The lightweight design of aluminum automobile wheel can easily bring about all kinds of defects during die-casting, which often causes wheel frame deformation and creep damages in the future use and in turn affects traffic safety. To understand the evolution of mold flow, temperature field, and solidification, the low pressure die-casting processes of A356 aluminum wheel were simulated by Anycasting software package. Various casting parameters combined with the designs of flow channel and overflows were adopted to reduce the defects occurred in wheel products. In addition, we adopted the retained melt modulus (RMM) to predict the position of defects to be formed as well as their distribution so as to eliminate the shrinkage voids and porosity defects during die-casting. The research findings showed that the setting up of overflow tank could effectively prevent the formation of shrinkage void and porosity of die-castings and significantly promote the quality and productivity of die-casting wheel products.

This study conducted mold flow analyses on low pressure die-casting A356 aluminum rims to improve the shrinkage and porosity defects which usually occurs in die-castings so as to enhance the quality of die-casting wheels. We adopted different lift tube designs with cylindrical, taper opening and back taper opening structures while discussing the filling, exhaust, and solidification of molten flows and predicting the shrinkage and porosity formed based on the retained melt modulus. The study found that the configuration of lift tube as well as the optimization of process parameters such as the processing pressure and progressive time could effectively reduce the formations of shrinkage and porosity defects and improve the quality of die-castings.