MANUFACTURE OF RARE EARTH PERMANENT MAGNET EXCELLENT IN OXIDATION RESISTANCE AND DEVICE THEREFOR

摘要

PURPOSE: To manufacture a rare earth permanent magnet excellent in oxidation resistance through allowing the magnet material not to contact with components responsible for corrosion in a plating solution, which corrosion causes deterioration of the adhesion of the Ni coating film, at the time of forming a nickel coating film on a magnet material with electroplating to provide the magnet with oxidation resistance in the manufacturing process of a R-T-B system rare earth magnet. ;CONSTITUTION: This permanent magnet has excellent oxidation resistance and is manufactured by forming an oxidation-resistant metallic coating film on the surface of an R-T-B system permanent magnet material consisting essentially of R, Fe and B (wherein: R is at least one element selected from the rare earth elements including Y; and T is a transition metal). In the device for manufacturing this magnet, an anode and a cathode is placed so as to provide a space between them and a partition wall consisting of cation exchange membranes is disposed between the anode and the cathode and an anode chamber contg. the anode and a cathode chamber contg. the cathode are defined by this partition wall to form a two-chamber type electrolytic tank. An anode electrolytic solution contg. halide ions is held in the anode chamber and a cathode electrolytic solution contg. no halide ions is held in the cathode chamber.;COPYRIGHT: (C)1996,JPO