Synthesis of novel FeSiBPCCu alloys with high amorphous forming ability and good soft magnetic properties

Abstract

Novel Fe83.3Si4B8P4-xCxCu0.7 (x = 0–4) alloys were developed with the aim of increasing amorphous forming ability (AFA) without deteriorating the soft magnetic properties. Microstructure analysis revealed that the substitution of C for P inhibited the precipitation of α-Fe phase during the quenching process hence increased the AFA. The critical thickness increased from 18 μm for the alloys with composition of x = 0 to 43 μm for x = 4, respectively, owing to the decrease in the melting entropy (∆Sm), the approach of eutectic point and micro-alloying effect. Saturation magnetic flux density (Bs) increased obviously after proper annealing with increasing C substitution due to the increase in volume fraction of α-Fe nanocrystals, while excessive C content leaded larger coercivity (Hc) but improved the frequency and DC superposition performance. The Fe83.3Si4B8P2C2Cu0.7 nanocrystalline alloy was successfully synthesized with high Bs of 1.84 T, low Hc of 4.8 A/m and high effective permeability (μe) of 13,540. The combination of high Bs and high resistance to DC bias promises potential material in DC superposition application.