二元合金非等温凝固过程的相场法模拟  

Phase-field Simulation of Non-isothermal Solidification of Binary Alloy

作　　者：龙文元[1] 蔡启舟[2] 魏伯康[2] 陈立亮[2] 

机构地区：[1]南昌航空工业学院 [2]华中科技大学

出　　处：《特种铸造及有色合金》2005年第2期88-91,共4页Special Casting & Nonferrous Alloys

基　　金：江西省材料科学与工程研究中心开放基金项目 (ZX2 0 0 30 1 0 1 7)

摘　　要：基于Ginzburg Landau理论 ,发展了一个新的相场模型。并利用该相场模型与溶质场、温度场进行耦合计算 ,以Al 6.5Cu合金为例模拟了二元合金非等温凝固和等温凝固的等轴枝晶生长过程。研究了凝固潜热对过冷合金熔液中的等轴枝晶生长以及溶质场和温度场的分布的影响。结果表明 :潜热的释放在一定程度上抑制了枝晶的生长 ,使非等温凝固时枝晶没有等温凝固时发达 ,并且凝固界面的溶质浓度也会降低 ,但不会改变在枝晶生长过程中浓度分布情况。A new phase-field model was developed based on the Ginzberg-Landau theory.The dendrite growth of a Al-6.5Cu binary alloy under non-isothermal and isothermal conditions were simulated by the model coupled with solute field and temperature field.The effects of solidification latent heat on the growth of equiaxed dendrite,distribution of solute field and temperature field in undercooled liquid alloy were analyzed.It was indicated that there is less developed dendrite at non-isothermal solidification than that at isothermal solidification,and the solute composition in the interface can be reduced due to restrain the dendrite growth with the latent heat releases but the composition distribution was independent.Morever,the Peclet value is well in agreement with the Ivantsov theoretical value during non-isothermal solidification.

关 键 词：相场法 二元合金 非等温凝固 数值模拟 

分 类 号：TG111.4[金属学及工艺—物理冶金]