Simultaneously improving mechanical properties and damping capacity of Al-Mg-Si alloy through friction stir processing

In this study, friction stir processing (FSP) was performed on an Al-Mg-Si alloy (AA 6082-T4) at a low tool rotation rate of 200 rpm, and good mechanical and damping properties were simultaneously obtained after FSP. The combination of excellent ductility, moderate strength and excellent room/high temperature damping capability at FSP sample was attributed to the ultrafine recrystallized grains with predominant high-angle grain boundaries and moderate dissolution of metastable phases, and the fragmentation of micron-sized second phase during FSP. This work provided an effective strategy to improve the damping capacity of commercial Al alloys without sacrificing their mechanical properties.