Consequences of the rotational speed and profile of tool pin in microstructure and mechanical properties of AA8011/ZrO2 composite produced by FSW

Producing defect-free and high-quality welds are still challenging by the friction stir welding process. In this paper, ZrO2 nanoparticles of 20 nm average size were used in the weld area of Aluminium 8011 alloy. Three different types of tool profiles semi-circular, plus tool and trapezium profiles were used for better material mixing and improved joint strength. All of the experiments were performed with rotational speeds of 1800, 1120, and 560 RPM, and a constant welding speed of 25 mm/min. It was observed that there is no significant effect of the ZrO2 addition in the weld area. On the other hand, tool profile plays a great role in increasing tensile strength. The maximum tensile strength of 116.70 MPa was obtained with the semi-circular tool at 1800 RPM and 25 mm/min welding speed because of the improved material mixing and defect-free joint.