A comparative study of GMAW- and DE-GMAW-based additive manufacturing techniques: thermal behavior of the deposition process for thin-walled parts

The surface temperature of the thin-walled parts deposited by gas metal arc welding (GMAW)- and double-electrode gas meal arc welding (DE-GMAW)-based additive manufacturing (AM) techniques was captured through the infrared thermography technique. The dimensions of the molten pool in the deposition process including length, depth, and width were reduced in different degrees by the bypass arc during the DE-GMAW-based AM. The volume of the molten pool can decrease by about 30% in DE-GMAW under the same deposition rate. The volume of the high-temperature metal for the deposited parts during DE-GMAW-based AM was smaller than that during GMAW-based AM when depositing the high layer. The mean temperature of the deposited parts after the cooling process in DE-GMAW-based AM was lower under the same condition. The bypass arc in DE-GMAW-based AM is conducive to the reduction of the heat accumulation in the deposited thin-walled parts without a corresponding decrease in the deposition rate.