Hf optimizes the glass forming ability and controls the crystallization behavior in Fe-rich Fe-B-Cu alloys

Abstract The Fe-rich Fe-B-Cu system alloys are hopeful for the apply as a new type soft magnetic material in both electron and information fields because of its high permeability (μe), low coercivity (Hc), high saturation magnetization (Ms) and low loss cost (W). However, the poor glass forming ability (GFA) and difficult structure-controlled which hinder the progress of industrializations and applications. Therefore, the transition group and big atom size element Hf is introduced into Fe86B13Cu1-xHfx alloys for partially replacing of the seeds and clusters element Cu, the result proves that Hf plays a positive role in perfecting GFA, enhancing thermal stability, improving structure-controlled, and impeding intermediate compounds. Both Fe86B13Cu0.5Hf0.5 and Fe86B13Cu0.4Hf0.6 as-quenched ribbons exhibit an entire amorphous structure and have the low Ms values, after annealing by 723 K × 10 min, the latter alloy shows a better structure-controlled on adjusting the uniform α-Fe/amorphous complex phase structure. In addition, the crystalized Ms value can be enhanced to the maximum of approximately 208 emu/g and the Hc value is effectively decreased from 9.3 to 2.3 A/m by an auxiliary annealing process of 673 K × 60 min applied the 1000 Gs magnetic field. The new developed Fe-B-Cu-Hf system alloys with good soft magnetic properties exhibit an acceleration applying progress in the Fe-rich alloys field.