Permanent magnet, motor, and generator

Patent metadata

Field	Value
Publication number	US-10770208-B2
Application number	US-201514661122-A
Country	US
Kind code	B2
Filing date	Mar 18, 2015
Priority date	Mar 18, 2014
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

Abstract

A high performance permanent magnet is provided. The permanent magnet includes a composition represented by a composition formula: RpFeqMrCutCo100-p-q-r-t, and a metallic structure including cell phases having a Th2Zn17 crystal phase and Cu-rich phases having higher Cu concentration than the cell phases. An average diameter of the cell phases is 220 nm or less, and in a numeric value range from a minimum diameter to a maximum diameter of the cell phases, a ratio of a number of cell phases having a diameter in a numeric value range of less than upper 20% from the maximum diameter is 20% or less of all the cell phases.

First claim

What is claimed is:

1. A permanent magnet, comprising:
a composition expressed by a composition formula:
R p Fe q M r Cu t Co 100-p-q-r-t

where 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 10.5≤p≤12.5 atomic %, q is a number satisfying 26≤q≤29.4 atomic %, r is a number satisfying 0.88≤r≤4.5 atomic %, and t is a number satisfying 5.23≤t≤10.7 atomic %, and a total of p, q and r is 41.02 atomic % or less; and
a metallic structure including cell phases having a Th 2 Zn 17 crystal phase and Cu-rich phases having higher Cu concentration than the cell phases,
an average diameter of the cell phases being 220 nm or less,
the cell phases having diameter of a numeric value range from a minimum diameter to a maximum diameter, a ratio of a number of cell phases having diameters in a numeric value range of upper 20% from the maximum diameter being 20% or less of all the cell phases,
a squareness ratio of the magnet being 93.5% or more and 94.5% or less, and
a residual magnetization of the magnet being 1.185 T or more and 1.215 T or less.

2. The magnet of claim 1 , wherein the Cu-rich phases are provided to surround the cell phases.

3. The magnet of claim 1 , wherein the Cu-rich phases have a CaCu 5 crystal phase.

4. The magnet of claim 1 , wherein the Cu concentration of the Cu-rich phases is 45 atomic % or more.

5. The magnet of claim 1 , wherein a full width at half maximum of a concentration profile of Cu in the Cu-rich phases is 5 nm or less.

6. The magnet of claim 1 , wherein 50 atomic % or more of a total amount of the element R in the composition formula is Sm, and wherein 50 atomic % or more of the element M in the composition formula is Zr.

7. The magnet of claim 1 , wherein r is a number satisfying 0.88≤r≤3.11 atomic %.

8. A motor comprising the permanent magnet of claim 1 .

9. A generator comprising the permanent magnet of claim 1 .

10. A vehicle comprising the motor of claim 8 .

11. A vehicle comprising the generator of claim 9 .

12. A permanent magnet, comprising:
a composition expressed by a composition formula:
R p Fe q M r Cu t (Co 100-x A x ) 100-p-q-r-t

where 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 10.5≤p≤12.5 atomic %, q is a number satisfying 26≤q≤29.4 atomic %, r is a number satisfying 0.88≤r≤4.5 atomic %, t is a number satisfying 5.23≤t≤10.7 atomic %, x is a number satisfying x≤20 atomic %, and a total of p, q and r is 41.02 atomic % or less; and
a metallic structure including cell phases having a Th 2 Zn 17 crystal phase and Cu-rich phases having higher Cu concentration than the cell phases,
an average diameter of the cell phases being 220 nm or less,
the cell phases having diameter of a numeric value range from a minimum diameter to a maximum diameter, a ratio of a number of cell phases having diameters in a numeric value range of upper 20% from the maximum diameter being 20% or less of all the cell phases,
a squareness ratio of the magnet being 93.5% or more and 94.5% or less, and
a residual magnetization of the magnet being 1.185 T or more and 1.215 T or less.

13. A permanent magnet, comprising:
a composition expressed by a composition formula:
R p Fe q M r Cu t Co 100-p-q-r-t

where 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 10.5≤p≤12.5 atomic %, q is a number satisfying 26≤q≤40 atomic %, r is a number satisfying 0.88≤r≤4.5 atomic %, and t is a number satisfying 5.23≤t≤10.7 atomic %; and
a metallic structure including cell phases having a Th 2 Zn 17 crystal phase and Cu-rich phases having higher Cu concentration than the cell phases,
an average diameter of the cell phases being 220 nm or less,
the cell phases having diameter of a numeric value range from a minimum diameter to a maximum diameter, a ratio of a number of cell phases having diameters in a numeric value range of upper 20% from the maximum diameter being 20% or less of all the cell phases,
a squareness ratio of the magnet being 93.5% or more and 94.5% or less, and
a residual magnetization of the magnet being 1.185 T or more and 1.215 T or less.

Assignees

• Toshiba Kk

Inventors

• Horiuchi Yosuke
• Sakurada Shinya
• Okamoto Keiko
• Hagiwara Masaya
• Kobayashi Tsuyoshi
• Endo Masaki
• Kobayashi Tadahiko
• Sanada Naoyuki

Classifications

• C22C19/07 Primary

  based on cobalt · CPC title

• H01F7/0226

  PM with variable field strength (H01F7/0284 takes precedence) · CPC title

• H01F1/0551

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

• B22F2009/048

  by pulverising a quenched ribbon · CPC title

• B22F2009/044

  by jet milling · CPC title