Al-Cu-Mg三元合金的溶质分凝与凝固进程的数值模拟研究  

Numerical Simulation on Solute Partition and Solid Fraction Evolution in Solidification of Al-Cu-Mg Alloys

作　　者：钟斌[1] 介万奇[1] 刘永勤[1] 何志[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《铸造》2009年第8期813-816,共4页Foundry

基　　金：国家重点基础研究(973)课题(2006CB605202)

摘　　要：基于相图计算方法,耦合微观凝固模型,研究了Al-Cu-Mg合金溶质分配因数在凝固过程中的变化规律,并获得了分凝特性与固相体积分数变化的定量关系。以Al-3.9%Cu-0.9%Mg为例计算表明,Cu与Mg的溶质分配因数在凝固过程中变化较大,并且,冷却速率的变化对Cu和Mg的分配因数有较大的影响。以溶质分凝规律为基础,定量预测了Al-15.0%Cu-4.0%Mg合金在不同冷却速率下的固相体积分数随温度的变化曲线。计算表明,随着冷却速率的增大,该曲线向低固相体积分数方向移动,并且非平衡共晶的体积分数增大。其中,在6K/min下的计算结果与DTA分析结果基本一致。By coupling micro-scale solidification model with CALPHAD technology, the variation of solute partition coefficients for elements Cu and Mg was numerically studied during dendritic solidification process of Al-Cu-Mg alloys. By taking alloy Al-3.9%Cu-0.9% Mg as an example, the variation of solute partition coefficients as the function of solid volume fraction was obtained. It was found that the partition coefficients changed greatly during solidification process and strongly depended on the cooling rate. Furthermore, the evolution of solid volume fraction, i.e., fs-Tcurve, for Al-15.0% Cu-4.0% Mg alloy was also quantitatively predicted at different cooling rates. With the increase of cooling rate, the fs-Tcurve shifts to the side of low fs values at the same temperature, and the volume fraction of the non-equilibrium eutectic increases. The numerical results at the cooling rate of 6 K/min are well in agreement with the DTA analysis results.

关 键 词：溶质分凝因数 AL-CU-MG合金 微观凝固模型 凝固曲线 

分 类 号：TG131[一般工业技术—材料科学与工程]