Investigation on joint properties of AA5754 and AA6013 dissimilar aluminum alloys welded using automatic GMAW

Abstract

Aluminum alloys AA5754 and AA6013 were joined using gas metal arc welding (GMAW) and the mechanical, microstructure and corrosion properties of the joints were investigated. The welding process was performed using argon as shielding gas with three different wire feed speeds and welding speeds. Metal wire (ER5356 filler) with a diameter of 1.2 mm was used in the welding process. In order to determine the mechanical properties of the joints, the welded specimens were subjected to tensile and hardness tests. In addition, an electrochemical corrosion test was conducted to determine the corrosion resistance of the specimens. The welding zone of the specimens was characterized via microstructure examination. In the tensile tests, fractures occurred in the weld metal and the heat affected zone (HAZ). However, tensile strength performance of the joints exceeded 90% under the appropriate welding parameters. The corrosion test results showed that the samples with joint defects (insufficient melting) were exposed to corrosion more rapidly than the others. Hardness test results revealed that maximum hardness values were measured at the HAZ of the AA6013 specimen, followed by the weld metal and HAZ of the AA5754 specimen, respectively. Microstructure inspections showed the structures of all the weld metals to be dendritic. © 2019 Karabuk University