The transition of corrosion pitting to surface fatigue cracks in 2024-T3 aluminum alloy

Pitting corrosion experiments were executed to characterize the dynamics. of accelerated corrosion for the combination of 2024-T3 aluminum and a 3.5% NaCl solution at room temperature. Platinum was used as a counter electrode and a silver-silver chloride electrode was used as a reference.; A corrosion protocol was developed to accelerate pitting corrosion on 2024-T3 aluminum. The developed protocol allowed for the relative control of pitting depth on fatigue dog-bone specimens. A pitting damage threshold was encountered for depths beyond an average value of approximately 135μm.; Corrosion fatigue experiments were performed on specimens that had been prior corroded using the developed corrosion protocol. Pitting depths from approximately 40μm-200μm were examined for fatigue characterization. Corrosion pitting to surface fatigue crack transition was captured and fatigue crack growth behavior was documented. As well as the pit to crack transition, the short crack behavior to long crack behavior transition was captured and analyzed.; Fractographic analysis of corrosion fatigue specimens revealed cracks nucleating, propagating and causing subsequent failure from accelerated prior pitting corrosion damage.