Influence of Dynamic Environments on Microstructural Evolution During Alloy Solidification

这项研究的长期目标是更好地了解凝固过程中的微观结构形成。对糊状区凝固进行了实验研究，建立了改进的凝固过程模型。重点是糊状带的演变，特别是在糊状带形成的早期阶段，以及这种结构如何与与合金凝固相关的大规模输运过程耦合。在不同的流动条件下观察到成核和晶粒破碎。确定了强制对流、溶质浓度和过冷对破碎过程的影响。计划进行实验以确定最终固相形成如何与糊状区相互作用。这种方法的成功将为实际铸造和凝固过程的预测理论发展到细观（0.1 - 100微米）尺度。

The long term goal of this research is to achieve a better understanding of microstructure formation during solidification. Experimental studies are conducted on mushy zone solidification to create improved models of the process. The emphasis is on mushy zone evolution, particularly in the early phases of the mushy zone formation, and how this structure couples with the large-scale transport processes associated with alloy solidification. Nucleation and grain fragmentation is observed under various flow conditions. Effects of forced convection, solute concentration, and undercooling on the fragmentation process is determined. Experiments are planned to determine how the final solid phase formation interacts with the mushy zone. %%% Success in this approach would permit development of a predictive theory for real casting and solidification processes down to the mesoscopic (0.1 - 100 micron) scale.