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A major part of laser additive manufacturing focuses on the fabrication of metallic parts for applications in the space and aerospace sectors. Especially, the processing of the very brittle titanium aluminides can be particularly challenging because of their distinct tendency to lamellar interface cracking. In the present paper, a gamma titanium aluminide (γ-TiAl) nozzle, manufactured via electron beam melting, is extended and adapted via hybrid laser metal deposition. The presented example considers a new field of application for this class of materials and approaches the process-specific manipulation of the composition and/or microstructure via the adjustment of processing temperatures, temperature gradients and solidification conditions. Furthermore, intrinsic heat treatment is investigated for electron beam melting and laser metal deposition with powder, and the resulting influence is releated to conventional processing.

Ceramic matrix composites (CMCs) are refractory ceramic materials with damage-tolerant behavior. Coming from the space industry, this class of materials is increasingly being used in other applications, such as automotive construction for high-performance brake discs, furnace technology, heat coatings for pipe systems and landing flaps on reusable rocket sections. In order to produce CMC faster and more cost-efficiently for the increasing demand, a new additive manufacturing process is being tested, which in the future should also be able to realize material joints and higher component wall thicknesses than conventional processes. The main features of the process are as follows. A ceramic fiber bundle is de-sized and infiltrated with ceramic suspension. The bundle infiltrated with matrix material is dried and then applied to a body form. During application, the matrix material is melted by laser radiation without damaging the fiber material. For the initial validation of the material system, samples are pressed and analyzed for their absorption properties using integrating sphere measurement. With the results, a suitable processing laser is selected, and initial melting tests of the matrix system are carried out. After the first validation of the process, a test system is set up, and the first test specimens are produced to determine the material parameters.

In this study, we provide novel in situ monitoring of strain during laser metal deposition of Inconel 718 by neutron diffraction. Thermal, phase and stress-related contributions to the lattice parameter evolution are addressed for the representative regions during processing: melt pool, near melt pool, and far-field. The evolution showed a strong dependency on the build height and distance to the melt pool, i.e., time and temperature gradient, as expected. The different regions of interest reached at different moments the processing stable regime, which is contrasted with microstructural characterization. A homogeneous microstructure of coarse epitaxial dendrites and Laves phase was found from the third printed layer on, with fine globular delta phase precipitation at the grain boundaries. In comparison, neutron diffraction strain monitoring highlighted an offset of process stabilization after 24 layers for the melt pool and near-melt pool regions.

The Fraunhofer Institutes IWS and IWU as well as Edag combine the high productivity of die casting and free shaping in additive manufacturing. This reduces the manufacturing costs of previously additive components and increases the complexity of die cast components. This makes the process interesting for automotive applications. Additive manufacturing processes such as Laser Beam Melting (LBM) or Laser Metal Deposition (LMD) offer the advantage of tool-free, near net shape production of complex geometries. The production of geometrically complex, topology-optimized components up to small batches is particularly interesting for aerospace, medical technology, tooling industry and increasingly for the automotive industry. Despite the variety of advantages, additive manufacturing processes are still slow to enter industrial production. The main reasons for this are relatively long production times and therefore high production costs. In contrast to additive manufacturing, high quantities can be produced in a short time during die casting. Among other things, this is due to the very high mold filling speed of up to 12 m/s and the associated short cycle time of only a few minutes per component [1]. However, the high productivity is also associated with disadvantages. Components of higher complexity with undercuts and cooling channels are not or only partially produced and require elaborate molds. High mechanical requirements, wear on impact of the melt and temperature fluctuations result in expensive die casting molds. In addition, only one component geometry can be produced with one mold. The project CastAutoGen, funded by the German Federal Ministry of Education and Research as part of the joint project Agent-3D, has set itself the goal of combining additive manufacturing with die casting to form a hybrid production chain and use the advantages of both processes optimally. Simply shaped, large-volume areas are die casted due to time and cost reasons. Functionalized or highly complex component areas are produced additively. As shown in the project, hybrid production can occur in two different scenarios. Scenario 1 describes the way of inserting and fitting additively fabricated parts into a unitary mold while Scenario 2 explaining how to create additive structures on a unitary die cast component by LMD.

Conventional infrared lasers (1070 nm) are not ideal for processing materials such as copper or gold. The reason for this is the corresponding high reflectivity of the aforementioned materials for infrared radiation. Since 2017, so-called “green lasers” {wavelengths around 500 nm [Kaliudis, see https://www.trumpf.com/de_DE/magazin/gruene-welle-fuers-kupferschweissen/ for “Grune Welle furs Kupferschweisen, TRUMPF Media Relations,” Press Release (2017)]} are available for welding processes and additive manufacturing technologies, viz., laser powder bed fusion (LPBF) and laser metal deposition (LMD). These lasers are specially designed for the processing of highly reflective materials and have been recently used for the fabrication of specimens from pure copper. Due to process reasons, only one alloy is typically used for the manufacturing of components if powder bed based methods (LPBF) are applied. For many components, however, it is the combination of different materials (differences in thermophysical properties) that leads to an improvement in the component performance. The LMD process, in contrast to LPBF, can be adjusted with relative low efforts for the processing of two or more different materials. This offers new possibilities for the functionalization of parts that are already fabricated through a combination of subtractive and additive technologies (hybrid manufacturing). A mould insert for polymer injection molding will be presented in this contribution. It was produced by using a combination of different processes (subtractive, additive) and materials (pure copper, steel 1.2764).2–5 For a conventionally manufactured basic body (1.2764), copper cores were integrated in the corner areas by means of LMD. The cladding of the cores with 1.2764 was carried out with regard to the basic body and guaranteed dimensional accuracy for further processing. In order to improve the flow of coolant to the copper cores in the later application, the upper part of the mould insert with conformal cooling channels was manufactured using LPBF. The entire tool insert demonstrator was then finished and case-hardened. Initial tests under real conditions on the overall component are intended to prove full functionality. Simultaneously, we discuss the added value of the hybrid manufacturing approach that was funded by the Federal Ministry of Education and Research (BMBF) in Germany as part of the AGENT-3D project IMProVe.

In the future, ceramic materials will find even more applications in aerospace, energy, and drive technology. Reasons for this are the comparatively low density and good long-term stability at high temperatures for applications for components exposed to high temperatures, e.g., of engines. By using increasing combustion temperatures through the use of ceramics increases the efficiency of modern drive systems [Ohnabe, Masaki, Onozuka, Miyahara, and Sasa, Compos. Part A Appl. Sci. Manuf. 30, 489–496 (1999)]. Despite the high interest of the aviation industry to increase the use of ceramic materials, the time- and energy-consuming classical production of these materials and the concomitant limiting factors in terms of shape and size are still a drawback [Krenkel, Ceramic Matrix Composites Fiber Reinforced Ceramics and their Applications (WIY-VCH Verlag GmbH & Co. KGaA, Weinheim, 2008)]. This paper follows a new approach to producing ceramic matrix composites (CMCs). The laser material deposition (LMD) and selective laser melting techniques were used to investigate the coupling of different laser wavelengths into ceramic materials. By combining different energy sources and utilizing wavelength-dependent energy coupling, the additive manufacturing application of ceramic materials to metallic substrates was tested. With the knowledge gained from wavelength-dependent energy coupling, the potential for the production of CMCs should be demonstrated by means of LMD.In the future, ceramic materials will find even more applications in aerospace, energy, and drive technology. Reasons for this are the comparatively low density and good long-term stability at high temperatures for applications for components exposed to high temperatures, e.g., of engines. By using increasing combustion temperatures through the use of ceramics increases the efficiency of modern drive systems [Ohnabe, Masaki, Onozuka, Miyahara, and Sasa, Compos. Part A Appl. Sci. Manuf. 30, 489–496 (1999)]. Despite the high interest of the aviation industry to increase the use of ceramic materials, the time- and energy-consuming classical production of these materials and the concomitant limiting factors in terms of shape and size are still a drawback [Krenkel, Ceramic Matrix Composites Fiber Reinforced Ceramics and their Applications (WIY-VCH Verlag GmbH & Co. KGaA, Weinheim, 2008)]. This paper follows a new approach to producing ceramic matrix composites (CMCs). The laser material deposition (LMD) and se...

A major part of additive manufacturing focuses on the fabrication of metallic parts in different fields of applications. Examples include components for jet engines and turbines and also implants i ...

In order to lead to a competitive advantage, there is the need to carefully consider the pros and cons of state-of-the-art manufacturing techniques. This is frequently carried out in a competitive ...