The laser sintering process has been a well-established AM process for many years. Disadvantages of LS are the low material variety and the thermal damage of the unprocessed material. The low temperature laser sintering attacks at this point and processes powder material at a build chamber temperature lower than the recrystallization temperature. This drastic reduction in temperature results in significantly less thermal damage to the material. This work deals with the low temperature laser sintering of Polyamide 12 (PA12) on a commercial, unmodified laser sintering system to compare it to standard laser sintered PA12 and to create the basis for low temperature laser sintering of high temperature materials on such a system. First results by changing the exposure parameters and by fixing parts on a building platform show a processing of PA12 on an EOS P396 at a build chamber temperature less than 100 °C instead of standard approx. 175 °C.

Structural parts for aviation have very high demands on the development and production process. Therefore, the entire process must be considered in order to produce high-quality AM metal parts. In this case study, a conventional part was selected to be optimized for AM. The process presented includes component selection, design improvement with a novel approach for topology optimization based on the AMendate algorithm as basis of MSC Apex Generative Design,component production on a SLM 250 HL and post-processing including heat treatment and surface smoothing. With the topology optimization a weight reduction of ~60 % could be realized, whereby the stress distribution is more homogeneous. Furthermore, the challenges of support optimization and post-processing have to be addressed, in order to produce competitive parts.

Function integration is a key issue for an efficient and economic usage of Additive Manufacturing. An efficient heat transfer by topology optimized structures is a rarely considered approach which will be outlined with an exemplary electronic housing which has been newly designed. A commercial projector unit, whose electrical components in total produce 38 W, shall be integrated in the closed housing and passively cooled by natural convection. Topology optimized structures shall be generated in the inner part of the housing to transfer the heat homogenously from the projector components to the housing wall while simultaneously minimizing the mass. At the outside of the housing walls, lattice and rib structures are applied to increase the effective surface for heat transfer by natural convection and radiation. Furthermore, the housing geometry is optimized regarding a minimization of support structures to reduce the post-processing effort. Finally, the housing shall be built of AlSi10Mg by SLM.

The implementation of lattice structures into additive manufactured parts is an important method to decrease part weight maintaining a high specific payload. However, the manufacturability of lattice structures and mechanical properties for polymer laser sintering are quite unknown yet. To examine the manufacturability, sandwich structures with different cell types, cell sizes and lattice bar widths were designed, manufactured and evaluated. A decisive criterion is for example a sufficient powder removal. In a second step, manufacturable structures were analyzed using four-point-bending tests. Experimental data is compared to the density of the lattice structures and allows for a direct comparison of different cell types with varied geometrical attributes. The results of this work are guidelines for the design and dimensioning of laser sintered lattice structures.