J. Mater. Sci. Technol. ›› 2023, Vol. 142: 253-259.DOI: 10.1016/j.jmst.2022.10.034

• Research article • Previous Articles    

Two-dimensional interface superstructures assembled by well-ordered solute atoms

Peijun Yanga, Shanshan Lia,b,*, Hongbo Xiea,*, Jianfeng Jina, Chuangwei Liua, Hucheng Pana, Yuping Rena, Weitao Jiac, Yaping Zonga, Gaowu Qina   

  1. aKey Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China;
    bSchool of Mechanical and Power Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China;
    cCollege of Mechanical Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China
  • Received:2022-09-22 Revised:2022-09-22 Accepted:2022-09-22 Online:2022-12-05
  • Contact: *E-mail addresses: . shanshanli_work@126.com (S. Li), xiehongbo@mail.neu.edu.cn (H. Xie)

Abstract: Segregation of solutes/impurities in the interfaces plays a decisive role in material performances. However, the segregation of solutes/impurities remains elusive due to the diversity of interfacial structures. Here, in a Mg-Nd-Mn ternary model system, two ordered novel two-dimensional (2D) interfacial superstructures formed by periodic segregation of solute atoms in special symmetric and asymmetric tilt grain boundaries (GBs) have been systematically investigated. Z-Contrast high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) observations provided the atomic-level details on how solute atoms were arranged on these special partially coherent tilt GBs. The strained conditions of each atomic site at the tilt GBs were accurately reproduced by molecular dynamics (MD) simulations plus Voronoi analysis, and the rationality of solute segregation in each atomic-site was evaluated carefully based on the first-principles calculations. These findings expand our knowledge of solute/impurity segregation behaviors in the interfaces, especially the co-segregation behaviors in multi-component materials.

Key words: Magnesium alloy, Interfacial segregation, Molecular dynamics, First-principles, HAADF-STEM