Of aluminum alloys, pure aluminum is characterized by the highest corrosion resistance, which, unfortunately, also has the lowest strength. Stronger corrosion-resistant aluminum alloys contain small amounts of magnesium, for example, AlMg2, AlMg2,5 alloys. The strongest aluminum alloys, duralumin, are distinguished by low corrosion resistance.

Thus, if corrosion resistance is a priority for your application and low strength is not an issue, then pure aluminum is the best choice.

Dear Dr. Atik Islam ,

on Al Alloys intense localised corrosion, ranging from small pits to extensive corrosion over the whole surface, can occur within narrow crevices that may be formed by:

-The geometry of the structure, e.g. riveted plates, threaded joints etc.

- Contact of metal with non-metallic solids, e.g. plastics, rubber etc.

-Deposits of sand, dirt or permeable corrosion products on the metal surface.

Differential aeration plays an important part in the mechanism of crevice corrosion, but it is not the sole cause. The situation in reality is far more complex, owing to the formation of acid within the crevice.In an aluminium crevice, corrosion makes little progress, probably due to the precipitation of aluminium oxide, a corrosion product that restricts the entrance to the recess.

For more details about Al Alloys selection, please see the source:

-Aluminium and Corrosion

Available at: https://alfed.org.uk/files/Fact%20sheets/2-aluminium-and-corrosion.pdf

My best regards, Pierluigi Traverso.

Aluminium is a reactive metal with a substantially high affinity for oxygen. The metal is highly resistant to most environments and wide chemical agents. This resistance is due to the inert and protective character of the aluminum oxide film, which typically forms on the metal surface. I would agree with Dr. Vadim Verlotski - if corrosion resistance is the priority and strength is not a major issue, then pure aluminum should be the choice. Thank you.