镁合金枝晶生长的相场法研究  

Research on Dendrite Growth of Magnesium Alloys by Using Phase Field Method

作　　者：袁训锋[1] 杨燕[1] 李春[1] 刘宝盈[1] 李英[1] 丁雨田[2] 

机构地区：[1]商洛学院,陕西商洛726000 [2]兰州理工大学,甘肃兰州730050

出　　处：《中国铸造装备与技术》2014年第1期35-38,共4页China Foundry Machinery & Technology

基　　金：商洛学院博士启动基金项目(12SKY01-1);国家自然基金资助项目(10834015)

摘　　要：采用有限差分法求解考虑界面能各向异性的相场模型,对镁合金枝晶生长过程进行了模拟计算,研究了无量纲过冷度和各向异性强度对枝晶生长行为的影响。结果表明:镁合金枝晶在二维平面上具有6个最优生长方向,优先生长方向上枝晶生长迅速,形成枝晶主干,枝晶形貌具有六重对称性。随着过冷度和各向异性强度的增加,枝晶形貌由光滑的类六边形向具有侧向分支的六重对称形貌转变,温度扩散层由类球形向星形过渡,枝晶尖端生长速率增加,尖端曲率半径和温度值减小。The phase field model taken into account the interfacial energy anisotropy has been used to simulate the dendrite growth of magnesium alloys by the finite difference method.The effects of dimensionless undercooling and the anisotropy strength on the dendrite growth behavior have been studied. The results showed that the six preferential growth orientations of dendrite of magnesium alloys existed in the two dimensional XY-plane,the dendrite grew fast and developed to the dendrite trunks at the preferential growth orientation,the dendrite morphology showed sixfold symmetry.With the increasing of undercooling and anisotropy strength,the dendrite morphology changed from smooth quasi-hexagonal to the sixfold symmetry dendrite with side-branches,the thermal diffusion layer turned from near- spherical shape to star,the dendrite tip velocity inereased while radius in the tip and temperature decreased.

关 键 词：镁合金 相场法 枝晶生长 过冷度 各向异性强度 

分 类 号：TG292[金属学及工艺—铸造]