Delamination of a sensitized commercial Al–Mg alloy during fatigue crack growth

Fatigue crack growth experiments at 22 and −100 °C were conducted on 6.35 mm thick plate samples of a commercial Al–Mg alloy machined from the L–T orientation. Thermal exposures for times of up to 10,000 h at 80, 100 and 175 °C produced sensitization and delamination in the S–T direction during fatigue, dependent on the thermal exposure and level of ΔK (and Kmax) employed. Reduced S–T fracture properties were directly measured on sensitized samples.