Sintered magnet, motor and automobile

文件类型：PDF文档
文件大小：108K
PROBLEM TO BE SOLVED : To provide a sintered magnet that is superior in residual flux density and coercivity.SOLUTION : The sintered magnet includes a group of crystal grains 2 for an R-T-B rare-earth magnet having a core 4, a first shell 6 for covering the core 4 and a second shell 8 for covering the first shell 6. Percentage of the mass of heavy rare earth elements in the first shell 6 is higher than the percentage of the mass of heavy rare earth elements in the core 4, and the percentage of the mass of heavy rare-earth elements in the second shell 8 is higher than the content rate of the heavy rare elements in the first shell 6.