Fe-based bulk metallic glasses (BMGs) usually exhibit brittle behavior and unconspicuous β-relaxation in their dynamic mechanical spectroscopy. We report a distinct β-relaxation behavior in FeNi-based BMGs with excellent plasticity. The origin of pronounced β-relaxation and plastic behaviors for the FeNi-based BMGs were investigated by synchrotron X-ray diffraction and nanoindentation tests in detail. It is found that the structural heterogeneity plays a key role in the dynamic of the FeNi-based BMGs, leading to large amount of loosely packed regions. The pronounced β-relaxation is also found to have a good correlation with the plasticity for the FeNi-based BMGs. This study might provide guidance for us to develop plastic BMGs from an atomic structural and glass dynamic perspective.

铁基块状金属玻璃 (BMG)在其动态力学光谱中通常表现出脆性行为和不明显的β弛豫。我们报告了具有优异塑性的 FeNi 基 BMG 中独特的β-弛豫行为。通过同步加速器 X 射线衍射和纳米压痕测试详细研究了 FeNi 基 BMG显着β-弛豫和塑性行为的起源。发现结构异质性在 FeNi 基 BMGs 的动力学中起着关键作用，导致大量松散堆积区域。明显的β还发现松弛与 FeNi 基 BMG 的塑性有很好的相关性。这项研究可能为我们从原子结构和玻璃动力学的角度开发塑料 BMG 提供指导。