Effect of workpiece vibration frequency on heat distribution and material flow in the molten pool in tandem-pulsed gas metal arc welding

Versatility, high deposition rate, fine quality, and low equipment cost are known features of the tandem-pulsed gas metal arc welding (TP-GMAW) process. Concurrently, vibration-assisted welding has been considered one of the trends in developing advanced industrial concepts. This study presents a three-dimensional model of the TP-GMAW process to investigate heat transfer and material flow. The competition between the heat distribution beneath the surface and the physical movement caused by the workpiece sine-mode vibration are traced and discussed to understand how the penetration shape change was determined. It is found that applying the vibration extends the heat distribution along the welding direction beneath the molten pool surface, and this trend increases with increasing vibration frequency and effective heat input.In contrast, the heat extending is minimal in the sample without vibration having the highest heat input. This inconsistency can be explained by the physical movement of material in a molten pool due to the workpiece vibration. The vibration also changes the material flow from the surface to the depth in the central rear areas, although it follows an opposite direction in the sample without vibration. Thus, the material flow is vital in improving the penetration shape.