How to select a suitable shielding gas to improve the performance of MIG and TIG welding of aluminium alloys*

摘要

Welded aluminium alloy products are widely used in the construction and packaging sectors: in this context, in order to be competitive, the welding processes must offer valid solutions from both the productivity and quality viewpoints in addition to health-related aspects with regard to welders and operators. In this context, the technological goals of Air Liquide have been focused on improving the quality of welded joints made using the MIG and TIG processes. The approach adopted here is to examine the various gas mixtures from the viewpoint of influence on electrical parameters (voltage), regularity of filler metal transfer, the surface tension of the melt bath and the convection patterns present in the latter.