Results on Optimizing the Parameters for Friction Stir Welding of Dissimilar Aluminium Alloys AA 5383/AA 7075

An aluminium alloy which exhibits very attractive mechanical, physical and chemical properties have
intensive demand in various areas especially marine structure. In order to join aluminium alloys
various welding methods are employed but the recent innovative and environmental friendly
techniques is friction stir welding. In this study dissimilar aluminium alloys AA 5383 and AA7075 have
been joined using friction stir welding. The factors which influencing the welding parameter are tool
rotation speed, transverse feed which are varied to 700, 800, 900 rpm and 40, 60, 80 mm/min. The
6mm plates are joined by keeping the axial force constant at 10 kN. The weldment is achieved using a
square tool of pin diameter 8 mm. The effect of welding parameters chosen are evaluated using
hardness testing to know the resistance to wear of the weld metal and tensile testing to know the
properties and ductility of a weldment. The maximum tensile strength obtained is for the parameter of
700 rpm and 40 mm/min transverse feed produced a high tensile strength of 211 MPa. The Weld
quality for various tool rotational speed and transverse feed has been studied. When the transverse
feed increases lack of heat input affects the joints and its tensile properties gets affected. From the
experiment conducted the tool rotational speed of 700 rpm with 40 mm/min transverse feed gives
excellent mechanical property both tensile as well as hardness.