The effect of friction stir vibration processing on microstructure and mechanical properties of Al5052/SiC surface nano composite

Friction stir processing (FSP) is a surface processing method to modify the microstructure and enhance the mechanical properties of metal surface. In the current research, the work specimen is vibrated normal to processing line during FSP. Transverse and rotation movements of shoulder are accompanied with vibration motion of specimen. This new process is entitled FSVP (friction stir vibration processing). The effects of FSP and FSVP processes on microstructure and mechanical properties of Al5052 alloy matrix composite incorporated SiC nanoparticles are analyzed. The results show that the presence of vibration during FSP leads to the grain size decrease in the stir zone and it enhances the homogeneity of particles distribution. The results indicate that strength and ductility of FS processed specimens are lower than those processed by FSVP. These are related to increased deformation and strain of soft material in the stir zone as vibration is applied which promotes the dynamic recrystallization during FSP. The results also imply that the characteristics of FSV processed specimens improve as vibration frequency enhances.