The present application relates to the technical field of sintered Nd-Fe-B
magnet preparation technology, and particularly relates to a sintered Nd-Fe-B pressure-assisted enhanced
grain boundary diffusion method and a
magnet thereof, which comprises the following steps: S1, after
sintering, the Nd-Fe-B
magnet is pre-aged at low temperature and cooled to
room temperature; S2, the pre-aged magnet is sliced,
diffusion pre-processed, coated with a
rare earth diffusion source, pressure-combined with a non-
rare earth diffusion source, and diffusion
heat treated; the composition of a sintered Nd-Fe-B magnet substrate is RE x M y B z Fe 100‑x‑y‑z , wherein RE comprises at least two elements in Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu; the method increases the strength and
toughness of the magnetic steel and reduces the rate of missing corners, meanwhile, pre-aging increases the
grain boundary phase width, provides a channel for diffusion, improves the
diffusion effect, improves the
temperature coefficient of the product, and makes the diffusion source, especially the sprayed or printed diffusion source, better combined with the substrate.