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:
Sep. 22, 1998
Filed:
Jun. 25, 1996
Hitoshi Taguchi, Chiba, JP;
Fumihiko Hirata, Shizuoka, JP;
Taku Takeishi, Chiba, JP;
Teruo Mori, Chiba, JP;
TDK Corporation, Tokyo, JP;
Abstract
An anisotropic hexagonal barium ferrite sintered magnet is prepared by molding a powder barium ferrite raw material in a magnetic field into a compact and sintering the compact; or by molding a powder barium ferrite raw material in a magnetic field into a compact, disintegrating the compact into particles, compacting the particles in a magnetic field into a second compact, and sintering the second compact. In either case, the raw material contains calcined hexagonal barium ferrite, a silicon component, and a barium component. The resulting anisotropic hexagonal barium ferrite sintered magnet has improved sintered density and coercivity while the method minimizes deformation during sintering which is otherwise caused by the difference between the shrinkage factors in axis c and a directions, and simplifies or omits post-treatment like polishing.