Simulation of Grain Growth during Solidification of Twin-Roll Continuously Cast Pure Aluminum with a Modified CA Model

摘要:

基于枝晶生长的基本传输过程和元胞自动机(Cellular Automaton，简称CA)-有限元(Finite Element，简称FE)模型基本原理，建立了适应双辊连续铸轧纯铝薄带工艺特点的凝固过程形核和晶体生长的数学模型。模型耦合了宏观温度场和微观组织模拟计算，考虑了溶质扩散、曲率过冷和潜热释放等重要因素的影响，能够模拟凝固过程中枝晶生长的形态。应用本模型对双辊连续铸轧纯铝薄带凝固过程中等轴晶生长、等轴晶多晶粒生长及柱状晶生长、柱状晶向等轴晶演化进行模拟并与实验结果进行对比，模拟结果与实验结果吻合较好

Abstract:

A new mathematic model for the nucleation and the dendrite growth of twin-roll-continuously cast pure aluminum thin strip during solidification process was developed based on cellular automaton(CA)-finite element(FE) method and the classical transfer equations during dendrite growth. The model coupled the temperature field calculation and microstructure simulation. The solute diffusion, the curvature undercooling and the latent?heat?releasing were also considered in the model, all of which have significant influence on the dendrite evolution. So the dendrite growth morphology can be modeled. The applications of the model in equiaxed dendrite growth, multiple equiaxed dendrite growth, columnar grain growth, and columnar dendrite transformation to equiaxed dendrite in twin-roll-continuously cast aluminum thin strip solidification were presented. The microstructure simulation results were compared with the experimental results and they were in good agreement in dendrite morphology