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:
Jan. 11, 2011
Filed:
Jun. 26, 2007
Hiroyuki Tomizawa, Hirakata, JP;
Yuji Kaneko, Uji, JP;
Hiroyuki Tomizawa, Hirakata, JP;
Yuji Kaneko, Uji, JP;
Hitachi Metals, Ltd., Minato-ku, Tokyo, JP;
Abstract
In a rare earth magnet, an added heavy rare earth element Rsuch as Dy is effectively used without any waste, so as to effectively improve the coercive force. First, a molten alloy of a material alloy for an R-T-Q rare earth magnet (R is a rare earth element, T is a transition metal element, and Q is at least one element selected from the group consisting of B, C, N, Al, Si, and P), the rare earth element R containing at least one kind of element Rselected from the group consisting of Nd and Pr and at least one kind of element Rselected from the group consisting of Dy Tb, and Ho is prepared. The molten alloy is quenched, so as to produce a solidified alloy. Thereafter, a thermal treatment in which the rapidly solidified alloy is held in a temperature range of 400° C. or higher and lower than 800° C. for a period of not shorter than 5 minutes nor longer than 12 hours is performed. By the thermal treatment, the element Rcan be moved from the grain boundary phase to the main phase, so that the coercive force is increased.