Shear behaviors of single crystal nickel at different temperatures: molecular dynamics simulations

Abstract

Shear behaviors of a single crystal nickel along the [\( \overline{1} 10 \)], [\( 1\overline{1} 0 \)], [\( \overline{1}\,\overline{1} 2 \)] and [\( 11\overline{2} \)] directions in the (111) crystallographic plane have been investigated at different temperatures by performing molecular dynamics simulations with an embedded atom method potential. Results show that shear stress–shear strain curves and atomic trajectory during shear process exhibit periodic behaviors, while the periods are varied for different shear directions. It sheds light on the inherent relationship between shear displacement for a period of the curve and the atomic configuration in corresponding crystallographic direction. Furthermore, shear modulus is extracted from the curves over a temperature range from 0 to 1700 K. It is demonstrated that the modulus is independent from the size of shear models and the shear directions, and that the modulus decreases with increasing temperature. In addition, this work also demonstrates that the classical description of shear modulus is still valid at the nanoscale, which might suggest a simple and direct way to obtain shear modulus at the atomic scale.