As the metal transfer in the GMAW process has been of great interest because it affects the weld quality and productivity, it has been investigated to figure out the mechanism of molten drop formation and detachment at various welding conditions. The metal transfer mode is classified into the globular and spray modes. The force balance and pinch instability models have been most widely used to analyze the metal transfer in the globular and spray modes, respectively. Recently, an attempt was made to calculate the molten drop geometry using energy minimization method. The model proposed in this work overcomes the shortcomings of the previous energy model. It includes the effects of the surface tension, gravity, electromagnetic and drag forces with no presumed geometry. The system energy is minimized to obtain the molten drop geometry and its detaching conditions. Effect of various welding conditions on the metal transfer can be explained. The results show that the proposed model can be applied to the globular and projected transfer modes. When compared with other models, results of the model show better agreements the available experimental data, which demonstrates the validity of the present model.
