Sumitomo Special Metals Co., Ltd.

Sumitomo Special Metal Co. Ltd.

Setsuo Fujimura

Masato Sagawa

Yutaka Matsuura

Hitoshi Yamamoto

Naoyuki Ishigaki

Takaki Hamada

Norio Togawa

Satoshi Hirosawa

Michio Yamashita

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

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

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.

An (Fe, Co)-B-R tetragonal type magnet having a high corrosion resistance, which has a boundary phase stabilized by Co and Al against corrosion, and which consists essentially of:

Rare earth magnet having excellent corrosion resistance

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

Process for producing permanent magnets and products thereof

A magnetically anisotropic sintered permanent magnet of the FeBR system in which R is sum of R.sub.1 and R.sub.2 wherein:

Permanent magnet

Permanent magnet materials of the Fe--B--R type are produced by:

Permanent magnet materials

A rare earth alloy for producing permanent magnet comprised of: 15-65 atomic % R.sub.1, 35-83 atomic % Fe, and 0-15 atomic % B, where R.sub.1 represents at least one of heavy rare earth elements Gd, Tb, Dy, Ho, Er, Tm and Yb. This alloy is produced by reducing a mixture of corresponding rare earth oxides, Fe, and a boron containing material by Ca, contacting the reduced mass with water, and treating the resultant slurry with water. Using this alloy, Fe-B-R base magnets wherein R.sub.1 is substituted for part of R (R representing lanthanide and/or Y) having a high performance are produced with a reduced cost.

Rare earth alloy powder used in production of permanent magnets

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, Zv, 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.

Growing community of inventors

Kyoto, Japan

Setsuo Fujimura