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:
Jun. 22, 2004
Filed:
May. 29, 2003
Shigeru Takaki, Amagasaki, JP;
Ken Makita, Osaka, JP;
Sumitomo Special Metals Co., Ltd., Osaka, JP;
Abstract
A compact is produced from an alloy powder for R—Fe—B type rare earth magnets including particles having a size in a range of about 2.0 &mgr;m to about 5.0 &mgr;m as measured by a light scattering method using a Fraunhofer forward scattering in a proportion of approximately 45 vol. % or more and particles having a size larger than about 10 &mgr;m in a proportion of less than about 1 vol. %. The compact is then sintered to obtain a R—Fe—B type rare earth magnet having an average crystal grain size in a range of about 5 &mgr;m to about 7.5 &mgr;m, and an oxygen concentration in a range of about 2.2 at. % to about 3.0 at. %.