Droplet transfer in pulsed gas metal arc welding of aluminum

The droplet transfer mode is a critical element in the arc welding process. Multiple transfer modes have been identified, and the conditions under which they occur have been characterized. In the pulsed gas metal arc welding (GMAW-P) process, droplet transfer mode is affected not only by welding voltage and current, but also by the pulsing parameters. In this work, experimental techniques were used to investigate the transitions from pulsed globular to pulsed spray to pulsed streaming transfer in GMAW-P of 1.2-mm 4047 aluminum welding wire. A new method for characterizing one-droplet-per-pulse (ODPP) operating conditions is described and the transition from pulsed globular to pulsed spray transfer is characterized. The roles of pulse frequency and duty cycle on droplet transfer are explained.