A layers-overlapping strategy for robotic wire and arc additive manufacturing of multi-layer multi-bead components with homogeneous layers

A layers-overlapping strategy for robotic wire and arc additive manufacturing of multi-layer multi-bead components with homogeneous layers

Li, Y. (TU Delft Cyber-Physical Systems; Harbin Institute of Technology)
Han, Qinglin (Harbin Institute of Technology)
Zhang, Guangjun (Harbin Institute of Technology)
Horvath, I. (TU Delft Cyber-Physical Systems)

2018

Robotic wire and arc additive manufacturing (WAAM) systems are required to provide predictable and efficient operations to fabricate solid metallic parts with high morphological fidelity and geometric accuracy. Since the metallic parts are fabricated based on a layer-by-layer principle, the interactions between the neighboring beads and layers strongly influence the geometric accuracy of the fabricated part. The layers-overlapping process has been studied and a traditional layers-overlapping model (T-LOM) has been published in the literature. This paper proposes a layers-overlapping strategy (LOS), based on which a revised layers-overlapping model (R-LOM) was proposed for the fabrication of multi-layer multi-bead (MLMB) components with homogeneous layers. A mathematical model for layers-overlapping is presented, which considers the material shortage areas at the edges of the layers. This is important since the material shortage areas result in a situation that the component width is smaller than the expected value. In addition, they will be accumulated when multiple layers are overlapped through normal unidirectional parallel (NUP) paths. The proposed LOS addresses two aspects: (i) the deposition amount of the first bead and the last bead in the lap layers should be increased and (ii) the deposition position of the first bead and the last bead in the lap layers should be moved towards the edges with a given offset distance. Validation experiments were designed and conducted to test the proposed concepts and models. The experimental results indicated that (i) the R-LOM enables the MLMB components to achieve the expected width and (ii) for components deposited with NUP paths, the R-LOM eliminates the effect of accumulation of material shortage areas on the first bead and increases the surface flatness.

Additive manufacturing
Gas metal arc welding
Layers-overlapping model
Multi-layer multi-bead components

http://resolver.tudelft.nl/uuid:80618caf-93e0-41eb-8dc0-8a2ae6e464f0

https://doi.org/10.1007/s00170-018-1786-3

2019-06-30

0268-3768

International Journal of Advanced Manufacturing Technology, 96, 3331-3344

Accepted author manuscript

Institutional Repository

journal article

© 2018 Y. Li, Qinglin Han, Guangjun Zhang, I. Horvath