Effect of Hf addition on the glass forming ability, thermal and magnetic properties in the (Fe86B13Cu1)100−xHfx alloys

Abstract In this study, the effect of Hf addition on the glass formation ability (GFA), micro structural, thermal and magnetic properties were investigated in the Fe-B-Cu alloy with high saturation magnetization (Ms). It is found that the addition of Hf is beneficial for improving GFA of (Fe86B13Cu1)100 − xHfx Alloys. The melt-spun ribbons at x = 0.75 and x = 1.0 show an entirely amorphous structure by x-ray diffraction and have two obvious separated exothermic peaks on DSC curves, Hf element plays a positive role on postponing the first crystallization and improved the thermal stability of the amorphous Fe-B-Cu-Hf alloys. As x = 0.75, the melt-spun ribbon has a higher apparent activation energy of Fe3B phase than of the ribbon at x = 1.0, and the first crystallization is easier than the second crystallization. Therefore it was easy to obtain an α-Fe/amorphous dual phases structure alloy ribbons with few or without Fe3B phase by a suitable annealing process near peak temperature of the first crystallization. After annealing, the saturation magnetization (Ms) was tested by vibrating sample magnetometer, and the value of x = 0.75 changes slightly first, then increase obviously and reach the maximum 220 emu/g at 750 K higher Tp2. This alloy shows a good glass forming ability and a high saturation magnetization.