| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rare-earth permanent magnet optimized to an IPM type motor for an automobile by improving corrosion resistance, abrasion resistance, and impact resistance. <P>SOLUTION: The rare-earth permanent magnet 16 is configured by forming an electroplated Ni coating film 21 whose thickness is 15 μm or larger and 30 μm or smaller, and whose shape is of a columnar crystal structure on a surface of a R-Fe-B system permanent magnet (R is a rare-earth element) 22. The electroplated Ni coating film 21 has a high hardness region where the Vickers hardness is 300 or higher and 600 or lower, and a low hardness region where the Vickers hardness is 150 or higher and 300 or lower. The rare-earth permanent magnet 16 is used in a state that the rare-earth permanent magnet is inserted into a slot of a yoke in a rotor of an IPM type motor for an automobile. <P>COPYRIGHT: (C)2010,JPO&INPIT |
