Atomistic simulations of solidification process in B2-LiPb solid(001)-liquid system

作者:Xu, Chao; Gan, Xianglai; Meng, Xiancai; Xiao, Shifang*; Deng, Huiqiu; Li, Xiaofan; Hu, Wangyu*
来源:Journal of Crystal Growth, 2017, 470: 113-121.
DOI:10.1016/j.jcrysgro.2017.04.024

摘要

Li-Pb alloy is considered as a candidate for a blanket material in fusion reactors for its excellent physical and chemical properties. In this work, the solidification process in the B2-LiPb solid(001)-liquid system is studied using molecular dynamics (MD) simulations. The results indicate that the liquid phase atoms near the solid -liquid interface separate according to the crystal structure, and the separated atoms constitute (001) crystal planes through an ordering arrangement, which induces the B2-LiPb crystal to grow layer by layer. The velocity of moving solid -liquid interface in our case increases with the degree of thermostat undercooling. Nonequilibrium concentrations of point defects and a misshapen region are observed in the finally solidified crystal. The formation of the dominant point defect is dominated by defect formation energy. Additionally, Pb atoms are enriched in the misshapen region due to the formation of nonequilibrium concentrations of point defects.