Sacrificial supports are necessary for additive manufacturing (AM) technologies such as laser-based powder bed fusion with metals (PBF-LB/M) to produce defect-free parts. The production of supports increases production time and cost, and their removal during post-processing is tedious and expensive. Therefore, reducing sacrificial supports is economically advantageous. The purpose of this paper is the reduction of sacrificial supports through the automated generation of integrated support structures.
Sacrificial supports are reduced by designing integrated supports, which remain in the final part. Integrated supports are added to the functional geometry, which meets the functional requirements, resulting in a self-supporting part. However, the design of integrated support structures is challenging and increases engineering efforts. Therefore, this paper presents design automation algorithms, capable of automatically generating three types of integrated support (bulk, lattice and tree) for any functional geometry. Specific design parameters (e.g. minimum build angle) allow tailoring of the output to specific AM processes and materials.
The algorithms are applied to three parts in a case study: a hybrid hydraulic manifold, an AM hydraulic manifold and an AM brake caliper. Three design variants are generated per case and the design parameters are specified for each part and support type. The two most material-efficient variants of the hybrid hydraulic manifold add only 3.15% and 0.58% to the volume of the functional geometry. The fabrication of these two variants is validated using PBF-LB/M. One limitation of the approach is that not all overhang regions can be supported with integrated supports, depending on the design of the functional geometry and the use of a hybrid manufacturing strategy.
The presented algorithms enable the automated generation of three types of integrated supports that adapt to the functional geometry. Users can create design variants by modifying the design parameters to reduce AM production and post-processing costs.
