Effects of Nb Addition and Heat Treatment on the Crystallization Behavior, Thermal Stability and Soft Magnetic Properties of FeSiBPCuC Alloys

Abstract

In this paper, the effect of the replacement of Fe by Nb on the glass forming ability (GFA), the thermal stability and the crystallization behavior of Fe84.5−xSi0.5B10.5P3.5C0.7C0.3Nbx (x = 0, 1, 2) alloys were investigated. The results show that the addition of Nb increases the GFA. Increasing Nb content can enhance the first onset crystallization temperature (Tx1), the second onset crystallization temperature (Tx2) and ΔTx (ΔTx = Tx2 − Tx1), which broadens the range of annealing temperatures. The coercivity (Hc) of ribbons decreases with increasing Nb content after annealing at a low heating rate and reach as a minimum of 24.5 A/m when the Nb content is 2 at.%. The process of annealing at a high heating rate distinctly decreases Hc, and all samples present excellent soft magnetic properties. The nanocrystalline alloy exhibits the lowest Hc of 6.4 A/m after annealing at 460 °C for 5 min.