Nd-Fe-B磁体掺杂Tb-Fe-B制备高性能大块永磁体

Preparation of High-performance Bulk Permanent Magnets by Doping Tb-Fe-B in Nd-Fe-B Magnets

应新能源大型设备器件需求,制备兼具高剩磁、高矫顽力的大块永磁材料成为当前研发重点。不同于晶界扩散技术(GBDP),采用双合金工艺(Nd-Fe-B磁体掺杂Tb_(19)Fe_(75)B_(6))制备的多主相(Nd, Tb)-Fe-B烧结磁体,不仅可实现高剩磁与高矫顽力而且体型可控,体现出更高的实用价值。微组织分析显示,掺杂Tb_(19)Fe_(75)B_(6)使得磁体晶界优化并在Nd_(2)Fe_(14)B晶粒表层形成(Nd, Tb)_(2)Fe_(14)B壳层,结合Tb_(2)Fe_(14)B相的存在,矫顽力得以显著提升。而导致多主相(Nd, Tb)-Fe-B磁体同时实现高剩磁与高矫顽力,主要归因于微结构中Tb_(2)Fe_(14)B单晶与Nd_(2)Fe_(14)B单晶共存所触发的界面耦合效应。该研究结果为制备高性能大块永磁材料提供了一种可靠、有效的途径。

In response to the demand for large equipment components in new energy, the preparation of large permanent magnet materials with high remanence and high coercivity has become the focus of current research and development. Unlike grain boundary diffusion technology(GBDP), the multi-main-phase(Nd, Tb)-Fe-B sintered magnet prepared by the dual-alloy process(Nd-Fe-B magnet doped with Tb_(19)Fe_(75)B_(6)) not only achieves high remanence and high coercivity but also has controllable shape, demonstrating higher practical value. Microstructure analysis confirmed that doping with Tb_(19)Fe_(75)B_(6) optimizeed the grain boundary of the magnet and formed a(Nd, Tb)_(2)Fe_(14)B shell layer on the surface of Nd_(2)Fe_(14)B grain, combined with the presence of Tb_(2)Fe_(14)B phase, the coercivity is significantly improved. The simultaneous realization of high remanence and high coercivity of multi-main-phase(Nd, Tb)-Fe-B magnets is mainly attributed to the interface coupling effect triggered by the coexistence of Tb_(2)Fe_(14)B single crystal and Nd_(2)Fe_(14)B single crystal in the microstructure. The results provide a reliable and effective way to prepare high-performance bulk permanent magnet materials.