Which corrosion type is specifically associated with high strength aluminum alloys?

Exfoliation corrosion is a specific type of corrosion that is particularly associated with high strength aluminum alloys. This phenomenon occurs when the metal starts to corrode in layers, promoting separation in the material and creating blisters or scales. In high strength aluminum alloys, the microstructure is more susceptible to this type of corrosion due to the presence of different phases within the alloy that can lead to uneven corrosion rates.

High strength aluminum alloys often possess a fine microstructure, which, when exposed to corrosive environments, can result in exfoliation corrosion, especially if the alloys have been subjected to heat treatment and exhibit residual stresses. This type of corrosion typically occurs along the grain boundaries, causing the material to weaken significantly while maintaining an outer layer that appears intact.

In contrast, pitting corrosion is more localized and manifests as small pits on the surface, cavity corrosion involves the formation of cavities or pores in the metal, and galvanic corrosion occurs when two dissimilar metals are in contact in an electrolyte, leading to accelerated corrosion of the more anodic metal. While these other types of corrosion can affect aluminum alloys as well, exfoliation corrosion is particularly characteristic of high strength aluminum due to the reasons mentioned.