Rare-earth magnet and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-10468165-B2
Application number	US-201414896215-A
Country	US
Kind code	B2
Filing date	Jun 5, 2014
Priority date	Jun 5, 2013
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

A rare earth magnet comprising a crystal grain having an overall composition of (R2(1-x)R1x)yFe100-y-w-z-vCowBzTMv (wherein R2 is at least one of Nd, Pr, Dy and Tb, R1 is an alloy of at least one or two or more of Ce, La, Gd, Y and Sc, TM is at least one of Ga, Al, Cu, Au, Ag, Zn, In and Mn, 0<x<1, y=12 to 20, z=5.6 to 6.5, w=0 to 8, and v=0 to 2), wherein the average grain size of the crystal grain is 1,000 nm or less, the crystal grain consists of a core and an outer shell, the core has a composition of R1 that is richer than R2, and the outer shell has a composition of R2 that is richer than R1.

First claim

The invention claimed is:

1. A rare earth magnet,
wherein the rare earth magnet has an overall composition of (R2 (1-x) R1 x ) y Fe 100-y-w-z-v Co w B z TM v , wherein R2 is at least one of Nd and Pr, R1 is an alloy of at least one or two or more of Ce, La, Gd, Y and Sc, TM is at least one of Ga, Al, Cu, Au, Ag, Zn, In and Mn, 0<x<1 in molar ratio, and y=12 to 20, z=5.6 to 6.5, w=0 to 8, and v=0 to 2 in molar percentage; and comprises a crystal grain,
wherein the average grain size of the crystal grain is 1,000 nm or less,
wherein the crystal grain consists of a core and an outer shell,
wherein the core has a composition of R1 that is richer than R2, or a composition in which the concentrations of R1 and R2 are the same and
wherein the outer shell has a composition of R2 that is richer than R1.

2. The rare earth magnet according to claim 1 , wherein the average grain size of the crystal grain is 500 nm or less.

3. A rare earth magnet,
wherein the rare earth magnet has an overall composition of (Nd (1-x) Ce x ) y Fe 100-y-w-z-v Co w B z TM v , wherein TM is at least one of Ga, Al, Cu, Au, Ag, Zn, In and Mn, 0<x<1 in molar ratio, y=12 to 20, z=5.6 to 6.5, w=0 to 8, and v=0 to 2 in molar percentage; and comprises a crystal grain,
wherein the average grain size of the crystal grain is 1,000 nm or less and
wherein the crystal grain consists of a core and an outer shell and has a composition of Ce/(Nd+Ce) in the core that is larger than Ce/(Nd+Ce) in the outer shell.

4. The rare earth magnet according to claim 3 , wherein the Ce/(Nd+Ce) in the core is 0.25 or more and 1 or less.

5. The rare earth magnet according to claim 4 , wherein the average grain size of the crystal grain is 500 nm or less.

6. The rare earth magnet according to claim 3 , wherein the average grain size of the crystal grain is 500 nm or less.

7. A rare earth magnet,
wherein the rare earth magnet has an overall composition of (R2 (1-x) R1 x ) y Fe 100-y-w-z-v Co w B z TM v wherein R2 is at least one of Nd and Pr, R1 is an alloy of at least one or two or more of Ce, La, Gd, Y and Sc, TM is at least one of Ga, Al, Cu, Au, Ag, Zn, In and Mn, 0<x<1 in molar ratio, and y=12 to 20, z=5.6 to 6.5, w=0 to 8, and v=0 to 2 in molar percentage; and comprises a crystal grain,
wherein the average grain size of the crystal grain is 1,000 nm or less,
wherein the crystal grain consists of a core and an outer shell and has a composition of R1/(R2+R1) in the core is larger than R1/(R2+R1) in the outer shell.

8. The rare earth magnet according to claim 7 , wherein the R1/(R2+R1) in the core is 0.25 or more and 1 or less.

9. The rare earth magnet according to claim 8 , wherein the average grain size of the crystal grain is 500 nm or less.

10. The rare earth magnet according to claim 7 , wherein the average grain size of the crystal grain is 500 nm or less.

Assignees

• Toyota Motor Co Ltd

Inventors

• Ito Masaaki
• Yano Masao
• Kishimoto Hidefumi
• Sakuma Noritsugu
• Shoji Tetsuya
• Manabe Akira

Classifications

• B22F2207/01

  Composition gradients · CPC title

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title

• C22C38/005

  containing rare earths, i.e. Sc, Y, Lanthanides · CPC title

• B22F5/00

  Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product · CPC title