@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}},
}
@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}},
}
@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{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}}},
doi = {{https://doi.org/10.26153/tsw/50931}},
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}}},
doi = {{https://doi.org/10.26153/tsw/50926}},
year = {{2023}},
}
@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}},
}
@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{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}},
}
@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}}},
doi = {{https://doi.org/10.3139/9783446479425.001 }},
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}}},
doi = {{https://doi.org/10.26153/tsw/50920}},
volume = {{34}},
year = {{2023}},
}