Method for manufacturing sintered magnet and sintered magnet

A magnet preparation method comprising:

• coating powder slurry on at least one of a first surface or a second surface of an NdFeB matrix and carrying out a curing reaction, to obtain a coated magnet;
• subjecting the coated magnet to vacuum heat treatment, a grain boundary diffusion treatment, and an aging treatment;
• wherein:
• the first surface and the second surface are opposite to each other;
• the powder slurry includes powder containing heavy rare earth element, UV monomer including radical-cured UV monomer, polymerization inhibitor, photoinitiator, and dispersant, wherein based on a total mass of the powder slurry:
• an amount of the powder containing the heavy rare earth element is in a range from 60 wt % to 80 wt % of the total mass of the powder slurry,
• an amount of the UV monomer is in a range from 15 wt % to 35 wt % of the total mass of the powder slurry,
• an amount of the polymerization inhibitor is in a range from 0.01 wt % to 0.1 wt % of the total mass of the powder slurry,
• an amount of the photoinitiator is in a range from 0.5 wt % to 5 wt % of the total mass of the powder slurry, and
• an amount of the dispersant is a range from 0.02 wt % to 0.2 wt % of the total mass of the powder slurry;
• and
• a temperature of the vacuum heat treatment is in a range from 250° C. to 600° C.