Tissue evolution of Al0.67Cu0.33 alloy during melting and solidification by molecular dynamics simulation

Abstract

To analyze the various factors affecting the solidification organization of Al-Cu alloys, the melting and solidification processes of Al0.67Cu0.33 alloy were simulated by the embedded atomic method (EAM) potential. It is found that the diffusion coefficient of the system keeps rising with the increasing initial temperature and relaxation time. It is a positive correlation between initial temperature, relaxation time and diffusion coefficient. The RDF analysis results are shown that as the cooling rate decreases, the crystal content of the solidified tissue increases and crystal structure characteristics of the system become more obvious. At the cooling rate of 1 × 1010 K/s, the percentage of system crystal compositions reaches 78.4%. The system shows obvious crystal structure characteristics. However, when the cooling rate was 1 × 1014 K/s, the crystalline content of the system is only 0.3% and shows obvious non-crystalline characteristics. It provides a theoretical basis for improving the properties and optimizing the microstructure of Al-Cu alloy.