(西安理工大学材料科学与工程学院，西安710048)
摘 要: 基于枝晶生长的扩散界面模型，改进元胞自动机法，并结合有限差分法，综合考虑浓度场、温度场以及熔池形状，建立Fe-0.04%C(质量分数)合金枝晶生长和溶质浓度分布模型。模拟单个等轴晶的生长形貌及枝晶尖端生长速度随时间的变化关系、多个等轴晶的生长形貌和溶质浓度分布、柱状晶的生长形貌和耦合温度场后的柱状晶-等轴晶转变过程，并与实验进行对比。结果表明：取向角对枝晶形貌有一定的影响；枝晶尖端生长速度随时间的延长最后趋于稳定；熔池形状影响柱状晶生长形貌；溶质主要富集在枝晶根部及晶界处。模拟结果与实验结果吻合较好。
关键字: 元胞自动机-有限元法；枝晶生长；溶质分布；温度分布
（School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048, China）
Abstract:Based on the diffusive interface model of dendritic growth, a new model of dendrite growth and solute concentration distribution of Fe-0.04%C (mass fraction) alloy was developed by the improved cellular automaton method, combined with the finite difference method, considered concentration field, temperature field and the shape of molten pool. This model simulated the growth morphologies of a single equiaxial crystal, the relationships between dendrite tip growth and time, multiple equiaxial crystals growth morphologies and solute concentration distribution, the growth of columnar crystal, columnar-to-equiaxed transition after coupling temperature field, and compared with the experimental results. The results indicate that the orientation angles have certain influence on dendrite morphologies, the dendrite tip growth rate tends to be stable with the extension of time in the end, the shape of molten pool influences the growth morphologies of columnar crystals, the solute concentrate in the dendrite roots and grain boundaries. The simulation results are in accord with the experimental ones well.
Key words: cellular automaton-finite difference method; dendrite growth; solute distribution; temperature distribution
