Forming characteristic analysis in twin tungsten electrode – Wire electrode indirect arc based additive manufacturing

Abstract

In this study, the forming characteristics of twin tungsten electrode – wire electrode indirect arc (TTWIA) based additive manufacturing were preliminarily investigated. Arc shape, droplet transfer behavior, molten pool temperature field, and molten pool flow state were obtained respectively. Results showed that the increase of arc current enhanced the coupling degree of TTWIA arc, and promoted the detachment of the droplet from the wire, which contributed to streaming spray transfer of the droplet. Besides, the temperature and fluidity of the molten pool both increased with the increase of the arc current due to the increasing temperature of the arc, enthalpy carried by the droplets, and driving forces acting on the molten pool. Moreover, the driving forces acting on the liquid metal in the deposited layer achieved equilibrium and a stable molten pool was acquired only when the arc current was selected appropriately, which resulted in a well forming quality of the deposited part with a lower surface roughness and a higher material utilization rate.