SUPERPLASTICITY OF A RAPIDLY SOLIDIFIED AI-Li ALLOY

A rapidly solidified microcrystalline Al-Li-Cu-Mg-Zr alloy and its superplasicity have beeninvestigated.An optimum tensile elongation of 585% was obtained at 540℃ and strain rate1.67×10~(-2)s~(-1).The superplastic Al-Li alloy is manufaetured using thermomechanical pro-cessing:solution,overaging,warm rolling and recrystallization.Microstructural changes inthermomechanical processing and cavitation occurred during superplastic deformation havebeen observed.The superplastic failure of alloy may be caused mainly by nucleation andgrowth of cavities as well as the linkage around grains.