Forming appearance control of arc striking and extinguishing area in multi-layer single-pass GMAW-based additive manufacturing

Control strategies of arc striking and extinguishing area in multi-layer single-pass gas metal arc welding (GMAW)-based additive manufacturing are proposed to improve the forming appearance of fabricated parts. Appearance characteristics of arc striking as well as extinguishing area were analyzed. The effects of process parameters on inclined-plane length in the arc extinguishing area were researched. Corresponding control methods for forming appearance were also presented. For depositing closed-path parts, arc striking and extinguishing area in the same layer were superposed to make up for height difference. For open-path parts, a control strategy of alternating deposition direction in adjacent layers was used. As employing the same deposition direction, adjusting process parameters in the arc striking and extinguishing area were performed. It is demonstrated that the forming appearance of deposited parts can be improved efficiently by means of the control strategies.