Quantitative evaluation of porosity in aluminum alloy die castings by fractal analysis of spatial distribution of area

High-pressure die-casting processes are widely used, especially for automotive products, but pores in the die-casting process occasionally occur during production. To identify the cause of porosity and to take corrective action in the die-casting process accurately and rapidly, a quantitative estimation of the morphology of pores can be an effective technique. In this study, fractal analysis is proposed to characterize porosity quantitatively in terms of the spatial distribution of a number of pores appearing in a target region. The purpose of the present investigation is to evaluate the proposed fractal analysis by comparing the porosity in two types of aluminum alloy die castings manufactured by different die-casting processes, and to confirm that fractal analysis of the spatial distribution of pores can quantitatively characterize the porosity.