The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Nov. 08, 2022

Filed:

Mar. 07, 2019
Applicant:

Tdk Corporation, Tokyo, JP;

Inventor:

Makoto Iwasaki, Tokyo, JP;

Assignee:

TDK CORPORATION, Tokyo, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C22C 30/00 (2006.01); H01F 1/057 (2006.01); H01F 41/02 (2006.01); B22F 3/24 (2006.01); B22F 9/04 (2006.01); B22F 3/16 (2006.01);
U.S. Cl.
CPC ...
C22C 30/00 (2013.01); B22F 3/16 (2013.01); B22F 3/24 (2013.01); B22F 9/04 (2013.01); H01F 1/0577 (2013.01); H01F 41/0266 (2013.01); H01F 41/0293 (2013.01); B22F 2003/248 (2013.01); B22F 2301/45 (2013.01);
Abstract

An R-T-B based permanent magnet, in which R is a rare earth element, T is Fe or a combination of Fe and Co, and B is boron, includes main phase grains made of an RTB crystal phase and grain boundaries formed between the main phase grains. The grain boundaries include an R—O—C—N concentrated part having higher concentrations of R, O, C, and N than that of the main phase grains. The R—O—C—N concentrated part includes a heavy rare earth element. The R—O—C—N concentrated part has a core part and a shell part covering at least part of the core part. A concentration of the heavy rare earth element in the shell part is higher than a concentration of the heavy element in the core part. A covering ratio of the shell part with respect to the core part of the R—O—C—N concentrated part is 45% or more in average.


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