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Prediction of Shrinkage Porosity Defect in High Pressure Die Casting (HPDC) using computer simulation

High pressure die casting (HPDC) becomes more important as electric vehicles (EVs) usage gains more momentum. Shrinkage porosity occurs during solidification inside the mold/ die, in regions of casting that solidify slowly compared to neighboring regions. In such scenario, there is not enough liquid melt to feed and completely fill the mold cavity. Shrinkage is a thermally driven phenomena. Local instantaneous temperature and the cooling rates are factors that cause shrinkage porosity.

Using a very good casting simulation tool, the local instantaneous temperature and cooling rates can be determined. And hence shrinkage porosity detected. At ProSIM we have expertise in casting simulation of high pressure die casting (HPDC) process and predict the defects for optimization of gating design. We use ADSTEFAN for simulation of high pressure die casting. ADSTEFAN casting simulation developed by Hitachi ICS Japan is very effective tool in prediction of casting defects for variety range of castings. Below figure is comparison of Shrinkage porosity defect with actual casting trial.

In ADSTEFAN, engineer can consider effect of cooling lines and vary die temperature to simulate their effect in predicting temperature gradients in casting and hence shrinkage porosity. Figure (left) shows the shrinkage porosity prediction, including the location in x,y,z, coordinates and the size (volume) of the defect. Figure (right) shows the casting defect in a production sample. It can be seen that the prediction of shrinkage porosity defect by casting simulation is closely comparing with the sample in trial production. With this, the casting simulation model is used as a workbench to conduct experiments of different scenarios, and optimize the gating design to eliminate shrinkage porosity defect.

For more details on usage of casting simulation for HPDC, contact visit: