The superplastic property of the as-extruded Mg–8Li alloy

Tensile tests were conducted at the temperature of 423–563 K on a two-phase as-extruded Mg–8Li alloy with the initial strain rate of 5 × 10−5 to 1 × 10−3 s−1. The grain size of the as-extruded Mg–8Li alloy is less than 10 μm. Tensile testing data show that the superplastic property of the alloy behaves at the temperature of larger than 523 K, and the initial strain rate should be less than 2 × 10−4 s−1. The alloy exhibits a superplastic behavior with a maximum elongation of 164.5% at 563 K with an initial strain rate of 5 × 10−5 s−1. The processes of formation and merging of cavitations are favorable for the superplastic behavior of the alloy. When the size of cavitation is large enough, the tensile failure will happen.