三维相场法模拟定向凝固过程枝晶交叉生长研究  

Study on Three-Dimensional Phase-Field Simulation of Cross-Growth of Dendritic Crystals During Directional Solidification

作　　者：付金良 高亚龙 冯力[2] FU Jinliang;GAO Yalong;FENG Li(Henan Equipment Investment Group,Zhengzhou Coal Mining Machinery Group Co.,Zhengzhou 450016,China;School of Materials and Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]河南省装备投资集团郑州煤矿机械集团公司,河南郑州450016 [2]兰州理工大学材料科学与工程学院,甘肃兰州730050

出　　处：《铸造技术》2018年第9期1888-1892,共5页Foundry Technology

基　　金：国家自然科学基金资助项目(11504149;11364024与51661020)

摘　　要：以Al-Cu二元合金为例,基于三维相场模型,模拟了定向凝固过程中初始晶粒以锯齿形排列,枝晶交叉生长时的竞争生长行为,研究了晶粒取向对枝晶交叉生长的影响规律。设定两层晶粒交叉生长时晶粒取向角的绝对值相等。结果表明,在一定的计算区域内,交叉生长时晶粒生长方向与温度梯度方向之间夹角的绝对值越大,两组枝晶通过液相通道穿插过对方枝晶之后,其生长越早被抑制,枝晶生长速度越小;当晶粒生长方向与温度梯度方向之间夹角的绝对值达到30°时,两组枝晶互相穿插过对方枝晶后,其中一组枝晶产生新的分枝。这种三维竞争生长很好地解释了相关实验研究,组织中枝晶断断续续生长的现象。Based on the three-dimensional phase field model, the A1-Cu binary alloy is taken as an example to simulate the competitive growth behavior of the initial grains in zigzag arrangement and dendrite cross growth during directional solidification. The effect of grain orientation on the cross-growth of dendrites was studied. The absolute value of grain orientation angle is set to be equal when two layers of grain cross grow. The results show that the absolute value of the angle between the direction of grain growth and the direction of temperature gradient is greater in a certain calculation area. When two groups of dendrites are interspersed with each other through the liquid phase channel, their growth is inhibited as early as possible. When the absolute value of the angle between the direction of grain growth and the direction of temperature gradient reaches 30 degree, the two groups of dendrites are interspersed with each other, and one group of dendrites produces a new branch. This kind of three-dimensional competitive growth is a good explanation for the intermittent growth of dendrites structure in related experimental studies.

关 键 词：定向凝固 相场法 交叉生长 晶粒取向 锯齿形排列 

分 类 号：TG244[金属学及工艺—铸造]