Effect of strain rate on compressive mechanical properties of extruded Mg–8Li–1Al–1Ce alloy

The compressive mechanical properties of Mg–8Li–1Al–1Ce alloy were investigated under quasi-static strain rates (0.0001/s, 0.001/s, 0.01/s, and 0.1/s) and high strain rates up to ∼2700/s at room temperature. The experimental results indicate that the flow stress and strain rate sensitivity increase with increasing strain rate. Microstructure observation by optical microscopy reveals that the distribution of compound Al2Ce is influenced by the strain rate: when strain rate is higher, the compounds Al2Ce distribute in both α and β phases; when strain rate is lower, most of the compounds Al2Ce distribute in β phase and in the boundaries between α and β phases. Furthermore, it is found that the twinning forms in extruded Mg–8Li–1Al-1Ce alloys when deformed at high strain rates, and the amount of twinning increases with increasing strain rate, the deformation mechanism of Mg–8Li–1Al–1Ce alloy at high strain rates is a combination of dislocation motion and twinning.