Comparison between gas flame welding and shielded gas welding in case of aluminium alloys

Abstract

Although the assembly by welding of aluminum alloys is a common assembly process, it is done in quite difficult conditions, being forced to take into account a number of shortcomings, such as: high thermal conductivity which translates into losses of high heat in the welding area; formation of aluminum oxide films that melt at high temperatures, well above the melting temperature of the alloy; large expansion coefficients that result in the appearance of large deformations, the appearance of cracks in the joint at high temperatures due to loss of mechanical strength of the alloy, but also the appearance of pores, inclusions of aluminum oxide and corrosion in various aggressive environments. Despite all these shortcomings that occur in welding, aluminum alloys can be joined indestructibly by welding. The present paper aims, is to make a comparative study, based on experimental data, of two welding assembly processes, one with gas flame and another with shielded inert gas environments-WIG, for aluminum alloys of group 6000. The base material will be presented, the preparation of the basic material for welding through the two mentioned welding procedures and the steps taken to make the welded joints. The comparative study will include the parameters of welding regimes, non-destructive defectoscopy methods with which certain discontinuities can be identified and the destructive mechanical tests. The experimental results will be able to lead to pertinent conclusions on the possibilities of aluminum alloys welding assembly, using those two welding processes mentioned above, the results being easily generalized in the industrial fields.