Robot supported Wire Arc Additive Manufacturing - Parameter studies on dot-by-dot printed structures using carbon steel and different shielding gases

Wire Arc Additive Manufacturing (WAAM) is a robot-controlled welding process used to build up three-dimensional structures in steel. Like other Additive Manufacturing (AM) technologies, WAAM allows for geometrically complex structures to be manufactured which may be unfeasible to manufacture using conventional methods. Over recent years, WAAM has also gained prominence in the fields of architecture and civil engineering, with applications ranging from fully printed steel bridges to individualized steel components. This paper presents a workflow from design to manufacturing to destructive material testing of specimens for the use of WAAM with dot-by-dot printing. In a comprehensive parameter study, welding and process parameters for vertical structures are presented and investigated. The focus is on the influence of different shielding gases, the diameter of the wire electrode and the influence of the cooling of the structures during manufacturing. In a first step, the parameters are assessed and evaluated in regard to the geometric properties of the printed layers, as well as material and energy consumption. Finally, destructive tensile material tests of asbuilt test specimens provide a statement on the material characteristics and thus the suitability for future use in the additive manufacturing of complex lattice column structures.