Parametric Analysis of Wire Arc Additively Manufactured Low-Carbon Steel using Response Surface Methodology

As the manufacturing sector continues on its path towards sustainability, additive manufacturing (AM) remains as one of its most promising streams, aiming to reduce material waste while also allowing for increased design complexity. In the extensive area of metal 3D printing, one method that is steadily gaining traction is wire-arc additive manufacturing (WAAM). This method of AM utilizes the energy created by an electric arc formed between a continuous consumable metal wire and a metal base, fusing the two together and ultimately creating a 3D component layer by layer. WAAM has several notable advantages over other metal 3D printing methods such as its high deposition rate, low start-up cost and wide range of available materials. For the purposes of this research, the selected wire material (low-carbon steel) is one that is often considered for its tensile strength characteristics, high weldability and wide availability. The aim of this research is to outline the steps needed to create a WAAM setup using a CNC and welding machine and subsequently perform a multi-objective parameter analysis using Response Surface Methodology (RSM) to study the impact of printing parameters (Wire Feed Speed (WFS), Travel Speed (TS) and Voltage (V)) on the mechanical properties of the final print (Ultimate Tensile Strength (UTS), Yield Strength (YS) and Young’s Modulus (YM)). The resulting 3D printed steel test samples were shown to maintain up to 90% of the UTS and 80% of the YS compared to the metal in bulk form. The analysis also showed that prints with the highest TS and lowest WFS tended to fare better than those with low TS and high WFS, mainly due to lower heat generation which in turn led to lower porosity formation in the samples. Analysis also showed that UTS and YS responses were closely related, with WFS and TS having the biggest impact on both results. The multi-objective analysis used to maximize UTS, YS and YM led to the optimal values of 5.32 m/min for WFS, 768.18 mm/min for TS and 21.2 V for Voltage.