High Strain Rate Superplastic Behavior of Al-Li-Mg-Cu-Sc Alloy Subjected to Severe Plastic Deformation

Superplastic properties of an advanced Al-Li-Mg-Cu-Se alloy with fine-grained microstructure produced by two different processing ways (equal-channel angular extrusion and hot rolling) were studied in the temperature range of 350-525degreesC and at strain rates of 1.4x10(-3)-1.4x10(-1) s(-1). In both conditions the total elongations of about 400% were obtained at 450degreesC and a strain rate of 1.4x10(-2) s(-1) indicating a high strain rate superplasticity. The higher homogeneity of microstructure in the condition after equal-channel angular extrusion resulted in higher elongations and lower cavitation during superplastic deformation as compared to the hot rolled condition.