Patent ID: 8414709

Claim:
A method for producing an NdFeB sintered magnet, including steps of forming a layer containing Dy and/or Tb on a surface of an NdFeB sintered magnet base material and then performing a grain boundary diffusion process for diffusing Dy and/or Tb from the aforementioned layer through crystal grain boundaries of the magnet base material into the magnet base material by heating the magnet base material to a temperature equal to or lower than a sintering temperature of the magnet base material, wherein: a) a content of a rare earth in a metallic state in the magnet base material is equal to or higher than 12.7 at %; b) the aforementioned layer is a powder layer formed by depositing a powder; c) the powder layer contains 50 mass % or more Dy and/or Tb in a metallic state; and d) the powder layer contains 1 mass % or more Al.