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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).

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