The x(Tb0.15Ho0.85Fey)+(1–x)(Tb0.3Dy0.7Fey)(x=0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9; y=1.85, 1.9, 2.0) samples were prepared by a vacuum arc furnace, and annealed at 1000 oC for 1 d and at 950 oC for a week. Three vertical sections of Tb0.15Ho0.85Fey-Tb0.3Dy0.7Fey(y=1.85, 1.9, 2.0) in the Tb-Dy-Ho-Fe system were determined using optical microscopy, scanning electron microscopy, energy dispersion X-ray spectroscopy, X-ray diffraction, and differential thermal analysis. These vertical sections consisted of two single-phase regions: L and(Tb,Dy,Ho)Fe2; four two-phase regions: L+(Tb,Dy,Ho)Fe3, L+(Tb,Dy,Ho)Fe2,(Tb,Dy,Ho)Fe2+(Tb,Dy,Ho)Fe3, and(Tb,Dy,Ho)Fe2+(Tb,Dy,Ho). The high Ho content of(Tb,Dy,Ho)Fey alloys led to the elevation of the peritectic temperature of L+(Tb,Dy,Ho)Fe3→(Tb,Dy,Ho)Fe2. The region of(Tb,Dy,Ho)Fe2 phase was shifted towards the side of rich-Ho with the Fe content increasing. It meant that the substitution of Ho for Dy or Tb had a marked effect on the solidification process of(Tb,Dy,Ho)Fe2 compounds.
A new preparation method of Sm2Co17nanoflakes was investigated.Hard magnetic Sm2Co17nanoflakes with thickness of 20-100nm were obtained by milling in heptane and oleic acid under a magnetic field of 1.5Tfor0.5-20h.It was shown that higher anisotropic magnetic properties would be induced by the flake-shape anisotropy when the prepared Sm2Co17particles are milled with a magnetic field.The magnetic anisotropy of flakes after being aligned under the magnetic field of 1.5Tcould be further enhanced,and the value of(BH)m was 128kJ·m-3.Both anisotropyand properties are better than those of the nano-particles milled without a magnetic field.
利用AMH-1M-S型动态磁滞特性测试系统测试了铁镓合金的动态磁滞特性。以内径为5.5mm、外径为7.25 mm的环形<100>取向多晶Fe83Ga17合金为测量对象,分别对励磁磁场频率为50、100、200、300、400 k Hz和最大饱和磁密为0.01、0.03、0.05、0.07 T两个方面研究了磁滞曲线和磁特性参数变化规律。实验表明:当励磁磁场频率或最大饱和磁密增加,磁滞曲线变宽、面积增大,剩磁、矫顽力、损耗增加。本文的实验结果为铁镓材料的应用提供了基础参数。
