Influence of gas shielding atmosphere on weldability of AIMg4.5Mn alloy

Abstract

In this paper is shown the influence of gas shielding atmosphere on the weldability of AlMg4.5Mn alloy. Prepared plates were welded using tungsten inert gas (TIG) with four different shielding atmospheres. Metallographic testing, tensile testing, and hardness testing of welded joints were carried out. It has been shown that the composition of the shielding atmosphere has an effect on the weld appearance, depth of penetration, overflowing of filler material, and porosity in the weld metal, as well as on values of tensile strength and hardness. Weldments obtained by welding in a shielding atmosphere of Ar + 50% He + 0.015% N₂ have the best appearance of the weld metal, good overflowing of filler material, and a satisfactory width-to-height ratio. It was also established that these welds have the lowest weld metal porosity.