Stress Corrosion of AA2024 Aluminium Alloy: Effects of Shot Peening in Sodium Chloride Solution

Aluminum alloy 2024 is a high-strength aluminum alloy commonly used in aerospace applications. However, it is known to be susceptible to stress corrosion under certain conditions. Here, AA 2024 aluminum alloys underwent a shot peening process in a 3.5% sodium chloride solution at three different stresses: 0.35 Gpa, 0.32 Gpa and 0.29 Gpa. The microstructure of the alloy was characterized, as well as its effects on localized corrosion and stress crack propagation. Mass loss was also studied in a salt spray test according to ASTM B117 practice and standard (ISO 9227) for 103 h. Microscopic analysis showed us the particles that have a role in the susceptibility of the 2xxx series aluminum alloy to localized corrosion. Degradation of the alloy is due to solid-liquid interaction by the effect of hydroxyl salts producing salt spray and the depth of cracks increased with increasing stress.