Abstract: This invention provides a soft magnetic yoke-integrated bonded magnet in which a soft magnetic yoke has been integrally compression molded in such a state that the soft magnetic yoke is engaged in a joined face formed by bringing a binding material-containing magnetic powder into contact with a binding material-containing soft magnetic powder. The soft magnetic yoke part and the bonded magnetic part are constructed so that, when the soft magnetic yoke part and the bonded magnet part are compression molded separately from each other, the spring back level is identical upon the release of the compression force.

Abstract: The iron-based rare-earth nanocomposite magnet of the present invention has a composition T100?x?y?z?nQxRyTizMn, where T is Fe or a transition metal element in which Fe is partially replaced by Co and/or Ni; Q is B and/or C; R is at least one rare-earth element including substantially no La or Ce; and M is at least one metal element selected from Al, Si, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb. x, y, z and n satisfy 5?x?10 at %, 7?y?10 at %, 0.1?z?5 at % and 0?n?10 at %, respectively. The magnet includes R2Fe14B-type compound phases and ? —Fe phases forming a magnetically coupled nanocomposite magnet structure. The R2Fe14B-type compound phases have an average crystal grain size of 30 nm to 300 nm and the ? —Fe phases have an average crystal grain size of 1 nm to 20 nm. The magnet has magnetic properties including a coercivity of at least 400 kA/m and a remanence of at least 0.9 T.

Abstract: In known methods, an improvement of the coercive force is realized by allowing the Dy metal or the like to present selectively in crystal grain boundary portions of a sintered magnet. However, since these are based on a physical film formation method, e.g., sputtering, through the use of a vacuum vessel, there is a mass productivity problem when a large number of magnets are treated. Furthermore, there is a magnet cost problem from the viewpoint that, for example, an expensive, high-purity Dy metal or the like must be used as a raw material for film formation. The method for modifying grain boundaries of a Nd—Fe—B base magnet includes the step of allowing an M metal component to diffuse and penetrate from a surface of a Nd—Fe—B base sintered magnet body having a Nd-rich crystal grain boundary phase surrounding principal Nd2Fe14B crystals to the grain boundary phase through a reduction treatment of a fluoride, an oxide, or a chloride of an M metal element (where M is Pr, Dy, Tb, or Ho).

Abstract: Disclosed is a novel process for producing an NaZn13 magnetic alloy which enables to obtain a magnetic alloy having higher characteristics than ever before. Specifically disclosed is a magnetic alloy represented by the following composition formula: (La1?xRx)a(A1?yTMy)bHcNd (wherein R represents at least one or more elements selected from rare earth elements including Y; A represents Si, or Si and at least one or more elements selected from the group consisting of Al, Ga, Ge and Sn; TM represents Fe, or Fe and at least one or more elements selected from the group consisting of Sc, Ti, V, Cr, Mn, Co, Ni, Cu and Zn; and x, y, a, b, c and d respectively satisfy, in atomic percent, the following relations: 0?x?0.2, 0.75?y?0.92, 5.5 ?a?7.5, 73?b?85, 1.7?c?14 and 0.07?d<5.0; with unavoidable impurities being included).

Abstract: An objective of the present invention is to provide a rare earth metal-based sintered magnet having imparted thereto sufficient corrosion resistance by an oxidative heat treatment, which is resistant even in an environment of fluctuating humidity, while suppressing the deterioration of the magnetic characteristics ascribed to the oxidative heat treatment, and to provide a method for producing the same.

Abstract: An R—Fe—B based thin film magnet including an R—Fe—B based alloy which contains 28 to 45 percent by mass of R element (where R represents at least one type of rare-earth lanthanide elements) and which is physically formed into a film, wherein the R—Fe—B based alloy has a composite texture composed of R2Fe14B crystals having a crystal grain diameter of 0.5 to 30 ?m and R-element-rich grain boundary phases present at boundaries between the crystals. The magnetization characteristics of the thin film magnet are improved. The R—Fe—B based thin film magnet can be prepared by heating to 700° C. to 1,200° C. during physical film formation or/and the following heat treatment, so as to grow crystal grains and form R-element-rich grain boundary phases.

Abstract: An R-T-B based sintered magnet according to the present invention has a composition comprising: 12 at % to 15 at % of a rare-earth element R; 5.0 at % to 8.0 at % of boron B; 0.1 at % to 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: The present invention relates to a process of producing a permanent magnet, which includes extruding a preform to form a plate-shaped permanent magnet, in which the preform is extruded in such a way that a dimension of a cross section of the preform is reduced in an X-direction and enlarged in a Y-direction perpendicular to the X-direction. The present invention also relates to a plate-shaped permanent magnet formed by extruding a preform, in which the preform is extruded in such a way that a dimension of a cross section of the preform is reduced in an X-direction and enlarged in a Y-direction perpendicular to the X-direction, whereby the permanent magnet has a strain ratio ?2/?1 with respect to the preform in a range of 0.2 to 3.5, in which ?1 is a strain in the direction of the extrusion of the preform and ?2 is a strain in the Y-direction.

Abstract: The invention provides a method for producing alloy flakes for rare earth sintered magnets, which makes uniform the intervals, size, orientation, and shape of the R-rich region and the dendrites of the 2-14-1 phase, which inhibits formation of chill, and which produces flakes that are pulverized into powder of a uniform particle size in the pulverization step in the production of a rare earth sintered magnet, and that are pulverized into powder compactable into a product with a controlled shrink ratio, and alloy flakes for a rare earth sintered magnet obtained by the method, and a rare earth sintered magnet having excellent magnetic properties.

Abstract: A magnet comprising grains of a ferromagnetic material whose main component is iron and a fluorine compound layer or an oxy-fluorine compound layer of fluoride compound particles of alkali metals, alkaline earth metals and rare earth elements, present on the surface of the ferromagnetic material grains, wherein an amount of iron atoms in the fluorine compound particles is 1 to 50 atomic %.

Abstract: A method for producing an RE-containing alloy represented by formula R(T1?xAx)13?y (wherein R represents Ce, etc.; T represents Fe, etc.; and A represents Al, etc; 0.05?x?0.2; and ?1?y?1) including a melting step of melting alloy raw materials at 1,200 to 1,800° C.; and a solidification step of rapidly quenching the molten metal produced through the above step, to thereby form the first RE-containing alloy, wherein the solidification step is performed at a cooling rate of 102 to 104° C./second, as measured at least within a range of the temperature of the molten metal to 900° C.; and an RE-containing alloy, which is represented by a compositional formula of RrTtAa (wherein R and A represent the same meaning as above, T represents Fe, etc.; 5.0 at. %?r?6.8 at. %, 73.8 at. %?t?88.7 at. %, and 4.6 at. %?a?19.4 at. %) and has an alloy microstructure containing an NaZn13-type crystal structure in an amount of at least 85 mass % and ?-Fe in an amount of 5-15 mass % inclusive.

Abstract: There is provided a method of manufacturing a permanent magnet in which Dy and/or Tb adhered to the surface of a sintered magnet containing a lubricant can be efficiently diffused and in which the permanent magnet having high magnetic properties can be manufactured at good productivity. The permanent magnet is manufactured by executing a first step of adhering at least one of Dy and Tb to at least a part of a surface of a sintered magnet made by sintering iron-boron-rare earth based alloy raw meal powder containing a lubricant; and a second step of heat-treating the sintered magnet at a predetermined temperature to thereby disperse at least one of Dy and Tb adhered to the surface of the sintered magnet into grain boundary phase of the sintered magnet. At this time, as the sintered magnet, there is used one manufactured in an average grain size within a range of 4 ?m˜8 ?m.

Abstract: A reactive sintered magnetic article, a composite article comprising a mantle and at least one core and a laminate article comprising two or more composite articles are provided which each comprise (La1-aMa) (Fe1-b-cTbYc)13-dXe, wherein 0?a?0.9, 0?b?0.2, 0.05?c?0.2, ?1?d?+1, 0?e?3.

Abstract: An objective of the present invention is to provide a method for producing a rare earth metal-based permanent magnet having an Al film containing Mg, which exhibits an excellent salt water resistance. The present invention, which is to accomplish the objective, is a method for producing a rare earth metal-based permanent magnet having formed on the surface thereof an Al film containing Mg by a vapor deposition, characterized in that the production method comprises, in the case of cooling the magnet from a high temperature of 160° C. or higher after the completion of the vapor deposition step inside the treating chamber of a deposition apparatus, rapidly cooling down the magnet at a cooling rate of 10° C./min or higher until the temperature of the magnet reaches at least 60° C.

Abstract: A rapidly solidified Fe—Ga alloy containing 15 to 23 atomic percent of Ga having a particular rapidly solidified texture is formed into slices which are laminated to each other in a die, or is formed into a powder or chops which are filled in the die. Subsequently, spark plasma sintering is performed so that bonds between the slices, grains of the powder, or the chops are formed at a high density to form a bulk alloy and the rapidly solidified texture is not lost, followed by annealing whenever necessary, so that a magnetostriction of 170 to 230 ppm at room temperature is obtained.

Abstract: A rare earth magnet powder has a chemical composition which includes R: 5 to 20% (wherein, R represents one or two or more rare earth elements being inclusive of Y but exclusive of Dy and Tb), one or two of Dy and Tb: 0.01 to 10%, and B: 3 to 20%, with the balance comprising Fe and inevitable impurities; and an average particle diameter of 10 to 1,000 ?m, wherein 70% or more of the entire surface of the rare earth magnet powder is covered with a layer being rich in the content of one or two of Dy and Tb and having a thickness of 0.05 to 50 ?m.

Abstract: A rare earth magnet includes rare earth magnet particles; and amorphous and/or crystalline terbium oxide present at the boundary of the rare earth magnet particles and represented by the formula: TbOn, wherein 1.5<n?2. The rare earth magnet prevents decrease eddy current effectively.

Abstract: The present invention is an alloy lump for R-T-B type sintered magnets, including an R2T14B columnar crystal and an R-rich phase (in which R is at least one rare earth element including Y, T is Fe or Fe with at least one transition metal element except for Fe, and B is boron or boron with carbon), in which in the as-cast state, R-rich phases nearly in the line-like or rod-like shape (the width direction of the line or rod is a short axis direction) are dispersed in the cross section, and the area percentage of the region where R2T14B columnar crystal grains have a length of 500 ?m or more in the long axis direction and a length of 50 ?m or more in the short axis direction is 10% or more of the entire alloy.

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: A magnetic alloy material according to the present invention has a composition represented by Fe100-a-b-cREaAbCoc, where RE is a rare-earth element always including La, A is either Si or Al, 6 at %?a?11 at %, 8 at %?b?18 at %, and 0 at %?c?9 at %, and has either a two phase structure consisting essentially of an ?-Fe phase and an (RE, Fe, A) phase including 30 at % to 90 at % of RE or a three phase structure consisting essentially of the ?-Fe phase, the (RE, Fe, A) phase including 30 at % to 90 at % of RE and an RE(Fe, A)13 compound phase with an NaZn13-type crystal structure. The respective phases have an average minor-axis size of 40 nm to 2 ?m.

Abstract: A powder raw material is prepared by mixing at least two kinds of powders selected from a powder A, a powder B, a powder C, and a powder D. A sintered body of a magnetic material having an NaZn13 crystal structure phase is formed by heating the powder raw material while applying a pressure treatment. The powder A is at least one of elemental powder of element R selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. The powder B is at least one of elemental powder of element T selected from Fe, Co, Ni, Mn, and Cr. The powder C is at least one of elemental powder of element M selected from Si, B, C, Ge, Al, Ga, and In. The powder D is a compound powder composed of at least two kinds of elements selected from the element R, the element T, and the element M.

Abstract: Radially oriented ring-shaped preliminarily molded pieces of a ring magnet are stacked in an axial direction to form a ring-shaped molded body, in which end faces of the ring-shaped preliminarily molded pieces are bonded together. This ring-shaped molded body is sintered and heat-treated to produce the ring magnet. Ring magnets which are less susceptible to deterioration of magnetic properties due to a disturbance of magnetic orientation near lamination boundary surfaces are produced. The invention provides a method of manufacturing such ring magnets with high efficiency.

Abstract: A method of making a magnetically anisotropic magnet powder according to the present invention includes the steps of preparing a master alloy by cooling a rare-earth-iron-boron based molten alloy and subjecting the master alloy to an HDDR process. The step of preparing the master alloy includes the step of forming a solidified alloy layer, including a plurality of R2Fe14B-type crystals (where R is at least one element selected from the group consisting of the rare-earth elements and yttrium) in which rare-earth-rich phases are dispersed, by cooling the molten alloy through contact with a cooling member.

Abstract: To make a raw alloy, consisting mostly of amorphous structure, highly productively and at a reduced cost for a nanocomposite magnet, a molten alloy represented by Fe100-x-y-zRxQyMz (where R is at least one element selected from Pr, Nd, Dy and Tb; Q is B and/or C; M is at least one element selected from Co, Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Ag, Pt, Au and Pb; and 1 at %?x<6 at %, 15 at %?y?30 at % and 0 at %?z?7 at %) is prepared. This molten alloy is rapidly cooled by a strip casting process in which the alloy is fed onto a chill roller, rotating at a peripheral velocity of 3 m/s to less than 20 m/s, at a feeding rate per unit contact width of 0.2 kg/min/cm to 5.2 kg/min/cm. In this manner, an alloy including at least 60 volume percent of amorphous phase can be obtained.

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: Disclosed is an isotropic SmFeN powdery magnet material for producing resin-bonded magnets. The magnet powder is prepared by melt-spinning of a molten alloy and nitriding the alloy powder thus obtained to form a magnet alloy having an alloy composition of one of the formulae, by atomic %: SmxFe100-x-vNv, SmxFe100-x-y-vM1yNv and SmxFe100-x-z-vM2zNv wherein M1 is at least one member selected from the group consisting of Hf and Zr; and M2 is at least one member selected from the group consisting of Si, Nb, Ti, Ga, Al, Ta and C; 7?x?12, 0.1?y?1.5, 0.1?z?1.0 and 0.5?v?20; the crystal structure is TbCu7 type; and the thickness of the flakes is 10-40 ?m.

Abstract: A method for manufacturing a sintered compact includes the steps of preparing an alloy powder having a composition represented by Expression 1: RTW (where, R is at least one kind of rare earth metal, T is at least one kind of transition metal, and w defines a relation of 1<w<4), sintering the alloy powder in a vacuum atmosphere or an atmosphere containing gas with a molecular weight of 30 or less, and processing the alloy powder by a hot isostatic pressing. The sintered compact has a high density, and reduces deteriorations in its sintered compact properties such as magnetostrictive properties in an air atmosphere at high-temperatures.

Abstract: A magnetic stone device and assembly is provided. The magnetic stone device includes a magnetic stone and a metallic coating applied to at least part of the surface of the magnetic stone. The coating has a first color at a first portion of the magnetic stone and a second color different from said first color at a second portion of the magnetic stone. A method of manufacturing the magnetic stone device is also provided. A magnetic bead, assembly, and method of manufacture are also provided.

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 for preparing a rare earth permanent magnet material comprising the steps of: disposing a powder comprising one or more members selected from an oxide of R2, a fluoride of R3, and an oxyfluoride of R4 wherein R2, R3 and R4 each are one or more elements selected from among rare earth elements inclusive of Y and Sc on a sintered magnet form of a R1—Fe—B composition wherein R1 is one or more elements selected from among rare earth elements inclusive of Y and Sc, and heat treating the magnet form and the powder at a temperature equal to or below the sintering temperature of the magnet in vacuum or in an inert gas. The invention offers a high performance, compact or thin permanent magnet having a high remanence and coercivity at a high productivity.

Abstract: A method for processing CoPt alloys with improved magnetic properties. The method includes sealing a sample of a CoPt alloy in an evacuated quartz tube, and heating the alloy to a temperature of approximately 1000 degrees C. to homogenize the alloy for approximately 3 hours. The sample is then cooled at a controlled cooling rate of 120-150 degrees C. per minute to 600 degrees C. The sample is then held at 600 degrees C. for 10 hours to promote isothermal ordering. Finally, the sample is quenched in mineral oil.

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: 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: The present invention provides a tempering process for sintered Nd—Fe—B permanent magnet material, which optimizes the microstructure of the Nd—Fe—B magnet and improves intrinsic coercive force and its consistency by increasing the cooling rate after tempering. After heating to a temper temperature, the magnetic material is cooled in a cooling liquid within a cooling chamber into which a pressurized cooling gas is introduced.

Abstract: To avoid various problems caused by remnant magnetization and produce an anisotropic bonded magnet at a reduced cost, a method for producing an anisotropic bonded magnet by feeding a magnetic powder (such as an HDDR powder) into the cavity of a press machine and compacting it is provided. A weak magnetic field is created as a static magnetic field in a space including the cavity by using a magnetic member that is steadily magnetized. The magnetic powder being transported into the cavity is aligned parallel to the direction of the weak magnetic field. Next, the magnetic powder is compressed in the cavity, thereby obtaining a compact.

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: A solid material for a magnet, comprising a rare-earth/iron/nitrogen/hydrogen system magnetic material.

Abstract: An anisotropic bonded magnet is produced at a low cost by avoiding various problems caused by remanence. Also, the unit weight and density of a compact is increased by filling even a cavity, having no easily feedable shape, with a magnet powder just as intended. An anisotropic bonded magnet is produced by feeding the cavity of a press machine with a magnetic powder (e.g., an HDDR powder) and compacting it. After the magnetic powder has been positioned outside of the cavity, an oscillating magnetic field (e.g., an alternating magnetic field) is created in a space including the cavity. The magnetic powder is transported into the cavity while being aligned parallel to the oscillating direction of the oscillating magnetic field. Thereafter, the magnetic powder is compressed within the cavity to make a compact for an anisotropic bonded magnet.

Abstract: An anisotropic exchange spring magnet powder complexing a hard magnetic material and a soft magnetic material, wherein a rare earth metal element, a transition metal element, boron and carbon and the like are contained, and the hard magnetic material and soft magnetic material have crystal particle diameters of 150 nm or less. A method of producing an anisotropic exchange spring magnet powder comprises treating a crystalline mother material containing a hard magnetic material and soft magnetic material or the crystalline mother material having amorphous parts, in a continuous process composed of an amorphising process and the following crystallizing process, repeated once or more times. An anisotropic exchange spring magnet is obtained by treatment, in an anisotropy- imparting molding process and a solidification process, of an anisotropic exchange spring magnet powder.

Abstract: The present invention relates to a Sm—Co based magnet alloy useful as a raw material for producing magnets having high magnetic properties, such as sintered or bonded magnets, methods for producing such an alloy, and sintered or bonded magnets having excellent corrosion resistance and high magnetic properties, such as high coercivity and good squareness. The magnetic alloy is composed of an alloy represented by the formula RM with 32.5 to 35.5 wt % R such as Sm and the balance of M such as Co, wherein ratio (B/A) of the X-ray diffraction intensity (B) corresponding to the (119) plane of R2M7 phase to the X-ray diffraction intensity (A) corresponding to the (111) plane of RM5 phase is not higher than 0.1.

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 press machine 10 includes a die 12 with a through hole 12a that defines a cavity, a first press surface 14a and a second press surface 16a for pressing a magnetic powder 18 loaded in the cavity, and magnetic field generating means for applying an aligning magnetic field to the magnetic powder 18 in the cavity. At least one of the first and second press surfaces 14a and 16a has a region made of a material having a Vickers hardness that is higher than 200 but equal to or lower than 450. In pressing the powder under the aligning magnetic field, the press machine 10 minimizes the disturbance in the orientation of the powder.

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: A permanent magnet material is prepared by covering an anisotropic sintered magnet body of formula: R1x(Fe1-yCoy)100-x-z-aBzMa wherein R1 is a rare earth element, M is Al, Cu or the like, with a powder comprising an oxide of R2, a fluoride of R3 or an oxyfluoride of R4 wherein R2, R3, and R4 are rare earth elements, and having an average particle size up to 100 ?m, heat treating the powder-covered magnet body in a hydrogen gas-containing atmosphere for inducing disproportionation reaction on R12Fe14B compound, and continuing heat treatment at a reduced hydrogen gas partial pressure for inducing recombination reaction to said compound, thereby finely dividing said compound phase to a crystal grain size up to 1 ?m, and for effecting absorption treatment, thereby causing R2, R3 or R4 to be absorbed in the magnet body.

Abstract: A rare earth permanent magnet material is prepared by covering a sintered magnet body of R1—Fe—B composition wherein R1 is a rare earth element, with a powder comprising at least 30% by weight of an alloy of R2aTbMcAdHe wherein R2 is a rare earth element, T is Fe and/or Co, and M is Al, Cu or the like, and having an average particle size up to 100 ?m, and heat treating the powder-covered magnet body at a suitable temperature, for causing R2, T, M and A in the powder to be absorbed in the magnet body.

Abstract: A permanent magnet material is prepared by machining an anisotropic sintered magnet body having the compositional formula: Rx(Fe1-yCoy)100-x-z-aBzMa wherein R is Sc, Y or a rare earth element, M is Al, Cu or the like, to a specific surface area of at least 6 mm?1, heat treating in a hydrogen gas-containing atmosphere at 600-1,100° C. for inducing disproportionation reaction on the R2Fe14B compound, and continuing heat treatment at a reduced hydrogen gas partial pressure and 600-1,100° C. for inducing recombination reaction to the R2Fe14B compound, thereby finely dividing the R2Fe14B compound phase to a crystal grain size ?1 ?m.

Abstract: The present invention provides a rare earth magnet superior in magnetic properties and thermal stability. In an aspect of the present invention, a production method of an alloy thin ribbon for a rare earth magnet includes a step to obtain a quenched thin ribbon by feeding a molten alloy containing praseodymium (Pr), iron (Fe), cobalt (Co), titanium (Ti), boron (B), and silicon (Si) on a rotating roll and a step to apply heat treatment to the quenched thin ribbon at a heating rate within a range of 100° to 150° C./min to crystallize the quenched thin ribbon.

Abstract: A method of producing a sintered rare earth magnetic alloy wafer comprises a step of using a cutter to slice a wafer of a thickness of not greater than 3 mm from a sintered rare earth magnetic alloy having ferromagnetic crystal grains surrounded by a more readily grindable grain boundary phase and a step of surface-grinding at least one cut surface of the obtained wafer with a grindstone to form at a surface layer thereof flat ferromagnetic crystal grain cross-sections lying parallel to the wafer planar surface. The method enables high-yield production of a sintered rare earth magnetic alloy wafer having flat surfaces.

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.