Acta Metallurgica Sinica (English Letters) ›› 2010, Vol. 23 ›› Issue (2): 121-128.DOI: 10.11890/1006-7191-102-121

• 研究论文 • 上一篇    下一篇

对流作用下枝晶生长的相场法模拟

袁训锋1;丁雨田2   

  1. 1. 甘肃兰州理工大学
    2. 兰州理工大学材料科学与工程学院
  • 收稿日期:2009-09-15 修回日期:2010-01-13 出版日期:2010-04-25 发布日期:2010-04-08
  • 通讯作者: 袁训锋

Phase field simulation of dendrite growth under convection

Yutian DING, Xunfeng YUAN, Tingbiao GUO, Yong HU   

  1. State Key Laboratory of Gansu Advanced Non-Ferrous Metal Materials, Lanzhou University of Technology, Lanzhou 730050, China
  • Received:2009-09-15 Revised:2010-01-13 Online:2010-04-25 Published:2010-04-08
  • Contact: Xunfeng YUAN

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摘要：

采用耦合流场的相场模型模拟纯物质的凝固过程，用有限差分法对控制方程求解。研究了初始晶核半径、空间步长和界面厚度对枝晶生长的影响。结果表明：无对流情况下，晶粒以等轴晶形式生长；有对流情况下，晶粒以具有分支结构的枝晶形式生长。在初始晶核半径取值合适时，对流只影响侧向分支的生长，不影响枝晶尖端的稳定行为。随着空间步长的增大， 纵向主枝上游出现侧向分支且快速生长；随着界面厚度的增加，纵向上游主枝和水平主枝变得更细，更长，它们的侧向分支更发达。

关键词: 相场法, 强制对流, 枝晶生长, 模拟

Abstract:

The phase-field model coupled with a flow field was used to simulate the solidification of pure materials by the finite difference method. The effects of initial crystal radius, the space step and the interface thickness on the dendrite growth were studied. Results indicate that the grain grows into an equiaxial dendrite during free flow and into a typical branched structure under forced flow. The radius of an initial crystal can affect the growth of side-branches but not the stability of the dendrite's tip when an appropriate value is assigned to it. With an increase in space steps, side-branches appear at the upstream of the longitudinal principal branch and they grow rapidly. With an increase in the interface thickness, the trunk of the longitudinal upstream and lateral principal branches grow longer and become more slender while the number of secondary branches increases.

Key words: Phase field method, Forced flow, Dendrite growth, Simulation