面心立方结构金属纳米线弯曲变形机制研究进展

Research progress on bending deformation mechanism of face-centered cubic metallic nanowires

弯曲变形是金属纳米材料最常见的变形方式之一。揭示金属纳米材料弯曲状态下的变形机制,建立微观结构、变形机制与力学性质之间的关联性,可为材料设计提供重要的理论依据。本文综述了面心立方(FCC)单晶金属纳米线在弯曲变形下力学性质与变形机制研究的主要进展:介绍了尺寸效应对弯曲应变下的材料力学性能的影响,概述了弯曲应变的大小对变形机制的影响;总结了金属纳米线中孪晶厚度对位错滑移,相变等塑性变形机制的影响;对比了金属纳米线弯曲与拉伸,压缩中变形机制的异同。最后对金属纳米线弯曲塑性变形机制研究所面临的难题以及有望解决该难题的原位实验技术的发展进行了展望。

Bending deformation is one of the most important deformation modes in metallic nanomaterials.For material designs,it is critical to reveal the deformation mechanism in metallic nanomaterials under bending.In addition,it is also important to demonstrate the relation between microstructure,deformation mechanism and mechanical properties.In this work,we present the recent progress of mechanical properties and deformation mechanism of face-centered crystal metallic nanowires under bending.We briefly summarize the size effect on the mechanical properties and deformation mechanism of nanosized metallic nanowires.For the twin-structured metallic nanowires,the paper has outlined how the bending strain and twin thickness affect the deformation mechanism and deformation modes.New deformation mechanisms in metallic nanomaterials under bending are introduced briefly.Finally,the challenges and the development of in situ experimental technology in the future are prospected.