Abstract: Model equations have been developed for the investigation of the corrosion behaviour of duplex Al-Sn alloy systems of composition 2.5% by weight of Sn and 4.5% by weight of Sn subjected to different media concentrations: 0.5 and 1.0 M of H2SO4, HCl and NaCl, respectively. The comparison plot of the generated values from the model equations show that it correlates well with experimental data, hence its usefulness for the evaluation of the corrosion trend in the alloy compositions being investigated.