Abstract
To theoretically examine the structural transition of vacancy–solute complexes in Al–Mg–Si alloys, we performed first-principles calculations for layered vacancy–solute complexes with additional Mg atoms. The central Mg atom in the additional Mg layer shifted to the Si layer with the increase in the number of Mg atoms to weaken the repulsive Mg–Mg interaction and to form Mg–Si bonds. When five Mg atoms were added to the layered vacancy–solute complex, the central Mg atom completely shifted to the Si layer, and a Mg vacancy was formed in the Mg layer, which indicated that the β″-eye is formed upon the addition of Mg atoms. We reproduced β″-eye formation from a solid solution with a vacancy using first-principles-based Monte Carlo simulations. Once the β″-eye was formed on the layered vacancy–solute complex, the process can be repeated by the formation of alternate Mg and Si layers along (010) β″. These results clearly indicate that the layered vacancy–solute complex plays an important role in β″-eye formation.
Highlights
The use of 6000 series Al–Mg–Si alloys for manufacturing automobile body panels has increased because such alloys exhibit hardening characteristics
We investigated the stability and structure of vacancy–solute complexes VMg4 Si8 with additional Mg atoms in Al–Mg–Si alloys using the first-principles calculations
The central Mg atom in the additional Mg layer shifted to the Si layer with the increase in the number of Mg atoms to weaken the repulsive Mg–Mg interaction as well as to form Mg–Si bonds
Summary
The use of 6000 series Al–Mg–Si alloys for manufacturing automobile body panels has increased because such alloys exhibit hardening characteristics. We observed that the formation energy of the vacancy–solute complex decreased with the increasing number of solute atoms, and the VMg4 Si8 complex exhibited the lowest formation energy. The formation of the β00 phase, which requires a shift of Mg atoms to the Si layer, was not observed. To investigate the structural transition from the vacancy–solute complexes to the β00 -eye in Al–Mg–Si alloys, we performed first-principles calculations for the vacancy–. Solute complexes with additional Mg atoms in Al–Mg–Si alloys. To reproduce the structural transition of the vacancy–solute complexes from the solid solution in the Al–Mg–Si alloy, we performed first-principles-based Monte Carlo (MC) simulations. Metals 2022, 12, 2 of 11 structural transition of the vacancy–solute complexes from the solid solution in the2Al–.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
