Effect of prior corrosion on short crack behavior in 2024-T3 aluminum alloy

Two thicknesses of dogbone shaped 2024-T3 aluminum alloy specimens were notched and corroded prior to constant amplitude fatigue loading. The purpose of the subject research was to examine and characterize the effects of various levels of prior corrosion on the growth rate of short fatigue cracks. The specimens were notched and exposed to a corrosive environment per one of three defined protocols prior to experimentation. The notch was manually introduced at one edge of the test section of the specimen, which was later corroded to create a more natural site for crack origination. Fatigue crack nucleation was monitored and subsequent crack growth recorded, with results presented in the form of da/dN vs. ΔK curves.