Improved ductility of annealed Fe-based metallic glass with good soft magnetic property by cryogenic thermal cycling

The brittleness after annealing treatment severely restricts the subsequent processing and application of Fe-based magnetic metallic glass. Through proper annealing treatment combined with cryogenic thermal cycling, we obtained excellent comprehensive properties of Fe-based metallic glass ribbons with not only good soft magnetic properties but also high bending deformation ability. After thermal cycling, the sample rejuvenated with higher energy state and larger size of soft regions, which facilitated the initiation and branching of shear bands, leading to the improvement of bending plasticity. Although the large soft regions may act as pining sites for domain walls, the domain structure and coercivity of the sample remained nearly identical because of the reduced number of crystal-like structures. Our study indicates that the cryogenic thermal cycling is an effective method to regulate mechanical and magnetic properties, which makes it powerful means to obtain excellent performance of Fe-based magnetic metallic glasses.