摘要
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.
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.
基金
supported by the National Natural Science Foundation of China(51171057,51201055)
