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.
Patent No.:
Date of Patent:
Aug. 09, 2022
Filed:
Mar. 14, 2020
Tdk Corporation, Tokyo, JP;
Masashi Miwa, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
A permanent magnetincludes Nd, Fe, and B, the permanent magnetcontains a plurality of main phase grains; and grain boundaries positioned between the main phase grains, the main phase grains include Nd, Fe, and B, at least a portion of the grain boundaries contains an R'—O—C phase, the R′—O—C phase includes a rare earth element R′, O, and C, the concentration of each of R′, O, and C in the R′—O—C phase is higher compared to the main phase grains, the permanent magnetcomprises a surface layer portionand a central portion, the surface layer portionis positioned on the surface side of the permanent magnet, the central portionis positioned on the inner side of the permanent magnet, the proportion of the area of the R′—O—C phase occupying in a cross-section of the surface layer portionis S1 %, the proportion of the area of the R′—O—C phase occupying in a cross-section of the central portionis S2%, and S1 is higher than S2.