Influence of gas mixtures Ar-He and Ar-He-O2 on weldability of aluminum alloy AA5083-O using automated GMAW-P

Problems of industries and manufacturers of welded structures in aluminium alloys are centred on reduction of mechanical properties in welded joints due to heat input effects on the heat affected zone; as well as effects of discontinuities and metallurgical defects, high cost repairs, and low productivity. The aim of this paper is to evaluate the influence of gas mixtures 80Ar20He (MG1), 60Ar40He (MG2), 80Ar19He1O2 (MG3), and 60Ar39He1O2 (MG4), on aluminium alloy AA5083-O weldability using filler metal ER5183 using the automated GMAW-P process. Methodology has included a factorial experiment design, customisation of welding parameters, and characterisation of base metal and welding regions. Analysis of results were carried out based on microstructure evaluation of welding regions, measurements of hardness and tensile properties, observations of discontinuities and defects, costs evaluation, and welding speed. Results show that gas mixtures with O2 are highly beneficial to obtain good weldability of the studied alloy. © 2016 Taylor & Francis.