Experimental Analysis and Weld Joint Characteristics Study on Friction Stir Welded Dissimilar Joints Fabricated by Novel Hybrid Pin Profiles

Lightweight materials that offer a good strength-to-weight ratio have a significant demand in automotive, transportation, marine, defence, rail, and other industrial applications. In this work, friction stir welding (FSW) an eco-friendly process was used to make solid state joints with newly developed hybrid pin profiles. Weld trails were designed considering an orthogonal array of L27 runs with 5 parameters and 3 levels. FSW was carried out on a 10-mm-thick AA6061/AA7075 Al-alloys dissimilar combination. The present work mainly focused on finding the optimum weld parameters with good joint strength of FSW welded samples processed by using different hybrid pin profiles. Zener–Hollomon parameter studied the material flow pattern at the stir zone. XRD patterns revealed the presence of Al as a major phase and the presence of precipitation compounds as minor phase. Microstructural analysis revealed the formation of onion ring structured fine-grains at stir zone with well-mixed two different base materials. The joint efficiency factor achieved was 97%, which confirmed the AWS standards for aerospace applications.