等温凝固过程中枝晶生长与枝晶熟化的相场法模拟  

Simulation of Dendrite Growth and Coarsening during Isothermal Solidification Process by Phase Field Method

作　　者：胡春青[1] 张玉妥[1] 李东辉[1] 王承志[1] 

机构地区：[1]沈阳理工大学材料科学与工程学院,辽宁沈阳110159

出　　处：《沈阳理工大学学报》2010年第4期51-54,共4页Journal of Shenyang Ligong University

基　　金：辽宁省自然科学基金资助项目(20092061)

摘　　要：采用相场方法模拟了Al-2%Si合金等温凝固中枝晶生长与枝晶熟化过程。结果表明:在枝晶生长初期主要是初生枝晶臂的长大,形成二次或更高次枝晶臂。当侧向分枝生长到边界后,二次枝晶臂停止生长,从而进入熟化阶段。枝晶的等温熟化模式主要是小枝晶臂的熔化、枝晶臂的合并与熔断,枝晶分枝的平滑化以及小液滴的圆滑化。当凝固时间小于0.7ms,固相分数增加的快,枝晶的生长成为主导;当凝固时间大于0.8ms,固相分数变化不明显,枝晶的熟化成为主导.In this paper,the simulation of dendrite growth and dendrite coarsening for Al-2%Si alloy during isothermal solidification is carried out by phase field method.The results show that the dendrite arms grow mainly in initial stage and the then formation of second arms and higher arms follows.When the growing side arms contact with the boarder of domain,the dendrites stop growing and become ripen and thicken,then come into coarsening stage.The dendrite coarsening process is dominated by remelting fine dendritic arms,coalescing and burning out as well as the smoothing of side arms,the rounding of small liquid droplets.When the solidification time is less than 0.7ms,the fractions of solid increase rapidly,and the dendrite growth is overwhelming superiority.Whereas the time is more than 0.8ms,the fractions of solid change slightly,and the dendrite coarsening is overwhelming superiority.

关 键 词：相场法 枝晶生长 枝晶熟化 AL-SI合金 等温凝固 

分 类 号：TG146.21[一般工业技术—材料科学与工程]