Caracterização e análise da soldagem plasma com alimentação dinâmica de arame

PAW (Plasma Arc Welding) is a versatile welding process using a non-consumable tungsten electrode that can be applied at different energy levels, and also with or without filler material. It is also common in arc welding processes for the filler material to be fed continuously into the weld pool. However, an innovative technique of wire feeding, which promotes a forward and backward movement of the filler material into the weld pool, named dynamic feeding, is not widely spread in the technical literature but may offer some advantage to welding procedures. In this context, the present work has as main objective, to study and to characterize the dynamic wire feeding technique applied in the PAW process with the intention to verify, mainly, the characteristics of the metal transfer in comparison with the continuous wire feeding. Thus, the two wire feeding techniques (continuous and dynamic) were applied in the PAW process. Monitoring equipment of the welding electrical signals synchronized with advanced high speed videography techniques were used to highlight the effects referring to metal transfer, dynamics of the welding wire in the weld pool and general interactions related to the arc/wire/weld pool assembly. The experiments highlighted the main limitations and advantages of the PAW process with dynamic feeding and showed that this technique has advantages over continuous feeding, especially related to metal transfer at low levels of wire speed, i.e., below 1 m.min-1.