Moeen Enami - School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran.
Mohammadreza Farahani - School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran.
Majid Sohrabian - Department of Aerospace Engineering, Iran University of Science and Technology, Tehran, Iran.

Resistance Spot Welding and Friction Stir Spot Welding are two important and useful methods in automobile manufacturing industry and aerospace. In this study the effects of important parameters of both processes on joining strength of heat treatable and non-heat treatable aluminium alloys was investigated. In resistance spot welding method, the effects of welding current, welding time and electrode force on size of nugget and failure load and also, In friction stir spot welding method, the effects of parameters such as tool rotational speed and dwelling time on size of stir zone and failure load on aluminium alloys were investigated. In this study through the respective investigations it was proved that to obtain appropriate strength of spot welding, welding current in resistance spot welding method had similar behavior with tool rotational speed in friction stir spot welding.

Resistance Spot Welding, Friction Stir Spot Welding, aluminium alloys, joining strength