Abstract The mechanism of fatigue-induced interface damage in Cu/V nanoscale metallic multilayers was systematically investigated using the state-of-the-art in situ transmission electron microscopy. Upon cyclic compression, Cu/V nanoscale metallic multilayers show an interface-controlled fatigue deformation, and the interface morphology of Cu/V nanopillars changes significantly after 200 cyclic loadings. Cyclic deformation induced nanoscale intrusions/extrusions on the bimetal interface, while no sign of persistent slip bands or crack was observed. Formation of the nano-intrusions/extrusions can be attributed to the reciprocating defect motion and severe defect-interface interactions during the fatigue testing. This study provides a unique mechanistic understanding on the fatigue damage in metallic multilayers at nanoscale and sheds light on tailoring the damage tolerance of heterostructures via interface engineering.

中文翻译：

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Cu/V纳米级金属多层膜中疲劳引起的界面损伤

摘要 使用最先进的原位透射电子显微镜系统地研究了 Cu/V 纳米级金属多层膜中疲劳引起的界面损伤机制。在循环压缩时，Cu/V 纳米级金属多层膜表现出界面控制的疲劳变形，并且在 200 次循环加载后，Cu/V 纳米柱的界面形貌发生了显着变化。循环变形在双金属界面上引起纳米级侵入/挤压，而没有观察到持续滑移带或裂纹的迹象。纳米侵入/挤压的形成可归因于疲劳测试期间往复式缺陷运动和严重的缺陷界面相互作用。