Influence of Tool Traverse Speed on Structure, Mechanical Properties, Fracture Behavior, and Weld Corrosion of Friction Stir Welded Joints of Aluminum and Stainless Steel

Abstract

Herein, the effect of traverse speed on friction stir welding (FSW) of aluminum (Al) and stainless steel (SS 304) plates is studied. The microstructure of the joint sample is examined using optical microscope and scanning electron microscope equipped with energy dispersive spectroscopy. The intermetallic compound detected at the interface of friction stir welded (FSWed) joint is Al3Fe. X‐ray diffraction results reveal the formation of intermetallic compound like Al3Fe, Al5Fe2, AlFe, and Al13Fe4. Tensile results show that with the increase in tool traverse speed, the tensile strength increases to reach a maximum value and then decreases. The maximum tensile strength achieved is ≈75% of Al base metal at tool traverse speed of 75 mm min−1. Maximum hardness is observed at the Al|SS‐304 interfaces due to the presence of intermetallics. Interfacial hardness for slower tool traverse speed is higher when compared to higher traverse speed. The electrochemical behavior of the FSWed joint is measured using potentiodynamic polarization test so as to understand the corrosion failures of the FSWed joints. FSWed samples at higher traverse speed shows inferior corrosion resistance when compared to the slower traverse speed.