Co和Zr元素对纳米晶复合NdFeB永磁合金晶化行为和磁性能的影响

Effects of Co and Zr on Crystallization Behavior and Magnetic Properties of Nanocomposite NdFeB Alloys

摘要:

利用熔体快淬法和晶化退火处理工艺制备纳米晶复合NdFeB永磁合金，研究添加Co和Zr元素对合金晶化行为、微结构和磁性能的影响。结果表明，添加Co元素降低了晶化相的析出温度，提高了合金的剩磁；进一步增加Zr元素后，合金的晶化行为由两步晶化变为软硬磁相同步析出，合金的矫顽力明显提高，晶粒得到细化，软、硬磁相之间的交换耦合作用显著增强，从而使合金Nd9.5Fe76Co5Zr3B6.5表现出优异的综合磁性能，即Jr＝0.93 T，iHc=687 kA/m，(BH)max＝129 kJ/m3。

Abstract:

Nanocomposite NdFeB magnets were prepared by melt-spun and crystallization annealing. Effects of Co and Zr addition on the crystallization behavior, microstructure and magnetic properties of the magnets were investigated. Results show that Co addition decreases the precipitation temperature of crystalline phases and increases the remanence. After further addition of Zr, the crystallization behavior changes from a two-step to a single-step process, the coercivity is increased markedly and the grains are refined. The exchange coupling interaction between the soft magnetic phase and the hard phase is enhanced obviously; as a result, the Nd9.5Fe76Co5Zr3B6.5 alloy exhibits excellent overall properties, i.e. Jr＝0.93 T, iHc=687 kA/m and (BH)max＝129 kJ/m3.