Layer thickness dependent tensile deformation mechanisms in sub-10 nm multilayer nanowires
作者单位：State Key Laboratory of Nonlinear MechanicsInstitute of MechanicsChinese Academy of Science
会议名称：《第十二届全国物理力学学术会议》
会议日期：2012年
学科分类：07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学]
摘 要：Using molecular dynamics simulations,the tensile deformation behavior for two types of sub-10 nm multilayer nanowires(NWs) have been *** the structure with interfaces perpendicular to the wire axis,the deformation mechanism is changed from interface crossing by dislocations to interface rotation as the layer thickness is decreasing,causing a significantly reduction in yield ***,the deformation mechanisms are all accommodated through interface crossing by dislocations regardless of layer thickness for the structure with interfaces parallel to the wire ***,the yield strengths in the second structure are found to be controlled by two competing mechanisms:the interface strengthening by increased repulsive force and interface softening by increased dislocation source *** sudden stress drop after yielding point in NWs could be explained by the dislocation source-limited hardening mechanism:the more atomic fraction of newly formed stacking faults(SF) after stress drop,the larger normalized stress drop and the larger uniform tensile *** the second structure,the larger total tensile elongation for larger layer thickness could be related to the twinning induced plasticity at the necking *** findings should have implications for designing functionalized structures and devices in nanoelectromechanical systems.