基于CA-LBM模型的枝晶非对称生长行为研究  

Study of Dendritic Asymmetrical Growth Behavior Based on CA-LBM Model

作　　者：周靖超[1] 李日[1] 杨莹莹[1] 赵朝阳[1] 

机构地区：[1]河北工业大学材料科学及工程学院,天津300130

出　　处：《铸造技术》2017年第5期1088-1094,共7页Foundry Technology

基　　金：国家自然科学基金项目(51475138);国家重点基础研究发展计划项目(2011CB610402)

摘　　要：建立了用于模拟单相合金固溶体凝固过程温度场、流场、浓度场,以及微观组织模拟的二维元胞自动机-格子玻尔兹曼方法(cellular automaton-lattice Boltzmann method,CA-LBM)数值模型。对强制对流作用下不同工艺条件对枝晶非对称性生长(Dendritic asymmetrical growth,DAG)行为的影响进行了研究。模拟结果表明,与不计入流动过程的纯扩散型合金凝固模拟结果相比较,强制对流造成枝晶非对称性生长行为,且枝晶的凝固效率增加;当工艺条件改变时,枝晶非对称性生长行为也会随之发生变化,表现为初始过冷度越小、对流速度越大、冷却速率越小会使枝晶非对称性生长行为趋向更强。A new two-dimensional model used to simulate heat transport, fluid flow, solute diffusion, and dendritic growth of single phase alloy solid solution in solidification process was developed by the lattice Boltzmann model（LBM） and the cellular automaton（CA）. The effect of different process condition on dendritic asymmetrical growth behavior under forced convection was studied. The simulation results show that the forced convection results in the asymmetrical dendritic growth and the efficiency of dendritic growth increases, compared with that without accounting for convection. When changing solidification conditions, the dendritic asymmetrical growth behavior also changes accordingly. The smaller the initial subcooling, the greater the convective velocity and the smaller the cooling rate, dendritic asymmetric growth behavior tends to be stronger.

关 键 词：合金凝固 数值模拟 微观组织 CA-LBM 枝晶非对称性生长 

分 类 号：TG244.3[金属学及工艺—铸造]