Previous investigations demonstrated the notch strengthening, softening, and weakening effect on metallic glasses (MGs), accompanied by plasticity variations. In this work, systematical experiments, microstructure observations, and simulations confirmed the transition mechanism among three deformation modes induced by the size and acuteness of notches. It was found that small and sharp notches could result in notch strengthening while notch weakening occurs in samples with blunt notches. Besides, either notch strengthening or weakening is highly relevant to the competition of three deformation modes: in-plane single shear banding, large deformation induced by shear band intersection as well as out-of-plane shear gliding. In addition, by altering notch sizes and shapes, the shear mode of in-plane V-shaped shear band intersection could be shifted to the out-of-plane offset and in-plane single shear band. The present work provides significant insights into the macroscopic deformation and failure mechanism of notched MGs, as well as necessary guidance for designing MGs-based porous materials and composites.

中文翻译：

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金属玻璃中缺口敏感性引起的变形模式转变

先前的研究证明了金属玻璃（MG）的缺口强化、软化和弱化效应，并伴随着塑性变化。在这项工作中，系统的实验、微观结构观察和模拟证实了由缺口的尺寸和锐度引起的三种变形模式之间的过渡机制。研究发现，小而尖锐的缺口可能会导致缺口强化，而钝缺口的样品会导致缺口弱化。此外，缺口强化或削弱与面内单剪切带、剪切带相交引起的大变形以及面外剪切滑移三种变形模式的竞争密切相关。此外，通过改变缺口尺寸和形状，面内V形剪切带相交的剪切模式可以转变为面外偏移和面内单剪切带。目前的工作为缺口 MG 的宏观变形和失效机制提供了重要的见解，并为设计基于 MG 的多孔材料和复合材料提供了必要的指导。