有/无强制流动下定向凝固界面形貌的数值模拟研究  

Phase Field Simulation of the Interface Morphology during Directional Solidification in a Forced Flow/Free Flow

作　　者：陈志[1] 陈长乐[1] 郝丽梅[2] 

机构地区：[1]西北工业大学,陕西西安710129 [2]西安科技大学,陕西西安710054

出　　处：《稀有金属材料与工程》2010年第12期2117-2121,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金重大项目(50331040;60171034);西北工业大学基础研究基金(G9KY101502)

摘　　要：基于相场法对Ni-Cu合金的定向凝固过程进行了数值模拟,对比研究了抽拉速度、温度梯度对有/无强制流动下的凝固界面形貌的影响。结果表明,在强制流动的作用下,凝固界面向迎流方向倾斜生长;随着强制流速的增大,胞晶增大,沟槽的倾斜深度也逐渐增大,并且胞晶间的深度差别增大;在流动条件下,随着抽拉速度的增大,定向凝固界面演变模式为:平界面→深胞→浅胞→平界面,随着温度梯度的增大,凝固界面演化模式为:深胞→浅胞→平界面。此外,流动对凝固形成的胞晶一次间距产生重要影响。The directional solidification of Ni-Cu alloy was simulated numerically based on a phase filed method, and the effects of pulling speed and thermal gradient on the interface shape in a forced flow/free flow were studied comparatively. The results indicate that the growth of the solidification interface incline towards the upstream direction in the forced flow. With the forced flow velocity increasing, the cells become bigger, the inclination depth of grooves is increased gradually and the depth difference becomes more obvious. With the increase in the pulling speed, the morphological evolution mode of directional solidification is planar interface -> deep cells -> shallow cellular -> planar interface, while with the increasing thermal gradients the morphological evolution mode is deep cells -> shallow cellular -> planar interface. In addition, the forced flow has a great effect on the primary spacing of cells formed by solidification.

关 键 词：强制流动 定向凝固过程 界面形貌 数值模拟研究 Flow Directional SOLIDIFICATION during 凝固界面 温度梯度 抽拉速度 胞晶 Ni-Cu合金 重要影响 一次间距 演化模式 演变模式 深度差别 流动条件 对比研究 相场法 

分 类 号：TG111.4[金属学及工艺—物理冶金]