MANUFACTURE OF RARE-EARTH BOND MAGNET

PROBLEM TO BE SOLVED: To further improve the rust-preventing ability of a rare-earth bond magnet by binding rare-earth magnet powder in one body with a resin binder and removing organic matters, composed mainly of the resin binder from the surface of the bound body, and then plating the surface with Ni. SOLUTION: After 100 pts.wt. Nd16 Fe77 B7 rare-earth magnet powder, 10 pts.wt. epoxy resin, and 2 pts.wt. stearic acid are mixed together, the mixture is molded in a cylindrical body having an outside diameter of 20 mm, an inside diameter of 18 mm, and a height of 7 mm, and then, a blank rare-earth magnet body is obtained by curing the epoxy resin by heating the molded body at 140 deg.C. After the epoxy resin remaining on the surface of the rare-earth bond magnet thus obtained has been removed by performed plasma cleaning for ashing organic matters composed mainly of the resin binder, by uniformly generating oxygen plasma between two electrodes under a reduced-pressure condition of