晶粒长大过程的相场法模拟

Phase-field Simulation of Grain Growth Process

Fe-C合金凝固时微观组织所形成过程的模拟,对优化工艺参数、提高铸件质量,有着重要的工程应用价值.在KKS(Kim,Kim,Suzuki.)模型的基础上,采用相场和溶质场耦合的方法,对Fe-0.5mol%C合金的晶粒长大过程进行了数值模拟.结果表明:晶体生长初期,晶粒为球状,随着时间的推移,晶粒由球状向枝晶状转变,最后形成复杂的树枝晶.对Fe-C合金的凝固过程进行实验研究及对试样进行了微观组织分析.经对比得出,模拟得到的微观组织形貌与实际凝固所得到的微观组织形貌基本一致,验证了相场模型的正确性.

Simulation modeling of Fe-C alloy microstructure formation optimize the casting processing technology so as to improve the quality. The will help to evaluate and phase-field model based on KKS model,which is coupled with solute-field, has been used to simulate the grain growth process of Alloy Fe-0. 5mol% C. The results show that during the early stages of grain growth, the grain morphology is spherical. With increasing of time, the grain morphologies transform into star shape from spherical shape, and then complex dendrite from star shape. In order to confirm the results from computer simulation, the solidification process of Fe-C alloy is carried on experimentally, and the microstructure of testing sample is studied in detail. By comparison the conclusion is obtained that the simulation results are almost the same as the experimental results, which indicates that the phase-field model is feasible in the study.