Phase Equilibria, Thermodynamics and Related Studies of Multi-Component Alloy Systems

本文研究了三元铝合金和四分之一铝合金体系。热力学建模和相图计算与凝固建模相结合，以确定凝固路径。本研究感兴趣的合金是Al- mg - cu、Al- mg - zn、Al- zn - cu和Al- Mg-Zn-Cu等富铝合金。该方法结合了热力学建模和相平衡的实验测量。在确定凝固路径时，采用了考虑反向扩散的修正Schiel模型。将定向凝固实验结果与计算结果进行了比较，以改进模型。了解多组分合金的热力学和相平衡对开发新合金是至关重要的。本研究扩展了对该领域模型铝合金系统的基本认识，也具有商业意义。

This proposal examines three ternary aluminum alloys and one quartenary aluminum alloy system. Thermodynamic modeling and phase diagram calculations are coupled to solidification modeling to determine paths of solidification. Alloys of interest to the study are aluminum-rich alloys of Al-Mg-Cu, Al-Mg-Zn, Al-Zn-Cu, and Al- Mg-Zn-Cu. The approach combines thermodynamic modeling and experimental measurements of phase equilibria. A modified Schiel model is employed that accounts for back diffusion in determining the solidification path. Results from directional solidification experiments are compared with the calculations to improve the models. %%% A knowledge of the thermodynamics and phase equilibria of multi- component alloys is vital to the development of new alloys. This research expands basic understanding in this field for model aluminum alloys systems that also have commercial significance.