Role of Crystal Orientation, Temperature, and Strain Rate on the Mechanical Characterization of Nickel: An Atomistic-scale investigation

Abstract

In this article, the influence of crystallographic orientation on the mechanical properties of pristine nickel (Ni) during uniaxial tensile deformation was explored by utilizing molecular dynamics simulations. To study the influence of [0 01] and [11 8 5] crystal orientations on the mechanical properties and microstructural evolution of pristine Ni, simulations were performed at different temperatures ranging from 100 K to 900 K and at strain rates ranging from 107 to 1010 s–1. The results revealed that Ni with [11 8 5] orientation showed a higher elastic modulus than Ni with [0 0 1] orientation, whereas the yield strength of [0 0 1] orientation was higher than [11 8 5] orientation for a combination of temperatures and strain rates. Also, in comparison to [11 8 5] crystal orientation, the system with [0 0 1] orientation showed a high amount of dislocation density at the yield strain point for lower strain rates. At higher strain rates, the face-centered cubic to body-centered cubic transition was more prominent in the Ni system with [0 0 1] orientation, and it tends to decrease with the increase in temperature. Our present work may help materials scientists design materials with different crystal orientations that can perform according to the applied strain rates and temperatures. It is also proposed that tailoring of mechanical properties is achievable by exposing Ni with different crystal orientations to various environmental conditions (cryogenic, ambient, and elevated temperatures with different applied strain rates).