摘要
Cu/Ni多层纳米线因其特殊的结构和优异的物理性能在微/纳电子机械系统(MEMS/NEMS)中有广泛的应用。本文利用分子动力学方法模拟了Cu/Ni多层纳米线的拉伸变形,研究了纳米线屈服应力的尺寸效应,探讨了界面结构的差异对多层纳米线缺陷演化机制的影响。结果表明,带共格界面多层纳米线的屈服应力随单金属层厚度h的减小先升高后降低,表现出明显的尺寸效应;存在一个临界厚度,约为2个平均晶格常数,此时材料同时具有较高的屈服强度和良好的延展性。
Cu/Ni multi-layer nano-wires （NWs） are widely used in MEMS/NEMS for their novel structures and excellent physical properties. The tensile deformation of Cu/Ni NWs with periodic multi-layer structures are simulated by molecular dynamics （MD） and the size-effects on the yield stress as well as the effects of interfacial structures on the defects evolution mechanism are studied. The yield stresses of the multi-layer NWs increase firstly and then decrease afterward with the decrease of the single layer＇s thickness, which are strongly affected by the thickness leading to obvious size-dependency. The result also indicates that there exists a critical thickness, approximately twice of the average lattice constant of the single layer, which makes the materials show higher yield strength and better ductility.
出处
《计算力学学报》
EI
CAS
CSCD
北大核心
2011年第B04期147-151,共5页
Chinese Journal of Computational Mechanics
基金
国家自然科学基金(1093200 1
11072015
11002011)
中央高校基本科研业务费专项资金(YWF-10-02-002)资助项目
关键词
屈服应力
尺寸效应
界面
分子动力学
yield stress
size effects
interfaces
molecular dynamics
