Effect of Tool Rotation Direction on Mechanical Strength of Single Lap Friction Stir Welded Joints between AA5083 Aluminum Alloy and S355J0 Steel for Maritime Applications

This study aims to investigate a friction stir welded joint between steel and aluminum alloy that is employed in maritime applications (i.e., connection between the ship over-structures and the hull or deck). By changing the tool rotational direction, or the advancing or retreating side, a single lap configuration was studied. Tensile tests were conducted to evaluate the mechanical resistance and the surface fracture after a preliminary investigation consisting of morphological and microstructural analyses and microhardness measurements, with the goal of considering the possibility of replacing the typical joining processes, such as traditional welding or explosion welding, with friction stir welding. The testing showed that the joint produced on the advancing side performed better (+23.5% of the maximum load) than the joint made on the retreating side.