NiAl合金纳米线弯曲形变行为的分子动力学模拟  

Molecular Dynamics Simulation of Deformation Behavior of NiAl Nanowire Under Bending

作　　者：韦昭召 刘凯 李会军 WEI Zhaozhao;LIU Kai;LI Huijun(Intelligent Manufacture faculty,Wuyi University,Jiangmen,Guangdong 529020,China)

机构地区：[1]五邑大学智能制造学部,广东江门529020

出　　处：《计算物理》2023年第4期425-435,共11页Chinese Journal of Computational Physics

基　　金：广东省自然科学基金(2017A030310657);江门市创新科研团队引进项目(2018630100090019844)资助。

摘　　要：本文采用分子动力学模拟研究不同条件下NiAl合金纳米线的弯曲形变行为。研究结果表明:NiAl合金纳米线弯曲过程包括弹性和塑性形变两个阶段,其中,在弹性形变阶段计算得到纳米线的弯曲模量为48.9 GPa,与已有计算结果接近;而纳米线塑性形变以应力诱发B2→L10马氏体相变为变形载体,且形变行为不依赖于体系温度、应变速率及纳米线尺寸等因素,即使在低温和高应变速率下纳米线也表现出良好的弯曲塑性和弯曲强度。此外,NiAl合金纳米线在弯曲作用下具有近零滞后的超弹性特征,弯曲形变在卸去载荷时可完全回复。To date most studies of metallic nanowire are mainly focused on the atomistic mechanisms in tensile or compressive deformation,while little attention has been paid to the bending deformation behavior of nanowire.A full understanding of the bending properties of nanowire,however,can help improve the reliability and service life of nanodevices,particularly for the flexible and stretchable systems.In this work,we investigate the bending behavior of a NiAl nanowire on different loading conditions using molecular dynamics simulations.The NiAl nanowire under bending loads was shown to undergo elastic and plastic deformation.The bending modulus during elastic deformation was determined to be around 48.9 GPa,showing good agreement with the reported calculations.The plastic deformation,independent of temperature,strain rate and size,was produced by stress⁃induced martensitic transformation from B2 to L10 phases,leading to good bending ductility even under low temperature and high strain rate.Moreover,the NiAl nanowire exhibits superelasticity under bending with total recovery of deformation,which is driven by the reverse transformation from the L10 to B2 phases.

关 键 词：NiAl合金纳米线 弯曲形变 超弹性 分子动力学模拟 

分 类 号：O469[理学—凝聚态物理] O792[理学—电子物理学] TG139.6[理学—物理]