| 摘要 |
The present invention has an object to provide a NdFeB system sintered magnet in which irreversible partial demagnetization and heat generation under a high temperature environment hardly occur. The NdFeB system sintered magnet according to the present invention is a NdFeB system sintered magnet produced by diffusing Dy and/or Tb which are/is attached to a surface of a base material produced by orienting powder of a NdFeB system alloy in a magnetic field, and sintering the powder of the NdFeB system alloy, into grain boundaries inside the base material by grain boundary diffusion treatment, wherein a squareness ratio is equal to or higher than 95%. The NdFeB system sintered magnet like this can be produced by producing a base material of the NdFeB system sintered magnet by using a NdFeB system alloy with lamellas of a rare-earth rich phase dispersed substantially uniformly at predetermined spaces, as a starting alloy, and causing the alloy to occlude hydrogen, without performing heating for desorbing the occluded hydrogen thereafter until a sintering process, and applying grain boundary diffusion treatment to the base material. |
