晶界扩散Dy合金对烧结NdFeB磁体磁性能的影响

Influence of grain boundary diffusing Dy alloy on the magnetic properties of sintered NdFeB magnet

采用晶界扩散工艺制备烧结NdFeB磁体。研究了不同渗材、不同扩散时间对烧结NdFeB磁体性能的影响,研究不同磨削量对扩散镝合金磁体性能的影响。结果表明,镝合金(Dy_(80)Fe_3Al_(10)Cu_4Ga_3)具有较低的熔点,在900℃扩散温度下呈液相,其扩散速度大于氟化物的固相扩散速度。900℃保温5h,晶界扩散镝合金,取向5mm厚N52磁体的矫顽力提升46.28%。距离磁体表面70μm以内可以检测出较高的镝含量,说明在磁体表面存在较薄的高镝浓度区域,该区域磁体具有较高矫顽力,距离表面100μm以外直至磁体芯部,镝含量分布均匀,矫顽力趋于一致。

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(Dy80Fe3Al10Cu4Ga3)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 N52magnet increased by 46.28%by grain boundary diffusing Dy alloy at 900℃for 5h.The higher content of Dy can be detected within 70μm 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 the area has a higher coercivity.100μm from the surface to the core of the magnet,the Dy content is evenly distributed and the coercivity tends to converge.