Demonstration of the Fabrication of a Large-Scale Aluminum Structure by Wire-Arc Directed Energy Deposition Using a Novel Aluminum Alloy

The manufacturing of parts with medium complexity using wire-arc directed energy deposition (waDED) gets constantly improved by the development of tailored alloys and improvements in the generation of welding paths. In this study, both aspects are considered by proposing a novel aluminum alloy based on Al-Mg-Zn, which is then used for the waDED manufacturing of a car rim. The alloy was characterized in small-scale samples, in which no hot cracks and only a few gas porosities were found. In addition, the high quality of the alloy was verified by tensile tests of the heat-treated samples. The determined yield strength was >365 MPa, the ultimate tensile strength was >450 MPa, and the fracture strain was at least 3.9%. To put the new alloy to use, a standard aluminum car rim model was modified for the needs of waDED. Difficulties due to the steep overhang of the outer ring in the intersecting area with the spokes could be resolved by utilizing and adapting the collision avoidance of the path generation tool in the critical area. The optimization of the welding paths was simplified by first planning the paths using a section of the rim model. The rim geometry was manufactured successfully, and valuable findings regarding the waDED process of parts with medium complexity could be derived.