Evaluation of Residual Stress in Die Castings of Al-Si-Cu Alloy Considering Material Composition Change in Thickness Direction

This study investigated a method for accurately predicting the residual stress in die castings manufactured using aluminum alloy. To account for the mechanical properties caused by the material composition differences that occur in the thickness direction of the die castings, a model split in the thickness direction was used in the simulation model. Norton’s law was applied to the constitutive equation of the material, and the stress relaxation phenomenon was examined. The composition of Al-Si-Cu alloy (JIS-ADC12) die castings in the thickness direction were analyzed using scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS), and differences in composition were confirmed. As a result of calculating the residual stress using the simulation, it was possible to calculate the residual stress that could not be reproduced by the simulation model of uniform composition. This suggested that the difference in mechanical properties of die castings in the micro-region influences the residual stress.