Jean-Marie Fortain

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

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.

Recent developments in arc welding with shielding gas of aluminium and its alloys

Summary Aluminium and its alloys are frequently used in many sectors of industry. Arc welding should adapt to these metals, particularly with regard to productivity and quality. Optimisation of recent innovations are presented here. In order to adapt to the technological developments of the various sectors of the transport industry (automotive, rail, shipbuilding, aircraft and aerospace), the electricity industry, and the chemical and food‐processing industries, welding processes must also adapt to light metals (aluminium and its alloys) in terms of the productivity and quality required by these industrial sectors. Recent developments (refinements and innovations) in welding processes, notably MIG welding (dual‐wire welding, modulated spray MIG welding) due to a global approach (procedure, consumables, gas) enable useful alternative solutions to be found for the usual applications of the process.