Analysis of wire arc additive manufacturing of ER70S-6 steel beads through experimental, statistical, and numerical analysis

This study investigates the Wire Arc Additive Manufacturing (WAAM) process for fabricating single beads from ER70S-6 steel under varying deposition speed and arc power. A combined experimental, statistical, and FEM approach is employed to evaluate the effects of arc power and deposition speed on bead geometry, specifically bead width, height, aspect ratio, and wetting angle. Using a Design of Experiments (DOE) methodology, nine single-layer beads were deposited at arc power levels of 1616, 2434, and 2839 W and deposition speeds of 5, 7, and 9 mm/s. The previously mentioned characteristics were analyzed using Analysis of Variance (ANOVA) and Response Surface Methodology (RSM). Furthermore, a FEM model based on Computational Fluid Dynamics (CFD) and a two-phase field approach provided insights into the molten metal flow behavior and thermal evolution during deposition. A statistical optimization identified process parameters (arc power of 2592 W and deposition speed of 5 mm/s) that yield an aspect ratio and wetting angle close to literature-reported optimal values (2.50 and 60°, respectively). Experimental validation demonstrated strong agreement between predicted and measured values (aspect ratio: 2.70 vs 2.50; wetting angle: 58.80° vs 60.79°), confirming the accuracy of the developed statistical model.