process is rendered much simplified. This is also because the conventional heat aging step may be eliminated, particularly when the z value is within the preferred range.