双主相工艺制备烧结Nd-Fe-B基永磁体的研究进展

Significant Progress of Dual-Main-Phased Process for Sintered Nd-Fe-B Permanent Magnets:A Review

双主相工艺是近年提出的改善Nd-Fe-B基烧结磁体性能的有效途径。该工艺通过对Nd-Fe-B和(Nd,Re)-Fe-B两种粉末的成分设计,使磁体形成一种双主相结构,优化晶界相成分及分布,显著提升矫顽力。特别是对高丰度铈(Ce)磁体、混合(MM)稀土磁体,可以有效地抑制由于低各向异性场相铈铁硼(Ce-Fe-B)、镧铁硼(La-Fe-B)等的引入引起的矫顽力降低的问题。同时,对于重稀土(Dy/Tb)磁体,在相同矫顽力提升的情况下,双主相法对比传统单主相法所需的重稀土含量更低。本文详细阐述了通过双主相工艺制备磁体的性能改善及相关机制,为制备高性能稀土磁体提供思路及支撑。

The dual-main-phased method is an effective way to improve the magnetic performance of sintered NdFe-B magnets proposed in recent years.By designing the composition of Nd-Fe-B and(Nd,Re)-Fe-B powders,this method makes the magnet form a dual-main-phased structure,optimizes the distribution of grain boundary phase,and significantly improves the coercivity.Especially for high-abundance cerium(Ce)magnets and mischmetal(MM)magnets,it can effectively solve the problem of reduced coercivity caused by the introduction of low-anisotropy field phases Ce-Fe-B and La-Fe-B.On the other hand,for heavy rare earth(Dy/Tb)magnets,the magnets prepared by the dual-main-phased method possess a lower content of heavy rare earths than that of the magnets prepared by the traditional single-main-phased method under the same coercivity increase.In this paper,the performance improvement and related mechanism of magnets prepared by dual-main-phased method are described in detail,which provides ideas and support for the preparation of high-performance rare earth magnets.