The behaviour to welding of the aluminum alloys is determined by their work out and the casting technology. Also, there are very important the design, the processing by plastic deformation and the heat treatment applied to the welded pieces (welded structures) made from these alloys.
The elaboration of the welding procedures specifications and of the welding procedures qualification must be done by the welding engineer, knowing the „metallurgical history”
of the piece, also the physical and mechanical characteristics, and the chemical composition of the analyzed alloy.
In this paper, it was made a study about the recommendations concerning the welding procedures qualification for the aluminum alloys. It can draw the conclusion that the welded joints made on the thin walled cast pieces cast pieces from Al-Si alloys have a different behaviour in comparison with the pieces made from rolled aluminum alloys. For example,
in the tensile test, the fracture occurs always in the heat affected zone, but the elongation is not influenced by the fact that the deposited metal by welding has an elongation few times more than the base metal.
In the paper, a standard for the welding procedures qualification for the aluminum alloys used to make the thin-walled cast pieces, it is proposed.