Laser Powder Bed Fusion (PBF-LB/M) is a popular additive manufacturing (AM) technology for producing complex metal components. This layer-by-layer manufacturing process enables the production of intricate internal structures that conventional manufacturing processes cannot manufacture. Heat exchangers and heat sinks represent an area of application that can benefit significantly from novel internal structures. Due to the geometric freedom offered by PBF-LB/M, new solutions are possible for designing heat sinks, such as complex flow paths or increased surface-to-volume ratio, which can be used to increase heat transfer efficiency. Despite the design freedom offered by PBF-LB/M, design restrictions also need to be considered. One example of these restrictions is the requirement for support structures while manufacturing overhang features. Internal structures are an example of such features. The support structures must be mechanically removed after the manufacturing process, which becomes complicated or sometimes impossible, particularly for internal structures.

To fully exploit the design freedom, this work focuses on a novel design method to enable support-free production of complex internal cooling structures via PBF-LB/M. The proposed solution in this work is to use the necessary support structures during manufacturing as the cooling structures, which can be adapted to the requirements of the heat sinks or heat exchangers to increase thermal efficiency. In this work, five cooling structures are investigated using conjugate heat transfer (CHT) simulation to maximize the ratio of heat transfer to pressure loss. Test samples are manufactured from AlSi10Mg via PBF-LB/M and examined using optical measurements to validate the manufacturability and dimensional accuracy. Finally, a cylinder head is used to demonstrate how a cooling structure suitable for a real-life application can be designed using the proposed design methodology in this work.

For additive manufacturing (AM) using Powder Bed Fusion of Metals using a Laser Beam (PBF-LB/M), digital preparation steps (part design, part orientation in the chamber, supporting, etc.) are required. In the current state of the art digital process chains, these steps are done manually by an engineer, utilizing specialized AM preparation software, e.g., Autodesk Netfabb or Materialise Magics. Especially the part orientation has a significant impact on part quality and costs. However, setting up a suitable orientation algorithm is a complex and multi-dimensional engineering problem, so computationally intensive evaluation procedures are necessary. The orientation selection is usually done by comparing the pre-evaluated part orientations relative to each other. The selection strategy thus significantly influences the quality of the orientation schemes and the computational effort. The selection strategy often follows brute force logic to investigate the entire orientation space. This approach divides the solution space into equidistant steps that limit the search resolution. Therefore, this paper conducts a comparative evaluation of different new strategies to replace the brute force algorithm with a suitable optimization algorithm that selects the calculated partial orientations based on a priori decision logic. Three optimization algorithms Covariance Matrix Adaption Evolution Strategy (stochastic method), Multilevel Coordinate Search (direct search method), and Efficient Global Optimization (surrogate model optimization) are evaluated regarding their orientation evaluation results. The number of objective function evaluations required is compared to brute force. Each orientation optimization algorithm is applied to 42 parts. All algorithms reduce the number of orientation evaluations compared to the discrete method of brute force, but differ in the evaluated orientation quality. The Covariance Matrix Adaption Evolution Strategy produced the best-evaluated orientation but also required the highest number of orientation evaluations. In the future, the work should help to find a suitable optimization algorithm for the automatic part orientation finding for PBF-LB/M.

Due to globalization and the resulting increase in competition on the market, products must be produced more and more cheaply, especially in series production, because buyers expect new variants or even completely new products in ever shorter cycles. Injection molding is the most important production process for manufacturing plastic components in large quantities. However, the conventional production of a mold is extremely time-consuming and costly, which creates a contradiction to the fast pace of the market. Additive tooling is an area of application of additive manufacturing, which in the field of injection molding is preferably used for the prototype production of mold inserts. This allows injection molding tools to be produced faster and more cheaply than through the subtractive manufacturing of metal tools. Material Jetting processes using polymers (MJT-UV/P), also called Polyjet Modeling (PJM), have a great potential for use in additive tooling. Due to the poorer mechanical and thermal properties compared to conventional mold insert materials, e.g. steel or aluminum, the previously used design principles cannot be applied. Accordingly, new design guidelines are necessary, which are developed in this paper. The necessary information is obtained with the help of a systematic literature research. The design guidelines are mapped in a uniform design guide, which is structured according to the design process of injection molds. The guidelines do not only refer to the constructive design of the injection mold or the polymer mold insert, but to the entire design process and describe the four phases of planning, conception, development and realization. Particular attention is paid to the special geometric designs of a polymer mold insert and the thermomechanical properties of the mold insert materials. As a result, design guidelines are available that are adapted to the special requirements of additive tooling of molds inserts made of plastics for injection molding.