Beyond Porosity: Multi-Defect Simulation Studies for Improved Solidification Analysis of Castings

The quality of casting results is traditionally generally evaluated primarily through porosity analysis. However, industry experience shows that the final mechanical performance of a cast component is determined by the interaction of different types of defects that arise simultaneously. This study proposes a comprehensive multi-defect simulation framework that goes beyond a mere porosity-based approach, through simultaneous analysis of shrinkage porosity, gas entrapment, oxide film formation, hot tearing tendency, and residual stress due to solidification processes. A Computational Fluid Dynamics (CFD)-based flow simulation and solidification approach is used to model the behavior of molten metals during mold filling and cooling processes. Variations in process parameters, including pouring temperature, filling speed, and gating system design, were systematically analyzed. The simulation results showed that casting defects did not appear separately, but rather interacted with each other and significantly affected the severity and spatial distribution of defects. The optimized process parameters are able to reduce the predictable defect volume fraction by more than 30% compared to the initial condition. The proposed methodology provides a more realistic evaluation of the integrity of cast results and offers practical guidance for the optimization of casting processes in the industry. This study contributes to the development of digital-based foundry design by encouraging an integrated quality evaluation approach rather than just one defect criterion.