Method for producing a rare-earth magnet

PROBLEM TO BE SOLVED : To provide a method for producing a rare-earth magnet, capable of producing a rare-earth magnet excellent in coercive force performance.SOLUTION : In a method for producing a rare-earth magnet, a sintered body S is produced by sintering magnetic powder MF serving as a rare-earth magnet material, a rare-earth magnet precursor C is produced by subjecting the sintered body S to hot plastic working that imparts magnetic anisotropy, and a rare-earth magnet RM is produced by diffusively permeating a modified alloy SL into the rare-earth magnet precursor C. In the method, when characteristics of the rare-earth magnet precursor is represented by the Kronmuller formula : Hc=αHa-NMs (where, Hc : coercive force; α : a factor contributed by parting properties between main phases (nanocrystal particles); Ha : crystal magnetic anisotropy (inherent to a main phase material); N : a factor contributed by the particle diameter of the main phase; and Ms : saturation magnetization (inherent to the main phase material)), a rare-earth magnet precursor that satisfies α≥0.440 and N≤1.10 is used.SELECTED DRAWING : Figure 8