Prediction of elastic and electronic properties of cubic Al18Ti2Mg3 phase coexisting with Al3Ti in Al-Ti-Mg system

The elastic and electronic properties of an ordered intermetallic phase Al18Ti2Mg3 with cubic structure are first investigated by an ab initio method based on density functional theory (DFT) implemented in the Cambridge Serial Total Energy Package (CASTEP) code. The elastic constants are calculated to characterize the elastic anisotropy, the direction-dependent Young's modulus and the macroscopic elastic modulus. The calculated results show that compared with binary compound Al3Ti, Al18Ti2Mg3 exhibits lower stiffness, slighter elastic anisotropy and better ductility, and the bond of Al18Ti2Mg3 has both covalent and ionic properties. (C) 2012 Elsevier B.V. All rights reserved.