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、曲率过冷和各向异性等重要因素的影响,定义了界面单元捕获规则,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,验证了模型的正确性.%A new mathematic model for the nucleation and dendritic growth of twin-roll continuous casting pure aluminum thin strip during solidification process was developed,which was based on cellular automaton(CA)-finite element(FE) method and the classical transfer equations during dendritic growth.The model coupled the temperature field calculation and microstructure simulation.The solute diffusion,curvature undercooling and anisotropy were also considered in the model,all of which have significant influence on the dendrite evolution.By setting up the CA cell capturing rules,the dendritic growth morphology can be simulated.Applications of the model in equiaxed dendritic growth,multiple equiaxed dendritic growth,and columnar grain growth,transformation of columnar dendrite to equiaxed dendrite in solidification of twin-roll continuous casting pure aluminum thin strip solidification were presented.The microstructure simulation results were compared with the experimental results and they were in good agreement in dendritic morphology,which validated the correctness of the proposed model.
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