Especially in the Laser Powder Bed Fusion (L-PBF) technology for metals, current manufacturing systems require the use of support structure to withstand recoater forces and lower thermal induced stresses. These support structures set limitations on the design freedom and affect the surface quality, part cost and lead-time in an undesirable manner. Complex parts, which were not possible with conventional manufacturing methods, can be produced without these limitations. While some companies claim to print parts with horizontal overhangs without the use of support structure, academic research seems to deal with these limitations by defining design guidelines rather than eliminating them. In order to highlight the discrepancies between academia and industry, a structured review is presented. As result, severe differences in knowledge were discovered, which might emerge from the use of unconstrained cutting-edge systems in industry. Eventually support-free L-PBF is not yet fully developed, but the use of support structure can be drastically reduced by optimizing the build process.

The production of spare parts using Additive Manufacturing (AM) is an emerging area that impacts the supply chain management. To give designers a way to proceed at the moment of redesign and produce a spare part using AM, this contribution presents a methodology for the design and manufacturing of digital spare parts using AM in decentralized facilities. The re-design of the spare parts is tackled by giving design considerations based on agile hardware development practices to improve the quality of the spare parts and reduce the lead time. Since this methodology is derived from different case studies of the military over two years, the approach is suited for the defence industry but can be adapted to other industries that operate reduced facilities abroad. Additionally, three different use cases following the methodology are presented. The weaknesses of the processes are highlighted and some recommendations for production engineers and designers are given.

In the laser powder bed fusion processes for metal additive manufacturing, a support structure is needed to fix the part to the base plate and to support overhanging regions. Currently the importance of support structure for a successful build process is often underestimated and some effects are not yet well understood. Therefore, this study investigates the fracture behavior and mechanical properties of thin additive manufactured struts using the titanium alloy Ti-6Al-4V and specific machine parameters for support structures. Tensile tests were performed for different strut diameters and the fracture surfaces were analyzed using a laser microscope and a scanning electron microscope. Additionally, the porosity was examined with micro-CT scans. The results were compared with a different set of parameters used for solid parts. The experiments revealed that struts produced with support parameters had no significantly lower tensile strength than the comparative parts. Despite that, some porosity and around two percent of defects on the fracture surface for parts using the solid parameter set have been found. Parts with support parameters show no porosity, even though the energy density is around 30% lower compared to the solid parameter set.