Metal transfer in the aluminum gas metal arc welding

Among the aluminum welding processes, the GMAW (Gas Metal Arc Welding) process can be easily made automatic, has high productivity and great versatility regarding the type and thickness of material used in welding. The possibility of changing the transfer mode to adapt to different thickness, joint types, among other aspects, is another important and attractive feature. However, little is known about the transfer modes in aluminum GMAW process. For this reason, in this study an analysis of the metal transfer modes in the aluminum welding was made, and the objective was to generate maps that could identify the metal transfer modes and their regions in relation to the shielding gas and the wire diameter. The experimental procedure was the execution of weld on aluminum plate in a flat position with a constant voltage power source. The methodology used was laser Shadowgraphy combined with a high-speed movie camera. Therefore, it was possible to design the maps in which four metal transfer modes and their respective transition zones were determined. The maps also permit determination of the transition current zone between the globular and the spray mode, and modeling of the melting rate.