2.2.1 Nano-indentation
Nano-indentation was applied to characterize the hardness values of the α-Mg phase and β-Li phase. The nano-indentation test sample was cut by a precision cutting machine, then it was mechanically ground. After that, the electrolytic etching was employed to present the microstructure and distinguish the α-Mg phase and β-Li phase of the material, and eliminate the residual stress as well. The nano-indentation tests were performed in KLA iNano, the maximum load and target depth were set as 20000 μN and 1000 nm to make indentations inner α-Mg phase and β-Li phase.