Mechanical, micro-, and macrostructural analysis of AA7075-T6 fabricated by friction stir butt welding with different rotational speeds and tool pin profiles

Friction stir welding (FSW) is a solid state welding process for joining aluminium alloys, has been employed in different industries, and is a new and promising welding process that can produce low-cost and high-quality joints of heat-treatable aluminium alloys because this process uses a non-consumable tool to generate frictional heat in the abutting surfaces and can eliminate some welding defects such as crack and porosity. The various parameters such as rotational speed, welding speed, axial force, and attack angle play vital roles in the FSW process in order to analyse the weld quality. In this research, the impact of processing parameters such as different rotational speed and tool pin profiles on the mechanical, micro-, and macrostructural properties during the FSW process involving the butt jointing of AA7075 T6 is investigated. It is important to note that four-flute and taper threaded pin profiles are utilized and the mechanical characteristics are determined by comparing the ultimate strength, percentage of elongation, and microhardness profiles for different rotational speeds and tool pin profiles.