Effect of pin profile and rotational speed on microstructure and tensile strength of dissimilar AA8011, AA01 T6 friction stir welded aluminum alloys
Abstract Aluminum alloys are mainly focused on shipbuilding and aerospace industries due to its unique characteristics and it has low cost, high reliability and severe service conditions. The tool geometry and parameters play a vital in the performance of the similar and dissimilar friction stir welding process to improve the microstructure and mechanical properties of the joints. Due to the complex behavior of material flow on dissimilar different grades of aluminium alloys welding, the study is desired to examine the material flow behaviour and the mechanical properties. The aim of this research work is to investigate the influence of the pin profiles and rotational speed on microstructure and tensile strength of dissimilar friction stir welding of AA8011 and AA6061 T6 aluminum alloys. The FSW process parameters such as rotational speed, Plunge depth, welding speed and three different pin profiles (square, pentagon and hexagon) are selected for this investigation. The microstructural analysis is applied on the dissimilar FS welded joints using scanning electron microscope and optical microscope. The defect free welds are found for the optimum settings of rotational speed 1500 rpm, plunge depth of 2.5 mm with a welding speed 40 mm/min for hexagonal tool pin profile and also the hexagon pin profile gives the superior properties of the welded joints related to other pin profiles.