Abstract
Extremely good soft magnetic properties of high saturation magnetization (B-s) above 1.8 T and low coercivity (Hc) below 5 A/m were obtained for (Fe1-xCox)(83)B16Si1 (x = 0.1-03) amorphous ribbons annealed at the temperature between T-x1-120 K and T-x1-40 K. Here T51 is the onset temperature of the first exothermic crystallization peak. The best characteristics were 1.86 T for Bs and 3 Aim for Hc at x = 0.2. There are no previous data on the melt-spun alloys with high Bs above 1.8 T and low below 5 A/m and hence the present amorphous alloys are regarded as a novel good soft magnetic alloy with high Bs comparable to Fe-Si steels. Curie temperature (T-c) of the x = 0.2 alloy was above T51 (708 K), implying high thermal stability of magnetic characteristics. The saturated magnetostriction for x = 0.2 was about 32 ppm and the effective permeability at 1 kHz showed as high as 1.6 x 10(4). The high Bs can be attributed to the low metalloid content containing mainly B element which suppresses effectively the reductions of Bs and Tc among metalloid elements, as well as the optimum Co/Fe content ratio with the maximum magnetic interaction in conjunction with maximum atomic volume. Moreover, these alloy ribbons exhibited good bending ductility even after optimum annealing treatment, in addition to high Vickers hardness of about 1000 and improved corrosion resistance comparing with the corresponding Co-free alloy. The excellent soft magnetic amorphous alloys are promising for further extension as engineering soft magnetic materials. (C) 2017 Elsevier B.V. All rights reserved.