Fatigue crack growth testing and evaluation for aluminum alloys at temperatures of 25°C and −70°C

This paper seeks to measure and evaluate crack growth behaviors and residual lives of aluminum alloys (AAs) 2524-T3 and 7050-T7452 subjected to fatigue loading at temperatures of 25°C and −70°C. Fatigue crack growth tests were performed on AAs 2524-T3 and 7050-T7452 subjected to constant-amplitude and actual random-spectra loading histories at temperatures of about 25°C and −70°C, respectively, to determine the crack growth behaviors and residual lives. The interaction mechanisms between cryogenic temperature and the fatigue load were deduced on the basis of the results of fractographic analysis. The crack growth behaviors and residual lives were evaluated and compared at both temperatures of 25°C and −70°C. Good correlation was achieved between the predictions and actual experiments.