Mechanical Properties of Al-5 wt%Mg from First Principles Study

Abstract

We have investigated the mechanical properties of Al-5 wt%Mg using the first-principles method. The elastic constants, shear modulus, Young's modulus, Poisson's ratio and the brittle/ductile characteristics of Al-5 wt%Mg are successfully obtained. The stress-strain relations and ideal strengths under tension and compression loading of Al-5 wt%Mg have also been determined. Results show that Al-5 wt%Mg is found to have larger moduli and higher strengths than Al, which is consistent with its exploitation in Al precipitate-hardening mechanisms. The electronic structure is investigated to unveil the intrinsic mechanism for the mechanical properties of Al-5 wt%Mg. It turns out that the partly covalent-like bonding through Al p-Mg s hybridization is the origin of excellent mechanical properties of Al-5 wt%Mg. We expect that the present work should be helpful to the performance of Al-5 wt%Mg.