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. 17, 1991
Filed:
Jan. 25, 1989
Toshiro Kuji, Agro, JP;
Robert C O'Handley, Andover, MA (US);
Nicholas J Grant, Winchester, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
A magnetic material melt is solidified by cooling the material from two opposing surfaces while deforming the material by applying compressive pressure to the two opposing surfaces. Twin roller quenching is a preferred method for producing the flakes. The flakes exhibit strong texture normal to their surface, that is, there is a high degree of alignment of the magnetically easy axes of the crystals within the polycrystalline flake. The strong crystal orientation appears to result both from directional solidification in a thermal gradient and uniaxial deformation of the solid phase in the twin rollers. Magnetization studies on individual flakes show intrinsic coercivities of 14 kOe and a nearly 50% higher remanance for field normal to the flake surface than in the flake plane. Splat quenching is another suitable technique for carrying out the invention.