Studies on the inhibition of aluminum dissolution by hexamine–halide blends: Part II: Surface analysis (SEM, AES investigations)

The results of investigations by scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) to study the surface morphology, the composition and thickness of the adsorbed film formed on the surface of aluminum samples in 2 M hydrochloric acid solution containing optimum doses of the blends hexamine–KI and hexamine–CaCl2 as inhibitors are discussed. The data explained the effectiveness of the additives on the properties of the adsorbed films on the aluminum surface. It is concluded that much higher corrosion resistance and improvement in the surface morphology of aluminum observed due to the marked layer enrichment on the aluminum surface from the blends additives. The results could also explain the effectiveness of the halide ions to facilitate the adsorption of hexamine.