Optimizing robot weaving width improves the microstructure and mechanical performance of 4043 aluminum alloy in CMT-WAAM

This study explores the influence of robot weaving width on the microstructure and mechanical properties of 4043 aluminum alloy thin-walled components fabricated using cold metal transfer (CMT)-based wire arc additive manufacturing (WAAM). Thin-wall structures composed of 20 layers were deposited using weaving widths of 4 mm, 6 mm, and 8 mm. As the weaving width increased, the microstructure evolved from coarse lath-like dendrites to finer dendrites. The phase composition remained consistent across all samples, consisting of Al and Si. Mechanical testing in both the travel (X) and building (Z) directions, along with hardness profiling through the wall height, revealed that a 6 mm weaving width achieved an optimal balance between structural refinement and mechanical performance. This condition also minimized anisotropy in mechanical performance. In contrast, at 8 mm, ductility decreased, and fracture surface at building (Z) direction exhibited mixed ductile-brittle fracture mode. These findings demonstrate that robot weaving width is a useful parameter in optimizing the WAAM-CMT process. A properly selected weaving width can enhance deposition efficiency without compromising material integrity, offering a practical approach for the rapid and reliable fabrication of large-scale aluminum alloy components.