添加Zr元素对纳米复相Nd10．5Fe78．4-xCo5ZrxB6．1粘结永磁体结构和磁性能的影响

Effect of Zr Addition on Microstructure and Magnetic Properties of Nanocomposite Nd10.5Fe78.4-xCo5ZrxB6.1 (x=0, 1.0, 1.5, 2.0, 2.5) Bonded Magnets

摘要:

采用快淬、热处理及模压成形工艺，制备了成分为Nd10．5Fe78．4-xCo5ZrxB6．1（x=0，1．0，1．5，2．0，2．5）的5种粘结永磁体。采用XRD,DTA，TEM等方法对合金的组织结构和晶化行为进行了研究。结果表明：Zr含量的增加可提高材料的非晶形成能力；当Zr添加到一定量时，形成高熔点的Fe2Zr相，产生细化晶粒的作用；添加Zr元素显著地提高了合金的矫顽力，改善了退磁曲线矩形度，从而提高了最大磁能积。Nd10．5Fe78．4-xCo5ZrxB6．1永磁体在x=2时获得最佳磁性能，Br=0．659T，Hcj=628kA／m，Hcb=419kA／m，（BH）m=73kJ／m^3。

Abstract:

Five kinds of bonded magnets with the compositions (at%) of Nd10.5Fe78.4-xCo5ZrxB6.1 (x= 0, 1.0, 1.5, 2.0, 2.5) were prepared by melt-spinning, post heat treatment and mould pressing. The microstructure and crystallization behavior was studied by X-ray diffraction (XRD), differential thermal analysis (DTA) and transmission electron microscopy (TEM). The results suggest that high Zr concentration can increase the glass formation ability (GFA) of alloys. The Fe2Zr with high melting point forms in the alloys, when the content of Zr is controlled at a certain amount, and it can reduce the grain size. The coercivity and the squareness of demagnetization loop are obviously improved by the addition of Zr, and the energy product is accordingly increased. As a result, the excellent magnetic properties with Br= 0.659 T, Hcj=628 kA/m, Hcb=419 kA/m, (BH)m=73 kJ/m3 are obtained in Nd10.5Fe78.4-xCo5ZrxB6.1 bonded magnet with x=2.