Enhanced Active Control of Metal Transfer in GMAW

Abstract

An optimized current waveform is proposed in this study to first excite enhanced droplet oscillation and then utilize it to enhance the droplet detachment. The excitation is intentionally generated by reducing the current from a peak level, referred to as the exciting peak, to the base level. Another peak level, referred to as the detaching peak, is then applied after a time interval called the detaching phase delay to synchronize the detaching action with the beneficial droplet momentum as a phase match such that the droplet detachment is enhanced by the beneficial momentum. The active metal transfer control utilizing the enhanced droplet oscillation, referred to as the enhanced active metal transfer control, is further systematically studied in this paper. Experimental research shows that the minimum detaching peak current in the enhanced active metal transfer control is not only remarkably lower than the spray transition current, but also significantly lower than that of the original active control process.