Experimental Study on Mechanical Properties of Friction Stir Welded Dissimilar Joints of Aluminium Alloys AA8011-AA6082

Abstract

In this research article, the mechanical properties and microstructure analysis ofFriction Stir Welded (FSW) of dissimilar aluminium alloys AA8011-AA6082 were evaluated. The FSW tool with taper cylindrical shape of H13 steel was selected to fabricate the weld joints between the dissimilar alloys. In this regard, three different rotational speed tools, three welding speeds and an unvarying axial load of 7 kN are used in this investigation. The tool rotational speeds are 800 rpm, 1000 rpm and 1200 rpm. The tool travelling speeds are 25mm/min, 30 mm/min and 35 mm/min. These constraints are used to generate frictional heat and interface into the soft range where the joining process can take place between the two materials. The mechanical tests were carried out on the weld joints. Microstructure analysis, tensile and hardness tests were considered by changing the tool rotating speed, welding speed and maintaining a constant axial force during material joining process. The micro hardness of the FSW weld joints in the stir zone increased to increase the tool rotational speed as well as to maintain a low range of welding speed during material joining process. The micro hardness of the stir zone in the FSW weld joints is increased as to reduce the welding speed. It was found that the highest value of the tensile strength in the joints is made-up of using the taper-shaped tool at 800 rpm, welding speed of 35mm/min and unvarying downward force of 7kN. These identified parameters give sufficient mechanical properties and fewer defects in weld joints such as tensile strength of 68 N and micro hardness of 42 Hv. The tensile and hardness tests values are examined by the part of mechanical characterization and the values are correlated to recognize the superiority of the weld joint.