Abstract：Abstract: The sintered NdFeB magnet was prepared by grain boundary diffusion process. The effects of different Diffusion materials and diffusion time on the magnetic properties of sintered NdFeB magnets were studied. The results show that the Dy alloy has a low melting point and is liquid at a diffusion temperature of 900 ℃, and its diffusion speed is greater than that of fluoride. The coercivity of the 5mm thick N52 magnet increased by 46.28 % by grain boundary diffusing Dy alloy at 900 °C ,5h. Then, a 50H magnet was prepared. The higher content of Dy can be detected within 70 μm from the surface of the magnet, indicating that there is a thin area of high Dy concentration on the surface of the magnet. The magnet in this area has a higher coercivity.100 μm from the surface to the core of the magnet, the Dy content is evenly distributed and the coercivity tends to converge.
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2019, Vol. 26 
