Abstract: A melt of an iron-based rare earth material alloy, represented by (Fe1-mTm)100-x-y-zQxRyMz, is prepared. T is Co and/or Ni; Q is B and/or C; R is selected from Y (yttrium) and the rare earth elements; M is selected from Al, Si, Ti, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb; 10≦x≦30 at %; 2%≦y<10 at %; 0≦z≦10 at % and 0≦m≦0.5. The melt is fed onto a guide to form a flow of the melt thereon and move the melt onto a melt/chill roller contact region, where the melt is rapidly cooled by the chill roller to make a rapidly solidified alloy. An oxygen concentration of the melt yet to be fed onto the guide is controlled at about 3,000 ppm or less in mass percentage.

Abstract: A method of making an iron base magnetic material alloy powder includes the steps of: preparing an iron base magnetic material alloy containing at least 50% by mass of iron; and pulverizing the magnetic material alloy using a pin mill. A portion of the mill, which comes into contact with the magnetic material alloy, is made of a cemented carbide material at least partially.

Abstract: A method of making a material alloy for an iron-based rare earth magnet includes the step of forming a melt of an alloy with a composition of (Fe1−mTm)100−x−y−z−n(1−pCp)xRyTizMn. T is Co and/or Ni; R is at least one element selected from Y (yttrium) and the rare earth elements; and M is at least one element selected from Al, Si, V, Cr, Mn, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb, wherein the following inequalities are satisfied: 10<x≦25 at %, *6≦y<10 at %, 0.5≦z≦12 at %, 0≦m≦0.5, 0≦n≦10 at % and 0≦p≦0.25. Next, the melt is fed onto a shoot with a guide surface tilted at about 1 degree to about 80 degrees with respect to a horizontal plane, thereby moving the melt onto a melt/roller contact region. The melt is then rapidly cooled using a chill roller to make a rapidly solidified alloy including an R2Fe14B phase.

Abstract: The inventive method for preparing nanocomposite magnet powder includes the step of preparing material alloy powder for a nanocomposite magnet represented by a general formula Fe100−x−y−z−uRxByCozMu where R is a rare-earth element of which 90-100 atomic percent is Pr and/or Nd while 0-10 atomic percent is another lanthanoid and/or Y, and the molar fractions x, y, z and u meet the inequalities of 2≦x≦6, 16≦y≦20, 0.2≦z≦7 and 0.01≦u≦7, respectively. The powder includes a metastable phase and an amorphous structure existing in a metal structure. Heat treatment is performed for the material alloy powder to crystallize Fe3B and Fe—R—B compounds from the amorphous structure. An integral value of the difference between a temperature-time curve represented by the temperature of the material alloy powder as a function of the heat treatment time during the heat treatment and a reference temperature-time curve is in a range from 10° C.

Abstract: In this invention, enhancement of the coercive force of the Fe-B-R based magnetic anisotropic sintered magnets was studied by increasing a content of B and, in addition, containing into material a small amount of such as Al, Si, Cu, Cr, Ni, and Mn effective of enhancing the coercive force and excluding from the material harmful impurities such as P, S, and Sb. This material was powdered by usual melting, casting, crushing, or direct reduction method. This powder was subjected to orientation in a magnetic field, compacted, sintered and subjected to heat treatment. Thus the Fe-B-R based sintered permanent magnets were obtained that have the maximum energy product more than 20MGOe and the coercive force more than 15kOe.

Abstract: A method of making a material alloy for an iron-based rare earth magnet includes the step of forming a melt of an alloy with a composition of (Fe1-mTm)100-x-y-z-n(B1-pCp)xRyTizMn. T is Co and/or Ni; R is at least one element selected from Y (yttrium) and the rare earth elements; and M is at least one element selected from Al, Si, V, Cr, Mn, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb, wherein the following inequalities are satisfied: 10<x≦25 at %, *6≦y<10 at %, 0.5≦z≦12 at %, 0≦m≦0.5, 0≦n≦10 at % and 0≦p≦0.25. Next, the melt is fed onto a shoot with a guide surface tilted at about 1 degree to about 80 degrees with respect to a horizontal plane, thereby moving the melt onto a melt/roller contact region. The melt is then rapidly cooled using a chill roller to make a rapidly solidified alloy including an R2Fe14B phase.

Abstract: The present invention is presented with the object of providing a manufacturing method for thin-plate magnets that, as cast, exhibit an intrinsic coercive force iHc of 2.5 kOe or greater and a residual magnetic flux density Br of 9 kG or greater, exhibit a performance-to-cost ratio comparable to hard ferrite magnets, and exhibit a fine crystalline structure with a thickness of 70 to 500 &mgr;m wherewith magnetic circuits can be made smaller and thinner. By employing alloy melts to which specific elements have been added, in a process wherein alloy melts of specific composition are continuously cast on a rotating cooling roller or rollers in a reduced-pressure inert or inactive gas atmosphere at 30 kPa or less, and fine crystalline permanent magnets having a fine crystalline structure of 10 to 50 nm are fabricated, fine crystalline permanent magnets having a thickness of 70 to 500 &mgr;m can be obtained wherein iHc is improved to 2.

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: With the intention of establishing fabrication methods for cheaply produced (Fe,Co)—Cr—B—R-type bonded magnets or (Fe,Co)—Cr—B—R—M-type bonded magnets containing few rare earth elements and having a coercive force iHc above 5 kOe and a residual magnetic flux density Br above 5.

Abstract: The purpose of the present invention is to present a thin-plate magnet with a fine crystalline structure that is 70 &mgr;m to 500 &mgr;m thick, making miniature, thin magnetic circuits possible, and has, as cast, an inherent coercive force iHc of 2.5 kOe or higher and residual magnetic flux density of 9 kG or higher and a performance-to-cost ratio rivaling that of hard ferrite magnets when Nd—Fe—B fine crystalline permanent magnets with a low rare earth content that are a mixture of a soft magnetic phase and a hard magnetic phase are produced. iHc can be increased to 2.

Abstract: An inventive material alloy for a nanocomposite magnet is represented by a general formula Fe100−x−yRxBy, Fe100−x−y−zRxByCoz, Fe100−x−y−uRxByMu or Fe100−x−y−z−uRxByCozMu. R is a rare-earth element. 90 atomic percent or more of R is Pr and/or Nd, while equal to or larger than 0 atomic percent and less than 10 atomic percent of R is another lanthanoid and/or Y. M is at least one element selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W, Pt, Pb, Au and Ag. The molar fractions x, y, z and u meet the inequalities of 2≦x≦6, 16≦y≦20, 0.2≦z≦7 and 0.01≦u≦7, respectively. The alloy includes a metastable phase Z represented by at least one of a plurality of Bragg reflection peaks observable by X-ray diffraction analysis. The at least one peak corresponds to a lattice spacing of 0.179 nm±0.005 nm.

Abstract: In this invention, enhancement of the coercive force of the Fe—B-R based magnetic anisotropic sintered magnets was studied by increasing a content of B and, in addition, containing into material a small amount of such as Al, Si, Cu, Cr, Ni, and Mn effective of enhancing the coercive force and excluding from the material harmful impurities such as P, S, and Sb. This material was powdered by usual melting, casting, crushing, or direct reduction method. This powder was subjected to orientation in a magnetic field, compacted, sintered and subjected to heat treatment. Thus the Fe-B-R based sintered permanent magnets were obtained that have the maximum energy product more than 20MGOe and the coercive force more than 15kOe.

Abstract: A method of making an iron base magnetic material alloy powder includes the steps of: preparing an iron base magnetic material alloy containing at least 50% by mass of iron; and pulverizing the magnetic material alloy using a pin mill. A portion of the mill, which comes into contact with the magnetic material alloy, is made of a cemented carbide material at least partially.

Abstract: A method for manufacturing a permanent magnet by fabricating rapidly cooled alloy thin strip of amorphous composition which has good tenacity, simple working properties and an average thickness of 10 &mgr;m˜200 &mgr;m, from a molten alloy of a specific composition containing 6 at % or less of rare-earth element and 15 at %˜30 at % of boron, by means of specific rapid cooling conditions, and then subjecting this rapidly cooled alloy thin strip, after cutting or punching to a prescribed shape, to crystallization heat treatment such that the average crystal grain size thereof becomes 10 nm˜50 nm, and by layering together two or more of these thin permanent magnets and bonding and uniting the layered thin strips by means of an inorganic adhesive material or a resin, it is possible readily to provide a high-performance layered permanent magnet having a desired thickness and a prescribed shape, without using a method involving crushing and bonded magnet forming processes and without needing to car

Abstract: An object of this invention is to provide a thin-film magnet having a residual magnetic flux density Br of not less than 10 kG, a cost performance equal to that of a hard ferrite magnet, and a thickness of 70-300 &mgr;m contributing to the miniaturization and thinning of a magnetic circuit, and a method of manufacturing the same. When a molten alloy of a predetermined structure having a small content of a rare earth element is subjected to continuous casting using a cooling roll in an inert gas atmosphere with reduced pressures of not more than 30 kPa at a predetermined peripheral speed of the roll, it turns into a crystalline structure substantially not less than 90% of which comprises a Fe3B type compound and a compound phase having &agr; —Fe and Nd2Fe14B type crystalline structures compatible with the former.

Abstract: With the intention of establishing fabrication methods for cheaply produced (Fe,Co)--Cr--B--R-type bonded magnets or (Fe,Co)--Cr--B--R--M-type bonded magnets containing few rare earth elements and having a coercive force iHc above 5 kOe and a residual magnetic flux density Br above 5.5 kG matching the cost performance of hard ferrite magnets, we have obtained iron-based permanent magnets consisting of microcrystal clusters where the average crystal size of each component phase is in the range 1 nm .about.30 nm and where both a soft magnetic phase consisting of a ferromagnetic alloy whose main components are .alpha.-Fe and a ferromagnetic alloy having iron, and a hard magnetic phase having a Nd.sub.2 Fe.sub.

Abstract: For the purpose of establishing the manufacturing method to obtain the Fe.sub.3 B type Fe--Co--B--R--M system high performance resin bonded magnet which possesses improved iHc and (BH)max and can be reliably mass produced, the specific composition of Fe--Co--B--R (Pr, Nd)--M(Ag, Al, Si, Ga, Cu, Au) type molten alloy was rapidly solidified by the melt-quenching or atomization methods, or a combination of the two methods to obtain more than 90% of the solid in an essentially amorphous structure. After the temperature was raised at the rate of 1.degree..about.15.degree. C./min., the alloy was heat treated at 550.degree..about.730.degree. C. for 5 minutes.about.6 hours to obtain Fe-rich the boron compound phase, which crystallizes the body centered tetragonal Fe.sub.3 P type crystalline structure, and the Nd.sub.2 Fe.sub.14 B type crystalline structure phase both coexisting as fine crystalline clusters of the average crystalline diameter of 5 nm.about.100 nm.

Abstract: A densified high performance rare earth-iron-nitrogen permanent magnet obtained from a powder of a Th.sub.2 Zn.sub.17 compound containing nitrogen at interlattice sites, without using autogeneous sintering and yet preventing decomposition and/or denitrification from occurring. The process for producing the same need not necessarily use a binder, and it comprises compaction molding, or charging while applying a magnetic field, a powder of a nitrogen intrusion T--R--N compound having a specified composition and a Th.sub.2 Zn.sub.17 crystal structure, and applying thereto shock compression at a drive pressure of from 10 to 25 GPa as reduced to an equivalent drive pressure in an iron capsule.

Abstract: An anisotropic sintered permanent magnet consists essentially of 12 to 18 at % R, wherein R represents Pr, Nd, Dy, Tb and other rare earth element or elements contained as inevitable impurities provided that 0.8.ltoreq.(Pr+Nd+Dy+Tb)/R.ltoreq.1.0, 5 to 9.5 at % B, 2 to 5 at % Mo, 0.01 to 0.5 at % Cu, 0.1 to 3 at % Al, and balance being Fe. B(x) and Mo(y) are (x-4.5).ltoreq.y.ltoreq.(x-3.0), and part of Fe may be replaced by Co to be 3-7 at % Co. Up to 90 at % of Mo may be replaced by V. The magnet is characterized by main tetragonal R.sub.2 (Fe, Mo).sub.14 B or R.sub.2 (Fe, Co, Mo).sub.14 B phase and boundary phase of (Fe, Mo)-B, or (Fe, Co, Mo)-B and R.sub.m (Fe, Co, Mo).sub.n where m/n=1/2 to 3/1. B-rich phase Nd.sub.1+.epsilon. Fe.sub.4 B.sub.4 disappears. Dy and/or Tb linearly increase iHc. High coercivity and maximum energy product are obtained: iHc.gtoreq.15 kOe (or 21 kOe) and (BH)max.gtoreq.20 MGOe (or 28 MGOe) with high corrosion resistance and high pulverizability of alloy.

Abstract: With the invention of establishing fabrication methods for cheaply produced (Fe,Co)—Cr—B—R-type bonded magnets or (Fe,Co)—Cr—B—R—M-type bonded magnets containing few rare earth elements having a coercive force iHc above 5 kOe and a residual magnetic flux density Br above 5.