What types of corrosion are aluminum alloys particularly susceptible to?

Aluminum alloys are particularly susceptible to pitting, intergranular corrosion, and stress corrosion cracking due to their electrochemical properties and microstructural characteristics.

Pitting corrosion occurs when localized breakdown of the protective oxide layer on aluminum happens, leading to small pits forming on the surface. This type of corrosion is especially problematic in environments containing chlorides, which can penetrate the oxide layer and initiate the pitting process.

Intergranular corrosion affects the grain boundaries in aluminum alloys, where the microstructure is compromised. This occurs because the alloying elements may segregate at the grain boundaries during processing, making those areas more vulnerable to attack from corrosive elements.

Stress corrosion cracking is a type of corrosion that occurs in the presence of tensile stress and a corrosive environment, often found in aluminum alloys used in aerospace applications. The combination of stress and a corrosive agent can lead to sudden and unexpected failures.

Understanding these types of corrosion is essential for proper maintenance and preventive measures in environments where aluminum alloys are used, ensuring the longevity and integrity of structures built from these materials.