A quantitative Study on Mechanical properties and Size Sensitivity of FCC Nanowires
The deformation and failure mechanism of face-centered cubic nickel nanowires subject to uni-axial tension was studied using molecular dynamics (MD) method and the size effect on mechanical behavior and properties of nano-structures was captured. Simulation reveals that initial unstable energy takes large effects on the deformation and failure mechanism of nanowires. As a result of free surfaces and reconstruction, surface atoms depart from perfect crystal lattice positions and nano voids come into being along the surfaces firstly subject to external load. The deformation process of nanowires behaves as expansion and connection of nano cavities from surface into inner lattices, which agrees well with experimental phenomena. Elastic stiffness, yield and fracture strength of nickel nanowires with different cross section sizes were obtained, and the size effect on mechanical properties was analyzed further. Based on numerical results, a set of quantitive prediction formulae discribing the size sensitivity of nickel nanowires on elastic modulus, yielding strength and fracture strength were proposed, in which the elastic modulus and yielding strength of metal nanowire are both linear to the logarithm of cross section size, and fracture strength has an inverse relation to exponential cross section size. The formulae can predict the elastic modulus, yielding strength and fracture strength of a nanocrystalline nickel wire according to its cross section size, describe the correlativity between mechanical properties of metallic nanowire and cross section size reasonably, and keep remarkable accordance with simulation and experimental results.
size sensitivity FCC nanowire molecular dynamics mechanical properties
黄丹 章青 郭乙木
河海大学工程力学系,江苏南京 210098 浙江大学固体力学研究所,浙江杭州 310027
国际会议
成都
英文
2007-11-19（万方平台首次上网日期，不代表论文的发表时间）