GMAW-based additive manufacturing of inclined multi-layer multi-bead parts with flat-position deposition

Mathematical modelling of the shape-forming process of multi-layer multi-bead parts dealing with (i) a single layer, (ii) inclination angles and (iii) various slopes, is carried out. In the layers-overlapping model, material shortage areas are generated at the edges of layers. To solve the problem, the deposition amount of beads at the edges of the second and above layers should be modified, in association with the parameters applied to fabricate the slope. Various basic inclined components were deposited to validate the proposed mathematical formulation. Findings from the basic experiments were: (i) depositing additional material to compensate for the material shortage areas is necessary for realizing the designed geometries of the layers, (ii) depositing the bead at the layer edges alongside an already-deposited neighboring bead enables a better shape-forming in the case of negative slopes and (iii) the deposition order of beads in a layer has little influence on the shape formation of positive slopes. A complex part was also fabricated as a case study to validate the model and findings in the real-life context. Practical issues with regard to using the model and the solutions to the issues were discussed.