添加元素对稀土粘结磁体退磁曲线方形度的影响

采用快淬法制备镨基(Nd,Pr)10.5(Fe,Co)83.5-xMxB6(M=Zr,Nb,Ti)系列粘结磁体,研究添加Zr、Nb和Ti等元素对快淬合金显微结构和磁性能的影响.(Nd,Pr)10.5(Fe,Co)83.5B6合金中适量添加Zr、Nb和Ti元素能有效细化合金晶粒,获得细小、均匀的晶粒,平均晶粒尺寸为50～70 nm.添加Zr、Nb和Ti元素的粘结磁体,由于晶粒细化和非磁性相对磁畴畴壁钉扎的共同作用,Hk/Hcj值大幅度增加,退磁曲线方形度得到明显改善,磁性能也显著提高.在Zr、Nb和Ti3种元素中,Zr对细化晶粒和提高磁性能的效果最好.含1％Zr(原子分数)的(Nd,Pr)10.5(Fe,Co)82.5Zr1B6合金薄带晶粒细小、均匀,平均尺寸约为60 nm,其粘结磁体退磁曲线方形度最好,Hk/Hcj值达到了39.9％,剩磁Br为0.675 T,内禀矫顽力Hci为616 kA/m,最大磁能积(BH)m为77 kJ/m3.

Effects of Metal Element Addition on Hysteresis Loop Rectangularity of Bonded Permanent Magnets

A series of bonded magnets of (Nd,Pr)10.5(Fe,Co)83.5-xMxB6 (M=Zr, Nb, Ti) alloys were prepared by the melt-spun method. The effects of Zr, Nb and Ti element on the microstructure and magnetic properties of alloys have been investigated. The grains of (Nd,Pr)10.5(Fe,Co)83.5B6 with suitable addition of Zr, Nb, or Ti element are finer and more homogeneous. The average grain size is about 50~70 nm. Due to the combined effect of grains refining and pinning to magnetic domain wall of non-magnetic phases, the demagnetization curve rectangularity is improved notably, and the value of Hk/Hcj and other magnetic properties are also greatly increased for the bonded magnets with Zr, Nb, and Ti element addition. Compared with Nb and Ti, Zr has the best effect on refining the grains and increasing magnetic property. For the (Nd,Pr)10.5(Fe,Co)82.5Zr1B6 alloy with 1% Zr, the grains are ~60 nm and homogeneous, the demagnetization curve rectangularity is the best, the Hk/Hcj reaches to 39.9%, and Br, Hcj, and (BH)m are 0.675 T, 616 kA/m and 77 kJ/m3, respectively.