**4. Conclusion**

In this study, the microstructure and mechanical properties of the Al5083 joint fabricated by FSSW and FSSVW methods were compared. The results showed that the presence of vibration affected the microstructure and led to more grain refinement. The results also indicated that:

The grain size of the stir zone and thermo-mechanically affected zone decreased as the vibration was applied during FSSW.

The shear strength and ductility of FSSV welded specimens were higher than those relating to FSS welded specimens.

Fracture surfaces of all specimens showed that dimples for FSSV welded specimens with high plunge depth are smaller than those observed in FSS welded specimens with low plunge depth.

Shear strength and hardness values of the FSSV welded specimen increased as vibration frequency increased.
