A novel approach to path planning related to the intersections of aluminum WAAM

摘要

Abstract Wire-arc additive manufacturing (WAAM) has become the most cost-effective and time-efficient metal AM process in its field. However, while the creation of infill path plans has been already developed for plastic filament-based AM processes, it has been underexplored in wire-based metal AM processes. A key barrier to achieving this capability for WAAM is the metal material’s heat sensitivity. WAAM processes using lower heat sensitivity metals (like mild steel) are better able to create the intersecting path plan segments that are critical for infill toolpaths, whereas the process is more difficult for lower heat sensitivity metals such as aluminum. This study aims to answer the question of how to create these intersecting path plan segments with minimal overbuild defects and reduced lack of fusion areas utilizing the cold-metal transfer (CMT) WAAM process for aluminum. A robotic WAAM system is used to fabricate sample intersection geometries using multiple path plan strategies. The part topography is then 3D scanned to quantify the intersection geometry, after which each intersection’s porosity and lack of fusion is characterized utilizing computer tomography. An optimal path plan of a rotating deposition pattern of intersecting single-bead walls with a distance between beads of 45% of the bead’s width is proposed, which maximizes an intersection’s fusion (84% in lower layers) while minimizing its porosity (below 7% of the build area).