PURPOSE: To remarkably improve corrosion resistance by regulating each content of C and S contained in an Ni plating film to specified ppm.
CONSTITUTION: A sintered magnetic alloy is composed of, by wt.%, 5-40 R (R is the combination of a kind or more of rare earth elements including Y), 50-90 TM (TM is a transition metal mainly including Fe, a part of which may be substituted by the other metal or non-metal.) and 2-8 BO. The Ni plating film is formed on the surface of this alloy. The Ni plating film is specified to contain 50-800ppm C and 100-800ppm S. Saccharin of 2g/l is added into a Watts bath and current density is regulated as a means slightly containing S in the Ni plating film. In order to add C, carbonized Ni is used for an anode, whereby the amount of C to be contained is regulated. By this method, the magnetic alloy having highly reliable corrosion resistance is provided.
KAWADA KENICHI
USHIJIMA MAKOTO
