A first-principles study of stacking faults and long periodic stacking order structures in Mg and Mg alloys

摘要

Since the main challenges in developing Mg alloys are to increase their strength, ductility, as well as stability at high temperatures, it is crucial to understand the fundamental properties which affect their mechanical properties. Formation of stacking faults is fundamental in deformation of materials with the hcp structure such as Mg and Ti alloys, affecting core structures and the mobility of dislocations, twinnability and ductility, and creep rate. Moreover, long periodic stacking order (LPSO) structures, such as 6H, 10H, 14H, 18R and 24R, play significant roles in enhancing the mechanical properties of Mg alloys and have been largely investigated separately.;In the present work, contributions of stacking faults, LPSOs and alloying elements to the formation energy, elastic, electronic and phonon properties of Mg and Mg alloys are investigated through the first-principles calculations. (Abstract shortened by UMI.).