Transport Phenomena During Solidification of Multi-ComponentMixtures

提出的研究目的是为了更好地理解多组分混合物凝固过程中发生的输运现象。研究了浮力和固液密度差驱动的液相流动对传热传质和凝固过程的影响。将建立一个统一的模型，该模型集成了发生在宏观水平上的传输现象的描述，如动量、能量和对流和扩散引起的物质转移，以及微观水平上的传输现象，如成核、界面转移和微观结构的生长。理论工作将由一个全面的实验计划来补充，通过该计划可以获得有关输运现象的定性和定量信息，并用于验证模型预测。通过提出的研究获得的结果将有助于提高对涉及凝固的广泛过程的理解和控制，并将导致更现实的预测和材料性能的优化。该工作涉及铸锭凝固、形状铸造、定向凝固、连铸、焊接工艺、快速凝固、电渣重熔，以及涂层、净化、晶体生长和聚合物生产。

The objective of the proposed research is to obtain an improved understanding of the transport phenomena occurring during solidification of multicomponent mixtures. The research is aimed at investigating the effects of buoyancy and solid/liquid density difference driven flow in the liquid phase on the heat and mass transfer and solidification processes. A consistent model that integrates the description of the transport phenomena occurring on a macroscopic level, such as momentum, energy, and species transfer due to convection and diffusion, as well as on a microscopic level, such as nucleation, interfacial transfer, and growth of the microstructures will be developed. The theoretical work will be supplemented by a comprehensive experimental program through which qualitative and quantitative information about the relevant transport phenomena can be obtained and which serves to validate the model predictions. The results obtained through the proposed research will contribute to improved understanding and control of a wide range of processes involving solidification and will lead to more realistic predictions and optimization of material properties. The work is pertinent to ingot solidification, shape casting, directional solidification, continuous casting, welding processes, rapid solidification, electroslag remelting, as well as coating, purification, crystal growth and polymer production.