显微偏析数值模拟的微观模型和数值方法  

Micro models and numerical methods of microsegregation simulation

作　　者：刘永刚[1] 孙瑜[1] 邱宗文[1] 孙国雄[1] 

机构地区：[1]东南大学机械系,南京210096

出　　处：《中国有色金属学报》2004年第3期335-339,共5页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(59974011)

摘　　要：研究显微偏析数值模拟中的微观模型和数值方法,在微观模型中考虑了树枝晶粗化、固相溶质逆扩散、枝晶尖端过冷、随温度变化的溶质扩散系数等影响显微偏析形成的动力学因素。数值方法中采用变网格技术跟踪移动界面,通过迭代求解溶质扩散方程和溶质守恒方程计算显微偏析参数。并给出了微观计算流程图,这种数值方法可以方便地与宏观计算、相图计算相耦合。模拟算例表明模拟结果与实验结果吻合较好。The numerical methods and micro models in the simulation on microsegregation were investigated. The main kinetic effects that can influence microsegregation were taken into account in the modeling such as secondary arm coarsening, solid state back diffusion, primary tip undercooling and variable diffusion coefficients according to temperature. The deforming grids technology was applied for tracking the moving interfaces, and the iterative method was applied for resolving diffusion equation and solute balance equation. The flow chart for the micro calculation which can be coupled easily with macro calculation and calculation of phase diagrams were also provided. A example calculation was carried out and the simulation results were in good agreement with experiment results.

关 键 词：显微偏析 数值模拟 微观模型 数值方法 溶质扩散方程 凝固 

分 类 号：TG111.4[金属学及工艺—物理冶金] TB115[金属学及工艺—金属学]