压铸镁合金微观组织模拟  

Microstructure Simulation of Mg Die-casting Alloy

作　　者：曹运锋[1] 许庆彦[1] 熊守美[1] 

机构地区：[1]清华大学

出　　处：《特种铸造及有色合金》2003年第6期13-15,共3页Special Casting & Nonferrous Alloys

基　　金：国家高技术研究发展计划 (863)子课题 (2 0 0 1AA331 0 30 - 0 4 );国家自然科学基金项目 (50 2 750 81 );清华大学机械学院重点基金资助项目

摘　　要：采用CellularAutomaton微观模型 ,对压铸镁合金的三维微观组织演变进行了模拟。在模拟过程中 ,采用连续形核模型处理液态金属的异质形核现象 ,通过正态分布函数描述形核质点密度随温度的分布关系 ,在给定过冷度时对分布函数积分可得到该时刻的形核密度 ,晶粒生长模型则考虑了枝晶尖端生长动力学和择优生长方向 <10 10 >,也考虑了温度场的影响 ,并完成了宏观温度场和微观计算的耦合。最后通过压铸镁合金标准拉伸试棒金相试验 ,对模拟结果进行了验证 。D microstructure evolution simulation of Mg die casting alloy was conducted by CA(Cellular Automaton) model. Continuous nucleation model was used to describe heterogeneous nucleation of the liquid metal. Gauss distribution function was employed to reveal the relation between the density of nucleation sites and the temperature. At a given undercooling, the nuclei density can be done by intergrating the function. Dendritic tip growth kinetics, effects of temperature field and crystal preferential growth direction < 1 0 1 0> were taken into account in grain growth model. The macro temperature field coupled with microstructure calculation was made. The simulated results were verified by standard tensile bar of Mg die casting alloy. The simulated results were well in agreement with the experiment on average grain sizes.

关 键 词：压铸镁合金 微观组织模拟 CA方法(Cellular Automaton) 

分 类 号：TG146.22[一般工业技术—材料科学与工程]