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:
Oct. 23, 2018
Filed:
Jul. 16, 2014
Tdk Corporation, Tokyo, JP;
Eiji Kato, Tokyo, JP;
Yoshinori Fujikawa, Tokyo, JP;
Taeko Tsubokura, Tokyo, JP;
Chikara Ishizaka, Tokyo, JP;
Katsuo Sato, Ichikawa, JP;
TDK CORPORATION, Tokyo, JP;
Abstract
The present invention provides a rare earth based magnet that inhibits the high temperature demagnetization rate even when less or no heavy rare earth elements such as Dy, Tb and the like than before are used. The rare earth based magnet according to the present invention is a sintered magnet which includes RTB crystal grains as main phase and grain boundary phases between the RTB crystal grains. When the grain boundary phase surrounded by three or more main phase crystal grains is regarded as the grain boundary multi-point, the microstructure of the sintered body is controlled so that the ratio of the grain boundary triple-point surrounded by three main phase crystal grains in all grain boundary multi-points to be specified value or less.