Characterization of superplastic material SPF8090 Al-Li with variation of the strain rate and the temperature

Abstract

A superplastic material, aluminum-lithium alloy 8090, was examined with uniaxial tensile tests to investigate its thermomechanical behavior. The tests were carried out at the strain rate ranging from 2 x 10^-4 to 1 x 10^-2 and at the temperature from 480℃ to 540℃. The experiments produced force-displacement curves which were converted to stress-strain curves. From the curves, the optimum conditions of superplastic forming were obtained by determining the strain rate sensitivity, the optimum strain rate, and the strength coefficient for various forming temperatures.