METHOD FOR PRODUCING RARE-EARTH PERMANENT MAGNET AND METAL PLATING BATH

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A method for producing a rare-earth permanent magnet, which comprises laminating a first protective layer comprising nickel and a second protective layer comprising nickel and sulfur on a magnet base material comprising a rare earth element in this order, wherein the first protective layer is formed through electroplating by using a plating bath comprising a nickel source, an electroconductive salt and a pH stabilizer and having a nickel content of 0.3 mol/l to 0.7 mol/l in terms of a nickel atom and an electroconductivity of 80 mS/cm or more; and a plating bath for use in the method. The method allows the suppression of the elution of a rare- earth rich phase from the magnet base material, resulting in the reduction in the formation of pinholes, which leads to the production of a rare-earth permanent magnet improved in corrosion resistance. © KIPO & WIPO 2007