PREPARATION OF RARE EARTH PERMANENT MAGNET

摘要

A rare earth permanent magnet is prepared by immersing a portion of a sintered magnet body of R1—Fe—B composition (wherein R1 is a rare earth element) in an electrodepositing bath of a powder dispersed in a solvent, the powder comprising an oxide, fluoride, oxyfluoride, hydride or rare earth alloy of a rare earth element, effecting electrodeposition for letting the powder deposit on a region of the surface of the magnet body, and heat treating the magnet body with the powder deposited thereon at a temperature below the sintering temperature in vacuum or in an inert gas.

主权项

1. A method for preparing a rare earth permanent magnet, comprising the steps of:
immersing a portion of a sintered magnet body having a R1—Fe—B base composition wherein R1 is at least one element selected from rare earth elements inclusive of Y and Sc, in an electrodepositing bath of a powder dispersed in a solvent, said powder comprising at least one member selected from the group consisting of an oxide of R2, a fluoride of R3, an oxyfluoride of R4, a hydride of R5, and a rare earth alloy of R6 wherein R2, R3, R4, R6 and R6 each are at least one element selected from rare earth elements inclusive of Y and Sc, effecting electrodeposition for letting the powder deposit on the preselected region of the surface of the magnet body, and heat treating the magnet body with the powder deposited on the preselected region of its surface at a temperature equal to or less than the sintering temperature of the magnet body in vacuum or in an inert gas.