Experimental investigation of tensile properties and microstructure of TIG welded dissimilar joints of Al6061/Al5083 Aluminium alloy

Abstract

The welding of aluminium alloys especially in dissimilar combination is challenging owing to numerous problems. The present study focuses to optimize processes parameters for dissimilar welding of 6 mm thick dissimilar Al-6061 and Al-5083, using Tungsten Inert Gas welding as well as to investigate the influence of the process parameters on tensile properties and microstructure of developed welds. A single V-butt joint configuration (bevel angle 60 ̊ and root gap 2 mm) of plates was used for welding. Three levels of input parameters viz. voltage, current and welding speed were selected for performing experiments as per L9 orthogonal array. The hardness and tensile strength were taken as output parameters or performance characteristic in the study. The optimum parameter settings for highest heat affected zone hardness and ultimate tensile strength of dissimilar welds have been suggested by using S/N ratio. The result predicted by optimization has an error of 2-3%. Finally, the effects of voltage, current and welding speed on m icro structure, hardness and tensile strength of welds have been investigated. Welding speed and current were the most influencing process parameter for controlling the hardness of HAZ and tensile strength of the welds.