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:
Mar. 26, 2019
Filed:
Feb. 16, 2016
Tdk Corporation, Tokyo, JP;
Akihiro Ohsawa, Tokyo, JP;
Yasushi Enokido, Tokyo, JP;
TDK CORPORATION, Tokyo, JP;
Abstract
A rare earth based permanent magnet has a sintered compact with R-T-B based composition. The compact has two kinds of main phase grains M1 and M2 having different concentration distributions of R including R1 and R2 respectively representing at least one rare earth element including Y and excluding Dy, Tb and Ho, and at least one from Ho, Dy and Tb. M1 and M2 have a core-shell structure containing a shell part coating a core part. In M1, when the R1 and R2 atom concentrations in the core and shell parts are defined as αR1, αR2, βR1 and βR2, respectively, αR1>βR1, αR2<βR2, αR1>αR2 and βR1<βR2. In M2, when the R1 and R2 atom concentrations in the core and shell parts are defined as γR1, γR2, εR1 and εR2, respectively, γR1<εR1, γR2>εR2, γR1<γR2 and εR1>εR2. Ratios occupied by the main phase grains having the core-shell structure are 5% or more, respectively.