| 摘要 |
PURPOSE:To improve corrosion resistance, and to prevent the breaking of the corner section of an outer circumference by sealing void sections among the crystal grains of a surface layer section and plating the void sections with a metal. CONSTITUTION:Voids among the crystal grains of the surface layer section of a magnet manufactured through a powder sintering method are sealed with the so called low-melting alloy represented by an Anatomical alloy, a Wood's alloy, a Newton alloy, a Rose's alloy, etc., and coated with a desired metal through a plating method. A sintered magnet 1 is manufactured in such a manner that an implalpable-powder raw material mainly comprising Nb-Fe B is mixed by a ball mill, molded to a desired shape by using a magnetic field press, sintered and aging treated, and dipped in the melt of a Wood's alloy as a Bi Pb-Sn-Cd group low-melting alloy, a low-melting alloy layer 2 is shaped to the surface layer section of the sintered magnet 1, void sections among crystal grains are sealed and the surface is coated, and plating pretreatment is executed and Ni plating is conducted, thus completing a metallic plating layer 3.
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