Proceedings of the
9th International Conference of Asian Society for Precision Engineering and Nanotechnology (ASPEN2022)
15 – 18 November 2022, Singapore

Wire Arc Additive Manufacturing Stepover Optimization based on Varying-Ratio Flat-Top Overlapping Model

Gim Song Soh1,a and Xi Yu Oh2

1Singapore University of Technology and Design, 8 Somapah Road Singapore 487372

2Open Robotics, 3 Fusionopolis Way Singapore 138633


Wire Arc Additive Manufacturing (WAAM) is a manufacturing process that deposits weld beads layer-by-layer in a planar fashion, leading to a final part. Due to the layer-by-layer nature of weld bead deposition in WAAM, the accuracy of the printed geometry is largely dependent on the knowledge of the bead profile employed, which by itself is dependent on a variety of process parameters, such as wire feed rate, torch speed, and stepover ratio. Existing models for modeling bead profiles are based on their width and height, which do not necessarily capture the geometry of the weld bead accurately. This could affect the stepover increment strategy, which dictates the geometry of the resulting overlapping multi-bead valley. In this paper, a Varying-Ratio Flat-Top Overlapping Model (VFOM), for the derivation of an optimal multi-bead stepover ratio based on a particular bead geometry is proposed. In this approach, the stepover ratios of each bead are calculated based on their input process parameters to achieve a flat-top multi-bead surface. Experiments are conducted with bronze material using our proposed model and evaluated against a variety of overlapping models found in literature based on the resulting print ‘bumpiness’ and height consistency. Results show that the proposed VFOM approach is better in producing a smooth surface but does not perform as well in maintaining the multi-bead height thickness for the bronze material.

Keywords: Wire Arc Additive Manufacturing, Stepover Ratio, Optimization.

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