Effect of Stacking Fault Energy on Mechanism of Plastic Deformation in Nanotwinned FCC Metals

TL;DR

This study uses molecular dynamics simulations with tailored potentials to explore how stacking fault energy influences the plastic deformation mechanisms and mechanical properties of nanotwinned FCC metals.

Contribution

It introduces a set of semi-empirical potentials with varying stacking fault energies to systematically study their effect on deformation in nanotwinned FCC metals.

Findings

Yield strength and stability are regime-dependent, not linearly related to stacking fault energy.

Two distinct deformation regimes are identified for low and high stacking fault energies.

Abstract

Starting from a semi-empirical potential designed for Cu, we developed a series of potentials that provide essentially constant values of all significant (calculated) materials properties except for the intrinsic stacking fault energy, which varies over a range that encompasses the lowest and highest values observed in nature. These potentials were employed in molecular dynamics (MD) simulations to investigate how stacking fault energy affects the mechanical behavior of nanotwinned face-centered cubic (fcc) materials. The results indicate that properties such as yield strength and microstructural stability do not vary systematically with stacking fault energy, but rather fall into two distinct regimes corresponding to low and high stacking fault energies.