Effect of ultrasound on the characteristics of superplastic deformation

The deformation of aluminum–lithium alloy 1420 is investigated in the region of temperatures of its superplasticity T = 320–395°C under the simultaneous action of stretching load and axial ultrasonic vibrations. The estimates of the activation parameters of deformation show that the activation energy of deformation during stretching with ultrasonic vibrations and without them are close both at the stage of hardening and at the stage of softening. It is concluded that the ultrasonic vibrations facilitate intragranular deformation at the hardening stage and promote an increase in its contribution to the total deformation without changing the deformation mechanisms.