Weldability Evaluation of GMAW and GTAW for Al-6.7 wt.% Mg Alloy

In this study, the arc weldability of an aluminum alloy was investigated based on its Mg content. The base materials used in the experiments were aluminum with a Mg content of 6.7 wt.% (referred as Al-6Mg) and commercial Al5083-O. The weldability of two types of fusion welding methods was evaluated: gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW). The tensile strength, hardness, alloy composition, and microstructure properties of the welds of two types of the aluminum alloys were compared. The tensile strength values of the GMAW and GTAW welds of Al-6Mg were 20% and 10% higher than those of Al5083-O, respectively. The weld hardness of the GMAW and GTAW welds of both aluminum alloys were similar. Al-6Mg by GMAW and GTAW were smaller than those of Al5083-O. Based on the results of analysis of the welds, the residual magnesium content was as high as 37% by GMAW and 30% by GTAW.