Inhibition of abnormal grain growth during hot deformation behavior of friction stir processed 5083 Al alloys

Friction stir processing (FSP) has demonstrated to refine the microstructure of different alloys resulting in superior mechanical properties. Abnormal grain growth (AGG) has been recognized as a critical issue during hot deformation of FSPed Al alloys. 5083 Al alloys with different Mn content were subjected to heat treatments at 350 and 535 °C before FSP to avoid AGG during subsequent hot deformation. As a result, heat treatment of 350 °C was able to retard AGG significantly. Also, an improvement in the refinement of the microstructure was observed. Consequently, a better ductility of 861% at elevated temperature was reached in the alloy with lower Mn content comparing with the same alloy without heat treatment prior to FSP.