Rapidly solidified microcrystalline Al-Li alloys are prepared. Full study on superplasticity of the alloys is made. Microstructure of powders produced by ultrasonic Argon atomization and effects of impurity elements and different thermomechanical processes on superplasticity are analysed. A solution heat treated, overaged and rolled Al-Li alloy exhibites a maximum tensile elongation of 585% at 540 ℃ for an initial strain rate of 1.67 * 10~(-2) s~(-1). Microstructural changes in thermomechanical processing and cavities produced during superplastic deforming are observed. Cavity formation, growth and linkage around grains are the main cause of superplastic failure.
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