Computational modeling of effects of alloying elements on elastic coefficients

Models for composition and temperature dependencies of single-crystal elastic stiffness coefficients are developed and applied to the Al12Mg17 and hexagonal closed-packed solution phases in the Mg–Al system based on data from first-principles calculations. In combination with models for multi-phases, the bulk, shear, and Young’s moduli of Mg–Al alloys are predicted and compared with available experimental data in the literature. It is noted that both phase transition and grain boundary sliding may play important roles in the elastic coefficients as a function of temperature.