Exfoliation Corrosion Impact on Microstructure, Mechanical Properties, and Fatigue Crack Growth of Aeronautical Aluminum Alloy

In this paper, quantitative investigation of localized corrosion, in particular, exfoliating corrosion (EXCO) of aluminum alloys 2024 T3 and 7075 T6, is carried out. The mechanism of EXCO focusing on the effects of the combination of materials/environment/mechanical stress was also considered. An optical microscope (MO) and a scanning electron microscope coupled with a energy-dispersive spectroscope (EDX) were used to examine the microstructural stat. Tensile tests were conducted on plate specimens to discern the degradation of mechanical properties after the corrosion attack. Fatigue tests were conducted on compact tension specimens to correlate the influence of corrosion/microstructure coupling on the fatigue behavior of different aluminum alloys. The crack growth rate of the different materials for pre-corroded specimens was affected according to the microstructure of these two alloys.