Sinter-based process routes have economic and ecological potential, especially compared to popular metallic AM-processes such as Laser Powder Bed Fusion (L-PBF). However, the steps of debinding and sintering create additional requirements for the design of components. Components consistently experience shrinkage, and their design can lead to warpage or collapse. The studies described subsequently are part of the SIGNAL project, which is funded by the TTP LB. One aim within the project is to establish a design methodology that optimizes components for sintering and additive manufacturing.

As a necessary condition, the collapse of titanium components during debinding and sintering is investigated. The focus here is on the Cold Metal Fusion (CMF) process, one of six different sinter based AM process routes investigated in the SIGNAL project. Test specimens experiencing different stresses due to their dead load are investigated. Occurring stresses are determined using commercial FEM software. In contrast to simulation approaches that describe the debinding process in order to predict collapse, a purely static-mechanical simulation is used. The next step involves comparing the gravity-induced warping behavior of solid cross-section structures with that of lightweight structures. A following case study shows a structural bracket receiving a topology-optimized redesign based on the insights gained.

The results show that there is a critical stress range and indicate the applicable failure hypothesis. The results also show that lightweight structures can increase material efficiency compared to reference geometries and thereby reduce existing stresses and warpage. The case study carried out demonstrates the usability of the results. Two optimized component versions were designed and manufactured, with only one version incorporating the determined stress limit as a target function for optimization. This version is reproducibly manufacturable, the other version collapses during debinding and sintering.