Ultracold-Wire and Arc Additive Manufacturing (UC-WAAM)

Abstract This study presents a new variant of Wire and Arc Additive Manufacturing named Ultracold-Wire and Arc Additive Manufacturing (UC-WAAM), in which the electric arc is established between the wire feedstock material and a non-consumable tungsten electrode. A feasibility study was performed on HSLA steel. A comparison with conventional Gas Metal Arc Welding-based WAAM was performed. By removing the electric current through the substrate and distancing the electric arc from the molten pool, this new WAAM variant can reduce the process temperatures and increase cooling rates, without compromising the integrity or deposition rate of the as-built parts. Mechanical testing showed the preservation of the high mechanical strength and ductility of the HSLA steel parts built with UC-WAAM. Lastly, one of the unique features of this new variant is also presented: the use of a non-conductive/non-metallic block to produce overhang structures, highlighting the potential for UC-WAAM to be used to fabricate supportless complex-shaped 3D structures.