超细镍纳米线拉伸性能的温度和应变率相关性的分子动力学研究(英文)

Molecular dynamics study on temperature and strain rate dependences of mechanical tensile properties of ultrathin nickel nanowires

基于EAM势,采用分子动力学方法对超细镍纳米线(直径分别为3.94、4.95和5.99 nm)在?100?晶向的拉伸性能进行研究,并对其温度相关性和拉伸应变率相关性进行探讨。结果表明:弹性模量和屈服强度随着温度的升高而逐渐降低,并且随着拉伸应变率的增大,应力—应变曲线波动程度变大,超细镍纳米线发生断裂时的应变越来越小。在0.01 K温度下,超细镍纳米线屈服强度随拉伸应变率的升高迅速降低;但在其它温度条件下,拉伸应变率对弹性模量和屈服强度的影响较小。简要分析尺寸大小对镍纳米线拉伸性能的影响。

Based on the EAM potential, a molecular dynamics study on the tensile properties of ultrathin nickel nanowires in the （100〉 orientation with diameters of 3.94, 4.95 and 5.99 nm was presented at different temperatures and strain rates. The temperature and strain rate dependences of tensile properties were investigated. The simulation results show that the elastic modulus and the yield strength are gradually decreasing with the increase of temperature, while with the increase of the strain rate, the stress--strain curves fluctuate more intensely and the ultrathin nickel nanowires rupture at one smaller and smaller strain. At an ideal temperature of 0.01 K, the yield strength of the nanowires drops rapidly with the increase of strain rate, and at other temperatures the strain rate has a little influence on the elastic modulus and the yield strength. Finally, the effects of size on the tensile properties of ultrathin nickel nanowires were briefly discussed.