STUDY AND ANALYSES OF ARC LENGTH CORRECTION AND MECHANICAL PROPERTIES ON WELD BEAD GEOMETRY FOR AA6061T6 BY COLD METAL TRANSFORMATION PROCESS

Abstract

Welded aluminium AA6061T6 joints have a wide range of industrial applications due to their low cost, lightweight, and excellent efficiency. In the automation industry, thin aluminium AA6061T6 of various thicknesses is widely utilized. Traditional welding procedures have always had issues with burn-through and distortion when welding these light aluminium AA 6061T6 joints due to their high heat input and large spatters. Because of its low distortion rate and low heat input, the CMT welding technique is an excellent choice for attaching thin sheets. In this study, Aluminium AA 6061T6 joints of grade 6000 series welded using the CMT welding process, and the mechanical properties of the joints investigated. The Taguchi L9 optimization technique was utilised to determine the best process factors for achieving the highest tensile strength. The maximum tensile strength of Aluminium 6061T6 joints welded at 100 A current, 6 mm/s welding speed, and a -10 percent Arc length correction factor was determined to be 206 MPa. The weld zone obtained its maximum micro-hardness value of 81.05 HB, but the heat-affected zone had a lower value (HAZ). The residual stresses of the welded junction detected using the X-ray diffraction (XRD) technique. In the weld zone and base plate, residual stress was compressive, while in the heat-affected zone, it was tensile (HAZ). The CMT welding procedure may use to create high-strength aluminium 6061T6 joints of various thicknesses.