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

• Published in: Journal of crystal growth Vol. 601; p. 126928
• Main Authors: Zhou, Tao, Wu, Yongquan, You, Jinglin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2023
• Subjects: A1. Embedded-seed-method molecular dynamics simulation; A1. Initial stress; A1. Solidification; A2. Growth morphology; A2. Nucleation thermodynamics; B1. Metals; A1. Solidification; A1. Embedded-seed-method molecular dynamics simulation; A1. Initial stress; A2. Nucleation thermodynamics; A2. Growth morphology; B1. Metals
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2022.126928

•Effect of initial stress on solidification during ESM-MD simulation was studied.•Density stress increases and distortion stress decreases the critical temperature.•Initial stress enhances the growth of NTL and weakens the LAM and FFT patterns.•Spontaneous crystallization below 665 K prompts a spinodal-like crystallization.•A new microscopic kinetics of ln(-ln(1-Rs)) vs τ instead of lnτ, was reconfirmed. Recently, the embedded-seed-method molecular dynamics simulation is prevailing on diverse issues of the solidification 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 temperature 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 crystallization 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 τ instead of the traditional macroscopic kinetics of linearity between ln(-ln(1-Rs)) vs lnτ, and the initial stress is proven almost no impact on the growth kinetics.