The mechanisms of the high-strain-rate superplastic deformation of Al-Mg-based alloy

High-performance aluminum-based alloys exhibiting a high-strain-rate superplasticity improve the formability of lightweight constructions with complex shapes. The microstructural evolution and contributions of the defor-mation mechanisms to the total strain during high-strain-rate superplastic deformation of Al-Mg-based alloy with minor Sc and Zr additions were analyzed. Strain-induced changes in the grain/subgrain structure confirmed the dynamic recrystallization even at large strains. The evolution of the surface structure with focus ion beam milled grids confirmed that grain boundary sliding provided up to 40% of the total strain. The role of dislocation slip/ creep increased and diffusional creep decreased with an increase in the strain rate.

Automated summary

High-performance aluminum-based alloys with high-strain-rate superplasticity improve the formability of lightweight constructions with complex shapes. The microstructural evolution and the contributions of deformation mechanisms were analyzed in an Al-Mg-based alloy with minor Sc and Zr additions. The results showed dynamic recrystallization and the importance of grain boundary sliding and dislocation slip/creep in the superplastic deformation process.