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:
Feb. 24, 2015
Filed:
Aug. 02, 2012
Takuma Hayakawa, Tokyo, JP;
Ryota Kunieda, Tokyo, JP;
Tetsuya Chiba, Tokyo, JP;
Kenichi Nishikawa, Tokyo, JP;
Takuma Hayakawa, Tokyo, JP;
Ryota Kunieda, Tokyo, JP;
Tetsuya Chiba, Tokyo, JP;
Kenichi Nishikawa, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
The present invention provides a rare earth based sintered magnet. The magnet is a rare earth based permanent magnet with a R-T-B (R represents one or more elements selected from Y and rare earth elements, T represents one or more metal elements including Fe or the combination of Fe and Co, and B represents B or the combination of B and C) based composition. When a R-rich phase (R represents rare earth element(s)) with atomic ratio of (Fe+Co)/(LR+HR+Fe+Co)≦0.2 (LR represents Y and light rare earth element(s) selected fromLa toEu, and HR represents heavy rare earth element(s) selected fromGd toLu) is present in the grain boundary triple point, a region with HR/(LR+HR)≧0.01 (atomic ratio) is present in the R-rich phase, and the region with HR/(LR+HR)≧0.01 accounts for 10% to 90% of the area of the grain boundary triple point.