Elastic properties of magnesium with virtual long-period stacking-ordered structure: First-principles study

摘要

The effect of virtual long-period stacking-ordered (v-LPSO) structures (6H, 10H, 14H, 18R and 24R) on the second order elastic constants and third order elastic constants of pure Mg are systematically investigated using first principles methods combined with finite strain theory. The predicted lattice constants and formation energies are in a good agreement with the available data. The pressure effect on anisotropy, Pugh ratio, Vickers hardness and Debye temperature are also presented. The anisotropy and Pugh ratio of 2H and v-LPSO Mg are not sensitive to pressure, except for 10H. The anisotropy of 10H increases with pressure, but Pugh ratio decreases. v-LPSO structures can only slightly improve the ductility of Mg. It is also found that 2H and 18R have nearly the same Pugh ratio and Vickers hardness. (C) 2015 Elsevier B.V. All rights reserved.