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 (mu M-0(s)) together with the Curie temperature (T-c) 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/mm(2) for both alloys. (C) 2009 Elsevier B.V. All rights reserved.