A phase-field model coupled with a thermodynamic database
A phase-field model coupled with a thermodynamic database
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DOI：
10.1016/s1359-6454(03)00443-9
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发表时间：
2003-12
期刊：
影响因子：
9.4
通讯作者：
R. Qin;E. Wallach
中科院分区：
文献类型：
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作者：
R. Qin;E. Wallach
建立了一个多组分合金凝固的相场模型，该模型可与热力学数据库集成。固-液界面被建模为固相和液相的混合物。固相的溶质浓度仅取决于局部温度，而液相的溶质浓度受来自所形成的固体的溶质排斥（或吸收）以及液体中任何化学扩散的程度的影响。相场模型的控制方程已经推导出在一个物理一致的方式，使这些方程中的参数是完全确定的。通过与热力学数据库MTDATA的直接连接，该模型能够模拟真实的合金的微观组织演变。铝硅合金的数值计算表明，相场驱动力的变化以类似的方式的热力学驱动力，虽然相场驱动力的变化更快的热力学驱动力时，系统接近平衡。的相场迁移率示出不是一个平凡的功能的宪法过冷。新的相场模型在保持相场模型中各参数连续性和界面性质的前提下，允许液固界面区的宽度较大，适合于模拟大规模体系。
A phase-field model for the solidification of multi-component alloys, capable of being integrated with thermodynamic databases, has been developed. The solid–liquid interface is modelled as a mixture of solid and liquid phases. The solute concentration of the solid phase depends only on the local temperature while the solute concentration of the liquid phase is affected by solute rejection (or absorption) from the solid being formed together with the extent of any chemical diffusion in the liquid. The governing equations for the phase-field model have been derived in a thermodynamically consistent way such that the parameters in these equations are fully determined. By linking directly with the thermodynamic database MTDATA, the model is capable of simulating the microstructural evolution of real alloys. Numerical calculations for aluminium–silicon alloys show that the phase-field driving force changes in a similar manner to the thermodynamic driving force, although the phase-field driving force changes more quickly than the thermodynamic driving force when the system approaches equilibrium. The phase-field mobility is shown not to be a trivial function of constitutional undercooling. With the new phase-field model, the width of the liquid–solid interface region is allowed a much large value with the continuity of all parameters in the phase-field model and properties of interface maintained, and hence the model is suitable for simulating large-scale systems.