The embedded-seed-method molecular dynamics simulation of the crystallization of Al and the influence of the artificial initial stress

T Zhou and YQ Wu and JL You, JOURNAL OF CRYSTAL GROWTH, 601, 126928 (2023).

DOI: 10.1016/j.jcrysgro.2022.126928

Recently, the embedded-seed-method molecular dynamics simulation is prevailing on diverse issues of the so-lidification process of diverse materials. But the key universal issue that how the initial stress introduced by the artificially embedded seed affects the process is completely unknown. In this paper, we designed three groups of seeds at different states of initial stresses to explore the influence of initial stress on thermodynamics, growth morphology, and kinetics, of solidification. We found, the density difference stress increases the critical tem-perature and the effect is independent on the critical radius of seed, while the distortion stress decreases the critical temperature and the effect is inversely proportional to the critical radius. The failure phenomenon of tiny seeds for working as nucleus under 665 K prompts that in this deepest undercooling, a spinodal-like crystalli-zation occurs in liquid. For growth morphology, both initial stresses enhance the growth pattern of nested -tetrahedral-lamellar and conversely weaken the traditional lamellar and five-fold-twinning patterns. Finally, we further confirmed the new microscopic kinetics of linear relationship between ln(-ln(1-Rs)) vs tau instead of the traditional macroscopic kinetics of linearity between ln(-ln(1-Rs)) vs ln tau, and the initial stress is proven almost no impact on the growth kinetics.

Return to Publications page