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.

Date of Patent:
Sep. 11, 2012

Filed:

Dec. 19, 2007
Applicants:

Hiroshi Nagata, Ibaraki, JP;

Kyuzo Nakamura, Kanagawa, JP;

Takeo Katou, Kanagawa, JP;

Atsushi Nakatsuka, Kanagawa, JP;

Ichirou Mukae, Kanagawa, JP;

Masami Itou, Kanagawa, JP;

Ryou Yoshiizumi, Kanagawa, JP;

Yoshinori Shingaki, Ibaraki, JP;

Inventors:

Hiroshi Nagata, Ibaraki, JP;

Kyuzo Nakamura, Kanagawa, JP;

Takeo Katou, Kanagawa, JP;

Atsushi Nakatsuka, Kanagawa, JP;

Ichirou Mukae, Kanagawa, JP;

Masami Itou, Kanagawa, JP;

Ryou Yoshiizumi, Kanagawa, JP;

Yoshinori Shingaki, Ibaraki, JP;

Assignee:

ULVAC, Inc., Kanagawa, JP;

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H01F 1/057 (2006.01);
U.S. Cl.
CPC ...
Abstract

There is provided a method of manufacturing a permanent magnet which has an extremely high coercive force and high magnetic properties is manufactured at high productivity. There are executed: a first step of causing at least one of Dy and Tb to adhere to at least part of a surface of iron-boron-rare-earth based sintered magnet; and a second step of diffusing, through heat-treatment at a predetermined temperature, at least one of Dy and Tb adhered to the surface of the sintered magnet into grain boundary phase of the sintered magnet. As the sintered magnet, there is used one which is manufactured by: mixing each powder of principal phase alloy (constituted primarily by RTB phase, where R is at least one rare earth element primarily including Nd and where T is a transition metal primarily including Fe), and a liquid phase alloy (having a higher content of R than RTB phase and primarily constituted by R-rich phase) in a predetermined mixing ratio; press-forming in magnetic field a mixed powder thus obtained; and sintering a press-formed body in vacuum or inert gas atmosphere.


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