| 摘要 |
PROBLEM TO BE SOLVED: To improve anticorrosive property by forming a multilayer film composed of an alkaline electroless nickel plating layer as an underlying layer, an alkaline electroless copper plating layer as an intermediate layer, and an electroless nickel- phosphorus plating layer as a surface layer, with each of these layers having a specified thickness, on the surface of a rare earth, transition metal, boron-based sintered permanent magnet body. SOLUTION: A multilayer film composed of an underlying layer, an intermediate layer and a surface layer which are made of electroless plating layers on the surface of a rare earth, transition metal, boron based sintered permanent magnet body. The underlying layer is an alkaline electroless nickel plating layer having a thickness of 0.1-5μm and the intermediate layer is an alkaline electroless copper plating layer having a thickness of 5-15μm, while the surface layer is an electroless nickel-phosphorus plating layer having a thickness of 5-15μm, thus forming a high anticorrosive rare earth magnet. Thus, a uniform plating film thickness may be obtained, and the adhesiveness between the plating film and the sintered permanent magnet body may be improved. In addition, a magnet may be provided which exhibits a high anticorrosive property and has no temporal change in magnetic property at the time of plating and after plating. |
