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:
Aug. 25, 1987
Filed:
Feb. 28, 1986
Sumitomo Metal Mining Company Limited, Tokyo, JP;
Abstract
A rare earth-element/cobalt type magnetic powder which possesses outstanding magnetic properties and which is useful for making a resin magnet is produced by a method which comprises thermally reducing a mixture consisting of oxide of samarium, oxide of praseodymium, optionally oxide of neodymium, and cobalt powder, thereby causing diffusion of consequently produced samarium, praseodymium, and/or neodymium in the cobalt powder, subjecting the resultant reaction product to a heat-treatment involving standing at 600.degree. to 900.degree. C. for 30 minutes to 5 hours and subsequent quenching from this temperature at a rate of not less than 10.degree. C./minute, adding the product of the heat-treatment to water, thereby converting the product into a slurry, treating the slurry with water and an aqueous acid solution, and comminuting the resulting powder into particles of an average diameter of 3 to 10 .mu.m thereby obtaining a magnetic powder having a composition represented by Sm.sub.1-x Pr.sub.x Co.sub.z or Sm.sub.1-x Pr.sub.x-y Nd.sub.y Co.sub.z (wherein x, y, and z satisfy the relations 0.05.ltoreq.x.ltoreq.0.40, 0.01.ltoreq.y.ltoreq.0.39, 0.01.ltoreq.x-y.ltoreq.0.39 and 4.7.ltoreq.z.ltoreq.5.3).