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. 09, 1996
Filed:
Dec. 02, 1993
Alain Barzasi, Allevard, FR;
Hiroshi Nagata, Kyoto, JP;
Masato Sagawa, Kyoto, JP;
Fernand Vial, Meylan, FR;
Ugimag SA, St. Pierre D'Allevard, FR;
Abstract
A magnetic powder for the manufacture of sintered magnets of the RE-T-B family, where RE represents at least one rare earth, T represents at least one transition element and B represents boron, the powder possibly containing other minor elements, is constituted by a mixture of two powders (A) and (B): a) Powder (A) consists of grains with a quadratic structure RE.sub.2 T.sub.14 B, T being mainly iron with Co/Fe<8%, and which may possibly contain up to 0.5% Al, up to 0.05% Cu and up to 4% in total of at least one element of the group V, Nb, Hf, Mo, Cr, Ti, Zr, Ta, W and unavoidable impurities, the Fisher granulometry being between 3.5 and 5 .mu.m; b) Powder (B) is rich in RE, contains Co, and has the following composition by weight: RE 52-70%, comprising at least 40% (absolute value) of one or more light rare earth(s) selected from the group La, Ce, Pr, Nd, Sm, Eu; a hydrogen content (in ppm by weight) greater than 130.times.%RE; Co 20-35%; Fe 0-20%; B.ltoreq.0-0.2%; Al 0.1-4%; and unavoidable impurities, the powder having a Fisher granulometry of between 2.5 and 3.5 .mu.m. Powder (B) may be produced by mixing a RE rich powder (C) which contains Co with a B rich powder (D).