Molecular dynamics simulation studies on tensile mechanical properties of zirconium nanowire: effect of temperature, diameter, and strain rate

Abstract

ABSTRACT Molecular Dynamics simulations are used to characterise tensile mechanical properties of zirconium single crystal nanowire by employing the second nearest neighbour modified embedded atom method (2NN-MEAM). In order to investigate the effect of temperature, diameter, and strain rate on various mechanical properties under tensile loading, the temperature is varied from 10 to 700 K for a nanowire of 2 nm diameter and at strain rate 0.0005 ps−1; diameter is varied from 1–10 nm under strain rate 0.0005 ps−1 at 300 K; strain rate is varied from 0.0005 to 0.05 ps−1 for a 2 nm diameter nanowire at 300 K. The variation of potential energy and stress with respect to strain are used to characterise different deformation regions and for the calculation of mechanical properties, such as; Young’s modulus, yield stress/strain, neck and fracture strain, ductility, etc. The results show that nanowires at lower temperature, with smaller diameter, and under high strain rate depict higher elastic responses and possess high tensile strength. The increase in fracture strain with increase in temperature, diameter, and strain rate results in increase in the ductility of the nanowire. Temperature and diameter are found to have significant roles in characterising Young’s modulus of the nanowire, whereas strain rate has no specific role in the same. Young’s modulus of bulk zirconium is calculated and the value is matched with the experimental value.