Welding of the 6061 Aluminum Alloy Using Innovative Arc Welding Process

Recent developments of arc welding techniques have extended and opened new fields of applications. At the same time, the development of the aluminum alloys in the industry has induced specific demands of joining, especially, in the transportation domain. To meet the industrial exigencies new arc welding processes were improved. So, the last generation of arc processes integrate optimization due to different electronic controls. These features induce a gain of productivity and of quality of aluminum welds. Moreover it allows a better control of the electric parameters and make easier the process monitoring. In this study, an arc welding process of new generation was used to join plates in 6061 aluminum alloy.

The 6061 aluminum alloy belongs to Al-Si-Mg alloys. It is strengthened by the Mg₅Si₆ precipitation which appears during natural or artificial ageing. This alloy is widely used in industry in particular for structural applications because of its good ratio weight/strength, its corrosion resistance and its ease manufacturing (extruding, welding).

Different heat treatments were realized on welded samples. Weld zone and heat affected zone were characterized by macrographies, microhardness measurements and by EBSD analysis. Additionally, tensile tests were done to evaluate the influence of post weld heat treatment on the mechanical properties of the welds.

First results show a decrease of the heat affected zone size and a lower damaging of the parent metal. Moreover it was demonstrated that heat treatment improve the mechanical strength of the welds.