Solidification Of Subcooled Gallium Poured Into A Vertical Cylindrical Mold

The present investigation is aimed at the solidification of subcooled liquid gallium. The gallium, in its liquid state, is contained in a cylindrical shell of copper or polypropylene, and poured into the shell, which is immersed in a cold bath. The phenomena empirically observed have been simulated in four stages: subcooling of the liquid gallium down to its nucleation temperature, a rapid transfer from nucleation to the stable solidification temperature, stable solidification up to its completion and finally cooling down of the solid gallium. The entire process for initially contained liquid gallium is analyzed by formulation of heat transfer rates at each stage. The model presents time-dependent temperatures and melt fraction. The model agrees well with the experiments. For the flowing liquid gallium, the numerical study explored solidification of the flow of liquid gallium by a two-dimensional ( axially symmetric) model. Previous investigations in our laboratory, using other flowing phasechange materials, have demonstrated that the solidified phase at the cooled boundaries adheres to the walls with irregular cavities. In the present study the flowing and solidifying gallium has formed an irregular boundary at the walls, too. However, the numerical model has closely predicted the entire process of solidification and cooling of the solid.