PURPOSE: To improve the residual flux density of a rare-earth permanent magnet so as to increase the maximum energy product of the magnet by wet-molding a heated mixture of specific fine particles for rare-earth permanent magnet and mineral oil, synthetic oil, or vegetable oil under a magnetic field and sintering the molded body.
CONSTITUTION: After mixing fin powder for R-Co5 magnet, R2-Co17 magnet, or R-Fe-B magnet (where, the R is one or more kinds of elements selected from among rare-earth elements including Y) in mineral oil, synthetic oil, or vegetable oil, the mixture is heated. Then, after filling the cavity of a metallic mold with the heated raw material and lowering a punch 1 to the upper surface of a die 4, an oriented magnetic field is impressed upon the cavity and the ray material is wet-molded under the magnetic field. The molded body is deoiled by heating the body in a vacuum, sintered in an Ar-gas atmosphere, and heat- treated. Therefore, a sintered permanent magnet body having a high density and magnetic characteristic can be manufactured stably.
TAKAHASHI MASAHIRO
HAGIWARA HIROYUKI
MIKAMOTO TSUKASA
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