Permanent magnet, motor, and generator

Patent metadata

Field	Value
Publication number	US-9715956-B2
Application number	US-201514644410-A
Country	US
Kind code	B2
Filing date	Mar 11, 2015
Priority date	Nov 28, 2014
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

The magnet has a composition expressed by R p Fe q M r Cu t Co 100-p-q-r-t . The magnet has a metallic structure including a main phase having a Th 2 Zn 17 crystal phase. The main phase has crystal grains. 5% or less of the crystal grains having a grain diameter equal to or smaller than 10 μm, 40% or less of the crystal grains having crystal orientation perpendicular to (001) plane of the Th 2 Zn 17 crystal phase in a direction deviated 30 degrees or more relative to an axis of easy magnetization.

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 10.8≦p≦12.5 atomic percent, q is a number satisfying 25≦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; and
a metallic structure including a main phase having a Th 2 Zn 17 crystal phase, the main phase having crystal grains,
5% or less of the crystal grains having a grain diameter equal to or smaller than 10 μm,
40% or less of the crystal grains having a crystal orientation perpendicular to a (001) plane of the Th 2 Zn 17 crystal phase in a direction deviated 30 degrees or more relative to an axis of easy magnetization.

2. The magnet of claim 1 , wherein an average grain diameter of the crystal grains of the main phase is equal to or greater than 35 μm.

3. The magnet of claim 1 , wherein the metallic structure includes a Cu-M rich phase having a higher Cu concentration and a higher M concentration than the main phase.

4. The magnet of claim 3 , wherein the metallic structure includes a grain boundary phase disposed between the crystal grains of the main phase, and the grain boundary phase has the Cu-M rich phase.

5. The magnet of claim 3 , wherein the Cu-M rich phase has a composition expressed by a composition formula R p1 Fe q1 M r1 Cu t1 C 100-p1-q1-r1-t1 , where p1 is a number satisfying 8≦p1≦20 atomic percent, q1 is a number satisfying 15≦q1≦35 atomic percent, r1 is a number satisfying 2<r1≦15 atomic percent, and t1 is a number satisfying 5≦t1≦25 atomic percent.

6. The magnet of 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 higher Cu concentration than the cell phase.

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

8. A motor comprising a permanent magnet recited in claim 1 .

9. A generator comprising a permanent magnet recited in claim 1 .

Assignees

• Toshiba Kk

Inventors

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

Classifications

• H01F1/086

  sintered · CPC title

• H01F1/0596

  of rhombic or rhombohedral Th2Zn17 structure or hexagonal Th2Ni17 structure · CPC title

• H01F1/053 Primary

  containing rare earth metals · CPC title

• C22C19/07 Primary

  based on cobalt · CPC title

• C22C30/02

  containing copper · CPC title