Preparation of rare earth permanent magnet material

A method for preparing a rare earth permanent magnet material, comprising steps as follows:

• S1) magnet preparation step:
• preparing a sintered rare earth magnet;
• S2) atomizing spray step:
• placing the sintered rare earth magnet in an atomizing spray device, wherein the atomizing spray device comprises a solution tank, an ultrasonic vibrator, an atomizing nozzle, and a recovery tank;
• storing a solution containing an element of R2 into the solution tank;
• mixing the solution containing the element of R2 homogeneously by the ultrasonic vibrator;
• atomizing the solution containing the element of R2;
• spraying the atomized solution containing the element of R2 on the sintered rare earth magnet through the atomizing nozzle while the remaining atomized solution falls into the recovery tank;
• and baking the sintered rare earth magnet after spraying;
• and
• S3) infiltrating step:
• placing the sintered rare earth magnet obtained from the atomizing spray step S2) in a stainless steel closed container, placing the stainless steel closed container in a vacuum infiltrating furnace, evacuating the vacuum infiltrating furnace to an absolute vacuum degree of lower or equal to 0.01 Pa, starting to heat the vacuum infiltrating furnace to 700-850° C. and keeping the temperature for 0.5-5 hours with the aim to remove the oxidation layer on a surface of the sintered rare earth magnet;
• and then adjusting the temperature to 900-950° C. and keeping the temperature for 1-8 hours;
• wherein the sintered rare earth magnet is R1-Fe(Co)—B-A-X-M based rare earth magnet,
• wherein R1 is one or more elements selected from Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu, Y or Sc;
• B represents Boron element;
• A is one or more elements selected from H, Li, Na, K, Be, Sr, Ba, Ag, Zn, N, F, Se, Te, Pb or Ga;
• X is one or more elements selected from S, C, P or Cu;
• M is one or more elements selected from Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf or Si;
• and
• R2 is one or more elements selected from Tb, Dy, Ho or Gd;
• S4) aging treatment step:
• the aging treatment is carried out on the sintered rare earth magnet obtained from the infiltrating step S3).