Rare earth permanent magnetic powder, bonded magnet and device using the bonded magnet

Patent metadata

Field	Value
Publication number	US-9859042-B2
Application number	US-201214380060-A
Country	US
Kind code	B2
Filing date	Jul 2, 2012
Priority date	Jul 2, 2012
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

The application discloses a rare-earth permanent magnetic powder, a bonded magnet, and a device using the bonded magnet. The rare-earth permanent magnetic powder comprises 4 to 12 at. % of Nd, 0.1 to 2 at. % of C, 10 to 25 at. % of N and 62.2 to 85.9 at. % of T, wherein T is Fe or FeCo and the main phase of the rare-earth permanent magnetic powder is a hard magnetic phase with a TbCu 7 structure. Material volatilization can be avoided effectively during a preparation process of the rare earth permanent magnetic powder, thus improving the wettability with a water-cooling roller during the preparation process and final prepared materials are provided with good magnetic properties.

First claim

What we claim is:

1. A rare-earth permanent magnetic powder, wherein the rare-earth permanent magnetic powder comprises 4 to 12 at. % of Nd (neodymium), 0.1 to 2 at. % of C (carbon), 10 to 25 at. % of N (nitrogen) and 62.2 to 85.9 at. % of element T, wherein the element T is Fe or FeCo, and the main phase of the rare-earth permanent magnetic powder is a hard magnetic phase with a TbCu 7 structure, wherein the rare-earth permanent magnetic powder further comprises 1 to 5 at. % of element A and a 0.1 to 2 at. % of B (boron); the element A is Zr and/or Hf, the ratio of the content of B (boron) to the element of A is 0.1 to 0.5.

2. The rare-earth permanent magnetic powder according to claim 1 , wherein the rare-earth permanent magnetic powder has the structure in General Formula (II), and the General Formula (II) is shown as follows:
Nd x A w T 100-x-y-z-a C y B z N a   (II),

wherein element T is Fe (iron) or FeCo (iron-cobalt); element A is Zr (zirconium) and/or Hf (hafnium);
5≦x+w≦12, 1≦w≦5, 0.1≦z≦2, 10≦a≦25, 0.1≦z/w≦0.5 and 0.1≦y≦2.

3. The rare-earth permanent magnetic powder according to claim 1 , wherein the content of B (boron) in the rare-earth permanent magnetic powder ranges from 0.3 to 2 at. %.

4. The rare-earth permanent magnetic powder according to claim 1 , wherein the contents of Nd (neodymium) and element A in the rare-earth permanent magnetic powder are 5 to 12 at. % of the total contents of the rare-earth permanent magnetic powder, and the ratio of the content of C (carbon) to the sum of the contents of Nd (neodymium) and element A in the rare-earth permanent magnetic powder is 0.03 to 0.15.

5. The rare-earth permanent magnetic powder according to claim 4 , wherein the ratio of the content of C (carbon) to the sum of the contents of Nd (neodymium) and element A in the rare-earth permanent magnetic powder is 0.05 to 0.12.

6. The rare-earth permanent magnetic powder according to claim 4 , wherein the rare-earth permanent magnetic powder has the structure in General Formula (II), and the General Formula (II) is shown as follows:
Nd x A w T 100-x-y-z-a C y B z N a   (II)

wherein element T is Fe (iron) or FeCo(iron-cobalt); element A is Zr (zirconium) and/or Hf (hafnium);
5≦x+w≦12, 1≦w≦5, 0.1≦z≦2, 10≦a≦25, 0.1≦z/w≦0.5 and 0.1≦y≦2.

7. The rare-earth permanent magnetic powder according to claim 1 , wherein the rare-earth permanent magnetic powder further comprises 0.3 to 10 at. % of element M, and the element M is at least one of Ti (titanium), V (vanadium), Cr (chromium), Ni (nickel), Cu (copper), Nb (niobium), Mo (molybdenum), Ta (tantalum), W (tungsten), Al (aluminum), Ga (gallium) and Si (silicon).

8. The rare-earth permanent magnetic powder according to claim 7 , wherein the content of element M in the rare-earth permanent magnetic powder is 0.5 to 8 at. %.

9. The rare-earth permanent magnetic powder according to claim 8 , wherein the content of element M in the rare-earth permanent magnetic powder is 0.5 to 5 at. %, and the element M is at least one of Nb (niobium), Ga (gallium), Al (aluminum)and Si (silicon).

10. The rare-earth permanent magnetic powder according to claim 1 , wherein the roller contact surface roughness Ra of the rare-earth permanent magnetic powder is below 2.8 μm.

11. The rare-earth permanent magnetic powder according to claim 1 , wherein the average grain size of the rare-earth permanent magnetic powder is 3 to 100 nm.

12. The rare-earth permanent magnetic powder according to claim 1 , wherein the Nd (neodymium) in the rare-earth permanent magnetic powder is partly substituted by Sm (samarium) and/or Ce (cerium); the content of Sm (samarium) and/or Ce (cerium) in the rare-earth permanent magnetic powder is 0.5 to 4.0 at. %.

13. A bonded magnet, wherein the bonded magnet is obtained by bonding the rare-earth permanent magnetic powder according to claim 1 with a binder.

14. A device, wherein the device uses the bonded magnet according to claim 13 .

15. The rare-earth permanent magnetic powder according to claim 1 , wherein the roller contact surface roughness Ra is below 1.6 μm.

Assignees

• Luo Yang
• Li Hongwei
• Yu Dunbo
• Li Kuoshe
• Yan Wenlong
• Xie Jiajun
• Lu Shuai
• Grirem Advanced Mat Co Ltd

Inventors

• Luo Yang
• Li Hongwei
• Yu Dunbo
• Li Kuoshe
• Yan Wenlong
• Xie Jiajun
• Lu Shuai

Classifications

• B22F1/0551

  Flake form nanoparticles · CPC title

• B22F1/054

  Nanosized particles · CPC title

• C22C38/001

  containing N · CPC title

• B22F1/0018

  Operations & Transport · mapped topic

• C22C38/10

  containing cobalt · CPC title