Analysis of arc voltage, current, and light signals in pulsed gas metal arc welding of aluminium

Abstract

The use of readily acquired weld arc data such as voltage, current, or light emissions to identify droplet transfer events or transfer mode, or for quality purposes such as seam tracking is of interest for thin section applications in arc welding of aluminium. In the present study, voltage, current, and light emission signals are acquired at high rates, and synchronised with high speed shadowgraphing. The usefulness of the various signals for identifying droplet detachment events and transfer modes during pulsed gas metal arc welding of aluminium is compared. It is found that individual droplet detachments are consistently identifiable during globular, spray, and streaming transfer, and during peak and background current detachment, using the voltage signal. Although the arc light signal also contains droplet detachment data, it is difficult to identify droplet detachments occurring during the background phase at low background current levels. Preliminary measurements show that these signals can also be used for seam location in thin section lap fillet welding.