Experimental investigation on improving the deposition rate of gas metal arc-based additive manufacturing by auxiliary wire feeding method

Traditional gas metal arc-based additive manufacturing (GMA-AM), also referred to as wire arc additive manufacture (WAAM), improves deposition rate via increasing deposition current, but it is easy to affect the shape-forming and microstructure of the deposited part due to the increased heat input. To avoid such problems, a novel auxiliary wire feeding GMA-AM (A-GMA-AM) approach is proposed to achieve high deposition rate at low deposition current. This paper investigates the effects of A-GMA-AM when the deposition current ranges from 100 to 180 A. The process window was explored, and the influence of the feeding speed of auxiliary wire on the bead geometries and the heat-affected zone area was analyzed. It was observed that the increase in the feeding speed of the auxiliary wire can increase the bead height and remain the bead width unchanged. When the feeding speed of the auxiliary wire reaches the upper limit at the corresponding deposition current, the deposition rate of A-GMA-AM is at least 1.65 times than that of traditional GMA-AM at the same deposition current, and the heat-affected zone area is reduced by at least 28.6%. The results showed that the A-GMA-AM method is more efficient in increasing deposition rate and reducing the heat in AM components.