Prediction of hot tears in DC-cast aluminium ingots

The present work aims to investigate hot tearing in a two-dimensional thermo-mechanical finite element (FE) model of aluminium DC ingot casting. Using the RDG criterion, the depression pressure within the mush of an AAS182 ingot has been calculated. For this work, the depression pressure was calculated directly over the solidification distance, without any transformation to temperature. Thus, variation in parameters such as the evolution of fraction solid and the strain rate over the mushy zone length could be captured, instead of held constant. The model predictions seem to be consistent with the hot tearing behaviour observed industrially, as the highest depression pressure is observed near the surface of the ingot, just above the lip of the bottom block.