Computer simulation of casting process of aluminium wheels – a case study

Aluminium disc wheels intended for normal use in passenger cars are commonly produced by gravity casting. If the cooling process and the initial temperature of the mould are not well controlled, shrinkage cavity will occur after solidification, causing leakage in the disc wheel. In this research, a casting simulation software is used to simulate the casting process of aluminium wheels. The casting simulation is done iteratively until the mould temperature converges to a stable temperature. A ‘shrinkage index’ (SI) is defined to provide a quantified index of casting quality of aluminium wheels, based on the phenomenon of liquid entrapped at the joints of rim and spokes of the wheel where shrinkage cavity usually happens. This shrinkage index shows good correlation with the aluminium wheel leakage test results. This paper also discusses the influence of cooling process parameters on SI, including initial mould temperature, and geometry of the wheel, which verifies engineers’ empirical data. This iterative simulation process and SI can be used to predict the casting quality of aluminium wheels and to find the optimal parameters of the casting process.