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. 09, 1997
Filed:
May. 05, 1992
TDK Corporation, Tokyo, JP;
Abstract
A permanent magnet material is prepared by cooling with a chill roll a molten alloy containing R wherein R is at least one rare earth element inclusive of Y, Fe or Fe and Co, and B. The chill roll has a plurality of circumferentially extending grooves in a circumferential surface, the distance between two adjacent ones of the grooves at least in a region with which the molten alloy comes in contact being 100 to 300 .mu.m average in an arbitrary cross section containing a roll axis. Permanent magnet material of stable performance is obtained since the variation of cooling rate caused by a change in the circumferential speed of the chill roll is small. The variation of cooling rate is small even when it is desired to change the thickness of the magnet by altering the circumferential speed. The equalized groove pitch results in a minimized variation in crystal grain diameter.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile