Development of high Bs FeNiBSiNb bulk metallic glasses by using combined CALPHAD and experimental approaches

Magnetic metallic glasses (MGs) have been widely used, however, their trade-off between glass-forming ability (GFA) and magnetic properties is hard to be broken for novel alloys development. Here, combined CALPHAD and experimental approaches are proposed and used to efficiently design high B_s FeNiBSiNb bulk MGs. The phase diagrams obtained by using CALPHAD method can help us to select glass-forming elements and determine the optimal composition ranges. Accordingly, the (Fe_0.5Ni_0.5)_x(B_16.5Si₅Nb_2.5)_{(100- x )/24} alloys with x = 74–80 exhibit high GFA are successfully developed and then cast into bulk samples. After optimal annealing, these alloys exhibit excellent magnetic properties, including high B_s of 0.70–0.93 T, ultra-low H_c of 0.5–2.0 A/m and a moderate µ_e with low sensitivity to the composition, applied field and frequency. These results provide technical and theoretical guidance for developing high performance soft magnetic MGs to be used in a variety of electronic devices.