Axial Solidification Experiments to Mimic Net-Shaped Castings of Aluminum Alloys

Net-shaped casting processes in the automotive Industry have proved difficult to simulate due to the complexities of the interactions amongst thermal, fluid, and solute transport regimes in the solidifying domain. The existing casting simulation software lacks the necessary correlations of the fraction of solid as a function of cooling rate and other process parameters. To address the shortcomings, an axial directional solidification experiment setup was developed to map the thermal data as the melt solidifies unidirectionally from the chill surface under unsteady-state conditions. Pure Al was used to demonstrate the validity of the experiments in our ability to determine transient thermal diffusivity of the solidifying metal using an inverse heat transfer algorithm (IHTA). The thermal diffusivity (α) results evaluated by Laser Flash Analysis experiments, IHTA are both in good agreement with the published data on the same. The uniqueness of the α estimate using these experiments and IHTA is in its transient nature. The results demonstrate the reliability of the axial solidification experiment apparatus in accurately providing input to the casting simulation interface and aid in reproducing casting numerical simulation models efficiently.