METHOD FOR IMPROVING MAGNETIC PROPERTY OF SINTERED NEODYMIUM-IRON-BORON MAGNET

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A method for improving the magnetic property of a sintered neodymium-iron-boron magnet, comprising coating the surface of a sintered neodymium-iron-boron magnet with a raw material comprising elements R, H and X, to form a coating layer, and then subjecting the sintered neodymium-iron-boron magnet having the coating layer to a diffusion treatment and an ageing treatment in a vacuum or inert gas environment; wherein R is at least one of elements Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, H is element hydrogen, and X is at least one of elements C, O, N, S, B, Cl and Si; and the advantages are : due to the interaction of the three elements R, H and X, the coating layer has lower activity and is not easily oxidized when exposed to air, so that there is no product consistency problem resulting from raw material oxidation, and thus the product has a higher consistency and higher safety and can be applied to mass production; moreover, the raw material has good stability and is convenient for recycling, and therefore the utilization rate of rare earth elements is higher, so that the production costs are saved.