Tensile Mechanical Properties of Aluminium Nanowire: MD Simulation Studies

Abstract

Nanoscale structures have drawn significant attention due to their unique and interesting properties. At nano size, surface stress and crystal orientation are the key factors in defining the properties. In this context, mechanical properties of an aluminium nanowire, subjected to uniaxial tensile loading have been investigated by utilizing molecular dynamics (MD) simulations. Specifically, under uniaxial tensile loading, the effect of strain rate (0.0005 ps-1-0.05 ps-1), temperature (10K-800K) and diameter (4nm-6nm) of the NW on several mechanical properties have been examined in the current work. Mechanical properties, like- Young’s modulus, yield stress, yield strain, fracture strain, ductility are obtained from variation of stress with respect to strain analysis. Decrease in Young’s Modulus and increase in yield stress, yield strain, fracture strain, ductility with rise in strain rate are observed. Temperature is found to significantly influence the mechanical characteristics of the nanowire as it affects both the elastic and plastic characteristics. With increase in temperature, Young’s modulus, yield stress, yield strain and fracture strain are found to decrease whereas ductility remained unaffected. On increasing diameter of the NW, the Young’s modulus, yield stress, yield strain showed marginal decrease whereas, fracture strain and ductility increased noticeably. These results show that with rise in strain rate and decrease in temperature/diameter, the strength of aluminium nanowire increases.