Toyota Jidosha Kabushiki Kaisha

National Institute for Materials Science

Centre National De La Recherche Scientifique

Nichia Corporation

The University of Tokyo

Tohoku University

The University of Sheffield

Leibniz Institute for Solid State and Materials Research Dresden

Leibniz-Institut FÜr FestkÖrper-Und Werkstoffforschung Dresden E.v.

Noritsugu Sakuma

Tetsuya Shoji

Masao Yano

Hidefumi Kishimoto

Masaaki Ito

Akihito Kinoshita

Akira Kato

Kazuaki Haga

Akira Manabe

Daisuke Ichigozaki

Shunji Suzuki

Kurima Kobayashi

Kazuhiro Hono

Yukiko Takahashi

Daisuke Sakuma

Weibin Cui

Noritaka Miyamoto

Motoki Hiraoka

Michiya Kume

Hisashi Maehara

Takashi Miyake

Noriyuki Ueno

Akira Kano

Naoki Kawashima

Shinya Omura

Tatsuhiko Hirano

Mikiya Nozaki

Kota Washio

Oliver Gutfleisch

Tomonori Inuzuka

Nora Dempsey

Satoshi Sugimoto

Kosuke Yonekawa

Thomas Schrefl

Masashi Matsuura

Dominique Givord

Tetsuya Syoji

Kazuya Yokota

Yosuke Harashima

Keiichi Tamai

Hisazumi Akai

Munehisa Matsumoto

Thomas George Woodcock

Gino Hrkac

Thomas Georg Woodcock

Olivier Gutfleisch

Hrkac Gino

Shoichi Harakawa

The production method of a rare earth magnet of the present disclosure includes a coated magnetic powder preparation step, a mixed powder preparation step, and a pressure sintering step. In the coated magnetic preparation step, a zinc-containing coatingis formed on the particle surface of a samarium-iron-nitrogen-based magnetic powder to obtain a coated magnetic powder. In the mixed powder preparation step, a binder powderhaving a melting point not higher than the melting point of the coatingand the coated magnetic powderare mixed to obtain a mixed powder. In the pressure sintering step, denoting as T° C. the temperature at which the peak disappears in an X-ray diffraction pattern of the binder powderand as T° C. the temperature at which the magnetic phase in the samarium-iron-nitrogen-based magnetic powderdecomposes, the mixed powder is pressure-sintered at T° C. or more and (T−50° C.) or less.

Production method of rare earth magnet

A rare-earth magnet and a method of manufacturing the same are provided. The method includes: preparing Sm—Fe—N magnetic powder; preparing reforming material powder containing metallic zinc; mixing the magnetic powder and the reforming material powder to obtain mixed powder; subjecting the mixed powder to compression molding in a magnetic field to obtain a magnetic-field molded body; subjecting the magnetic-field molded body to pressure sintering to obtain a sintered body; and subjecting the sintered body to heat treatment. A content proportion of the metallic zinc in the reforming material powder is 10 to 30% by mass with respect to the mixed powder. When a temperature and time in conditions for the heat treatment are defined as x° C. and y hours, respectively, the formulas y≥−0.32x+136 and 350≤x≤410 are met.

Rare-earth magnet and method of manufacturing the same

An Sm—Fe—N-based magnetic material according to the present disclosure includes a main phase having a predetermined crystal structure. The main phase has a composition represented by (SmLaCeR)(FeCoNiM)N(where, Ris predetermined rare earth elements and the like, M is predetermined elements and the like, and 0.04≤x+y≤0.50, 0≤z≤0.10, 0≤p+q≤0.10, 0≤s≤0.10, and 2.9≤h≤3.1 are satisfied). A crystal volume of the main phase is 0.833 nmto 0.840 nm. A manufacturing method of the Sm—Fe—N-based magnetic material according to the present disclosure includes nitriding a magnetic material precursor including a crystal phase having a composition represented by (SmLaCeR)(FeCoNiM).

Sm—Fe—N-based magnetic material and manufacturing method thereof

A magnetic material according to the present disclosure includes a main phase having an RTB type crystal structure (R is a rare earth element and T is a transition metal element). The main phase has a composition represented by ((Nd, Pr)LaR))((Fe(Co, Ni)M))B (where, Ris a rare earth element other than Nd, Pr, and La, M is an element other than Fe, Co, Ni, and a rare earth element, and the like, and 0.25≤x≤1.00, 0≤y≤0.10, 0.15≤z≤0.40, and 0≤w≤0.1 are satisfied). A manufacturing method of the magnetic material according to the present disclosure includes melting a raw material containing the elements constituting the main phase and solidifying the melted raw material.

Magnetic material and manufacturing method thereof

An Sm—Fe—N-based magnetic material according to the present disclosure includes a main phase having a predetermined crystal structure. The main phase has a composition represented by a molar ratio formula (SmLaCeR)(FeCoNiM)N(where, Ris a predetermined rare earth element, M is a predetermined element, and 0≤x+y<0.04, 0≤z≤0.10, 0<p+q≤0.10, 0≤s≤0.10, and 2.9≤h≤3.1 are satisfied). A lattice volume of the main phase is 0.830 nmto 0.840 nm, and a density of the main phase is 7.70 g/cmto 8.00 g/cm.

A rare earth magnet in which the amount used of a heavy rare earth element is more reduced while maintaining enhancement of the coercive force, and a producing method thereof are provided. The rare earth magnet of the present disclosure has a main phaseand a grain boundary phase. The main phasehas a composition represented by RTB. The main phasehas a core partand a shell part. Denoting the abundances of Rand Ce (Ris heavy rare earth element) occupying 4f site of the shell partas Rand Ce, respectively, and denoting the abundances of Rand Ce occupying 4g site of the shell partas Rand Ce, respectively, the rare earth magnet satisfies 0.44≤R/(R+R)≤0.70 and 0.04≤(Ce+Ce)/(R+R). The rare earth magnet-producing method of the present disclosure uses a modifier containing at least Rand Ce.

Rare earth magnet and producing method thereof

A rare earth magnet including a magnetic phase having the composition represented by (NdLaCe)(FeCo)B. When the saturation magnetization at absolute zero and the Curie temperature calculated by Kuzmin's formula based on the measured values at finite temperature and the saturation magnetization at absolute zero and the Curie temperature calculated by first principles calculation are respectively subjected to data assimilation. The saturation magnetization M(x, y, z, T=0) at absolute zero and the Curie temperature obtained by machine learning using the assimilated data group are applied again to Kuzmin's formula and the saturation magnetization at finite temperature is represented by a function M(x, y, z, T), x, y, and z of the formula in an atomic ratio are in a range of satisfying M(x, y, z, T)&#x3e;M(x, y, z=0, T) and 400&#x2264;T&#x2264;453.

Rare earth magnets

A rare earth magnet includes a main phase and a particle boundary phase and in which an overall composition is represented by a formula, (RR)FeCoBM.(RM).(RM), where Ris a light rare earth element, Rand Rare a medium rare earth element, Ris a heavy rare earth element, M, M, Mare a predetermined metal element. The main phase includes a core portion, a first shell portion, and a second shell portion. The content proportion of medium rare earth element is higher in the first shell portion than in the core portion, the content proportion of medium rare earth element is lower in the second shell portion than in the first shell portion. The second shell portion contains heavy rare earth elements.

Rare earth magnet and manufacturing method therefor

A method of producing a motor core includes preparing a soft magnetic plate containing a transition metal element, preparing a modifying member containing an alloy having a melting point lower than a melting point of the soft magnetic plate, bringing the modifying member into contact with a part of a plate surface of the soft magnetic plate, causing the modifying member to diffuse and penetrate into the soft magnetic plate from a contact surface between the soft magnetic plate and the modifying member and forming a hard magnetic phase-containing part in a part of the soft magnetic plate, and laminating a plurality of soft magnetic plates on each other after the modifying member is brought into contact with the part of the plate surface of the soft magnetic plate.

Method of producing motor core

To provide a rare earth magnet having excellent coercive force and a production method thereof. A rare earth magnet, wherein the rare earth magnet comprises a magnetic phase containing Sm, Fe, and N, a Zn phase present around the magnetic phase, and an intermediate phase present between the magnetic phase and the Zn phase, wherein the intermediate phase contains Zn and the oxygen content of the intermediate phase is higher than the oxygen content of the Zn phase; and a method for producing a rare earth magnet, including mixing a magnetic raw material powder having an oxygen content of 1.0 mass % or less and an improving agent powder containing metallic Zn and/or a Zn alloy, and heat-treating the mixed powder.

Rare earth magnet and production method thereof

A method for producing a rare earth magnet, including preparing a melt of a first alloy having a composition represented by (RRR)TBM(wherein Ris a light rare earth element, Ris an intermediate rare earth element, Ris a heavy rare earth element, T is an iron group element, and Mis an impurity element, etc.), cooling the melt of the first alloy at a rate of from 10to 10K/sec to obtain a first alloy ingot, pulverizing the first alloy ingot to obtain a first alloy powder having a particle diameter of 1 to 20 &#x3bc;m, preparing a melt of a second alloy having a composition represented by (RR)M(wherein Ris a light rare earth element, Ris an intermediate or heavy rare earth element, Mis an alloy element, etc.), and putting the first alloy powder into contact with the melt of the second alloy.

A magnetic compound represented by the formula (RR)(FeCo)TMwherein Ris one or more elements selected from the group consisting of Sm, Pm, Er, Tm and Yb, Ris one or more elements selected from the group consisting of Zr, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho and Lu, T is one or more elements selected from the group consisting of Ti, V, Mo, Si and W, M is one or more elements selected from the group consisting of unavoidable impurity elements, Al, Cr, Cu, Ga, Ag and Au, 0&#x2264;x&#x2264;0.7, 0&#x2264;y&#x2264;0.7, 4&#x2264;a&#x2264;20, b=100-a-c-d, 0&#x3c;c&#x3c;7.7, and 0&#x2264;d&#x2264;3, the magnetic compound having a ThMn-type crystal structure, wherein the volume fraction of &#x3b1;-(Fe, Co) phase is less than 12.3%.

Magnetic compound and production method thereof

To provide a motor control method ensuring that dragging loss at the time of high rotation can be reduced. A motor control method, wherein a composite permanent magnet has a core part and a shell part, the Curie temperature of one of the core part and the shell part is TK, and the Curie temperature of another is TK, and wherein when the magnitude of the reluctance torque is equal to or greater than the magnitude of the magnet torque, the temperature of the composite permanent magnet is set at TK that is (T&#x2212;100) K or higher and lower than TK and when the magnitude of the reluctance torque is less than the magnitude of the magnetic torque, the temperature of the composite permanent magnet is set at lower than the temperature TK or TK, whichever is lower.

Motor control method

A rare earth magnet includes a main phase, a grain boundary phase present around the main phase and an intermediate phase interposed between the main phase and the grain boundary phase, and has an overall composition that is represented by the formula ((CeLa)R)TBM(RM)(where, Rand Rare rare earth elements other than Ce and La, T is at least one selected from among Fe, Ni, and Co, Mis an element having a small amount that does not influence magnetic characteristics, and Mis an alloy element for which a melting point of RMis lower than a melting point of R). A total concentration of Ce and La is higher in the main phase than in the intermediate phase, and a concentration of Ris higher in the intermediate phase than in the main phase.

Rare earth magnet and method of producing the same

To provide a rare earth magnet ensuring excellent magnetic anisotropy while reducing the amount of Nd, etc., and a manufacturing method thereof. A rare earth magnet comprising a crystal grain having an overall composition of (R2R1)FeCoBTM(wherein R2 is at least one of Nd, Pr, Dy and Tb, R1 is an alloy of at least one or two or more of Ce, La, Gd, Y and Sc, TM is at least one of Ga, Al, Cu, Au, Ag, Zn, In and Mn, 0&#x3c;x&#x3c;1, y=12 to 20, z=5.6 to 6.5, w=0 to 8, and v=0 to 2), wherein the average grain size of the crystal grain is 1,000 nm or less, the crystal grain consists of a core and an outer shell, the core has a composition of R1 that is richer than R2, and the outer shell has a composition of R2 that is richer than R1.

Rare-earth magnet and method for manufacturing same

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Mishima, Japan

Noritsugu Sakuma