Abstract: Corrosion tests were carried out on locally processed aluminum-based alloys with varying weight percentages of zinc. Test coupons of dimensions 17x16.8x15 mm were machined from the as-cast alloy to an average surface area of 1271 mm2. The coupons were immersed in 0.1, 0.25, 0.5 and 1.0 M NaCl solutions with a coupon withdrawn simultaneously from each medium at 24 hourly rate for characterization. The results revealed that the coupons gained weight in all the media indicating the phenomenon of passivation; with the greatest layer thickness observed in the range 0.25 to 0.5 M brine. This behavior is attributed to the increasing electrical conductivity of the solutions; a consequence of increasing solubility of the media which progressively increased peaking within this range and hence, increased passivation kinetics before declining due to the immobility of current carrying ions.