aluminium alloys

aluminium alloys are corrosion resistant in atmosphere, but often have poor corrosion resistance when submerged in aqueous environments. Aluminum corrosion resistance is also often only high in a restricted range of pH. For example, data has been published6 that shows aluminum corrosion rates are very low when the chemical stream pH is between approximately 4 and 7, but the corrosion rates are very high when the pH is either below 4 or above 7.