Formation of weld defects in cold metal transfer arc welded 7075-T6 plates and its effect on joint performance

Abstract

This study aims at investigating the formation of weld defects (i.e., pores) and determining the effect of pores on mechanical performance of the AA7075-T6 plate joints produced using cold metal transfer (CMT) gas metal arc welding (GMAW) technique. For this purpose, AA7075-T6 Al-alloy plates with a thickness of 2 mm were joined using CMT welding technique. The microstructural and mechanical properties of the welded plates were investigated by detailed optical microscopy investigations, micro-hardness measurements and tensile tests. A correlation between the joint performance and the formation of porosity in the fusion zone (FZ) was also attempted to show the effect of the presence of large pores on the mechanical behavior of the joint.