Strain-induced gradient nanostructure formation is an effective method for improving the strength of Mg-Li alloys. However, the microstructural and resulting mechanical stability of gradient-nanostructured Mg-Li alloys during thermal exposure have… Click to show full abstract
Strain-induced gradient nanostructure formation is an effective method for improving the strength of Mg-Li alloys. However, the microstructural and resulting mechanical stability of gradient-nanostructured Mg-Li alloys during thermal exposure have never been studied, thereby limiting their successful application. In this study, we fabricated a gradient-nanostructured Mg-Li alloy by sliding friction treatment and investigated its microstructural and mechanical stability by annealing at different temperatures up to 250°C. The results showed that (1) the lattice parameter c of the Mg phases gradually decreased with increasing temperature, (2) the Mg-Li nanograins exhibited a significantly lower grain growth activation energy (72 kJ/mol) compared with other Mg-based alloys, and (3) the yield strength of the annealed samples was higher than that of the matrix due to synergetic strengthening of the gradient microstructures at the micron scale.
               
Click one of the above tabs to view related content.