Influence of Ta, Y substitutions on the thermal stability, microhardness and magnetic properties of melt spun Fe–B–Si amorphous alloys

In the present research work, thermal stability, magnetic properties and microhardness of Fe72B19.2Si4.8M4 (M = Ta or Y) amorphous ribbons obtained by chill block melt-spinning technique are reported. The crystallization temperatures resulted as high as 1129 K (for M = Ta) and of 1167 K (for M = Y), which indicate a considerable thermal stability for both alloys. On the other hand, the saturation polarization (μ0Ms) together with the Curie temperature (Tc) also showed excellent combination of values, with 0.95 ± 0.12 T and 586 ± 8 K, respectively (for the Ta-containing alloy) and of 1.55 ± 0.18 T and 698 ± 6 K, respectively (for the Y-containing alloy). Additionally, the Vickers microhardness exhibited values over 1100 kg/mm2 for both alloys.