You have a piece of aluminum that is caused by wet, absorbent material in contact with it. What type of corrosion would this be?

The scenario describes a situation where aluminum is in contact with wet, absorbent material, which leads to corrosion. This is indicative of poultice corrosion. Poultice corrosion occurs when moisture, often trapped in contact with a metal surface by absorbent materials, creates an environment conducive to localized corrosion. This condition can cause corrosion beneath the absorbent material, with the metals left untreated and moisture being unable to evaporate effectively.

In this case, the wet absorbent material retains moisture around the aluminum, leading to the deterioration of the metal due to the electrochemical processes that occur in the presence of stagnant water. This type of corrosion is particularly problematic because the corrosion can go undetected until significant damage has occurred, as it often takes place underneath the corroding material, shielded from direct view.

Understanding this form of corrosion helps in implementing preventive measures, such as ensuring proper drainage and avoiding the use of absorbent materials that can trap moisture against metal surfaces in marine environments.