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

Bin Tanga, Xiang Yu Hanb, c aInstitute of Finance & Trade, Chongqing City Management College, Chongqing 401331, PR China bCollege of Materials Science and Engineering, Chongqing Jiaotong University, Chongqing 400074, PR China cInstitute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, PR China

Received: November 23, 2017; in final form September 14, 2018

Full Text PDF

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.

DOI:10.12693/APhysPolA.134.1115 topics: Al-5 wt%Mg, mechanical properties, first principles, stress- strain relations, ideal strength