Corrosion protection of AZ91 magnesium alloy in cooling systems

The effect of a salicylic Schiff base compound (Salcn) on the corrosion of AZ91 alloy in 30% ethylene glycol aqueous solution (30% EG/W) was investigated by electrochemical methods. Scanning electron microscope was used to observe the alloy surface in corrosive solution before and after the addition of inhibitor. There was no significant corrosion inhibition at the room temperature but high inhibition efficiencies were obtained at elevated temperatures due to the formation of chemisorbed inhibitor monolayer. As the inhibitor concentration increased, the inhibition efficiency increased probably due to more inhibitor adsorption on the alloy surface.