@misc{50816, author = {{Hücker, Lars}}, title = {{{Stickstoff basierte Flammschutzmittel für das Lasersintern: Optimierung und Analyse der Recyclingfähigkeit (Studienarbeit)}}}, year = {{2024}}, } @misc{50815, author = {{Schulz, Maurice}}, title = {{{Phosphorhaltige Lasersinter-Materialien mit Flammschutzwirkung: Optimierung und Analyse der Recyclingfähigkeit (Studienarbeit)}}}, year = {{2024}}, } @article{43128, author = {{Rüther, Moritz Johannes and Klippstein, Sven Helge and Ponusamy, SathishKumar and Rüther, Torben and Schmid, Hans-Joachim}}, issn = {{0032-5910}}, journal = {{Powder Technology}}, keywords = {{General Chemical Engineering}}, publisher = {{Elsevier BV}}, title = {{{Flowability of polymer powders at elevated temperatures for additive manufacturing}}}, doi = {{10.1016/j.powtec.2023.118460}}, volume = {{422}}, year = {{2023}}, } @phdthesis{44509, author = {{Kruse, Anne}}, isbn = {{978-3-8440-8955-4}}, pages = {{145}}, title = {{{Entwicklung einer Methode zur Integration der Additiven Fertigung in die Serienproduktion am Beispiel des Lasersinterns}}}, volume = {{27}}, year = {{2023}}, } @inbook{45360, author = {{Haase, Michael and Bieber, Maximilian and Tasche, Frederik and Schaper, Mirko and Hoyer, Kay-Peter and Ponik, Bernd and Magyar, Balázs}}, booktitle = {{Proceedings of the 19th Rapid.Tech 3D Conference Erfurt, Germany, 9–11 May 2023}}, editor = {{Kynast, Michael and Eichmann, Michael and Witt, Gerd}}, isbn = {{978-3-446-47941-8}}, publisher = {{Carl Hanser Verlag GmbH & Co. KG}}, title = {{{Umsetzung einer optimierten Oberflächenschlitzung zur Wirbelstromverlustreduktion auf der Oberfläche eines additiv gefertigten Permanentmagnet-Rotors}}}, year = {{2023}}, } @article{44078, author = {{Andreiev, Anatolii and Hoyer, Kay-Peter and Hengsbach, Florian and Haase, Michael and Tasche, Lennart and Duschik, Kristina and Schaper, Mirko}}, issn = {{0924-0136}}, journal = {{Journal of Materials Processing Technology}}, keywords = {{Industrial and Manufacturing Engineering, Metals and Alloys, Computer Science Applications, Modeling and Simulation, Ceramics and Composites}}, publisher = {{Elsevier BV}}, title = {{{Powder bed fusion of soft-magnetic iron-based alloys with high silicon content}}}, doi = {{10.1016/j.jmatprotec.2023.117991}}, volume = {{317}}, year = {{2023}}, } @article{46815, abstract = {{In this work, the influence of the filler–matrix adhesion on the tensile properties of laser-sintered parts built with Polyamide 613 filled with glass beads was investigated. For this purpose, dry blends of glass beads with and without organosilane coupling agents and polyamide powder were prepared and processed into tensile specimens on an EOS P396 laser sintering system. The samples were tested both in the dry state and after an accelerated conditioning in a climate chamber. Furthermore, finite element method (FEM) simulations were performed to model the extreme cases of optimum adhesion and no adhesion. By correlating the tensile tests with the simulation results and by analyzing the fracture surfaces, it was shown that the filler–matrix adhesion is sufficient in the dry state but is strongly degraded by conditioning. Even the presence of various organosilane thin films could not prevent a strong deterioration of the filler–matrix adhesion and the associated deterioration of the mechanical properties. Since a comparison with an injection-molded sample of the same polymer filler combination shows identical behavior after conditioning, it is assumed that this problem is not limited to additively manufactured parts.}}, author = {{Kletetzka, Ivo and Kosanke, Maren and Meinderink, Dennis and Neßlinger, Vanessa and Grundmeier, Guido and Schmid, Hans-Joachim}}, issn = {{2363-9512}}, journal = {{Progress in Additive Manufacturing}}, keywords = {{Industrial and Manufacturing Engineering}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Influence of the filler–matrix adhesion and the effects of conditioning on tensile properties of laser-sintered parts built with polyamide–glass bead dry blends}}}, doi = {{10.1007/s40964-023-00501-z}}, year = {{2023}}, } @unpublished{43049, abstract = {{Abstract In this work, the influence of the filler matrix adhesion on the tensile properties of laser-sintered parts built with Polyamide 613 filled with glass beads was investigated. For this purpose, dry blends of glass beads with and without organosilane coupling agents and polyamide powder were prepared and processed into tensile specimens on an EOS P396. The samples were tested both in the dry state and after an accelerated conditioning in a climate chamber. Furthermore, FEM simulations were performed to model the limiting cases of optimum adhesion and no adhesion. By correlating the tensile tests with the simulation results and by analyzing the fracture surfaces, it was shown that the filler matrix adhesion is sufficient in the dry state but is strongly degraded by conditioning. Even the presence of various organosilane thin films could not prevent a strong deterioration of the filler-matrix adhesion and the associated deterioration of the mechanical properties. Since a comparison with an injection molded sample of the same polymer filler combination shows identical behavior after conditioning, it is assumed that this problem is not limited to additively manufactured parts.}}, author = {{Kletetzka, Ivo and Kosanke, Maren and Meinderink, Dennis and Neßlinger, Vanessa and Grundmeier, Guido and Schmid, Hans-Joachim}}, publisher = {{Research Square Platform LLC}}, title = {{{Influence of the filler matrix adhesion and the effects of conditioning on tensile properties of laser sintered parts built with polyamide glass bead dry blends}}}, year = {{2023}}, } @inproceedings{45783, author = {{Kletetzka, Ivo}}, location = {{Berlin}}, title = {{{Tensile Testing for Polymer AM - Best Pratice at the DMRC}}}, year = {{2023}}, } @article{43046, abstract = {{In the laser sintering technology, the semi-crystalline polymer material is exposed to elevated temperatures during processing, which leads to serious material ageing for most materials. This has already been investigated intensively by various authors. However, the ageing of the material at ambient temperatures during shelf life has not been the focus so far. The need to analyse the shelf life can be derived from an ecological and economic point of view. This work is focusing on the shelf life of PA2200 (PA12). To reduce the potential influences of powder production fluctuations, two different powder batches stored for 5.5 years and 6.5 years are investigated and compared to a reference powder produced 0.5 years before these investigations. Multiple powder analyses and part characterisations have been performed. A significant yellowing and molecular chain length reduction can be derived from the measurement results. Whereas the influence on mechanical part performance was minor, the parts built with the stored powders are more yellowish. As it is most likely that this is due to the consumption of polyamide stabilisers, it can be assumed that these parts will be subject to significantly faster ageing. Therefore, it is still not recommended to use the stored powders for critical parts or light intense and humid environments.}}, author = {{Klippstein, Sven Helge and Kletetzka, Ivo and Sural, Ilknur and Schmid, Hans-Joachim}}, journal = {{The International Journal of Advanced Manufacturing Technology }}, keywords = {{Selective laser sintering, Shelf life, Polyamide 12, powder, PA2200, material ageing}}, publisher = {{Springer}}, title = {{{Influence of a prolonged shelf time on PA12 laser sintering powder and resulting part properties}}}, doi = {{https://doi.org/10.1007/s00170-023-11243-1}}, year = {{2023}}, } @misc{46861, author = {{Sajadi, Said}}, title = {{{Charakterisierung und Bewertung von flammgeschützten PA12 Pulvermischungen hinsichtlich der Verarbeitbarkeit im Lasersinter-Prozess}}}, year = {{2023}}, } @inproceedings{46764, abstract = {{Polymer composites represent the industry standard in injection molding for the production of plastic components with increased requirements in terms of heat resistance and stiffness. In the field of laser sintering (LS), these materials are less common so far. In order to extend the available material variety for the LS process, new ceramic-filled Polyamide 613 powders are investigated within the scope of this work. Here, the resulting properties from two different powder production methods are compared. One filled powder is produced by dry blending and the other powder with the same filler and filling ratio is produced by encapsulating the filler particles inside the polymer particles within the dissolution-precipitation process. It was found that encapsulating the filler particles can provide certain benefits for the processability, for example an improved powder flowability or better filler dispersion. However, encapsulating the filler also alters the thermal properties of the precipitated powder.}}, author = {{Kletetzka, Ivo and Neitzel, Fabian and Schmid, Hans-Joachim}}, booktitle = {{Proceedings of the 34th Annual International Solid Freeform Fabrication Symposium}}, editor = {{Beaman, Joseph}}, location = {{Austin}}, publisher = {{Laboratory for Freeform Fabrication and University of Texas}}, title = {{{Assessing the Impact of the Powder Production Method on Ceramic-filled Polyamide Composites made by Laser Sintering}}}, volume = {{34}}, year = {{2023}}, } @inproceedings{48095, abstract = {{Fused deposition modeling (FDM) is an additive manufacturing process that can be used to manufacture three-dimensional thermoplastic components layer by layer. One disadvantage of FDM is the shrinkage of the components during the manufacturing process. The filament is molten in the nozzle, deposited layer by layer, and cools down again. During solidification, the filament shrinks inhomogeneously in the x/y/z direction, which leads to distortion of the component geometries. Particularly with higher nominal lengths and complex local geometries, there is a need for optimization with regard to dimensional accuracy. The aim of this paper is to counteract this on the software side with global as well as local shrinkage factors. The expected shrinkage within a layer is predicted with an in-house developed software. The geometric accuracy of the model is verified by experimental investigations on cylindrical test specimens. In these, the so-called clover effect occurs as a result of the shrinkage. The circular shape of the deposited layer is deformed by the distortion in the x–y plane comparable to a clover. Finally, the results are validated by analyzing a demonstrator in the form of a bracket.}}, author = {{Koers, Thorsten and Magyar, Balázs}}, booktitle = {{Macromolecular Symposia}}, editor = {{Lamanna, Giuseppe and Opran, Constantin}}, location = {{Bucharest, Romania}}, number = {{1}}, publisher = {{Wiley}}, title = {{{Compensation of the Shrinkage Behavior Occurring in Cylindrical Components in the FDM Process}}}, doi = {{https://doi.org/10.1002/masy.202200185}}, volume = {{411}}, year = {{2023}}, } @inproceedings{49774, author = {{Bieber, Maximilian and Haase, Michael and Tasche, Frederik and Zibart, Alexander and Ponick, Bernd}}, booktitle = {{2023 IEEE International Electric Machines & Drives Conference (IEMDC)}}, publisher = {{IEEE}}, title = {{{Additively manufactured air-cooled lightweight rotor for an automotive electric motor}}}, doi = {{10.1109/iemdc55163.2023.10238918}}, year = {{2023}}, } @inproceedings{50742, abstract = {{The nickel-based alloy Inconel 718, which is used in aerospace technology, poses a great challenge to conventional machining due to its high strain hardening and toughness. Here, the laser powder bed fusion process (LPBF) offers an alternative with potential savings if sufficiently high productivity can be achieved. Based on the parameter study carried out, starting from the SLM Solutions standard parameters for the manufacturing of components, exposure parameters could be developed to realize manufacturing with 120 μm and 150 μm layer thickness, with almost the same geometric accuracy. For this purpose, the process parameters of laser power, focus diameter, hatch distance and scan speed were varied. The negative defocusing of the laser showed a positive effect on the density of the parts, realizing densities ≥ 99.94 %, with high dimensional stability and good mechanical properties. Considering the reduced manufacturing time of up to 61 %, a significant increase in productivity was achieved.}}, author = {{Bödger, Christian and Gnaase, Stefan and Lehnert, Dennis and Tröster, Thomas}}, booktitle = {{Proceedings of the 34th Annual International Solid Freeform Fabrication Symposium – An Additive Manufacturing Conference}}, location = {{Austin}}, title = {{{Investigation of the influence of process parameters on productivity in the LPBF process for the material Inconel 718}}}, year = {{2023}}, } @inproceedings{46862, abstract = {{The high flammability of components manufactured by laser sintering (LS) using standard polyamide 12 (PA12) powder still severely restricts their use in industries such as electronics, aviation, and transportation. A key factor for the further establishment of LS is the expansion of the material portfolio with, for example, refreshable and halogen-free flame-retardant (FR) powder materials. Accordingly, various halogen-free FRs are investigated in this work and evaluated with respect to their use in LS. First, their decomposition behavior and mode of action are examined. Subsequently, the additives are dry blended with PA12 to investigate properties relevant for LS, such as particle morphology, thermal behavior and melt viscosity. Afterwards, test specimens for UL94 vertical flame-retardancy tests are produced by processing the dry blends on an EOS P3 LS system. Finally, the process stability of the process-aged powder blends is investigated by again examining the thermal behavior and melt viscosity.}}, author = {{Neitzel, Fabian and Kletetzka, Ivo and Schmid, Hans-Joachim}}, booktitle = {{Proceedings of the 34th Annual International Solid Freeform Fabrication Symposium}}, editor = {{Beaman, Joseph}}, keywords = {{Additive Manufacturing, Laser Sintering, Flame Retardant, Polyamide 12}}, location = {{Austin}}, title = {{{Halogen-Free Flame Retardant Powder Materials for Laser Sintering: Evaluation and Process Stability Analysis}}}, year = {{2023}}, } @inproceedings{51218, abstract = {{Polymer composites represent the industry standard in injection molding for the production of plastic components with increased requirements in terms of heat resistance and stiffness. In the field of laser sintering (LS), these materials are less common so far. In order to extend the available material variety for the LS process, new ceramic-filled Polyamide 613 powders are investigated within the scope of this work. Here, the resulting properties from two different powder production methods are compared. One filled powder is produced by dry blending and the other powder with the same filler and filling ratio is produced by encapsulating the filler particles inside the polymer particles within the dissolution-precipitation process. It was found that encapsulating the filler particles can provide certain benefits for the processability, for example an improved powder flowability or better filler dispersion. However, encapsulating the filler also alters the thermal properties of the precipitated powder. }}, author = {{Kletetzka, Ivo and Neitzel, Fabian and Schmid, Hans-Joachim}}, booktitle = {{Proceedings of the 34th Annual International Solid Freeform Fabrication Symposium}}, editor = {{Beaman, Joseph}}, keywords = {{Additive Manufacturing, Laser Sintering, Filled Materials, Composites, Polyamide 613}}, location = {{Austin}}, title = {{{Assessing the Impact of the Powder Production Method on Ceramic-filled Polyamide Composites made by Laser Sintering}}}, year = {{2023}}, } @article{48277, abstract = {{AbstractCurrently, the fused deposition modeling (FDM) process is the most common additive manufacturing technology. The principle of the FDM process is the strand wise deposition of molten thermoplastic polymers, by feeding a filament trough a heated nozzle. Due to the strand and layer wise deposition the cooling of the manufactured component is not uniform. This leads to dimensional deviations which may cause the component to be unusable for the desired application. In this paper, a method is described which is based on the shrinkage compensation through the adaption of every single raster line in components manufactured with the FDM process. The shrinkage compensation is based on a model resulting from a DOE which considers the main influencing factors on the shrinkage behavior of raster lines in the FDM process. An in‐house developed software analyzes the component and locally applies the shrinkage compensation with consideration of the boundary conditions, e.g., the position of the raster line in the component and the process parameters. Following, a validation using a simple geometry is conducted to show the effect of the presented adaptive scaling method.}}, author = {{Moritzer, Elmar and Hecker, Felix}}, issn = {{1022-1360}}, journal = {{Macromolecular Symposia}}, keywords = {{Materials Chemistry, Polymers and Plastics, Organic Chemistry, Condensed Matter Physics}}, location = {{Bukarest}}, number = {{1}}, publisher = {{Wiley}}, title = {{{Adaptive Scaling of Components in the Fused Deposition Modeling Process}}}, doi = {{10.1002/masy.202200181}}, volume = {{411}}, year = {{2023}}, } @inproceedings{48357, author = {{Moritzer, Elmar and Hecker, Felix and Knaup, Felix and Wächter, Julian}}, booktitle = {{Proceedings of the 37th International Conference of the Polymer Processing Society (PPS-37)}}, location = {{Fukuoka (Japan)}}, pages = {{170001--1 -- 170001--5}}, publisher = {{AIP Publishing}}, title = {{{Investigation of the Deposition Velocity Related Temperature Deviations for High Temperature Materials in the FDM Process}}}, doi = {{10.1063/5.0168548}}, year = {{2023}}, } @inproceedings{47084, abstract = {{Fused Deposition Modeling (FDM) is an additive manufacturing process to produce complex thermoplastic geometries layer by layer. The filament is melted in a nozzle, iteratively deposited, and then cools down. Due to the solidification process, the deposited filament strands deviate from their intended position due to shrinkage, resulting in significant geometric deviations in the final part. In terms of dimensional accuracy, there is a need for optimization, especially for local curved geometries in relation to the global part with higher nominal dimensions. The aim of this study is to investigate the size and shape deviations for cylindrical FDM elements and to compensate the expected deformations by using an in-house software with adaptive scaling factors in the x-y plane. Previous studies mainly focus on simple, non-curved objects, this study also considers the influence of curvature and global as well as local deviations on the final part.}}, author = {{Koers, Thorsten and Magyar, Balázs}}, booktitle = {{Proceedings of the 34th Annual International Solid Freeform Fabrication Symposium 2023}}, editor = {{Beaman, Joseph}}, location = {{Austin, Texas, USA}}, title = {{{Determination and Compensation of the Shrinkage Behavior of Cylindrical Elements in the FDM Process}}}, volume = {{34}}, year = {{2023}}, } @inproceedings{48790, abstract = {{To ensure uniform documentation of support structure information, a concept is presented that enables a standardized depiction of support structures in technical drawings based on ISO 128-3. To this end, requirements for a uniform depiction are defined and a procedure for drawing entry is presented. The drawing entry should contain all production-relevant support structure information. The standardized documentation of support structure information in technical drawings is intended to ensure a simple, clear and safe exchange of information between business units or different companies along the value chain. As a result a possible drawing entry of support structures was developed. To distinguish between different support structure types, a standardized depiction of geometrical information in a specification field is shown. The specification field gives a detailed description of the support structure type, the geometry as well as the connection to the part and the building platform. Also uncommon support types like lattice structures or CAD based support structures can be implemented. To ensure the usability the depictio is editable and extendable.}}, author = {{Lammers, Stefan and Koers, Thorsten and Magyar, Balázs and Zimmer, Detmar and Lieneke, Tobias}}, booktitle = {{Proceedings of the 34th Annual International Solid Freeform Fabrication Symposium 2023}}, editor = {{Beaman, Joseph}}, location = {{Austin, Texas, USA}}, title = {{{Depiction of support structures in technical drawings}}}, volume = {{34}}, year = {{2023}}, } @inproceedings{30229, author = {{Klippstein, Sven Helge}}, location = {{Online}}, title = {{{Reproducibility in Polymer Laser Sintering}}}, year = {{2022}}, } @techreport{34020, author = {{Haase, Michael and Tasche, Frederik and Bieber, Maximilian and Zibart, Alexander}}, pages = {{64}}, publisher = {{Forschungsvereinigung Antriebstechnik e.V.}}, title = {{{Innovative Leichtbau- und Kühlungskonzepte für elektrische Maschinen durch additive Fertigung (ILuKadd3D)}}}, volume = {{Heft 1526}}, year = {{2022}}, } @inproceedings{33355, author = {{Klippstein, Sven Helge}}, location = {{Berlin}}, publisher = {{7. AM Forum Berlin}}, title = {{{Neue Polymerwerkstoffe - Der Schlüssel für die Industrialisierung}}}, year = {{2022}}, } @article{33859, author = {{Moritzer, Elmar and Elsner, Christian Lennart}}, journal = {{Macromolecular Symposia}}, location = {{Bukarest}}, number = {{1}}, publisher = {{Wiley}}, title = {{{Investigation and Improvement of Processing Parameters of a Copper-Filled Polymer Filament in Fused Filament Fabrication as a Basis for the Fabrication of Low-Porosity Metal Parts}}}, doi = {{https://doi.org/10.1002/masy.202100390}}, volume = {{404}}, year = {{2022}}, } @article{33861, author = {{Moritzer, Elmar and Wächter, Julian}}, journal = {{Macromolecular Symposia}}, location = {{Bukarest}}, number = {{1}}, publisher = {{Wiley}}, title = {{{Development of a Procedure for the Assessment of Material Potentials under Consideration of the Weld Seam Quality for Multi-Material Applications in the FDM Process}}}, doi = {{https://doi.org/10.1002/masy.202100389}}, volume = {{404}}, year = {{2022}}, } @misc{33987, author = {{Moritzer, Elmar and Elsner, Christian Lennart}}, booktitle = {{Kunststoffe}}, issn = {{0023–5563}}, title = {{{Mit Gestaltungsrichtlinien zum Erfolg}}}, volume = {{11/2022}}, year = {{2022}}, } @article{33862, author = {{Moritzer, Elmar and Driediger, Christine}}, journal = {{Macromolecular Symposia}}, location = {{Bukarest}}, number = {{1}}, publisher = {{Wiley}}, title = {{{Reactive Direct Bonding of Digital Light Process Components}}}, doi = {{https://doi.org/10.1002/masy.202100396}}, volume = {{404}}, year = {{2022}}, } @article{35729, author = {{Rüther, Moritz Johannes and Klippstein, Sven Helge and Ponusamy, SathishKumar and Jesinghausen, Steffen and Schmid, Hans-Joachim}}, journal = {{Werkstoffe}}, pages = {{18 -- 19}}, publisher = {{HW-Verlag}}, title = {{{Innovative Werkstoffherstellung für das Polymer Laser Sintern – Teil 2}}}, volume = {{6}}, year = {{2022}}, } @article{35724, author = {{Rüther, Moritz Johannes and Klippstein, Sven Helge and Ponusamy, SathishKumar and Jesinghausen, Steffen and Schmid, Hans-Joachim}}, journal = {{Werkstoffe}}, pages = {{28--29}}, publisher = {{HW-Verlag}}, title = {{{Innovative Werkstoffherstellung für das Polymer Laser Sintern – Teil 1}}}, volume = {{5}}, year = {{2022}}, } @inbook{34113, author = {{Haase, Michael and Zimmer, Detmar}}, booktitle = {{Innovative Product Development by Additive Manufacturing 2021}}, isbn = {{9783031059179}}, publisher = {{Springer International Publishing}}, title = {{{Systematic Investigations Concerning Eddy Currents in Additively Manufactured Structures}}}, doi = {{10.1007/978-3-031-05918-6_10}}, year = {{2022}}, } @article{30228, abstract = {{Confidence in additive manufacturing technologies is directly related to the predictability of part properties, which is influenced by several factors. To gain confidence, online process monitoring with dedicated and reliable feedback is desirable for every process. In this project, a powder bed monitoring system was developed as a retrofit solution for the EOS P3 laser sintering machines. A high-resolution camera records each layer, which is analyzed by a Region-Based Convolutional Neural Network (Mask R-CNN). Over 2500 images were annotated and classified to train the network in detecting defects in the powder bed at a very high level. Each defect is checked for intersection with exposure areas. To distinguish between acceptable imperfections and critical defects that lead to part rejection, the impact of these imperfections on part properties is investigated.}}, author = {{Klippstein, Sven Helge and Heiny, Florian and Pashikanti,, Nagaraju and Gessler, Monika and Schmid, Hans-Joachim}}, journal = {{JOM - The Journal of The Minerals, Metals & Materials Society (TMS)}}, location = {{Online}}, pages = {{1149–1157}}, publisher = {{Springer}}, title = {{{Powder Spread Process Monitoring in Polymer Laser Sintering and its Influences on Part Properties}}}, doi = {{https://doi.org/10.1007/s11837-021-05042-w }}, volume = {{74}}, year = {{2022}}, } @inproceedings{33356, abstract = {{By monitoring the recoating process within polymer laser sintering production, it was shown that multiple powder-spread-flaws can be detected. Those groove-like flaws are expected to be the result of agglomerates jamming between the recoater and the last powder layer. This work is analyzing the interaction between powder-spread-flaws and part properties, showing the influence of the recoating process on the performance of laser sintering parts. Therefore, artificial powder-spread-flaws are applied to the build jobs of tensile test specimens which are measured and analyzed regarding the elongation at break, strength and fracture position. For the characteristics of the flaws, the artificial grooves are varied in depth and width. Furthermore, the position of the flaw is changed form mid part to close to surface areas. It was shown, that several flaws are visible at the part surface, resulting in stress concentration and reduced performance. But there are as well parts with flaw-layers, which are not visible after the build process on the part. Those parts can have significantly reduced mechanical properties as well.}}, author = {{Klippstein, Sven Helge and Schmid, Hans-Joachim}}, booktitle = {{Proceedings of the 33nd Annual International Solid Freeform Fabrication Symposium}}, keywords = {{Selective Sasersintering, Process Monitoring, Powder Spread}}, title = {{{Powder Spread Flaws in Polymer Laser Sintering and its Influences on Mechanical Performance}}}, year = {{2022}}, } @inproceedings{31871, author = {{Kletetzka, Ivo and Klippstein, Sven Helge}}, booktitle = {{3D-DRUCK HAUTNAH - Der Einfluss einer Zukunftstechnologie auf unser Leben }}, location = {{Paderborn}}, publisher = {{Universität Paderborn}}, title = {{{Pulver im 3D-Druck - von Mascarabürsten bis zum Interieur eines Mini-Coopers (Vortrag)}}}, year = {{2022}}, } @misc{43011, author = {{Hanselle, Felix Paul}}, title = {{{Untersuchung und Modellierung der Materialeigenschaften von glaskugelgefüllten, im Lasersinterprozess verarbeiteten Dry-Blends}}}, year = {{2022}}, } @misc{43010, author = {{Kosanke, Maren}}, title = {{{Oberflächenmodifikation von Glaskugeln zur Verbesserung der Adhäsion im Lasersinterverfahren}}}, year = {{2022}}, } @misc{43007, author = {{Henke, Frederic}}, title = {{{Potenzialanalyse für die Nutzung additiver Fertigungsverfahren bei einem Büromöbelhersteller und Realisierung eines Beispielbauteils (Studienarbeit)}}}, year = {{2022}}, } @misc{46858, author = {{Ostermeier, Jakob}}, title = {{{Einfluss des Lasersinter-Prozesses auf die Recyclingfähigkeit von flammgeschütztem PA12 Pulver}}}, year = {{2022}}, } @misc{43012, author = {{Sural, Ilknur}}, title = {{{Einfluss der Lagerdauer von PA12- Lasersinterpulver auf die Verarbeitungs- und Bauteileigenschaft}}}, year = {{2022}}, } @inproceedings{33852, author = {{Moritzer, Elmar and Hecker, Felix}}, booktitle = {{Proceedings of the 33rd Annual Freeform Fabrication Symposium}}, editor = {{Bourell, David L. and Beaman, Joseph J. and Crawford, Richard H. and Kovar, Desiderio and Seepersad, Carolyn C. and Tehrani, Mehran}}, location = {{Austin, Texas, USA}}, pages = {{2011--2018}}, title = {{{VALIDATION AND COMPARISON OF FEM-SIMULATION RESULTS OF THE FUSED DEPOSITION MODELING PROCESS UNDER CONSIDERATION OF DIFFERENT MESH RESOLUTIONS}}}, doi = {{10.26153/tsw/44657}}, year = {{2022}}, } @inproceedings{30220, abstract = {{In this work, the influences of spherical fillers on the processing properties and the resulting mechanical properties of laser sintered components are investigated. For this purpose, micro glass spheres, hollow glass bubbles and mineral spheres are dry blended to the matrix polymers polyamide 613 and polypropylene with a filling ratio of 20 and 40 vol%. First, relevant properties of the blends, such as powder flowability, thermal behavior and melt viscosity, are investigated. Based on the results, processing parameters are then developed for the LS process and the mechanical properties of the components are investigated. The aim is to be able to tailor the mechanical properties of LS components by adding fillers and thus to create new application areas for additively manufactured components. }}, author = {{Kletetzka, Ivo and Gawlikowicz, Roland and Schmid, Hans-Joachim}}, booktitle = {{Proceedings of the 33th Annual International Solid Freeform Fabrication Symposium}}, location = {{Austin}}, publisher = {{Laboratory for Freeform Fabrication and University of Texas}}, title = {{{Effects of spherical fillers on the processability and mechanical properties of PA613 and PP-based LS dry blends}}}, doi = {{http://dx.doi.org/10.26153/tsw/44558}}, volume = {{33}}, year = {{2022}}, } @inproceedings{32874, author = {{Kletetzka, Ivo and Klippstein, Sven Helge and Schmid, Hans-Joachim}}, booktitle = {{Proceedings of the 33th Annual International Solid Freeform Fabrication Symposium}}, location = {{Austin}}, publisher = {{Laboratory for Freeform Fabrication and University of Texas}}, title = {{{Shelf Life of Polyamide 12 (PA2200) Laser Sintering Powder}}}, doi = {{http://dx.doi.org/10.26153/tsw/44555}}, volume = {{33}}, year = {{2022}}, } @inproceedings{50744, abstract = {{The manufacturing industry contributes immensely to the global emissions and therefore is a key factor that has to be addressed when a more sustainable production is desired. Laser Powder Bed Fusion (LPBF) is an AM technique that offers the possibility to manufacture metal parts in a more material efficient way due to the layer-by-layer build-up. Nevertheless, the processing chain for parts from LPBF contains additional steps like powder atomization, which also influence the ecological footprint of the production chain. Within this work, a life-cycle model for the production step of parts from AlSi10Mg powder material is developed. The model is supplied with data from the powder atomization up to the production step, either by literature, database or experimental measurements during production. The footprint in terms of CO2 emissions is then analyzed and emission-intense steps are identified. Two manufacturing scenarios are considered to evaluate the sensitivity on the emissions.}}, author = {{Bödger, Christian and Weiss, Christian and Schiefer, Ekkehard and Heussen, Daniel and Haefner, Constantin}}, booktitle = {{Proceedings of the 33rd Annual International Solid Freeform Fabrication Symposium – An Additive Manufacturing Conference}}, location = {{Austin}}, title = {{{Evaluation of the Ecological Footprint for Parts from AlSi10Mg manufactured by Laser Powder Bed Fusion}}}, year = {{2022}}, } @inproceedings{33853, author = {{Moritzer, Elmar and Hecker, Felix}}, booktitle = {{Proceedings of the 33rd Annual Freeform Fabrication Symposium}}, editor = {{Bourell, David L. and Beaman, Joseph J. and Crawford, Richard H. and Kovar, Desiderio and Seepersad, Carolyn C. and Tehrani, Mehran}}, location = {{Austin, Texas, USA}}, pages = {{1844--1858}}, title = {{{INVESTIGATION OF THE PROCESS PARAMETERS AND GEOMETRY DEPENDENT SHRINKAGE BEHAVIOR OF RASTER LINES IN THE FUSED DEPOSITION MODELING PROCESS}}}, doi = {{10.26153/tsw/44654}}, year = {{2022}}, } @phdthesis{24760, abstract = {{Anwendungen von Laser-Sinter Bauteilen als Sichtteile sind aufgrund der vergleichsweise schlechten Oberflächenqualität sehr begrenzt. In dieser Arbeit werden dreidimensionale Kennwerte benutzt, um die Oberflächenqualität von Laser-Sinter Bauteiloberflächen und die Einflüsse aus unterschiedlichen Bereichen der gesamten Prozesskette zu evaluieren. Beispielsweise wurden objektive Kennwerte, mit deren Hilfe Orangenhaut zu identifizieren ist, und Prozessparameter, die diese deutlich vermindern, gefunden. Mittels Durchführung von haptischen Versuchen wurde das subjektive Empfinden ermittelt und konnten zu objektiven Kennwerten korreliert werden. Eine mikroskopische Betrachtung des flachen Oberflächenwinkels mit verschieden farbigen Pulvern zeigt neue Erkenntnisse zum Anschmelzvorgang von Partikeln an die Schmelze. Zur nachträglichen Glättung von Oberflächen wurden mechanische, chemische und optische Nachbehandlungsmethoden verwendet und deren Potential aufgezeigt. Eine abschließende neuartige Simulation der dreidimensionalen Topografie bildet die Grundlage für ein Programm zur automatischen und funktionsgerechten Orientierung von Bauteilen, welche am Beispiel eines realen Bauteils erfolgreich validiert wurde. Zusammengenommen zeigen die Ergebnisse, dass die richtige Wahl von Bauorientierung und Prozessparametern entscheidend für die Bauteilqualität ist und selbst eine aufwendige Nachbearbeitung eine ungeschickte Wahl derer nur schwerlich ausgleichen kann. }}, author = {{Delfs, Patrick}}, isbn = {{978-3-8440-7825-1}}, keywords = {{Additive Fertigung, Oberflächenqualität, 3D, Topografie, Simulation, PA12, Laser-Sintern, Rauheit}}, pages = {{126}}, publisher = {{Shaker Verlag GmbH}}, title = {{{Dreidimensionale Oberflächenanalyse und Topografie-Simulation additiv hergestellter Laser-Sinter Bauteile}}}, volume = {{22}}, year = {{2021}}, } @phdthesis{24770, abstract = {{Das Fused Deposition Modeling (FDM) ist ein Verfahren zur additiven Fertigung (AF), welches von der Firma Stratasys Ltd. (früher Stratasys Inc.) kommerzialisiert wurde. Heute existieren auch FDM Maschinen anderer Hersteller. Im Gegensatz zu den Maschinen von Stratasys können bei diesen die Prozessparameter frei gewählt werden. Dadurch ist die Verarbeitung herstellerfremder Materialien möglich. Wie in allen AF-Verfahren, werden im FDM bestimmte Anforderungen an die zu verarbeitenden Materialien gestellt. Die Materialien sollten daher speziell für das FDM ausgewählt bzw. entwickelt werden. Die für eine gute Verarbeitbarkeit notwendigen Materialeigenschaften sind aktuell jedoch nicht hinreichend bekannt. Vielmehr sind auch keine Vorgehensweisen bekannt, um die Verarbeitungseignung verschiedener Materialien im FDM zu bewerten. Im Rahmen dieser Arbeit werden daher Vorgehensweisen vorgestellt, um die Verarbeitungseignung thermoplastischer Kunststoffe im FDM anhand bestimmter Merkmale zu bewerten. Die Schweißnahtqualität, der Bauteilverzug und die Gestaltungsfreiheit werden als wichtige Merkmale identifiziert. Unter Beachtung relevanter Einflussgrößen werden je Merkmal Probekörper und Prüfmethoden entwickelt, um merkmalspezifische Kennwerte zu definieren. Dadurch ist der Vergleich unterschiedlicher Materialien, unabhängig von der verwendeten Maschine und der Datenaufbereitung, möglich. Letztendlich werden verschiedene Materialmodifikationen auf Basis von PA 6 erstellt und mit Hilfe der vorgestellten Vorgehensweisen untersucht und bewertet.}}, author = {{Schumacher, Christian}}, isbn = {{978-3-8440-7925-8}}, pages = {{262}}, publisher = {{Shaker Verlag}}, title = {{{Erarbeitung eines methodischen Vorgehens zur merkmalspezifischen Charakterisierung der Verarbeitungseignung von nicht verstärkten und faserverstärkten Kunststoffen im Fused Deposition Modeling am Beispiel von Polyamid 6}}}, volume = {{24}}, year = {{2021}}, } @article{28017, abstract = {{Processing aluminum alloys employing powder bed fusion of metals (PBF-LB/M) is becoming more attractive for the industry, especially if lightweight applications are needed. Unfortunately, high-strength aluminum alloys such as AA7075 are prone to hot cracking during PBF-LB/M, as well as welding. Both a large solidification range promoted by the alloying elements zinc and copper and a high thermal gradient accompanied with the manufacturing process conditions lead to or favor hot cracking. In the present study, a simple method for modifying the powder surface with titanium carbide nanoparticles (NPs) as a nucleating agent is aimed. The effect on the microstructure with different amounts of the nucleating agent is shown. For the aluminum alloy 7075 with 2.5 ma% titanium carbide nanoparticles, manufactured via PBF-LB/M, crack-free samples with a refined microstructure having no discernible melt pool boundaries and columnar grains are observed. After using a two-step ageing heat treatment, ultimate tensile strengths up to 465 MPa and an 8.9% elongation at break are achieved. Furthermore, it is demonstrated that not all nanoparticles used remain in the melt pool during PBF-LB/M.}}, author = {{Heiland, Steffen and Milkereit, Benjamin and Hoyer, Kay-Peter and Zhuravlev, Evgeny and Keßler, Olaf and Schaper, Mirko}}, journal = {{Materials}}, keywords = {{grain refinement, crack reduction, laser beam melting, aluminum alloy, titanium carbide, nanoparticle, PBF-LB/M}}, title = {{{Requirements for Processing High-Strength AlZnMgCu Alloys with PBF-LB/M to Achieve Crack-Free and Dense Parts}}}, doi = {{https://doi.org/10.3390/ma14237190}}, year = {{2021}}, } @misc{24095, author = {{Moritzer, Elmar and Hecker, Felix and Hirsch, André}}, booktitle = {{Kunststoffland NRW report}}, number = {{2}}, pages = {{42--43}}, title = {{{Aus der Forschung in die Anwendung - Materialqualifizierung im Kunststoff Freiformen}}}, volume = {{2021}}, year = {{2021}}, } @article{24168, author = {{Moritzer, Elmar and Wächter, Julian}}, issn = {{0032-1338}}, journal = {{Plastverarbeiter}}, number = {{04}}, pages = {{30--32}}, title = {{{Einfluss eines beheizten Bauraums auf die Schweißnahtqualität}}}, year = {{2021}}, } @misc{24556, author = {{Moritzer, Elmar and Hecker, Felix and Hirsch, André}}, booktitle = {{Kunststoffe}}, number = {{9/2021}}, pages = {{88--90}}, title = {{{Kleine Tropfen, große Wirkung}}}, year = {{2021}}, }