| 摘要 |
PURPOSE:To produce magnetic alloy powder having excellent coercive force by executing grinding of a sintered body in gaseous hydrogen at the time of producing magnetic powder for a resin bonded permanent magnet by subjecting rare earth-iron alloy powder to compression molding, sintering, aging treatment, grinding and aging treatment. CONSTITUTION:An R-Fe-B alloy (R is a rare earth element including Y) is melted by an arc in an inert gaseous atmosphere of Ar, etc., and is then cast into an ingot at the time of producing the R-Fe-B alloy powder to be used for producing the permanent magnet by binding the powder of the R-Fe-B alloy with a synthetic resin. After this ingot is ground by a stamp mill, the powder is pulverized by a vibration mill. The fine powder formed in such a manner is compressively molded in a magnetic field and is sintered and oil quenched in a gaseous Ar atmosphere; thereafter, the powder is subjected to the aging treatment for one hour at 600 deg.C in the gaseous Ar and is further subjected to exposing and grinding in a gaseous hydrogen treatment under 1-10kg/cm<2> pressure; the powder is in succession subjected to the aging treatment for 3hr. The magnetic powder for the resin bonded rare earth-iron alloy permanent magnet having extremely large coercive force is obtd. |
