ABSTRACT Nanostructured multilayer thin films (Ag/W, Cu/Ru, Cu/W), consisting of alternating ductility/brittle layers with wide ranges of modulation period (Λ) and modulation ratio (η), were prepared by magnetron sputtering. Under nanoindentation, cracking and/or shear banding behaviour was observed, which depended directly on the layer thickness of ductile and brittle layers respectively. By considering the distinct competition between crack initiation/propagation in brittle layers and the shielding/anti-shielding effect in ductile layers, the different deformation modes between these multilayers are discussed in terms of a micromechanical fracture criterion. The findings could be used in the design of nanostructured materials for superior toughness and deformation stability.

中文翻译：

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纳米结构韧性/脆性多层膜变形模式的纳米压痕研究：开裂与剪切带

摘要纳米结构多层薄膜（Ag/W、Cu/Ru、Cu/W）由具有宽范围调制周期（Λ）和调制比（η）的交替延展性/脆性层组成，通过磁控溅射制备。在纳米压痕下，观察到开裂和/或剪切带行为，这分别直接取决于韧性层和脆性层的层厚。通过考虑脆性层中裂纹萌生/扩展与延性层中的屏蔽/抗屏蔽效应之间的明显竞争，根据微观力学断裂准则讨论了这些多层之间的不同变形模式。这些发现可用于设计具有优异韧性和变形稳定性的纳米结构材料。