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:
Dec. 27, 2011
Filed:
Dec. 09, 2010
Matahiro Komuro, Hitachi, JP;
Yuichi Satsu, Hitachi, JP;
Matahiro Komuro, Hitachi, JP;
Yuichi Satsu, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The object of the present invention is to provide a rare earth magnet which enables to achieve a good balance between high coercive force and high residual magnetic flux density, and its manufacturing method. The present invention provides a rare earth magnet in which a layered grain boundary phase is formed on a surface or a portion of a grain boundary of NdFeB which is a main phase of an R—Fe—B (R is a rare-earth element) based magnet, and wherein the grain boundary phase contains a fluoride compound, and wherein a thickness of the fluoride compound is 10 μm or less, or a thickness of the fluoride compound is from 0.1 μm to 10 μm, and wherein the coverage of the fluoride compound over a main phase particle is 50% or more on average. Moreover, after layering fluoride compound powder, which is formed in plate-like shape, in the grain boundary phase, the rare earth magnet is manufactured by quenching the layered compound after melting it at a vacuum atmosphere at a predetermined temperature, or by heating and pressing the main phase and the fluoride compound to make the fluoride compound into a layered fluoride compound along the grain boundary phase.