Neodymium-iron-boron permanent magnet material prepared from Dy and preparation method of neodymium-iron-boron permanent magnet material

Abstract

The invention provides a neodymium-iron-boron permanent magnet material prepared from Dy and a preparation method of the neodymium-iron-boron permanent magnet material. The preparation method comprises the following steps that the surface of a neodymium-iron-boron regenerated magnet sample is coated with a layer of Dy element powder, and sintering is carried out in a vacuum sintering furnace, so that the Dy element diffuses on the Nd2Fe14B phase grain boundary, and finally, the neodymium-iron-boron permanent magnet material with a shell structure is formed. The Dy is diffused in the neodymiumiron boron grain boundary to synthesize the permanent magnet material with more excellent performance. The surface of the neodymium-iron-boron regenerated magnet is coated with the layer of Dy elementpowder; and sintering is carried out in the vacuum sintering furnace, so that the Dy element is diffused on the Nd2Fe14B phase grain boundary to synthesize the permanent magnet material with the core-shell structure in which the Nd2Fe14B phase wrapped by the heavy rare earth, and the coercive force, the magnetic energy product, the Curie temperature and the like of the neodymium-iron-boron regenerated magnet can be remarkably improved.

Description

technical field [0001] The invention relates to the field of material technology, in particular to an NdFeB permanent magnet material prepared by using Dy and a preparation method thereof. Background technique [0002] Since Park et al. discovered the excellent improvement effect of grain boundary diffusion technology on the coercive force of NdFeB, a large number of experts and scholars have been attracted to carry out research on NdFeB heavy rare earth grain boundary diffusion technology. Heavy rare earth elements Dy and Tb have a high anisotropy field. The traditional process is mainly added in the smelting process. Dy and Tb elements are evenly distributed inside the entire grain. After replacing Nd, the coercive force of the magnet is improved. However, due to Dy, Tb Elements and iron are antiferromagnetically coupled, and the partial substitution of Nd elements reduces the magnetic moment of iron atoms, resulting in a decrease in remanence. [0003] The structural com...

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Problems solved by technology

Heavy rare earth elements Dy and Tb have a high anisotropy field. The traditional process is mainly added in the smelting process. Dy and Tb elements are evenly distributed inside the entire grain. After replacing Nd, the coercive force of the magnet is improved. However, due to Dy, Tb Elements and iron are antiferromagnetically coupled, and the partial substitution of Nd elements reduces the magnetic moment of iron atoms, resulting in a decrease in remanence.

[0003] The structural composition of NdFeB scrap regenerative magnets is more complicated than that of magnets produced by smelting process. At present, there are few studies on the grain boundary diffusion of regenerative magnets.

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