Permanent magnet, rotary electrical machine, and vehicle

Patent metadata

Field	Value
Publication number	US-2017271929-A1
Application number	US-201715437474-A
Country	US
Kind code	A1
Filing date	Feb 21, 2017
Priority date	Mar 17, 2016
Publication date	Sep 21, 2017
Grant date	—

Abstract

A permanent magnet is expressed by a composition formula: R p Fe q M r Cu t Co 100-p-q-r-t . The magnet comprises a metal structure including a main phase having a Th 2 Zn 17 crystal phase and a grain boundary phase. The main phase includes a cell phase having the Th 2 Zn 17 crystal phase and a Cu-rich phase. A section including a c-axis of the Th 2 Zn 17 crystal phase has a first region in the crystal grain and a second region in the crystal grain, the first region is provided in the cell phase divided by the Cu-rich phase, the second region is provided within a range of not less than 50 nm nor more than 200 nm from the grain boundary phase in a direction perpendicular to an extension direction of the grain boundary phase, and a difference between a Cu concentration of the first region and a Cu concentration of the second region is 0.5 atomic percent or less.

First claim

What is claimed is:

1 . A permanent magnet expressed by a composition formula:
R p Fe q M r Cu t Co 100-p-q-r-t where R represents at least one element selected from the group consisting of rare earth elements, M represents at least one element selected from the group consisting of Zr, Ti, and Hf, p represents a number satisfying 10.5≦p≦12.4 atomic percent, q represents a number satisfying 26≦q≦40 atomic percent, r represents a number satisfying 0.88≦r≦4.3 atomic percent, and t represents a number satisfying 3.5≦t≦13.5 atomic percent, the magnet comprising: a metal structure including a main phase having a Th 2 Zn 17 crystal phase and a grain boundary phase provided between crystal grains of the main phase, wherein the main phase includes a cell phase having the Th 2 Zn 17 crystal phase and a Cu-rich phase, the Cu-rich phase is provided to divide the cell phase and has a Cu concentration higher than the cell phase, and wherein a section including a c-axis of the Th 2 Zn 17 crystal phase has a first region in the crystal grain and a second region in the crystal grain, the first region is provided in the cell phase divided by the Cu-rich phase, the second region is provided within a range of not less than 50 nm nor more than 200 nm from the grain boundary phase in a direction perpendicular to an extension direction of the grain boundary phase, and a difference between a Cu concentration of the first region and a Cu concentration of the second region is 0.5 atomic percent or less.

2 . The magnet according to claim 1 ,
wherein the Cu concentration of the first region is 1.5 atomic percent or more and 5 atomic percent or less.

3 . The magnet according to claim 1 ,
wherein an Fe concentration of the first region is 26 atomic percent or more.

4 . The magnet according to claim 1 ,
wherein 50 atomic percent or more of the element R in the composition formula is Sm, and wherein 50 atomic percent or more of the element M in the composition formula is Zr.

5 . The magnet according to claim 1 ,
wherein 20 atomic percent or less of Co in the composition formula is replaced with at least one element selected from the group consisting of Ni, V, Cr, Mn, Al, Ga, Nb, Ta, and W.

6 . A rotary electrical machine comprising the permanent magnet according to claim 1 .

7 . The rotary electrical machine according to claim 6 ,
wherein the machine is a motor or a generator.

8 . The rotary electrical machine according to claim 6 , comprising:
a stator; and a rotor, wherein the stator or the rotor has the permanent magnet.

9 . A vehicle comprising the rotary electrical machine according to claim 6 .

10 . The vehicle according to claim 9 ,
wherein rotation is transmitted to a shaft provided in one end of the rotary electrical machine.

Assignees

• Toshiba Kk

Inventors

• Horiuchi Yosuke
• Sakurada Shinya
• Hagiwara Masaya
• Kobayashi Tadahiko
• Takahashi Toshihide

Classifications

• B22D7/00

  Casting ingots, {e.g. from ferrous metals}(equipment for conveying molten metal B22D35/00) · CPC title

• B22F3/16

  in successive or repeated steps · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title

• H02K1/02 Primary

  characterised by the magnetic material · CPC title

• H01F1/0556

  pressed · CPC title