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This article discusses the use of Material Extrusion of Metals (MEX/M - defined in ISO/ASTM 52900) technology for producing multi-material components, which offers a cost-effective and efficient method without requiring major adaptations to existing equipment. The article presents the successful manufacture of 316L/17–4PH multi-alloy steel cubes for four different sintering temperatures using commercially available equipment and feedstock. The feasibility study of the multi-material samples was supported by analyzing the shrinkage, optical density, and microstructure as output parameters. Unlike other works, the multi-material produced parts showed regular shrinkage behaviour and no major deformation, indicating the possibility of creating functional parts without the need for post-processing. Interestingly, relevant findings were made on the different shrinkage values obtained for the constellations considered. Further in-depth investigation of each parameter involved in all the stages of the chain value (extrusion, debinding, and sintering) will be key to support the present results. Additional research into the mechanical and magnetic properties of the samples produced could lead this combination of materials to applications in various industries including automotive and aerospace.

Metal binder jetting shows great potential for medical technology. This potential can be exploited by integrating binder jetting into existing process routes known from metal injection molding. The biggest challenge here is the flowability and packing behavior of the powders used, due to their low size distributions. This paper investigates different powder-drying strategies to improve flowability using a statistical experimental design. Because of its relevance for medical applications, spherical Ti-6Al-4V powder with a size distribution under 25 µm is dried under various parameters using vacuum and gas purging. The investigated parameters, time and temperature, are selected in a central-composite-circumscribed test plan with eleven tests and three center points. The target parameters—water content, flowability and impurity levels (oxygen, nitrogen)—of the powder are analyzed. For validation, practical test trials are carried out on an industrial binder jetting system with unconditioned powder and conditioning with optimized parameters, comparing the manufactured parts and the powder bed. An optimized drying cycle with a duration of 6 h at 200 °C was determined for the investigated powder. Significant improvements in the dimensional accuracy (from ±1.5 to 0.3%) of the components and the visual impression of the powder bed are demonstrated.

Additive manufacturing (AM) has revolutionized the manufacturing industry, allowing the production of complex, lightweight components with specific properties. This has created opportunities for customized parts with optimized performance and cost-efficiency compared to traditional manufacturing. Infill structures are used to fill the voids inside the component during layer-by-layer manufacturing. These structures, such as grids and honeycombs, optimize mechanical properties, reduce weight, and save production time. However, investigating the mechanical properties of components with different infill structures is typically done experimentally, which is time-consuming and expensive. This paper proposes a simulation-based approach to investigate the influence of infill structure parameters on the mechanical properties of components made from AISI 316L stainless steel. Two-dimensional grid and honeycomb infill structures are studied, considering infill degree, cell wall thickness and spatial orientation relative to the load direction. The study employs a parametric design approach to generate different infill structures for simulation and validation. This paper provides a simulation-based methodology for varying and evaluating design parameters for AM processes using grid and honeycomb infill structures. The findings can be used to optimize lightweight component design for specific applications, improving performance and cost-efficiency. The study contributes to the field of Design for Additive Manufacturing (DfAM).

Additively manufactured mechanical components show great lightweight characteristics and can often be enhanced by integrating biomimetic geometrical features. This study focuses on one specific subcase, namely the substitution of solid cylindrical beams that are under bending with geometrically more complex biomimetic beams. Based on the pseudo-stem of the banana plant as a role model, six geometric beam designs were derived. Given the manufacturing constraints of the PBF-LB/M process, two abstractions were selected for detailed investigation in the main part of this study. The beam lengths were set to 100 mm. Based on parametric optimization simulations, optimal design parameters were identified for the two biomimetic abstractions for 26 different bending load cases ranging from 14 to 350 Nm. Analogous parameter optimizations were performed for a solid cylindrical beam design, which was used as a reference. The results provide detailed design solutions within the investigated intervals for biomimetic beams that can be substituted into more complex mechanical component designs with ease. The analysis provides information on which structures to use for the investigated loads. With the help of the developed numerical models, designers can easily generate biomimetic beam designs for specific bending load values.

In aerospace, thermal applications demand compact, lightweight, and efficient heat exchangers. Additive manufacturing processes offer the potential to create highly complex structures that are not achievable through traditional manufacturing methods. This work presents the development of an additively manufactured fluid-fluid heat exchanger that shows the potential to enhance the performance, reduce weight, and increase compactness compared to a conventional plate heat exchanger. A numerical model of the conventional plate heat exchanger was created, and fluid dynamics simulations with heat transfer were performed. Validation of the simulations was done by experiments. Then, a novel heat exchanger was designed using a bottom-up approach and investigated at different levels of complexity using computational fluid dynamics. The internal structure of the final heat exchanger consists of a repeating triply periodic Schwarz diamond minimum surface elongated in the direction of flow. The heat exchanger was manufactured with laser powder bed fusion process using AlSi10Mg. It had a 108% higher compactness and 54% lower weight compared to the plate heat exchanger. Numerical analysis yielded the pressure loss in pascal was reduced by 50%-59% while heat transfer in watts was improved by 3%-5%. Future researches should experimentally investigate the thermal and fluid mechanical characteristics of the novel additively manufactured heat exchanger and increase compactness and heat transfer further by analyzing the minimum partition wall thickness and the impact of wall roughness and deposit formation.

Improving mechanical topology optimization (TO) results by substituting biomimetic beams is one possibility to achieve designs of mechanical components that are highly sustainable and show good mechanical performance. Because of their geometric complexity, such designs were found to be well-suited for production by laser additive manufacturing. One obstacle of incorporating biomimetics beams in TO designs is the lack of detailed design methodologies. Röver et al. [“Methodology for integrating biomimetic beams in abstracted topology optimization results,” in Proceedings of the ASME 2022 International Mechanical Engineering Congress and Exposition. Volume 4: Biomedical and Biotechnology; Design, Systems, and Complexity Columbus, OH, 30 October-3 November (ASME, New York, 2022)] proposed a corresponding design concept. Building on their concept, we present in this work a detailed methodology for abstraction of TO results to a design consisting of ball nodes and cylindrical beams. Using such an auxiliary design, the internal forces and moments of the beams can be evaluated to allow for the substitution of suitable biomimetic beams to generate biomimetic component designs in a next step. We present a skeletonization algorithm based on the potential field approach. Using the skeletonization and an additional analysis of the dimensions of the beams in the TO result, the algorithm develops an auxiliary design of the original TO result. The final algorithm was applied to three common TO results to obtain one auxiliary component design each. The developed algorithm was found to generate abstractions that were well-suited for use in the methodology proposed in Röver et al. [“Methodology for integrating biomimetic beams in abstracted topology optimization results,” in Proceedings of the ASME 2022 International Mechanical Engineering Congress and Exposition. Volume 4: Biomedical and Biotechnology; Design, Systems, and Complexity Columbus, OH, 30 October-3 November (ASME, New Yor

This paper presents a five-step design methodology to generate designs of biomimetic structural components from topology optimization results. In step one, all material allocated by topology optimization is classified as either beam like structures or nodes to generate an auxiliary model consisting of preserved regions, cylindrical beams, and ball nodes, which is an abstraction of the original topology optimization result. In step two, the auxiliary model is exposed to the original boundary conditions in a finite element analysis. Then, internal forces, torsion, and bending moments in all beams of the auxiliary model are identified with respect to both of their ends. In step three, a database is used to find a suitable biomimetic beam for each previously analyzed beam in the auxiliary model. In step four, adapted nodes are designed to connect the biomimetic beams and preserved regions to generate an intermediate biomimetic component design. And in step five, a design iteration and a validation of the final design are performed. The design methodology allows for reproducible bio-mimetic component designs, a trackable and easily documentable component development process, and the possibility of automating the design process to ultimately save development costs when designing structural components.