Collaborative Research: Models, algorithms, simulations and applications for dendritic solidifications of two-phase multi-component alloys in the mushy zone

Alloys, typically formed by solidifying a molten mixture of multiple metal and non-metal components, find extensive applications in various fields and are vital to our economy. Unlike pure metals, solidification of alloys occurs in a mushy zone where phase change, solution diffusion, thermal diffusion, volume change, and melt convection interact and strongly influence the mechanical, physical, and chemical properties of the solidified alloy. This project aims to develop mathematical models and numerical algorithms for the solidification process in the mushy zone. The numerical results will advance the understanding on the complex physical processes in the mushy zone and provide guidance to the design of alloys with desirable properties. The team of PIs consists of the three researchers from three different institutions, where training of graduate students on the topics of the project is expected. This research project focuses on mathematical modeling, algorithm development and analysis, numerical simulations, and engineering applications of dendritic solidification of two-phase multi-component alloys in the mushy zone. The investigators will address these challenging problems numerically with the following goals: (i) to develop a general two-phase multi-component phase-field model for the solidification of alloys in the mushy zone, with the consideration of thermal diffusion, solute diffusion, convection, density variation, and energy law; (ii) to develop and analyze efficient, easy-to-implement, and energy-stable numerical schemes to accurately capture the solidification dynamics; and (iii) to perform numerical simulations to validate the models and numerical schemes, and further study physically motivated problems. The obtained modeling and numerical tools allow the investigators to simulate relevant physical problems of practical interest in a variety of applications due to the wide applicability of the models and algorithms. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.