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:
Jan. 07, 2020
Filed:
Feb. 23, 2017
Applicant:
Tdk Corporation, Tokyo, JP;
Inventors:
Takurou Iwasa, Tokyo, JP;
Masashi Miwa, Tokyo, JP;
Assignee:
TDK CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01F 1/053 (2006.01); B22F 9/04 (2006.01); B22F 3/12 (2006.01); B22F 5/00 (2006.01); C21D 3/06 (2006.01); C22C 38/00 (2006.01); C22C 38/06 (2006.01); C22C 38/10 (2006.01); C22C 38/14 (2006.01); C22C 38/16 (2006.01); H01F 1/06 (2006.01);
U.S. Cl.
CPC ...
H01F 1/053 (2013.01); B22F 3/12 (2013.01); B22F 5/00 (2013.01); B22F 9/04 (2013.01); C21D 3/06 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/06 (2013.01); C22C 38/10 (2013.01); C22C 38/14 (2013.01); C22C 38/16 (2013.01); H01F 1/06 (2013.01); B22F 2009/042 (2013.01); B22F 2009/044 (2013.01); B22F 2201/11 (2013.01); B22F 2201/20 (2013.01); B22F 2301/355 (2013.01); B22F 2998/10 (2013.01); B22F 2999/00 (2013.01); C22C 2202/02 (2013.01);
Abstract
An R-T-B based permanent magnet includes R-T-B based compounds as main-phase crystal grains. R is a rare earth element. T is iron group element(s) essentially including Fe or Fe and Co. B is boron. A two-grain boundary is contained between the two adjacent main-phase crystal grains. An average grain size of the main-phase crystal grains is 0.9 μm or more and 2.8 μm or less. A thickness of the two-grain boundary is 5 nm or more and 200 nm or less.