Abstract: A rare-earth sintered magnet according to the present invention, of which the main phase is an R2T14B type compound phase, includes: 27 mass % through 32 mass % of R, which is at least one rare-earth element that is selected from the group consisting of Nd, Pr, Tb, and Dy and that always includes at least one of Nd and Pr; 60 mass % through 73 mass % of T, which is either Fe alone or a mixture of Fe and Co; 0.85 mass % through 0.98 mass % of Q, which is either B alone or a mixture of B and C and which is converted-into B on a number of atoms basis when its mass percentage is calculated; more than 0 mass % through 0.3 mass % of Zr; at most 2.0 mass % of an additive element M, which is at least one element selected from the group consisting of Al, Cu, Ga, In and Sn; and inevitably contained impurities.

Abstract: A functionally graded rare earth permanent magnet is in the form of a sintered magnet body having a composition R1aR2bTcAdFeOfMg wherein the concentration of R2/(R1+R2) contained in grain boundaries surrounding primary phase grains of (R1,R2)2T14A tetragonal system within the sintered magnet body is on the average higher than the concentration of R2/(R1+R2) contained in the primary phase grains, R2 is distributed such that its concentration increases on the average from the center toward the surface of the magnet body, the oxyfluoride of (R1,R2) is present at grain boundaries in a grain boundary region that extends from the magnet body surface to a depth of at least 20 ?m, and the magnet body includes a surface layer having a higher coercive force than in the interior. The invention provides permanent magnets having improved heat resistance.

Abstract: A rare-earth alloy powder is obtained by rapidly cooling a melt of an alloy by an atomization process. The alloy has a composition represented by (Fe1-mTm)100-x-y-zQxRyTizMn, where T is at least one of Co and Ni, Q is at least one of B and C, R is at least one of the rare-earth metal elements and yttrium, and M is at least one of Nb, Zr, Mo, Ta and Hf. The mole fractions x, y, z, m and n satisfy 10 at %<x?25 at %, 6 at %?y<10 at %, 0.1 at %?z?12 at %, 0?m?0.5, and 0 at %?n?10 at %, respectively. By adding Ti to the alloy, the nucleation and growth of ?-Fe during the rapid quenching process can be minimized.

Abstract: Magnetic particles of the present invention comprising monocrystals of rare earth element-transition metal-metalloid having particle diameters of 5 nm to 50 nm. The magnetic particles are produced by a producing method comprising a step of fabricating a quenched thin band comprising rare earth element-transition metal-metalloid. A magnetic recording medium of the present invention includes the magnetic layer which contains therein the magnetic particles and the binder, and which is formed on the non-magnetic substrate.

Abstract: A rare earth permanent magnet is in the form of a sintered magnet body having a composition R1aR2bTcAdFeOfMg wherein F and R2 are distributed such that their concentration increases on the average from the center toward the surface of the magnet body, and grain boundaries having a concentration of R2/(R1+R2) which is on the average higher than the concentration of R2/(R1+R2) contained in primary phase grains of (R1,R2)2T14A tetragonal system form a three-dimensional network structure which is continuous from the magnet body surface to a depth of at least 10 ?m. The invention provides R—Fe—B sintered magnets which exhibit a high coercive force.

Abstract: A rare earth permanent magnet is in the form of a sintered magnet body having a composition R1aR2bTcAdFeOfMg wherein F and R2 are distributed such that their concentration increases on the average from the center toward the surface of the magnet body, the concentration of R2/(R1+R2) contained in grain boundaries surrounding primary phase grains of (R1,R2)2T14A tetragonal system within the sintered magnet body is on the average higher than the concentration of R2/(R1+R2) contained in the primary phase grains, and the oxyfluoride of (R1,R2) is present at grain boundaries in a grain boundary region that extends from the magnet body surface to a depth of at least 20 ?m. The invention provides R—Fe—B sintered magnets which exhibit high magnet performance despite minimal amounts of Tb and Dy used.

Abstract: A functionally graded rare earth permanent magnet having a reduced eddy current loss in the form of a sintered magnet body having a composition RaEbTcAdFeOfMg is obtained by causing E and fluorine atoms to be absorbed in a R—Fe—B sintered magnet body from its surface. F is distributed such that its concentration increases on the average from the center toward the surface of the magnet body, the concentration of E/(R+E) contained in grain boundaries surrounding primary phase grains of (R,E)2T14A tetragonal system is on the average higher than the concentration of E/(R+E) contained in the primary phase grains, the oxyfluoride of (R,E) is present at grain boundaries in a grain boundary region that extends from the magnet body surface to a depth of at least 20 ?m, particles of the oxyfluoride having an equivalent circle diameter of at least 1 ?m are distributed in the grain boundary region at a population of at least 2,000 particles/mm2, the oxyfluoride is present in an area fraction of at least 1%.

Abstract: An R—Fe—B based rare-earth alloy powder with a mean particle size of less than about 20 ?m is provided and compacted to make a powder compact. Next, the powder compact is subjected to a heat treatment at a temperature of about 550° C. to less than about 1,000° C. within hydrogen gas, thereby producing hydrogenation and disproportionation reactions (HD processes). Then, the powder compact is subjected to another heat treatment at a temperature of about 550° C. to less than about 1,000° C. within either a vacuum or an inert atmosphere, thereby producing desorption and recombination reactions and obtaining a porous material including fine crystal grains, of which the density is about 60% to about 90% of their true density and which have an average crystal grain size of about 0.01 ?m to about 2 ?m (DR processes). Thereafter, the porous material is subjected to yet another heat treatment at a temperature of about 750° C. to less than about 1,000° C.

Abstract: A R—Fe—B base rare earth permanent magnet material consists of, in percents by weight, 25 to 45 wt % of R, 0.1 to 4.5 wt % of Co, 0.8 to 1.4 wt % of B, 0.05 to 3.0 wt % of Al, 0.02 to 0.5 wt % of Cu, 0.03 to 0.5 wt % of M, 0.01 to 0.5 wt % of C, 0.05 to 3.0 wt % of O, 0.002 to 0.1 wt % of N, 0.001 to 2.0 wt % of F, with the balance of Fe and incidental impurities, wherein R is at least one element selected from among Nd, Pr, Dy, Tb and Ho, and M is at least one element selected from among Zr, Hf, Ti, Cr, Nb, Mo, Si, Sn, Zn, V, W and Cr.

Abstract: In a process of producing an R—Fe—B based rare-earth sintered magnet, first, an R—Fe—B based sintered magnet, including, as a main phase, R2Fe14B type compound crystal grains with a light rare-earth element RL (which is Nd and/or Pr) as a main rare-earth element R, is provided. Next, the surface of the sintered magnet body is coated with an RHM alloy layer including RH (which is at least one rare-earth element selected from Dy, Ho and Tb) and a metal M (which is at least one metallic element selected from Al, Cu, Co, Fe and Ag). Thereafter, a heat treatment is conducted at about 500° C. to about 1,000° C. within a vacuum or an Ar atmosphere, thereby diffusing the metallic element M and the heavy rare-earth element RH inward from the surface of the rare-earth sintered magnet body.

Abstract: An R-T-B exchange spring magnet alloy ingot is provided, wherein the R-T-B exchange spring magnet alloy ingot comprises at least one element selected from Nd, Pr, and Dy in a total amount of 1 to 12% by atom and B in an amount of 3 to 30% by atom, with a balance being T (T represents a substance predominantly comprising Fe, with a portion of Fe atoms being optionally substituted by Co, Ni, Cu, Al, Ga, Cr, and Mn). The R-T-B exchange spring magnet alloy ingot is produced through formation of a composite of crystal grains of a hard magnetic phase and crystal grains of a soft magnetic phase. The R-T-B exchange spring magnet alloy ingot contains crystal grains of a hard magnetic phase having a grain size of 1 ?m or less and crystal grains of a soft magnetic phase having a grain size of 1 ?m or less in a volume of at least 50% on the basis of the entire volume of the alloy.

Abstract: An R-T-B system permanent magnet 1 comprises a magnet body 2 comprising a sintered body comprising at least a main phase comprising R2T14B grains (wherein R represents one or more rare earth elements, and T represents one or more transition metal elements including Fe or Fe and Co essentially) and a grain boundary phase containing R in a larger amount than the main phase, the magnet body 2 having a 300 ?m or less thick (not inclusive of zero thick) hydrogen-rich layer 21 having a hydrogen concentration of 300 ppm or more formed in the surface layer portion, and an overcoat 3 covering the surface of the magnet body 2 can improve the corrosion resistance of the R-T-B system permanent magnet 1 with an overcoat 3 formed thereon without degrading the magnetic properties thereof.

Abstract: An R-T-B based sintered magnet according to the present invention has a composition comprising: 12 at % to 17 at % of a rare-earth element R; 5.0 at % to 8.0 at % of boron B; 0.1 at % to 1.0 at % of Al; 0.02 at % to less than 0.2 at % of Mn; and a transition metal T as the balance. The rare-earth element R is at least one element selected from the rare-earth elements, including Y (yttrium), and includes at least one of Nd and Pr. The transition element T includes Fe as its main element.

Abstract: Disclosed is a rare earth magnet in the R-T-B (rare earth element-transition metal-boron) system that is made from an improved composition and properties of main phase alloy in the R-T-B system containing Pr and a boundary alloy. Disclosed also is a manufacturing method of the rare earth magnet alloy flake by a strip casting method with improved rotating rollers such that the alloy flake has a specified fine surface roughness and has a small and regulated amount of fine R-rich phase regions. Consequently, the alloy flake for the rare earth magnet does not containing ?-Fe and has a homogeneous morphology so that the rare earth magnet formed by sintering or bonding the alloy flakes exhibits excellent magnetic properties.

Abstract: Hydrogen embrittlement is prevented in Sm2Co17-based magnets and R2Fe14B-based magnets by metal plating the magnet, then carrying out heat treatment, or by forming a metal oxide or metal nitride layer on the metal plating layer or directly on the magnet itself.

Abstract: A method of making a material alloy for an R-T-Q based rare-earth magnet according to the present invention includes the steps of: preparing a melt of an R-T-Q based rare-earth alloy, where R is rare-earth elements, T is a transition metal element, Q is at least one element selected from the group consisting of B, C, N, Al, Si and P, and the rare-earth elements R include at least one element RL selected from the group consisting of Nd, Pr, Y, La, Ce, Pr, Sm, Eu, Gd, Er, Tm, Yb and Lu and at least one element RH selected from the group consisting of Dy, Tb and Ho; cooling the melt of the alloy to a temperature of 700° C. to 1,000° C. as first cooling process, thereby making a solidified alloy; maintaining the solidified alloy at a temperature within the range of 700° C. to 900° C. for 15 seconds to 600 seconds; and cooling the solidified alloy to a temperature of 400° C. or less as a second cooling process.

Abstract: One object of the present invention is to provide a rare earth magnet alloy ingot, which has improved magnetic properties. In order to achieve the object, the present invention provides a rare earth magnet alloy ingot, wherein the rare earth magnet alloy ingot comprises an R-T-B type magnet alloy (R represents at least one element selected from among rare earth elements, including Y; and T represents a substance predominantly comprising Fe, with a portion of Fe atoms being optionally substituted by Co, Ni, Cu, Al, Ga, Cr, and Mn) containing at least one element selected from among Nd, Pr, and Dy in a total amount of 11.8 to 16.5% by atom and B in an amount of 5.6 to 9.1% by atom; and wherein as determined in an as-cast state of the alloy ingot, R-rich phase that measures 100 ?m or more is substantially absent on a cross section.

Abstract: A rare earth permanent magnet is prepared by disposing a powdered metal alloy containing at least 70 vol % of an intermetallic compound phase on a sintered body of R—Fe—B system, and heating the sintered body having the powder disposed on its surface below the sintering temperature of the sintered body in vacuum or in an inert gas for diffusion treatment. The advantages include efficient productivity, excellent magnetic performance, a minimal or zero amount of Tb or Dy used, an increased coercive force, and a minimized decline of remanence.

Abstract: A method for compacting a magnetic powder in a magnetic field comprising steps of filling a die with a magnetic powder, applying a pulsed magnetic field to the magnetic powder in the die to orientate the powder, and compressing the magnetic powder, wherein the pulsed magnetic field is applied twice or more when density ? of a compacted body of said magnetic powder satisfies the relationship ?=?×H0.5+?(?=0.63 and ?=1 to 2), where H is intensity (T) of the applied magnetic field.

Abstract: An inventive method of making a rare-earth alloy powder is used to produce a rare-earth sintered magnet, whose main phase has a composition R2T14A (where R is one of the rare-earth elements including Y; T is Fe with or without a non-Fe transition metal; and A is boron with or without carbon).

Abstract: A Nd—Fe—B type anisotropic exchange spring magnet is produced by a method of obtaining powder of a Nd—Fe—B type rare earth magnet alloy which comprises hard magnetic phases and soft magnetic phases wherein a minimum width of the soft magnetic phases is smaller than or equal to 1 ?m and a minimum distance between the soft magnetic phases is greater than or equal to 0.1 ?m, obtaining a compressed powder body by compressing the powder, and obtaining the Nd—Fe—B type anisotropic exchange spring magnet by sintering the compressed powder body using a discharge plasma sintering unit.

Abstract: The bonded magnet of the present invention, in which average particle diameter and compounding ratio are specified, is comprised of Cobalt-less R1 d-HDDR coarse magnet powder that has been surface coated with surfactant, R2 fine magnet powder that has been surface coated with surfactant (R1 and R2 are rare-earth metals), and a resin which is a binder. The resin, a ferromagnetic buffer in which R2 fine magnet powder is uniformly dispersed, envelops the outside of the Cobalt-less R1 d-HDDR coarse magnet powder. Despite using Cobalt-less R1 d-HDDR anisotropic magnet powder, which is susceptible to fracturing and therefore vulnerable to oxidation, the bonded magnet of the present invention exhibits high magnetic properties along with extraordinary heat resistance.

Abstract: The step of preparing a rapidly solidified alloy by rapidly quenching a melt of an R-T-B-C based rare-earth alloy (where R is at least one of the rare-earth elements including Y, T is a transition metal including iron as its main ingredient, B is boron, and C is carbon) and the step of thermally treating and crystallizing the rapidly solidified alloy are included. The step of thermally treating results in producing a first compound phase with an R2Fe14B type crystal structure and a second compound phase having a diffraction peak at a site with an interplanar spacing d of 0.295 nm to 0.300 nm (i.e., where 2?=30 degrees). An intensity ratio of the diffraction peak of the second compound phase to that of R2Fe14B type crystals representing a (410) plane is at least 10%. The present invention provides an R-T-B-C based rare-earth alloy magnetic material, including carbon (C) as an indispensable element but exhibiting excellent magnetic properties, and makes it possible to recycle rare-earth magnets.

Abstract: A sintered body comprising a main phase consisting of an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y), and T represents one or more transition metal elements essentially containing Fe, or Fe and Co), and a grain boundary phase containing a higher amount of R than the main phase, wherein a platy or acicular product exists. This sintered body enables to inhibit the grain growth, while keeping a decrease in magnetic properties to a minimum, and to improve a suitable sintering temperature range.

Abstract: A sintered body with a composition consisting of 25% to 35% by weight of R (wherein R represents one or more rare earth elements, provided that the rare earth elements include Y), 0.5% to 4.5% by weight of B, 0.02% to 0.6% by weight of Al and/or Cu, 0.03% to 0.25% by weight of Zr, 4% or less by weight (excluding 0) of Co, and the balance substantially being Fe. This sintered body has a coefficient of variation (CV value) showing the dispersion degree of Zr of 130 or less. In addition, this sintered body has a grain boundary phase comprising a region that is rich both in at least one element selected from a group consisting of Cu, Co and R, and in Zr. This sintered body enables to inhibit the grain growth, while keeping the decrease of magnetic properties to a minimum, and to improve the suitable sintering temperature range.

Abstract: An iron-based rare earth alloy magnet has a composition represented by the general formula: (Fe1-mTm)100-x-y-zQxRyMz, where T is at least one element selected from the group consisting of Co and Ni; Q is at least one element selected from the group consisting of B and C; R is at least one rare earth element substantially excluding La and Ce; and M is at least one metal element selected from the group consisting of Ti, Zr and Hf and always includes Ti. In this formula, the mole fractions x, y, z and m meet the inequalities of: 10 at %<x?20 at %; 6 at %?y<10 at %; 0.1 at %?z?12 at %; and 0?m?0.5, respectively.

Abstract: The present invention relates to a casting method which employs rapid solidification of metal, rare-earth metal or the like, as well as to a casting apparatus and a cast alloy. A centrifugal casting method includes the steps of pouring a molten material onto a rotary body; sprinkling the molten material by the effect of rotation of the rotary body; and causing the sprinkled molten material to be deposited and to solidify on the inner surface of a rotating cylindrical mold. The axis of rotation of the rotary body and the axis of rotation of the cylindrical mold are caused not to run parallel to each other. The centrifugal casting method can attain a decrease in average deposition rate. As a result, generation of the dendritic ?Fe phase or generation of a segregation phase of Mn or the like is suppressed, thereby realizing a high-performance R-T-B-type rare-earth magnet alloy.

Abstract: A stator is constructed by winding excitation coils around respective main poles. A rotor is constructed by fixing a first rotor unit, which consists of a pair of rotor cores and a magnetic material sandwiched between the rotor cores, and a second rotor unit, which has the same construction as the first rotor unit, to a rotation shaft. The rotor is assembled to the stator to form an assembled body. The magnet material of the first rotor unit is magnetized in the axial direction by a magnetizing flux passing through a half of the assembled body in the axial direction. The magnet material of the second rotor unit is magnetized in the axial direction in an opposite polarity by a magnetizing flux passing through the remaining half of the assembled body in the axial direction.

Abstract: A nanocomposite magnet has a composition represented by (Fe1-mTm)100-x-y-z-nQxRyTizMn, where T is at least one of Co and Ni, Q is at least one of B and C, R is at least one rare earth element that always includes at least one of Nd and Pr and optionally includes Dy and/or Tb, and M is at least one element selected from the group consisting of Al, Si, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb. The mole fractions x, y, z, m and n satisfy 10 at %<x?20 at %, 6 at %?y<10 at %, 0.5 at %?z?12 at %, 0?m?0.5 and 0 at %?n?10 at %, respectively. The nanocomposite magnet has an oxygen content of at most about 1,500 ppm by mass.

Abstract: In a rare earth magnet, an added heavy rare earth element RH such as Dy is effectively used without any waste, so as to effectively improve the coercive force. First, a molten alloy of a material alloy for an R-T-Q rare earth magnet (R is a rare earth element, T is a transition metal element, and Q is at least one element selected from the group consisting of B, C, N, Al, Si, and P), the rare earth element R containing at least one kind of element RL selected from the group consisting of Nd and Pr and at least one kind of element RH selected from the group consisting of Dy Tb, and Ho is prepared. The molten alloy is quenched, so as to produce a solidified alloy. Thereafter, a thermal treatment in which the rapidly solidified alloy is held in a temperature range of 400° C. or higher and lower than 800° C. for a period of not shorter than 5 minutes nor longer than 12 hours is performed.

Abstract: When an R-T-B system rare earth permanent magnet is obtained by a mixing method to obtain a sintered body with a composition consisting essentially of 25% to 35% by weight of R (wherein R represents one or more rare earth elements, providing that the rare earth elements include Y), 0.5% to 4.5% by weight of B, 0.02% to 0.6% by weight of Al and/or Cu, 0.03% to 0.25% by weight of Zr, 4% or less by weight (excluding 0) of Co, and the balance substantially being Fe, wherein a coefficient of variation (CV) showing the dispersion of Zr is 130 or lower, Zr is contained in a low R alloy. This sintered body enables to inhibit the grain growth, while keeping the decrease of magnetic properties to a minimum, and to improve the suitable sintering temperature range.

Abstract: A layered product prepared by applying a surface treatment to an adherend having a surface with a low binding property with an anaerobic adhesive, which does not require a complex work, primer application, effected by accelerating an adhesive curing rate, and does not change surface conditions of the adherend. The layered product comprises an adherend, an uneven deposition comprising Cu, V, a Cu alloy or a V alloy and having a height of 500 nm or less on the surface of the adherend, and an adhesive layer formed at least on the uneven deposition.

Abstract: A compound for a rare-earth bonded magnet includes a rare-earth alloy powder and a binder. The rare-earth alloy powder includes at least about 2 mass % of Ti-containing nanocomposite magnet powder particles with a composition represented by (Fe1-mTm)100-x-y-zQxRyMz, where T is Co and/or Ni; Q is B with or without C; R is at least one rare-earth element substantially excluding La and Ce; M is at least one metal element selected from Ti, Zr and Hf and always includes Ti; and 10<x?20 at %; 6?y<10 at %; 0.1?z?12 at %; and 0?m?0.5. The particles include at least two ferromagnetic crystalline phases, in which hard magnetic phases have an average crystal grain size of about 10 nm to about 200 nm, soft magnetic phases have an average crystal grain size of about 1 nm to about 100 nm; and the average crystal grain size of the soft magnetic phases is smaller than that of the hard magnetic phases.

Abstract: An R-T-B system rare earth sintered magnet having a high mechanical strength and excellent corrosion resistance is provided. The R-T-B system rare earth sintered magnet of the present invention comprises a sintered body comprising a main phase consisting of an R2T14B phase where R represents one or more rare earth elements and T represents one or more transition metal elements essentially containing Fe, or Fe and Co, and a grain boundary phase containing a higher amount of R than the above described main phase, wherein the surface of the above described sintered body is partially covered with a carbon compound layer. In the R-T-B system rare earth sintered magnet of the present invention, the area ratio of the partial surface of the above described sintered body covered with the above described carbon compound layer to the entire surface thereof is preferably between 10% and 90%.

Abstract: A rare earth alloy sintered compact includes a main phase represented by (LR1-xHRx)2T14A, where T is Fe with or without non-Fe transition metal element(s); A is boron with or without carbon; LR is a light rare earth element; HR is a heavy rare earth element; and 0<x<1. The sintered compact is produced by preparing multiple types of rare earth alloy materials including respective main phases having different HR mole fractions, mixing the alloy materials so that the sintered compact will include sintering a main phase having an average composition represented by (LR1-xHRx)2T14A, thereby obtaining a mixed powder, and the mixed powder. The alloy materials include first and second rare earth alloy materials represented by (LR1-uHRu)2T14A (where 0??&<x) and (LR1-vHRV)2T14A (where x<v?1) and including a rare earth element R(=LR+HR) at R1 and R2 (at%), respectively. ?=|R1?R2| is about 20% or less of (R1+R2)/2.

Abstract: An R-T-B system rare earth permanent is provided, which comprises a sintered body comprising: an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y) and T represents one or more transition metal elements essentially containing Fe, or Fe and Co) as a main phase; and a grain boundary phase containing a higher amount of R than the above main phase, wherein, when Pc (permeance coefficient) is 2, if a total flux is defined as f1 under the application of an effective magnetic field of 240 kA/m (providing that an effective magnetic field=an applied magnetic field?a demagnetizing field, and each value of them is absolute value), if a total flux is defined as f2 under the application of an effective magnetic field of 800 kA/m, and if a total flux is defined as f3 under the application of an effective magnetic field of 2,000 kA/m, a magnetization rate a (=f1/f3×100) is 40% or more, and a magnetization rate b (=f2/f3×100) is 90% or more.

Abstract: A sintered body with a composition consisting of 25% to 35% by weight of R (wherein R represents one or more rare earth elements, providing that the rare earth elements include Y), 0.5% to 4.5% by weight of B, 0.02% to 0.6% by weight of Al and/or Cu, 0.03% to 0.25% by weight of Zr, 4% or less by weight (excluding 0) of Co, and the balance substantially being Fe, wherein a coefficient of variation (CV) showing the dispersion of Zr is 130 or lower. This sintered body enables to inhibit the grain growth, while keeping the decrease of magnetic properties to a minimum, and to improve the suitable sintering temperature range.

Abstract: The object of the present invention is to provide a rare earth magnet which enables to achieve a good balance between high coercive force and high residual magnetic flux density, and its manufacturing method. The present invention provides a rare earth magnet in which a layered grain boundary phase is formed on a surface or a potion of a grain boundary of Nd2Fe14B which is a main phase of an R—Fe—B (R is a rare-earth element) based magnet, and wherein the grain boundary phase contains a fluoride compound, and wherein a thickness of the fluoride compound is 10 ?m or less, or a thickness of the fluoride compound is from 0.1 ?m to 10 ?m, and wherein the coverage of the fluoride compound over a main phase particle is 50% or more on average.

Abstract: A material for a rare earth permanent magnet having a high magnetic coercive force and a high residual magnetic flux density. 28 to 35% by weight of at least one rare earth element selected from the group consisting of neodymium, praseodymium, dysprosium, terbium, and holmium, 0.9 to 1.3% by weight of boron, 0.25 to 3% by weight of phosphorus, iron, and inevitable impurities. It can further comprise 0.1 to 3.6% by weight of cobalt and 0.02 to 0.25% by weight of copper.

Abstract: The present invention is a production method of an R-T-B—C rare earth alloy (R is at least one element selected from the group consisting of rare earth elements and yttrium, T is a transition metal including iron as a main component, B is boron, and C is carbon). An R-T-B bonded magnet containing a resin component, or an R-T-B sintered magnet with a resin film formed on the surface thereof is prepared, and a solvent alloy containing a rare earth element R and a transition metal element T is prepared. Thereafter, the R-T-B bonded magnet is molten together with the solvent alloy. In this way, a rare earth alloy can be recovered from a spent bonded magnet or a defective one generated in a production process stage, and a rapidly quenched alloy magnet can be obtained. As a result, magnet powder is recovered from the R-T-B magnet, and the recycling of a magnet including a resin component can be realized.

Abstract: A corrosion resistant rare earth magnet is characterized by comprising a rare earth permanent magnet represented by R-T-M-B wherein R is at least one rare earth element inclusive of Y, T is Fe or Fe and Co, M is at least one element selected from among Ti, Nb, Al, V, Mn, Sn, Ca, Mg, Pb, Sb, Zn, Si, Zr, Cr, Ni, Cu, Ga, Mo, W, and Ta, the contents of the respective elements are 5 wt %?R?40 wt %, 50 wt %?T?90 wt %, 0 wt %?M?8 wt %, and 0.2 wt %?B?8 wt %, and a coating on a surface of the permanent magnet comprising a silicone resin, a flake metal fine powder, and a complexing agent.

Abstract: A crucible comprising Al2O3 and at least one selected from rare earth oxides inclusive of Y2O3 as main components and characterized by firing at 500–1,800° C., the distribution of the rare earth oxide at a higher proportion in a fine particle portion having a particle size of up to 0.5 mm than in a coarse particle portion having a particle size in excess of 0.5 mm, and the substantial absence of the reaction product of the rare earth oxide with Al2O3 is suitable for the melting of a rare earth alloy.

Abstract: A rare earth magnet comprises rare earth magnet particles and a rare earth oxide being present between the rare earth magnet particles. The rare earth oxide is represented by a following general formula (I): R2O3??(I) where R is any one of terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.

Abstract: The present invention relates to highly quenchable Fe-based rare earth magnetic materials that are made by rapid solidification process and exhibit good magnetic properties and thermal stability. More specifically, the invention relates to isotropic Nd—Fe—B type magnetic materials made from a rapid solidification process with a lower optimal wheel speed and a broader optimal wheel speed window than those used in producing conventional magnetic materials. The materials exhibit remanence (Br) and intrinsic coercivity (Hci) values of between 7.0 to 8.5 kG and 6.5 to 9.9 kOe, respectively, at room temperature. The invention also relates to process of making the materials and to bonded magnets made from the magnetic materials, which are suitable for direct replacement of anisotropic sintered ferrites in many applications.

Abstract: A method of making an alloy powder for an R—Fe—B-type rare earth magnet includes the steps of preparing a material alloy that is to be used for forming the R—Fe—B-type rare earth magnet and that has a chilled structure that constitutes about 2 volume percent to about 20 volume percent of the material alloy, coarsely pulverizing the material alloy for the R—Fe—B-type rare earth magnet by utilizing a hydrogen occlusion phenomenon to obtain a coarsely pulverized powder, finely pulverizing the coarsely pulverized powder and removing at least some of fine powder particles having particle sizes of about 1.0 ?m or less from the finely pulverized powder, thereby reducing the volume fraction of the fine powder particles with the particle sizes of about 1.0 ?m or less, and covering the surface of remaining ones of the powder particles with a lubricant after the step of removing has been performed.

Abstract: A magnetic material manufacturing method, a ribbon-shaped magnetic material manufactured by the method, a powdered magnetic material formed from the ribbon-shaped magnetic material and a bonded magnet manufactured using the powdered magnet material are disclosed. The method and the magnetic materials can provide magnets having excellent magnetic properties and reliability. A melt spinning apparatus 1 is provided with a tube 2 having a nozzle 3 at the bottom thereof, a coil 4 for heating the tube and a cooling roll 5 having a circumferential surface 53 on which dimple correcting means is provided. A melt spun ribbon 8 is formed by injecting the molten alloy 6 from the nozzle 3 so as to be collided with the circumferential surface 53 of the cooling roll 5 in an inert gas atmosphere (ambient gas) such as helium gas, so that the molten alloy 6 is cooled and then solidified.

Abstract: A method for manufacturing an anisotropic magnet powder includes a high-temperature hydrogenation process of holding an RFeB-based alloy containing rare earth elements (R), B and Fe as main ingredients in a treating atmosphere under a first treating pressure (P1) of which a hydrogen partial pressure ranges from 10 to 100 kPa and at a first treating temperature (T1) which ranges from 953 to 1133 K, a structure stabilization process of holding the RFeB-based alloy after the high-temperature hydrogenation process under a second treating pressure (P2) of which a hydrogen partial pressure is 10 or more and at a second treating temperature (T2) which ranges from 1033 to 1213 K such that the condition T2>T1 or P2>P1 is satisfied, a controlled evacuation process of holding the RFeB-based alloy after the structure stabilization process in a treating atmosphere under a third treating pressure (P3) of which a hydrogen partial pressure ranges from 0.

Abstract: An R—Fe—B base sintered magnet having a composition of 12–17 at % of R (wherein R stands for at least two of yttrium and rare earth elements and essentially contains Nd and Pr), 0.1–3 at % of Si, 5–5.9 at % of B, 0–10 at % of Co, and the balance of Fe, containing a R2(Fe,(Co),Si)14B intermetallic compound primary phase and at least 1% by volume of an R—Fe(Co)—Si grain boundary phase, and being free of a B-rich phase exhibits a coercive force of at least 10 kOe despite a reduced content of heavy rare earth.

Abstract: A thin arc segment magnet made of a an R-T-B based, rare earth sintered magnet substantially comprising 28-33 weight % of R and 0.8-1.5 weight % of B, the balance being substantially Fe T, wherein R is at least one rare earth element including Y, and T is Fe or Fe and Co, which has an oxygen content of 0.3 weight % or less, a density of 7.56 g/cm3 or more, a coercivity iHc of 1.1 MA/m (14 kOe) or more at room temperature, and an orientation Br/4?Imax of 96% or more in an anisotropy-providing direction at room temperature can be produced by using a slurry mixture formed by introducing fine alloy powder of the above composition into a mixture liquid comprising 99.7-99.99 parts by weight of a mineral oil, a synthetic oil or a vegetable oil and 0.01-0.3 parts by weight of a nonionic surfactant and/or an anionic surfactant.

Abstract: The magnet powder-resin compound particles substantially composed of rare earth magnet powder and a binder resin are in such a round shape that a ratio of the longitudinal size a to the transverse size b (a/b) is more than 1.00 and 3 or less, and that an average particle size defined by (a/b)/2 is 50-300 ?m. They are produced by charging a mixture of rare earth magnet powder and a binder resin into an extruder equipped with nozzle orifices each having a diameter of 300 ?m or less; extruding the mixture while blending under pressure though the nozzle orifices to form substantially cylindrical, fine pellets; and rounding the pellets by rotation.