First-principles studies of crystal structure and mechanical properties of Mg(16-x)Tix(x=1-16) alloys

Abstract:

The design of new magnesium titanium alloy with good mechanical properties is of great significance for promoting automobile industry and solid hydrogen storage materials as well as biocomposite. In this article, the most stable crystal structure of each component in Mg(16-x)Tix(x=1~16) is selected using energy as criterion based on first principle calculation. At the same time, the structure of relatively stable Mg15Ti1, Mg2Ti2, Mg1Ti15 was studied using physical quantities such as forming energy, phonon spectrum and elastic constant. The results show that the magnesium-titanium alloy is incompatible, and forms thermodynamic stable metastable structure. The increase in titanium content is beneficial to increase the hardness and ductility of the magnesium-titanium alloy, which is consistent with experimental results, but it reduces the strength of the covalent bond.