Detwinning-induced reduction in ductility of twinned copper nanowires  

作　　者：ZHANG JunJie XU FangDa YAN YongDa SUN Tao 

机构地区：[1]Center for Precision Engineering,Harbin Institute of Technology [2]Interdisciplinary Centre for Advanced Materials Simulation(ICAMS),Ruhr University Bochum,Universit tsstr [3]Key Laboratory of Micro-systems and Micro-structures Manufacturing of Ministry of Education,Harbin Institute of Technology

出　　处：《Chinese Science Bulletin》2013年第6期684-688,共5页

基　　金：supported by China Postdoctoral Science Foundation(2012M511463);Heilongjiang Postdoctoral Foundation of China (LBH-Z11143);the ICAMS,Ruhr-University Bochum,Germany

摘　　要：Detwinning is a unique deformation mechanism of nanotwinned metals with twin lamellae thickness down to a few nanometers.In this work we investigate the impact of detwinning mechanism on the tensile ductility of twinned Cu nanowires containing high density of parallel twin boundaries by means of molecular dynamics simulations.Simulation results show that the fracture strain of twinned Cu nanowires has a strong dependence on twin boundary spacing,resulting from the competition between individual deformation modes.Particularly for the twinned Cu nanowires containing the thinnest twin lamellaes,the dominant detwinning mechanism leads to a significant reduction in the tensile ductility.It is found that detwinning originates from twin boundary migration,which is a result of the glide of lattice partial dislocations on the twin planes.This work advances our fundamental understanding of the twin boundary-related mechanical properties of twinned metallic nanowires.Detwinning is a unique deformation mechanism of nanotwinned metals with twin lamellae thickness down to a few nanometers. In this work we investigate the impact of detwinning mechanism on the tensile ductility of twinned Cu nanowires containing high density of parallel twin boundaries by means of molecular dynamics simulations. Simulation results show that the fracture strain of twinned Cu nanowires has a strong dependence on twin boundary spacing, resulting from the competition between individual deformation modes. Particularly for the twinned Cu nanowires containing the thinnest twin lamellaes, the dominant detwinning mechanism leads to a significant reduction in the tensile ductility. It is found that detwinning originates from twin boundary mi- gration, which is a result of the glide of lattice partial dislocations on the twin planes. This work advances our fundamental under- standing of the twin boundary-related mechanical properties of twinned metallic nanowires.

关 键 词：金属纳米线 孪晶界 延展性 分子动力学模拟 铜 诱导 变形机制 片层厚度 

分 类 号：TG146.11[一般工业技术—材料科学与工程] TB383.1[金属学及工艺—金属材料]