Theoretical and experimental investigation into friction stir welding of AA 5086

This research investigates the relationship between the microstructures of thermomechanically affected zone (TMAZ) and heat input in friction stir welding (FSW) of 5086 aluminum alloy. First, welding heat input has been predicted using a three-dimensional finite element analysis; then, welding experiments have been carried out on annealed and work-hardened conditions to study the developed microstructures and the mechanical properties of the welded metal. The results show that the temperature field in the FSW process is asymmetrically distributed with respect to the welding line. Also, both experimental and predicted data illustrates that peak temperatures are higher on the advancing side than the retreating side. In addition, the microstructures are strongly affected by the heat input, while the grain size within the TMAZ decreases with decreasing heat input per unit length during FSW.