Permanent magnet, motor, and generator

Patent metadata

Field	Value
Publication number	US-10923254-B2
Application number	US-201715413593-A
Country	US
Kind code	B2
Filing date	Jan 24, 2017
Priority date	Mar 23, 2015
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

A permanent magnet expressed by a composition formula: RpFeqMrCutCo100-p-q-r-t. The magnet comprises a metallic structure including crystal grains which constitutes a main phase having a Th2Zn17 crystal phase. An average value of Fe concentrations in the crystal grains of 20 or more is 28 atomic percent or more and an average value of R element concentrations in the crystal grains of 20 or more is 10 atomic percent or more.

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 is a number satisfying 10.5≤p≤12.4 atomic percent, q is a number satisfying 28≤q≤40 atomic percent, r is a number satisfying 0.88≤r≤4.3 atomic percent, and t is a number satisfying 3.5≤t≤13.5 atomic percent,
the magnet comprising:
a metallic structure including crystal grains which constitutes a main phase having a Th 2 Zn 17 crystal phase,
wherein an average value of Fe concentrations in the crystal grains of 20 or more is 28 atomic percent or more and an average value of R element concentrations in the crystal grains of 20 or more is 10 atomic percent or more,
a squareness ratio of the magnet is 92.1% or more and 95.9% or less, and
a magnetization when a magnetic field is −200 kA/m is 95.5% or more and 98.9% or less of a residual magnetization in an M-H curve of the magnet.

2. The magnet according to claim 1 ,
wherein the main phase has a composition expressed by a composition formula:
R p1 Fe q1 M r1 Cu t1 Co 100-p1-q1-r1-t1

where p1 is a number satisfying 11.1≤p1≤20 atomic percent, q1 is a number satisfying 28≤q1≤40 atomic percent, r1 is a number satisfying 1<r1≤15 atomic percent, and t1 is a number satisfying 4≤t1≤13.5 atomic percent.

3. The magnet according to claim 1 ,
wherein the main phase has a cell phase having the Th 2 Zn 17 crystal phase, and a Cu rich phase having a Cu concentration higher than that of the cell phase.

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

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

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

7. A vehicle comprising the motor according to claim 5 .

8. A vehicle comprising the generator according to claim 6 .

9. The magnet according to claim 1 ,
wherein the residual magnetization of the magnet is 1.17 T or more and 1.25 T or less.

Assignees

• Toshiba Kk

Inventors

• Horiuchi Yosuke
• Sakurada Shinya
• Hagiwara Masaya
• Kobayashi Tsuyoshi
• Kobayashi Tadahiko

Classifications

• H01F1/0551

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

• H01F1/0557

  sintered · CPC title

• C22C19/07

  based on cobalt · CPC title

• B22F3/1017

  Multiple heating or additional steps (B22F3/101 takes precedence) · CPC title

• H02K1/2766

  having a flux concentration effect · CPC title