Effect of Neutron Irradiation on the Stress Corrosion Properties of 7075 Aluminum

An investigation was conducted to determine the effect of irradiation on the stress corrosion susceptibility of 7075 aluminum. Specimens of 7075 in three heat treated conditions (-T6, -T73, and a condition intermediate to these) were irradiated with fast neutrons. The -T6 alone of the three tempers underwent a significant loss in stress corrosion resistance at fluences ⩾ 1018 nvt. The only corresponding change in mechanical properties was a decrease in reduction of area. Continuous ultrasonic monitoring of unirradiated and irradiated stress corrosion specimens indicated that crack initiation consumes ~90% of the total time to failure.