PLASMA WELDING OF ALUMINUM ALLOYS USED IN TRANSPORT INDUSTRIES
Jukka K.Martikainen★
The possibility and potential of applying VPPA (Variable Polarity Plasma Arc) welding to aluminum, especially to the alloys AA 5083 (AlMg4.5Mn) used in LNG carries and AA 7020 (AlZn4.5Mg1) used in railway carriages, has been examined. It is shown that it is possible to achieve high quality welds free of defects, but the tolerances for variations in welding parameters, especially for the highest weld quality, is narrow. Variable polarity plasma arc welding offers the facility of an arc cleaning action, the possibility of replacing multiple passes with a single pass and welds free from porosity, inclusions and other defects.
Table 2. Welding parameters used in AA 5083 and AA 7020 welding tests
