Behrouz Bagheri - MSc graduated, Department of Mining and Metallurgy, Amirkabir University of Technology, Tehran, Iran.
Amin Abdollahzadeh - PhD graduated, Institute of Materials Engineering and Advanced Processes, Department of Mining and Metallurgy,Amirkabir University of Technology, Tehran, Iran / Department of Materials Science and Engineering, Sharif University ofTechnology, Tehran, Iran.
Mahmoud Abbasi - Associated Professor, Faculty of Engineering, University of Kashan, Kashan, Iran.
Javad Hamidi - MSc student, Department of Mining and Metallurgy, Amirkabir University of Technology, Tehran, Iran.
Seyyed Ehsan Mirsalehi - Associated Professor, Department of Mining and Metallurgy, Amirkabir University of Technology, Tehran, Iran.

In the era of technological and industrial changes such as aerospace, automotive, defense and electronics industry, joining multi-functional materials and hybrid structures of dissimilar materials play an essential role. Friction stir spot welding (FSSW) is one of the most distinguished of the metals welding processes concerning the application for various purposes. In this work, a novel method was introduced to improve the conventional friction stir spot welding (FSSW) method. The vibration of work-pieces was followed by the rotating movement of the tool. This novel way can explain as friction stir spot vibration welding (FSSVW). Al 5083 alloy samples joined by two welding technologies, FSSW and FSSVW. Analyzing the substructure and mechanical characteristics of welded models in both methods had been showed that grain size reduces and hardness raise as vibration applies. Moreover, mechanical characteristics namely strength and ductility for friction stir spot vibration-welded samples are higher than those produced by friction stir spot-welding.

Friction stir spot vibration welding-Mechanical properties-Microstructure-Grain size.