Permanent magnet and manufacturing method thereof, and motor and generator using the same

Patent metadata

Field	Value
Publication number	US-9653198-B2
Application number	US-201213423535-A
Country	US
Kind code	B2
Filing date	Mar 19, 2012
Priority date	Sep 27, 2011
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

In one embodiment, a permanent magnet includes a composition represented by R p Fe q M r Cu s Co 100-p-q-r-s (R: rare earth element, M: at least one element selected from Zr, Ti and Hf, 10≦p≦13.5 atomic %, 28≦q≦40 atomic %, 0.88≦r≦7.2 atomic %, 4≦s≦13.5 atomic %), and a metallic structure in which a composition region having an Fe concentration of 28 mol % or more is a main phase. A Cu concentration in the main phase is 5 mol % or more.

First claim

What is claimed is:

1. A permanent magnet, comprising: a composition represented by the following composition formula:
R p Fe q M r Cu s Co 100-p-q-r-s
wherein R is at least one element selected from the group consisting of rare earth elements,
M is at least one element selected from the group consisting of Zr, Ti and Hf,
p is a number satisfying 10 atomic % ≦p ≦13.5 atomic %,
q is a number satisfying 28 atomic % ≦q ≦40 atomic %,
r is a number satisfying 0.88 atomic % ≦r ≦7.2 atomic %,
s is a number satisfying 4 atomic % ≦s ≦13.5 atomic %,
a metallic structure in which a composition region having an Fe concentration of 28 mol % or more is a main phase of a plurality of phases,
wherein a Cu concentration in the main phase is 5 mol % or more,
wherein the metallic structure includes a Cu-M rich phase having 5 mol % or more of a Cu concentration and 3 mol % or more of a concentration of the element M.

2. The permanent magnet according to claim 1 ,
wherein a volume ratio of the Cu-M rich phase in the metallic structure is in a range of 0.01 to 5%.

3. The permanent magnet according to claim 1 ,
wherein the main phase includes a Th 2 Zn 17 crystal phase, and a grain boundary phase having a Cu molar concentration which is 1.2 times or more a Cu molar concentration in the Th 2 Zn 17 crystal phase.

4. The permanent magnet according to claim 1 ,
wherein 50 atomic % or more of the element R is Sm, and 50 atomic % or more of the element M is Zr.

5. A motor comprising the permanent magnet according to claim 1 .

6. A generator comprising the permanent magnet according to claim 1 .

7. A method for manufacturing a permanent magnet, comprising:
preparing an alloy powder having the following composition represented by a composition formula:
R p Fe q M r Cu s Co 100-p-q-r-s

wherein R is at least one element selected from the group consisting of rare earth elements,
M is at least one element selected from the group consisting of Zr, Ti and Hf,
p is a number satisfying 10 atomic % ≦p ≦13.5 atomic %,
q is a number satisfying 28 atomic % ≦q ≦40 atomic %,
r is a number satisfying 0.88 atomic % ≦r ≦7.2 atomic %,
s is a number satisfying 4 atomic % ≦s ≦13.5 atomic %,
press-forming the alloy powder in a magnetic field to form a pressed powder body;
sintering the pressed powder body at a temperature Ts to form a sintered body;
performing a solution treatment to the sintered body; and
performing an aging treatment to the sintered body after the solution treatment,
wherein the alloy powder contains a M-rich phase, and the temperature Ts satisfies T M -50<Ts<T m , wherein T M is a melting start temperature (° C.) of the M-rich phase,
wherein the sintered body after the aging treatment includes a metallic structure comprising a plurality of phases in which a composition region having an Fe concentration of 28 mol % or more and a Cu concentration of 5 mol % or more is a main phase, and
wherein the metallic structure includes a Cu-M rich phase having 5 mol % or more of a Cu concentration and 3 mol % or more of a concentration of the element M.

8. The manufacturing method according to claim 7 , wherein a volume ratio of the Cu-M rich phase in the metallic structure is in a range of 0.01to 5%.

9. The manufacturing method according to claim 7 ,
wherein the aging treatment is performed at a temperature of from 700 to 900° C. for from 4 to 80 hours.

10. The manufacturing method according to claim 7 ,
wherein the aging treatment is performed at a temperature of from 700 to 900° C. for more than 8 hours and 60 hours or less.

11. The manufacturing method according to claim 7 ,
wherein the temperature T s is in a range of from 1160 to 1185° C.

12. A permanent magnet, comprising: a composition represented by the following composition formula:
R p Fe q M r Cu s (Co 1-t A t ) 100-p-q-r-s
wherein R is at least one element selected from the group consisting of rare earth elements,
M is at least one element selected from the group consisting of Zr, Ti and Hf,
A is at least one element selected from the group consisting of Ni, V, Cr, Mn, Al, Ga, Nb, Ta and W,
p is a number satisfying 10 atomic % ≦p ≦13.5 atomic %,
q is a number satisfying 28 atomic % ≦q ≦40 atomic %,
r is a number satisfying 0.88 atomic % ≦r ≦7.2 atomic %,
s is a number satisfying 4 atomic % ≦s ≦13.5 atomic %,
t is a number satisfying 0 atomic % ≦s ≦0.2 atomic %,
a metallic structure in which a composition region having an Fe concentration of 28 mol % or more is a main phase of a plurality of phases,
wherein a Cu concentration in the main phase is 5 mol % or more,
wherein the metallic structure includes a Cu-M rich phase having 5 mol % or more of a Cu concentration and 3 mol % or more of a concentration of the element M.

13. The permanent magnet according to claim 12 ,
wherein a volume ratio of the Cu-M rich phase in the metallic structure is in a range of 0.01 to 5%.

Assignees

• Horiuchi Yosuke
• Sakurada Shinya
• Kobayashi Tsuyoshi
• Okamoto Keiko
• Hagiwara Masaya
• Toshiba Kk

Inventors

• Horiuchi Yosuke
• Sakurada Shinya
• Kobayashi Tsuyoshi
• Okamoto Keiko
• Hagiwara Masaya

Classifications

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title

• B22F2003/248

  Thermal after-treatment · CPC title

• B22F3/24

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

• B22F3/10

  Sintering only · CPC title

• B22F3/02

  Compacting only · CPC title