Microstructural and mechanical evolution of ZnAlAg superplastic alloy under large deformation conditions

The Zn22Al4Ag alloy was studied to analyze the evolution through plastic deformation and static compression test. First, the master alloy comes from pure Zn, Al, and Ag elements; later, it rolled down to twelve passes. The microstructural characteristics were analyzed by scanning electron microscopy (SEM), Scilab algorithm image processing. Finally, static compression is carried out, including the as-cast, homogenized, and tempered conditions at different loads to measure microhardness. The SEM and XRD image analysis output a 97% plasticity increase in the Zn22Al4Ag alloy due to the rearrangement of the Al, ZnAl, and ZnAg3 phases, observing a phases homogenization from the sixth to the twelfth deformation pass. This deformation allowed the softening of the material as indicated by the microhardness results, relating this behavior to the inverse of the \(Hall-Petch\) relationship with hardness.