Influence of Tack Weld on Physical and Mechanical Properties of MIG Welding of AA5083H116

Abstract

The research objective is to determine the effect of tack weld on physical and mechanical properties of tandem-MIG (T-MIG) welding of AA5083H116 materials. A Tenjima 200S MIG machine, sample dimension of 300mm × 75mm × 3mm, and 0.8mm diameter ER5356 electrode were used. The distance between electrodes of T-MIG was varied of 18, 27, 36mm. Welding speed of 12.5mm/s, and welding process was shield using argon gas. First, T-MIG welding were employed for untacked and tacked welding. The leading current was 125A and trailing current was 120A, but current wave of each T-MIG welding machine was not taken into account. The welding voltage was set the same. Second, parameters resulting in better physical and mechanical properties were then employed for single-MIG (S-MIG) tack weld using 8, 10, 12mm/s welding speeds. The result shows that T-MIG tacked weld produced in bowing distortion and T-MIG untack weld in downward bending distortion. Higher peak temperature resulted in larger distortion. T-MIG tacked weld results in welding efficiency 76% being similar with that of bending strength (75%) in comparison with that of as received material. T-MIG tack weld results in better penetration and 37% shorter welding time in comparison with S-MIG tack weld.