Integrated model for describing the microstructure evolution of the inoculated Al-Zn-Mg-Cu alloys in continuous solidification

Abstract

An integrated model based on the population dynamics approach and the cellular automaton method has been developed to simulate the solidification process of the Al-Zn-Mg-Cu alloys. The nucleation, spherical growth/dissolving and dendritic growth of the α-Al nuclei/grains are taken into account. The model is validated by comparing with the experimental results firstly, and then is applied to calculate the details of the microstructure formation in Al-Zn-Mg-Cu alloys inoculated with Al-5Ti-1B master alloys. The effects of the size distribution of TiB2 and the solidification conditions on the grain size are investigated. At last, an empirical formula for predicting grain size has been put forward based on the numerical calculations. The formula gives the dependent relationship between the grain size, the cooling rate of melt, the additive amount of refiner, the composition of the solutes and the size distribution of TiB2 particles.