Phase transformation behavior of a dual-phase nanostructured Fe-Ni-B-Si-P-Nb metallic glass and its correlation with stress-impedance properties

A study of the phase transformation process of a Fe-Ni-B-Si-P-Nb metallic glass using a suite of advanced characterization tools is reported.Transmission electron microscopy(TEM)and small angle neutron scattering(SANS)experiments show that the as-spun metallic glass ribbon has a dual-phase structure with bcc nanoclusters of a size of 2-3 nm.In situ high-energy X-ray diffraction(XRD)reveals a three-stage crystallization process when heating the metallic glass into supercooled liquid states.The isothermal annealing experiment shows the nanoclusters grow instantly without incubation.The easy formation and phase stability of the nanoclusters are due to the low interfacial energy between the amorphous matrix and clusters,as real space analysis shows that the nanoclusters and the amorphous matrix share similar short-to-mediumrange orders.We further find that the dual-phase structure reduces local magneto-anisotropy and enhances effective magnetic permeability,resulting in an excellent stressimpedance effect without sacrificing coercivity.Our work sheds light on the structure-property engineering of soft magnetic metallic glasses and provides a foundation for developing novel magnetic functional materials with nanostructured dual-phases.

Phase selection rule of high-entropy metallic glasses with different short-to-medium-range orders

When an equiatomic multi-component alloy is quenched from its molten state down to room temperature,either a solid solution crystalline alloy or a metallic glass is formed.The former is called a high-entropy alloy,whereas the latter is referred as a high-entropy metallic glass(HE-MG).In such multicomponent alloys,thermodynamic parame-ters,e.g.,the mixing entropy,the mixing enthalpy and other parameters such as atomic size mismatch,determine the resulting phases.