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:
Sep. 14, 2021
Filed:
Mar. 29, 2018
Tdk Corporation, Tokyo, JP;
Shota Miyazaki, Tokyo, JP;
Keiji Takeda, Tokyo, JP;
TDK CORPORATION, Tokyo, JP;
Abstract
An object of the present invention is to provide an R-T-B based permanent magnet having a low coercive force and a low magnetizing field, and having a high residual magnetic flux density and a high minor curve flatness even in the low magnetizing field. Provided is an R-T-B based permanent magnet including a main phase crystal grain including a compound having an RTB type tetragonal structure and a grain boundary phase existing between the main phase crystal grains, in which R is at least one rare earth element including scandium and yttrium, T is at least one transition metal element including iron, or at least two transition metal elements including iron and cobalt, an average diameter D50 of the main phase crystal grain is 1.00 μm or less, and a content of carbon included in the R-T-B based permanent magnet is 3,000 ppm or more.