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:
Apr. 07, 2020
Filed:
Jul. 13, 2017
Tdk Corporation, Tokyo, JP;
Shota Miyazaki, Tokyo, JP;
Keiji Takeda, Tokyo, JP;
TDK CORPORATION, Tokyo, JP;
Abstract
An R-T-B based rare earth permanent magnet is expressed by formula: (R1(YCeLa))TBMin which, R1 is one or more kinds of rare earth element not including Y, Ce and La, 'T' is one or more kinds of transition metal, and includes Fe or Fe and Co as an essential component, 'M' is an element having Ga or Ga and one or more of Sn, Bi and Si, 0.4≤x≤0.7, 0.00≤y+z≤0.20, 0.16≤a/b≤0.28, 0.050≤c/b≤0.070, 0.005≤d/b≤0.028, 0.25≤(a-2c)/(b-14c)≤2.00 and 0.025≤d/(b-14c)≤0.500. The magnet has a structure having a main phase, having a compound having a RTB type tetragonal structure, and a grain boundary phase, on an arbitrary cross sectional area, an area ratio of R-T-M, T-rich and R-rich phases, with respect to a total grain boundary phase area is 10.0% or more, 60.0% or less and 70.0% or less, respectively, and the coating rate of the grain boundary phase is 70.0% or more.