Abstract Metallic nanoglasses are non-crystalline solids with interfacial regions, typically characterized by a modified short-range order and compositional gradients. These interfaces can act as nucleation sites for the formation of shear transformation zones during mechanical deformation, which gives rise to a deformation behavior distinct from the bulk glass counterpart. While various studies have investigated nanoglasses experimentally (mostly Fe–Sc) and in computer simulations (typically Cu–Zr), there is hitherto no study comparing compositionally identical nanoglasses and conventional metallic glasses by experiments and simulations. In this contribution, we investigate Pd–Si as a model system and compare nanoglasses produced by inert gas condensation with melt-spun ribbons. Molecular dynamics simulations and atom probe tomography provide evidence that glass–glass interfaces are primarily topological and chemical defects in this particular system. Differential scanning calorimetry shows a decrease in the glass transition and crystallization temperature of the nanoglasses compared to melt-spun ribbons. Nanoindentation and micropillar tests on Pd–Si metallic nanoglasses, however, provide evidence for shear band formation in both sample types, the melt-spun ribbons and nanoglass. Shear bands in the nanoglass samples appear more diffuse as compared to melt-spun ribbons. This is also evident from the reduced strain localization in the nanoglass. It is concluded that the topological inhomogenieties induced by forming glass–glass interfaces significantly affect the mechanical properties of nanoglasses.

中文翻译：

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拓扑结构和化学偏析对Pd-Si纳米玻璃热力学性能的影响

摘要 金属纳米玻璃是具有界面区域的非结晶固体，通常以改进的短程有序和成分梯度为特征。这些界面可以作为在机械变形过程中形成剪切转变区的成核位点，从而产生与大块玻璃对应物不同的变形行为。虽然各种研究已经通过实验（主要是 Fe-Sc）和计算机模拟（通常是 Cu-Zr）研究了纳米玻璃，但迄今为止还没有研究通过实验和模拟来比较成分相同的纳米玻璃和传统金属玻璃。在这篇文章中，我们研究了 Pd-Si 作为模型系统，并比较了通过惰性气体冷凝与熔纺带生产的纳米玻璃。分子动力学模拟和原子探针断层扫描提供了证据，证明玻璃-玻璃界面主要是这个特定系统中的拓扑和化学缺陷。差示扫描量热法显示与熔纺带相比，纳米玻璃的玻璃化转变温度和结晶温度降低。然而，Pd-Si 金属纳米玻璃的纳米压痕和微柱测试为两种样品类型（熔纺带和纳米玻璃）中剪切带的形成提供了证据。与熔纺带相比，纳米玻璃样品中的剪切带显得更加弥散。从纳米玻璃中应变局部化的减少也可以看出这一点。结论是，由形成玻璃-玻璃界面引起的拓扑不均匀性显着影响纳米玻璃的机械性能。