中国物理B ›› 2025, Vol. 34 ›› Issue (5): 56801-056801.doi: 10.1088/1674-1056/adb8b5

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Modeling of microstructure and microsegregation evolution in solidification of ternary alloys

Qiannan Yu(于芊楠)1,2,3, Mengdan Hu(胡梦丹)1,2,3, Jinyi Wu(吴津仪)1,2,3, and Dongke Sun(孙东科)1,2,3,†   

  1. 1 School of Mechanical Engineering, Southeast University, Nanjing 211189, China;
    2 Jiangsu Key Laboratory for Biomaterials and Devices, Southeast University, Nanjing 211189, China;
    3 Key Laboratory of Structure and Thermal Protection of High Speed Aircraft, Ministry of Education, School of Mechanical Engineering, Southeast University, Nanjing 211189, China
  • 收稿日期:2024-12-18 修回日期:2025-02-17 接受日期:2025-02-21 出版日期:2025-05-15 发布日期:2025-04-28
  • 通讯作者: Dongke Sun E-mail:dksun@seu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 52301035), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20230844), and the National Key Research and Development Program of China (Grant No. 2023YFB3710202).

Modeling of microstructure and microsegregation evolution in solidification of ternary alloys

Qiannan Yu(于芊楠)1,2,3, Mengdan Hu(胡梦丹)1,2,3, Jinyi Wu(吴津仪)1,2,3, and Dongke Sun(孙东科)1,2,3,†   

  1. 1 School of Mechanical Engineering, Southeast University, Nanjing 211189, China;
    2 Jiangsu Key Laboratory for Biomaterials and Devices, Southeast University, Nanjing 211189, China;
    3 Key Laboratory of Structure and Thermal Protection of High Speed Aircraft, Ministry of Education, School of Mechanical Engineering, Southeast University, Nanjing 211189, China
  • Received:2024-12-18 Revised:2025-02-17 Accepted:2025-02-21 Online:2025-05-15 Published:2025-04-28
  • Contact: Dongke Sun E-mail:dksun@seu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 52301035), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20230844), and the National Key Research and Development Program of China (Grant No. 2023YFB3710202).

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摘要： The microstructure formed during solidification has a significant impact on the mechanical properties of materials. In this study, a two-dimensional (2D) cellular automaton (CA)-finite difference (FD)-CALPHAD model was developed to simulate the formation of microstructure and solute segregation in the solidification processes of ternary alloys. In the model, dendritic growth is simulated using the CA technique, while solute diffusion is solved by the FD method, and the CALPHAD method is employed to calculate thermodynamic phase equilibrium during solidification. The CA-FD-CALPHAD coupled model is capable of reproducing the evolution of continuous nucleation and growth of grains as well as the evolution of the microstructure and solute distribution during solidification of ternary alloys. In this study, Al-Zn-Mg ternary alloy is taken as an example to simulate the growth of equiaxed and columnar grains and the columnar-to-equiaxed transition (CET) under different solidification conditions. The simulation results are compared with experimental data from the literature, showing a good agreement. Besides, the study also investigates the evolution of temperature and multicomponent solute fields during solidification and the effects of alloy composition and cooling rate on the microstructure morphology. The results reveal that the initial alloy composition and cooling rate significantly affect dendritic morphology and solute segregation. Higher initial alloy concentrations promote the growth of side branches in equiaxed grains, leading to more pronounced solute segregation between dendrites. As the cooling rate increases, the average grain size of the equiaxed grains decreases accordingly. Additionally, a higher cooling rate accelerates the columnar-to-equiaxed transition, leading to a finer grain structure.

关键词: ternary alloys, solidification, dendrite, columnar-to-equiaxed transition, cellular automaton

Abstract: The microstructure formed during solidification has a significant impact on the mechanical properties of materials. In this study, a two-dimensional (2D) cellular automaton (CA)-finite difference (FD)-CALPHAD model was developed to simulate the formation of microstructure and solute segregation in the solidification processes of ternary alloys. In the model, dendritic growth is simulated using the CA technique, while solute diffusion is solved by the FD method, and the CALPHAD method is employed to calculate thermodynamic phase equilibrium during solidification. The CA-FD-CALPHAD coupled model is capable of reproducing the evolution of continuous nucleation and growth of grains as well as the evolution of the microstructure and solute distribution during solidification of ternary alloys. In this study, Al-Zn-Mg ternary alloy is taken as an example to simulate the growth of equiaxed and columnar grains and the columnar-to-equiaxed transition (CET) under different solidification conditions. The simulation results are compared with experimental data from the literature, showing a good agreement. Besides, the study also investigates the evolution of temperature and multicomponent solute fields during solidification and the effects of alloy composition and cooling rate on the microstructure morphology. The results reveal that the initial alloy composition and cooling rate significantly affect dendritic morphology and solute segregation. Higher initial alloy concentrations promote the growth of side branches in equiaxed grains, leading to more pronounced solute segregation between dendrites. As the cooling rate increases, the average grain size of the equiaxed grains decreases accordingly. Additionally, a higher cooling rate accelerates the columnar-to-equiaxed transition, leading to a finer grain structure.

Key words: ternary alloys, solidification, dendrite, columnar-to-equiaxed transition, cellular automaton

中图分类号:  (Nucleation and growth)

  • 68.55.A-
68.08.De (Liquid-solid interface structure: measurements and simulations) 81.30.Fb (Solidification) 81.10.-h (Methods of crystal growth; physics and chemistry of crystal growth, crystal morphology, and orientation)