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. 18, 2020
Filed:
Mar. 29, 2018
Tdk Corporation, Tokyo, JP;
Yoshinori Fujikawa, Tokyo, JP;
Masashi Miwa, Tokyo, JP;
TDK CORPORATION, Tokyo, JP;
Abstract
An R-T-B based sintered magnet including main phase particles having an RTB type crystal structure. R is at least one rare earth element essentially including a heavy rare-earth element RH. T is at least one transition metal element essentially including Fe or Fe and Co. B is boron. At least one of the main phase particles includes low RH crystal phases inside the main phase particle. The low RH crystal phases include the RTB type crystal structure, wherein an RH concentration in the low RH crystal phases is relatively lower than the RH concentration in the whole main phase particles. The R-T-B based sintered magnet may satisfy r−r≥20% when an existence ratio of the main phase particles including the low RH crystal phases in a magnet surface layer part is r(%) and the same in a magnet central part is r(%).