Powder for magnet

Patent metadata

Field	Value
Publication number	US-2016180992-A1
Application number	US-201615044861-A
Country	US
Kind code	A1
Filing date	Feb 16, 2016
Priority date	Apr 15, 2010
Publication date	Jun 23, 2016
Grant date	—

Abstract

The present invention provides a powder for a magnet which can form a rare earth magnet having excellent magnetic characteristics and which has excellent moldability, a method for producing the powder for a magnet, a powder compact, and a rare earth-iron-boron-based alloy material.
Magnetic particles constituting a powder for a magnet each include a structure in which a particle of a phase 3 of a hydrogen compound of a rare earth element is dispersed in a phase 2 of an iron-containing material. Since the phase 2 of the iron-containing material is uniformly present in each of the magnetic particles 1 , the powder has excellent moldability and easily increases the density of a powder compact 4 . The powder for a magnet can be produced by heat-treating a powder of a rare earth-iron-boron-based alloy (R—Fe—B-based alloy) in a hydrogen atmosphere at a temperature equal to or higher than the disproportionation temperature of the R—Fe—B-based alloy to separate the powder into the rare earth element and the iron-containing material and to produce the hydrogen compound of the rare earth element. The powder compact 4 is produced by compacting the powder for a magnet. The powder compact 4 is heat-treated in a vacuum to produce a R—Fe—B-based alloy material 5 , and the R—Fe—B-based alloy 5 is magnetized to produce a R—Fe—B-based alloy magnet 6.

First claim

1 . A powder for a magnet used for a rare earth magnet,
wherein each of magnetic particles constituting the powder for a magnet is composed of less than 40% by volume of a hydrogen compound of a rare earth element, and the balance composed of an iron-containing material; the iron-containing material contains iron and an iron-boron alloy containing iron and boron; a phase of the hydrogen compound of a rare earth element and a phase of the iron-containing material are present adjacent to each other; and the distance between the phases of the rare earth element hydrogen compound adjacent to each other with the phase of the iron-containing material interposed therebetween is 3 μm or less.

2 . The powder for a magnet according to claim 1 , wherein the rare earth element is at least one element selected from Nd, Pr, Ce, Dy, and Y.

3 . The powder for a magnet according to claim 1 ,
wherein the phase of the hydrogen compound is granular, and the granular hydrogen compound of a rare earth element is dispersed in the phase of the iron-containing material.

4 . The powder for a magnet according to claim 1 , wherein the average particle diameter of the magnetic particles is 10 μm or more and 500 μm or less.

5 - 12 . (canceled)

Assignees

• Sumitomo Electric Industries

Inventors

• Maeda Toru
• Watanabe Asako

Classifications

• H01F1/0551 Primary

  in the form of particles, e.g. rapid quenched powders or ribbon flakes · CPC title

• B22F1/12 Primary

  Metallic powder containing non-metallic particles (containing lubricating or binding agents or organic material B22F1/10) · CPC title

• B22F3/03

  Press-moulding apparatus therefor · CPC title

• B22F3/24

  After-treatment of workpieces or articles {(B22F3/1146 takes precedence)} · CPC title

• H01F1/0578

  bonded together · CPC title