稀土含量对速凝工艺制备(Nd,Dy)-(Fe,Al)-B合金结构和磁性能的影响

采用双合金法制备了不同稀土含量的(Nd，Dy)-(Fe,Al)-B合金系列,研究了稀土含量的多寡对薄带和最终烧结磁体的微观结构和磁性能的影响.研究结果表明，适量的稀土含量(～3145%)不仅能改善速凝带主相(Nd,Dy)₂Fe₁₄B的单相性，还有利于富稀土(Nd,Dy)相在晶界的均匀分布.当主相薄带的稀土含量在接近2∶14∶1相稀土含量时，磁体的内禀矫顽力和磁能积显著提高.当稀土含量较少时,对速凝薄带的合适时效热处理将能有效地提高最终烧结NdFeB磁体的磁特性. 关键词： 双相烧结 速凝技术 微观结构 磁性能

Effects of rare earth content on microstructure and magnetic properties of (Nd,Dy)-(Fe,Al)-B alloys

The (Nd,Dy)-(Fe,Al)-B alloys with different rare earth (RE) contents were prepared using melt-spun and strip cast techniques, and the dependence of their microstructures and magnetic properties on RE contents were investigate. It is found that an appropriate RE in magnets is beneficial to the formation of (Nd,Dy)₂Fe₁₄B single phase and uniform distribution of the Nd-rich phase on grain boundaries. When the rare earth content of casting strip treated as main phase is close to the stoichiometric concentration, the coercivity and energy product of magnet are enhanced significantly. Moreover, heat treatment of casting strips can improve effectively the magnetic performance of final sintered magnets.