Effect of Tool Tilt Angle on the Mechanical and Metallurgical Properties of Aluminium Alloy 6061-T6 Welded by Friction Stir Welding Process

Abstract

AbstractThe present study investigates the effect of tool tilt angle on the weldability, mechanical and metallurgical properties of aluminium alloy when welded by friction stir welding process. During this study, 6 mm thick plates of aluminium alloy of grade AA6061-T6 were friction stir welded using heat-treated high strength steel tool material. The scroll tool consists of spiral geometry on the shoulder of 18 mm diameter and threaded tapered pin of 5.8 mm length. The friction stir welded joints of 80 mm weld length were fabricated at 45 mm/min tool travel speed using tool rotational speed of 800 rpm with 0° and 2° tool tilt angle. The weldability of the joints was measured in terms of mechanical and microstructural properties. The experimental results obtained as mechanical properties in terms of tensile strength and micro-hardness revealed a significant improvement by tool tilt angle as compared to without tool tilt angle. Further, the microstructural observations obtained using optical microscopy clearly depict the grain size reduction in stir zone and thermo-mechanically affected zones of welded joints fabricated by tool tilt angle.KeywordsFriction stir weldingScroll toolTilt angleMechanical propertiesMetallurgical characterization