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.

这项研究提出了一种新的线材和电弧增材制造变种，称为超冷线材和电弧增材制造（UC-WAAM），其中在线材原料和非消耗性钨电极之间建立了电弧。在HSLA钢上进行了可行性研究。与传统的基于气体金属电弧焊的WAAM进行了比较。通过去除流经基板的电流并从熔池中消除电弧，这种新的WAAM变型可以降低工艺温度并提高冷却速度，而不会影响成品零件的完整性或沉积速度。机械测试表明，使用UC-WAAM制成的HSLA钢制零件具有很高的机械强度和延展性。最后，还介绍了此新变体的独特功能之一：