Transformation Of The Theta-Phase In Mg-Li-Al Alloys: A Density Functional Theory Study

In Mg-Li-Al alloys, theta-phase MgAlLi2 is a strengthening and metastable phase which is liable to be transformed to the equilibrium phase AlLi on overaging. While the structural details of the theta-phase MgAlLi2 and the microscopic transformation are still unknown. In this paper, the structure of MgAlLi2 unit cell was determined through X-ray powder diffraction simulation. Microscopic transformation process of theta-phase MgAlLi2 was discussed in detail using first principles method.