R-t-b based sintered magnet and rotating machine

Patent metadata

Field	Value
Publication number	US-2016163435-A1
Application number	US-201414906682-A
Country	US
Kind code	A1
Filing date	Aug 8, 2014
Priority date	Aug 9, 2013
Publication date	Jun 9, 2016
Grant date	—

Abstract

The present invention provides an R-T-B based sintered magnet having excellent corrosion resistance together with good magnetic properties. The R-T-B based sintered magnet contains R 2 T 14 B crystal grains, wherein, an R—Ga—Co—Cu—N concentrated part exists in a grain boundary formed between or among two or more adjacent R 2 T 14 B crystal grains, and the concentrations of R, Ga, Co, Cu and N in the R—Ga—Co—Cu—N concentrated part are higher than those in the R 2 T 14 B crystal grains respectively.

First claim

What is claimed is:

1 . An R-T-B based sintered magnet comprising R 2 T 14 B crystal grains,
wherein, an R—Ga—Co—Cu—N concentrated part exists in the grain boundary formed between or among two or more adjacent R 2 T 14 B crystal grains, and the concentrations of R, Ga, Co, Cu and N in the R—Ga—Co—Cu—N concentrated part are higher than those in the R 2 T 14 B crystal grains respectively.

2 . A rotating machine comprising the R-T-B based sintered magnet of claim 1 .

Assignees

• Tdk Corp

Inventors

• Miwa Masashi
• Nakajima Haruna
• Kanada Isao

Classifications

• H01F1/0577 Primary

  sintered · CPC title

• H01F41/0293

  diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets · CPC title

• H01F1/0536 Primary

  sintered · CPC title