Effect of Co addition on crystallization and magnetic properties of FeSiBPCu alloy

The effects of Co addition on the microstructure, crystallization processes and soft magnetic properties of (Fe1-xCo)(83)Si4B8P4Cu1 (x=0.35, 0.5, 0.65) alloys were investigated. The experimental results demonstrated that the addition of Co decreased the thermal stability against crystallization of the amorphous phase, and thus improved the heat treatment temperature of this alloy. FeCoSiBPCu nanocrystalline alloys with a dispersed alpha'-FeCo phase were obtained by appropriately annealing the as-quenched ribbons at 763 K for 10 min. The alpha'-FeCo with grains size ranging from 9 to 28 nm was identified in primary crystallization. The coercivity (H-c) markedly increased with increasing x and exhibited a minimum value at x=0.35, while the saturation magnetic flux density (B-s) shows a slight decrease. The (Fe0.65Co0.35)(83)Si4B5P4Cu1 nanocrystalline alloy exhibited a high saturation magnetic flux density B-s of 1.68 T, a low coercivity, H-c of 5.4 A/m and a high effective permeability mu(e) of 29,000 at 1 kHz. (C) 2014 Chinese Materials Research Society. Production and hosting by Elsevier B.V. All rights reserved.