First-principles calculations of solute–vacancy interactions in aluminum**Project supported by the National Natural Science Foundation of China (Grant Nos. 51701095 and 51771185) and the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20170798).

Abstract

The interactions of solute atoms with vacancies play a key role in diffusion and precipitation of alloying elements, ultimately influencing the mechanical properties of aluminum alloys. In this study, first-principles calculations are systematically performed to quantify the solute–vacancy interactions for the 3d–4p series and the 4d–5p series. The solute–vacancy interaction gradually transforms from repulsion to attraction from left to right. The solute–vacancy binding energy is sensitive to the supercell size for elements at the beginning. These behaviors of the solute–vacancy binding energy can be understood in terms of the combination and competition between the elastic and electronic interactions. Overall, the electronic binding energy follows a similar trend to the total binding energy and plays a major role in the solute–vacancy interactions.