Multi-bead Overlapping Models for Tool Path Generation in Wire-Arc Additive Manufacturing Processes
Lam M. Nguyen, Johannes Buhl, Markus Bambach�
Abstract
Wire-arc additive manufacturing (WAAM) has received substantial attention in recent years due to the very high build rates. When bulky structures are generated using standard layer-by-layer tool paths, the build rate in the outer contour of the part may lag behind the build rate in the interior. In WAAM, the profile of a single weld bead resembles a parabola. In order to keep the build rate constant at each point of the layer, optimal overlapping distances can be determined. This paper presents novel multi-bead overlapping models for tool path generation. Mathematical models are established to minimize valleys between adjacent weld beads by accounting for the overlapping volume. The proposed models are validated by manufacturing solid blocks from mild steel with the recommended overlapping distances. The approach is compared to standard tool path strategies. Macrographs are recorded to analyze the boundary profiles. The specimens with the proposed overlapping distances show an even profile in contrast to specimens made using the standard strategy.