Optimizing stress impedance and medium-range ordered structure in Fe_46.6Mo_8.6Cr_24.5B_9.5C₁₀Si₆ amorphous alloy through tailored annealing treatment

Amorphous alloys are emerging as a highly promising category of materials for mechanical sensing, attributed to their favorable stress impedance performance. However, the practical achievement of the stress impedance ratio still falls considerably short of its theoretical potential, and the atomic-scale mechanisms underlying this phenomenon remain largely unexplored. Here, we report that the stress impedance ratio of Fe46.6Mo8.6Cr24.5B9.5C10Si6 amorphous alloy can be significantly enhanced by a tailored annealing treatment around the glass transition temperature (Tg ), giving rise to the highest stress impedance ratio reaching up to 124%. Utilizing the high-energy synchrotron X-ray total scattering technique, the strong correlation between the stress impedance performance and the medium-range ordered structure of amorphous alloys is elucidated. Our findings revealed that an increase in edge-sharing atomic connection mode plays a pivotal role in enhancing the stress impedance performance. Furthermore, a composite film combining the amorphous alloy with silicone rubber was fabricated under the same annealing treatment, demonstrating a significantly improved sensitivity compared to the ribbon (706.10 vs. 32.93 MPa-1). This work not only contributes valuable insights into the atomic-scale mechanisms governing stress impedance in amorphous alloys but also proposes a general annealing strategy that holds the potential for unlocking new avenues in advanced sensing applications.