DyF<sub>3</sub>掺杂热变形NdFeB磁体的微观结构和性能

Hot deformation and its effect on performance and microstructural of DyF<sub>3</sub>-doped NdFeB magnet

摘要:

基于热变形技术，研究制备了DyF3掺杂热变形NdFeB磁体的微观结构和磁性能。结果表明，通过热变形，磁体获得了具有明显C轴取向特征的扁平形状晶粒，其剩磁从前驱体烧结磁体的0.77 T提高至 1.34 T，提升了近74%。此外，热变形过程起到了晶界扩散的作用，使得DyF3进一步扩散至NdFeB主相之中，形成了(Nd, Dy)2Fe14B相，从而减小了因热变形带来的矫顽力损失。电化学测试表明，热变形过程可提高磁体腐蚀电位和减小电流密度。变形条件800 ℃/70%时，磁体具有最佳的综合磁性能和电化学性能，其磁性能可达：Br=1.34 T，Hcj=1225 kA/m和(BH)max=286 kJ/m3。

Abstract:

Based on the hot deformation technique, the microstructure and magnetic properties of DyF3-doped hot deformed NdFeB magnets were investigated. The results show that by hot deformation, the magnet obtains flat-shaped grains with obvious C-axis orientation characteristics, and the remanence is increased from 0.77 T of the precursor sintered magnet to 1.34 T, which is increased by nearly 74%. In addition, the hot deformation process can further diffuse DyF3 into the main phase of NdFeB, forming a (Nd, Dy)2Fe14B phase, and lead to reducing the coercivity loss. Electrochemical tests have shown that the hot deformation process increases the corrosion potential of the magnet and reduces the current density. When the deformation condition is 800 ℃/70%, the magnet has the best comprehensive magnetic and electrochemical properties, and its magnetic properties can reach: Br=1.34 T, Hcj=1225 kA/m and (BH)max=286 kJ/m3.