Image-based finite element evaluation of porosity reduction in compression process of aluminum alloy die castings

In the die casting process, a formation of porosity is unavoidable. The porosity influences the mechanical properties and air leakage resistance of the products. We have investigated optimum manner of post compression process of ADC 12 aluminum alloy die castings to reduce inside porosity size. The reduction efficiency was affected by initial size and distribution of the porosity. In this study, two-dimensional imaged-based finite element analysis was conducted to find the optimum manner of post compression process considering porosity size and porosity distribution inside die castings. The mesh for finite element analyses was generated from X-ray CT images of the ADC 12 aluminum alloy die casting specimen. Comparing the deformation of porosity of numerical result and experimental result, we proved that the two-dimensional image-based finite element method works well to estimate the effect of the post compression process. We investigated the porosity reduction efficiency of biaxial and triaxial compression by using the same two-dimensional image-based finite element mesh.