Fabrication strategy and macroscopic defect control of large-size component based on double-wire arc additive manufacturing

Double-wire arc additive manufacturing (DWAAM) has a broad application prospect in the fabrication of component because of its higher deposition efficiency than WAAM. However, in the fabrication process of large-size component, due to the large weld bead size, the complexity of structure, and serious heat accumulation, the overall deposition quality will be affected and macro defects will appear. In this paper, DWAAM deposition path strategy is studied in detail by finite element method and experiment. Compared with the change of temperature field and deformation, the heat accumulation of folding path is serious, but the deformation is small (< 3 mm). The folding path is selected as the final path based on the mechanical properties of the samples of 3 paths. The macroscopic defects (unmelted wire, droplet splashing, uneven weld bead, and melt pool collapse) of the deposited sample are analyzed, and the formation mechanism is studied. In addition, by reducing the arc length, improving the arc magnetic blow, and reducing the heat input, large-size special-shaped structural components are successfully manufactured. The defects in the macro morphology are improved. Graphical Abstract: [Figure not available: see fulltext.]