Effect of Ultrasonic Vibrations on the Structure and Mechanical Behavior of an Aluminum–Lithium Alloy during Superplastic Deformation

The deformation and structure of aluminum–lithium grade 1420 alloy are studied during uniaxial tension in the superplasticity temperature range, and the influence of ultrasonic vibrations on the deformation characteristics is investigated. The action of ultrasound is shown to manifest itself in a decrease in the strain resistance and an increase in the total strain. In contrast to standard stress–strain curves, true stress–true strain curves have an extended strain hardening section, which is larger for specimens deformed with ultrasound. The deformation activation energies are estimated, and ultrasound is shown to facilitate dislocation motion during intragranular deformation, which is characteristic of the stage of hardening. The application of ultrasonic vibrations is found not to influence the structure of the deformed alloy and its properties.