Sumitomo Special Metals Co., Ltd.

Hitachi Metals, Ltd.

Sumitomo Metal Industries, Inc.

Riken Corporation

Sumitomo Special Metal Co. Ltd.

Sumitomo Speical Metals Co., Ltd.

Yutaka Matsuura

Masato Sagawa

Setsuo Fujimura

Hitoshi Yamamoto

Norio Togawa

Naoyuki Ishigaki

Takaki Hamada

Tetsuji Hayakawa

Wataru Takahashi

Nobushige Hiraishi

Masakazu Ohkita

Yoshihisa Kishimoto

Takashi Tanaka

Hiroyuki Tomizawa

Tomoori Odaka

Noriyuki Nozawa

Hideo Kitamura

Toru Hara

Tsutomu Kohda

Akira Higuchi

A sintered rare-earth magnet includes an NdFeB type crystalline phase as its main phase and Al as an additive. The magnet includes at least one light rare-earth element LR selected from the group consisting of yttrium and the rare-earth elements other than Dy, Ho and Tb, and at least one heavy rare-earth element HR selected from the group consisting of Dy, Ho and Tb. The mole fractions &#x3b1;1, &#x3b1;2 and &#x3b2; of the light and heavy rare-earth elements LR and HR and Al satisfy the inequalities 25&#x2266;&#x3b1;1+&#x3b1;2&#x2266;40 mass %, 0&#x3c;&#x3b1;2&#x2266;40 mass %, &#x3b2;&#x3e;0.20 mass %, and 0.04&#x2266;&#x3b2;/&#x3b1;2&#x2266;0.12.

Rare earth sintered magnet and method for producing same

An undulator comprises a first magnetic circuit () for forming a periodic magnetic field, a first support body () for supporting the first magnetic circuit (), a second magnetic circuit () arranged opposite to the first magnetic circuit (), for forming a periodic magnetic field, a second support body () for supporting the second magnetic circuit (), a space () formed between the oppositely arranged first magnetic circuit () and the second magnetic circuit (), for passing an electron beam, a vacuum chamber () for vacuum-sealing the first magnetic circuit () and the second magnetic circuit (), and a refrigerant passing tube () for cooling a permanent magnet (m) constituting the first magnetic circuit () and the second magnetic circuit () below the room temperature.

Undulator

A rare-earth sintered magnet according to the present invention, of which the main phase is an RTB 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.

R-t-b sintered magnet and rare earth alloy

Magnetic materials comprising Fe, B, R (rare earth elements) and Co having a major phase of Fe--CO--B--R intermetallic compound(s) of tetragonal system, and sintered anisotropic permanent magnets consisting essentially of, by atomic percent, 8-30% R (at least one of rare earth elements inclusive of Y), 2-28% B, no less than 50% Co, and the balance being Fe with impurities. Those may contain additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf) providing Fe--Co--B--R--M type materials and magnets.

Method of making magnetic precursor for permanent magnets

Magnetic materials comprising Fe, B, R (rare earth elements) and Co having a major phase of Fe--Co--B--R intermetallic compound(s) of tetragonal systems and sintered anisotropic permanent magnets consisting essentially of, by atomic percent, 8-30% R (at least one of rare earth elements inclusive of Y), 2-28% B, no less than 50% Co, and the balance being Fe with impurities. Those may contain additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf) providing Fe--Co--B--R--M type materials and magnets.

Magnetic materials and permanent magnets

To a fine R-Fe-B alloy powder comprised predominantly of 10-30 atomic % of R (wherein R stands for at least one elements selected from rare earth elements including yttrium), 2-28 atomic % of B, and 65-82 atomic % of Fe in which up to 50 atomic % of Fe may be replaced by Co, at least one boric acid ester compound such as tributyl borate is added as a lubricant in a proportion of 0.01%-2% by weight and mixed uniformly before, during, or after fine grinding of the alloy powder. The resulting powder mixture is compacted by compression molding in a magnetic field and the green compacts are sintered and aged. Compression molding can be performed continuously without need of mold lubrication, and the resulting magnets have improved magnet properties with respect to residual flux density, maximum energy product, and intrinsic coercive force.

Powder mixture for use in compaction to produce rare earth iron sintered

To a fine R--Fe--B alloy powder comprised predominantly of 10-30 atomic % of R (wherein R stands for at least one element selected from rare earth elements including yttrium), 2-28 atomic % of B, and 65-82 atomic % of Fe in which up to 50 atomic % of Fe may be replaced by Co, at least one boric acid ester compound such as tributyl borate is added as a lubricant in a proportion of 0.01%-2% by weight and mixed uniformly before, during, or after fine grinding of the alloy powder. The resulting powder mixture is compacted by compression molding in a magnetic field and the green compacts are sintered and aged. Compression molding can be performed continuously without need of mold lubrication, and the resulting magnets have improved magnet properties with respect to residual flux density, maximum energy product, and intrinsic coercive force.

Magnetic materials comprising Fe, B, R (rare earth elements) and Co having a major phase of Fe-Co-B-R intermetallic compound(s) of tetragonal systems and sintered anisotropic permanent magnets consisting essentially of, by atomic percent, 8-30% R (at least one of rare earth elements inclusive of Y), 2-28% B, no less than 50% Co, and the balance being Fe with impurities. Those may contain additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf) providing Fe-Co-B-R-M type materials and magnets.

Magnetic precursor materials for making permanent magnets

Fe-B-R type permanent magnet is produced by: forming an anticorrosive coating film layer on a Fe-B-R base permanent magnet material body by means of vapor deposition to thereby improve the corrosion resistance thereof. The anticorrosive thin film is formed of metal, oxides, nitrides, carbides, borides, silicides, composite compositions thereof, or a mixture thereof. Additionally blasting, shot peening, heat treatment for forming an interdiffusion layer, and/or resin impregnation may be applied.

Process for producing magnets having improved corrosion resistance

A magnetically anisotropic sintered permanent magnet of the FeCoBR system (R is sum of R.sub.1 and R.sub.2) wherein:

Permanent magnets

Magnetic materials comprising Fe, B and R (rare earth elements) having a major phase of an Fe-B-R intermetallic compound which may be a tetragonal system, wherein at least 50 at % of R consists of Nd and/or Pr, and anisotropic sintered permanent magnets consisting essentially of 8-30 at % R, 2028 at %, B and the balance being Fe with impurities. These magnetic materials and permanent magnets may contain additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf), thus providing Fe-B-R-M type materials and magnets.

Magnetic materials

Isotropic permanent magnet formed of a sintered body having a mean crystal grain size of 1-160 microns and a major phase of tetragonal system comprising, in atomic percent, 10-25% of R wherein R represents at least one of rare-earth elements including Y, 3-23% of B and the balance being Fe. As additional elements M, Al, Ti, V, Cr, Mn, Zr, Hf, Nb, Ta, Mo, Ge, Sb, Sn, Bi, Ni or W may be incorporated. The magnets can be produced through a powder metallurgical process resulting in high magnetic properties, e.g., up to 7 MGOe or higher energy product.

Process for producing isotropic permanent magnets and materials

Magnetic materials comprising Fe, B and R (rare earth elements) having a major phase of an Fe-B-R intermetallic compound which may be a tetragonal system, wherein at least 50 at % of R consists of Nd and/or Pr, and anisotropic sintered permanent magnets consisting essentially of 8-30 at % R, 2-28 at %, B and the balance being Fe with impurities. These magnetic materials and permanent magnets may contain additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf), thus providing Fe-B-R-M type materials and magnets.

A process for producing permanent magnet materials, which comprises the steps of:

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Hyogo, Japan

Yutaka Matsuura