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:
Mar. 21, 2017
Filed:
Jul. 24, 2013
Hitachi Metals, Ltd., Minato-ku, Tokyo, JP;
HITACHI METALS, LTD., Tokyo, JP;
Abstract
A sintered ferrite magnet comprising main phases of ferrite having a hexagonal M-type magnetoplumbite structure, first grain boundary phases existing between two main phases, and second grain boundary phases existing among three or more main phases, the second grain boundary phases being dispersed in its arbitrary cross section, and the second grain boundary phases having an average area of less than 0.2 μm, are produced by calcining, pulverizing, molding and sintering raw material powders having the general formula of CaLaAFeCo, wherein 1−x−y, x, y and z and n representing a molar ratio are in desired ranges; 1.8% or less by mass of SiOand 2% or less by mass (as CaO) of CaCObeing added to a calcined body after calcining and before molding; and the sintering step being conducted with a temperature-elevating speed of 1-4° C./minute in a range from 1100° C. to a sintering temperature, and a temperature-lowering speed of 6° C./minute or more in a range from the sintering temperature to 1100° C.