3D weaving path optimization for enhanced surface quality in wire arc-based directed energy deposition

Wire arc-based directed energy deposition (DED) is a highly productive additive manufacturing (AM) technique; however, excessive heat input often results in distortion and irregular bead geometry, leading to increased surface waviness and necessitating extensive post-processing. To address these challenges, this study introduces a novel 3D weaving path aimed at enhancing wetting behavior and minimizing micro-scale waviness in wire arc-based DED. The weaving motion promotes metal spreading by adjusting the wetting area, thereby reducing the contact angle and improving surface smoothness. High-speed imaging and computational fluid dynamics (CFD) simulations were utilized to investigate molten metal behavior during deposition. Experimental results revealed that the 3D weaving path reduces surface waviness by more than 70 % compared to conventional stringer paths, significantly lowering the required machining depth. Additionally, mechanical property evaluations confirmed that the proposed approach maintains consistent hardness and tensile strength, ensuring structural integrity. These findings demonstrate the potential of 3D weaving path technology to enhance the efficiency and precision of large-scale metal AM, reducing post-processing demands and improving manufacturability. • Innovative 3D weaving reduces the side surface waviness of metal structures. • The tilting effect of metal wires controls the contact angle of molten metal. • Reduction of waviness in metal structures and post-processing significantly minimized. • CFD simulations confirmed enhanced wetting and a more uniform metal bead geometry.