@article{46494,
abstract = {{To improve the mechanical performance and to address current shortcomings of adhesive bonds such as bond degradation due to aging, a pulsed laser surface pretreatment of the metal surfaces of aluminum AW 6082-T6 joints with epoxy adhesive E320 is investigated. The surface treatment of the specimens resulted in increased single-lap shear (SLS) strengths before and after hydrothermal aging in 80°C hot water compared to nonpretreated reference specimens. In order to reveal the correlations of laser parameters, resulting surface morphologies and the SLS strength, differently laser pretreated surfaces were characterized at the micro- and nanoscale using optical and scanning electron microscopies. The surface enlargement was quantified with a digital image analysis of cross-sections prepared from the joint interfaces. An analysis of variances (ANOVA) of the SLS results indicated that the laser parameters power and pulse frequency were most critical for obtaining high SLS strengths. Pretreated joint surfaces with a high micro- and nano-surface enlargement and deep solidification structures provide high SLS strengths of up to 50 MPa and almost negligible aging losses of merely 4%. Undercut structures on the pretreated surfaces were found to be beneficial for the mechanical and aging properties when only limited micro- and nanostructuring was applied.}},
author = {{Freund, Jonathan and Löbbecke, Miriam and Delp, Alexander and Walther, Frank and Wu, Shuang and Tröster, Thomas and Haubrich, Jan}},
issn = {{0021-8464}},
journal = {{The Journal of Adhesion}},
keywords = {{Materials Chemistry, Surfaces, Coatings and Films, Surfaces and Interfaces, Mechanics of Materials, General Chemistry}},
pages = {{1--31}},
publisher = {{Informa UK Limited}},
title = {{{Relationship between laser-generated micro- and nanostructures and the long-term stability of bonded epoxy-aluminum joints}}},
doi = {{10.1080/00218464.2023.2223475}},
year = {{2023}},
}
@article{55760,
abstract = {{The transferability of structure–property relationships for laser-pretreated metal adhesive joints to laser-pretreated metal–carbon-fiber-reinforced plastic (CFRP) bonds was investigated. Single-lap shear tests were performed on hybrid AW 6082-T6–CFRP specimens pretreated with the same pulsed laser surface parameter sets on the metal surface as previously tested, AW 6082-T6–E320 metal adhesive joints. The fracture surfaces were characterized to determine the type of failure and elucidate differences and commonalities in the link between surface structures and single-lap shear strengths. Digital image analyses of the hybrid specimens’ fractured surfaces were used to quantify remaining CFRP fragments on the metallic joint side. The results indicate that high surface enlargements and the presence of undercut structures lead to single-lap shear strengths exceeding 40 MPa and 35 MPa for unaged and aged hybrid specimens, respectively. Whereas for the metal–polymer joints, the trend from high strength to weakly bonded specimens is largely continuous with the degree of surface structuring, hybrid metal–CFRP joints exhibit a drastic drop in joint performance after aging if the laser-generated surface structures are less pronounced with low surface enlargements and crater depths. Surface features and hydrothermal aging determine whether the specimens fail cohesively or adhesively.}},
author = {{Freund, Jonathan and Lützenkirchen, Isabel and Löbbecke, Miriam and Delp, Alexander and Walther, Frank and Wu, Shuang and Tröster, Thomas and Haubrich, Jan}},
issn = {{2504-477X}},
journal = {{Journal of Composites Science}},
number = {{10}},
publisher = {{MDPI AG}},
title = {{{Transferability of the Structure–Property Relationships from Laser-Pretreated Metal–Polymer Joints to Aluminum–CFRP Hybrid Joints}}},
doi = {{10.3390/jcs7100427}},
volume = {{7}},
year = {{2023}},
}
@article{46495,
abstract = {{A parameter investigation for manufacturing a hybrid system through the prepreg pressing process was carried out within the scope of this work to achieve optimal adhesion properties. The hybrid specimen comprises an aluminium sheet of alloy EN AW 6082 in T6 condition and a thermoset Carbon Fibre Reinforced Plastics prepreg. The prepreg pressing process allows the curing reaction of epoxy resin and the joining process to occur simultaneously to avoid an additional bonding process step. The surface of the aluminium sheet was pretreated in advance using a pulsed Nd:YAG laser to enhance the bonding properties. In the first step, the shear edge tests investigated the adhesion properties achieved with different consolidation (temperature, time and pressure) and laser parameters. Then, 3-point bending tests were carried out to investigate the influence of the consolidation parameters on the mechanical properties of the Carbon Fibre Reinforced Plastics-laminate. In this way, the optimal parameter sets for manufacturing hybrid structures were determined.}},
author = {{Wu, Shuang and Delp, Alexander and Freund, Jonathan and Walther, Frank and Haubrich, Jan and Löbbecke, Miriam and Tröster, Thomas}},
issn = {{0021-8464}},
journal = {{The Journal of Adhesion}},
keywords = {{Materials Chemistry, Surfaces, Coatings and Films, Surfaces and Interfaces, Mechanics of Materials, General Chemistry}},
pages = {{1--29}},
publisher = {{Informa UK Limited}},
title = {{{Adhesion properties of the hybrid system made of laser-structured aluminium EN AW 6082 and CFRP by co-bonding-pressing process}}},
doi = {{10.1080/00218464.2023.2245758}},
year = {{2023}},
}
@inproceedings{48597,
abstract = {{This paper introduces an intrinsic manufacturing process of a hat profile made of laser-pretreated aluminium sheet of alloy EN AW-6082 in T6 condition and carbon fibre-reinforced plastic (CFRP) prepreg. The resin system used in combination with CFRP was epoxy resin (EP). Before manufacturing, the laser-pretreated aluminium sheet and CFRP prepreg were stacked to form a multi-layer composite, which was pressed simultaneously in one process step. The optimal CFRP layer structure was calculated in advance using the finite element method. During the forming process, the curing reaction and the joining of the aluminium sheet and CFRP prepreg will take place simultaneously. Thus, further joining techniques such as bonding and riveting could be saved, and a much more efficient process could be achieved. After manufacturing, shear-edge test was used to characterize the adhesion properties of the hybrid part.}},
author = {{Wu, Shuang and Freund, Jonathan and Delp, Alexander and Haubrich, Jan and Löbbecke, Miriam and Walther, Frank and Tröster, Thomas}},
title = {{{Intrinsic forming of hybrid parts made of laser-structured aluminium sheet and CFRP-Prepreg}}},
year = {{2023}},
}
@inproceedings{49436,
author = {{Kaiser, Maximilian Alexander and Reitz, Alexander and Konrad, Stefan and Meyer, Thomas and Marten, Thorsten and Tröster, Thomas}},
booktitle = {{Workshop Warmblechumformung}},
editor = {{Merklein, Marion}},
isbn = {{978-3-00-077160-6}},
keywords = {{Presshärten, resistive Schnellerwärmung, Energieeffizienz}},
location = {{Fürth}},
pages = {{99--118}},
publisher = {{Lehrstuhl für Fertigungstechnologie}},
title = {{{Untersuchung energieeffizienter und serientauglicher Erwärmungsstrategien mittels resistiver Erwärmung für den Presshärteprozess}}},
volume = {{18}},
year = {{2023}},
}
@inbook{48642,
author = {{Akbulut Irmak, Emine Fulya and Hanses, Hendrik and Horwath, Ilona and Tröster, Thomas}},
booktitle = {{Climate Protection, Resource Efficiency, and Sustainable Engineering}},
editor = {{Horwath, Ilona and Schweizer, Swetlana}},
isbn = {{9783837663778}},
issn = {{2703-1543}},
publisher = {{transcript Verlag}},
title = {{{Case Study III: Challenges of lightweight design, vehicles, and rescuers}}},
doi = {{10.14361/9783839463772-006}},
year = {{2023}},
}
@article{47536,
abstract = {{AbstractEfforts to enhance sustainability in all areas of life are increasing worldwide. In the field of manufacturing technology, a wide variety of approaches are being used to improve both resource and energy efficiency. Efficiency as well as sustainability can be improved by creating a circular economy or through energy-efficient recycling processes. As part of the interdisciplinary research group "Light—Efficient—Mobile" investigations on the energy-efficient friction-induced recycling process have been carried out at the department of Forming and Machining Technology at Paderborn University. E.g. using the friction-induced recycling process, different formless solid aluminum materials can be direct recycled into semi-finished products in an energy-efficient manner. The results of investigations with regard to the influence of the geometrical shape and filling rate of the aluminum particles to be recycled as well as the rotational speed of the continuously rotating wheel are explained in this paper. In addition to the recycling of aluminum chips, aluminum particles like powders from the field of additive manufacturing are processed. Based on these results, the future potentials of solid-state recycling processes and their contribution to the circular economy are discussed. The main focus here is on future interdisciplinary research projects to achieve circularity in the manufacturing of user-individual semi-finished products as well as the possibility to selectively adjust the product properties with the continuous recycling process.}},
author = {{Borgert, Thomas and Milaege, Dennis and Schweizer, Swetlana and Homberg, Werner and Schaper, Mirko and Tröster, Thomas}},
issn = {{1960-6206}},
journal = {{International Journal of Material Forming}},
keywords = {{General Materials Science}},
number = {{6}},
publisher = {{Springer Science and Business Media LLC}},
title = {{{Potentials of a friction-induced recycling process to improve resource and energy efficiency in manufacturing technology}}},
doi = {{10.1007/s12289-023-01785-w}},
volume = {{16}},
year = {{2023}},
}
@article{46486,
author = {{Pfeifer, Florian and Knorr, Lukas and Schlosser, Florian and Marten, Thorsten and Tröster, Thomas}},
issn = {{1848-9257}},
journal = {{Journal of Sustainable Development of Energy, Water and Environment Systems}},
keywords = {{Energy Engineering and Power Technology, Water Science and Technology, Environmental Science (miscellaneous), Renewable Energy, Sustainability and the Environment}},
number = {{3}},
pages = {{1--20}},
publisher = {{SDEWES Centre}},
title = {{{Ecological and Economic Feasibility of Inductive Heating for Sustainable Press Hardening Processes}}},
doi = {{10.13044/j.sdewes.d11.0450}},
volume = {{11}},
year = {{2023}},
}
@inbook{34165,
author = {{Hanses, Hendrik and Akbulut Irmak, Emine Fulya and Horwath, Ilona and Tröster, Thomas}},
booktitle = {{ Climate Protection, Resource Efficiency, and Sustainable Engineering. Transdisciplinary Approaches to Design and Manufacturing Technology}},
editor = {{Horwath, Ilona and Schweizer, Swetlana}},
isbn = {{978-3-8376-6377-8}},
publisher = {{transcript Verlag}},
title = {{{Challenges of lightweight design, vehicles, and rescuers}}},
year = {{2023}},
}
@inproceedings{60905,
author = {{Ostermann, Moritz and Dierkes, Eric and Marten, Thorsten and Tröster, Thomas}},
booktitle = {{Proceedings of the 18th Conference on Sustainable Development of Energy, Water and Environmental Systems, Dubrovnik, Croatia 2023}},
location = {{Dubrovnik, Croatia}},
title = {{{Life Cycle Assessment of Lightweight Structures in Vehicles for New Mobility Concepts}}},
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}},
}
@article{37200,
abstract = {{(1) This work answers the question of whether and to what extent there is a significant difference in mechanical properties when different additive manufacturing processes are applied to the material 1.2709. The Laser-Powder-Bed-Fusion (L-PBF) and Laser-Metal-Deposition (LMD) processes are considered, as they differ fundamentally in the way a part is manufactured. (2) Known process parameters for low-porosity parts were used to fabricate tensile strength specimens. Half of the specimens were heat-treated, and all specimens were tested for mechanical properties in a quasi-static tensile test. In addition, the material hardness was determined. (3) It was found that, firstly, heat treatment resulted in a sharp increase in mechanical properties such as hardness, elastic modulus, yield strength and ultimate strength. In addition to the increase in these properties, the elongation at break also decreases significantly after heat treatment. The choice of process, on the other hand, does not give either process a clear advantage in terms of mechanical properties but shows that it is necessary to consider the essential mechanical properties for a desired application.}},
author = {{Gnaase, Stefan and Niggemeyer, Dennis and Lehnert, Dennis and Bödger, Christian and Tröster, Thomas}},
issn = {{2073-4352}},
journal = {{Crystals}},
keywords = {{Inorganic Chemistry, Condensed Matter Physics, General Materials Science, General Chemical Engineering}},
number = {{2}},
publisher = {{MDPI AG}},
title = {{{Comparative Study of the Influence of Heat Treatment and Additive Manufacturing Process (LMD & L-PBF) on the Mechanical Properties of Specimens Manufactured from 1.2709}}},
doi = {{10.3390/cryst13020157}},
volume = {{13}},
year = {{2023}},
}
@misc{52427,
author = {{Schlüter, Alexander}},
publisher = {{Marcus Nettelbeck}},
title = {{{2050 - The Future Podcast, Folge The Energy Systems of the Future}}},
year = {{2023}},
}
@article{30894,
author = {{Tuzgel, Firat and Akbulut Irmak, Emine Fulya and Guzel, Erkan and Yucesoy, Atacan and Sahin, Selim and Tasdemirci, Alper and Guden, Mustafa}},
issn = {{0263-8231}},
journal = {{Thin-Walled Structures}},
keywords = {{Mechanical Engineering, Building and Construction, Civil and Structural Engineering}},
publisher = {{Elsevier BV}},
title = {{{Testing and modeling blast loading of a sandwich structure cored with a bio-inspired (balanus) core}}},
doi = {{10.1016/j.tws.2022.109185}},
volume = {{175}},
year = {{2022}},
}
@article{30922,
abstract = {{AbstractPure iron is very attractive as a biodegradable implant material due to its high biocompatibility. In combination with additive manufacturing, which facilitates great flexibility of the implant design, it is possible to selectively adjust the microstructure of the material in the process, thereby control the corrosion and fatigue behavior. In the present study, conventional hot-rolled (HR) pure iron is compared to pure iron manufactured by electron beam melting (EBM). The microstructure, the corrosion behavior and the fatigue properties were studied comprehensively. The investigated sample conditions showed significant differences in the microstructures that led to changes in corrosion and fatigue properties. The EBM iron showed significantly lower fatigue strength compared to the HR iron. These different fatigue responses were observed under purely mechanical loading as well as with superimposed corrosion influence and are summarized in a model that describes the underlying failure mechanisms.}},
author = {{Wackenrohr, Steffen and Torrent, Christof Johannes Jaime and Herbst, Sebastian and Nürnberger, Florian and Krooss, Philipp and Ebbert, Christoph and Voigt, Markus and Grundmeier, Guido and Niendorf, Thomas and Maier, Hans Jürgen}},
issn = {{2397-2106}},
journal = {{npj Materials Degradation}},
keywords = {{Materials Chemistry, Materials Science (miscellaneous), Chemistry (miscellaneous), Ceramics and Composites}},
number = {{1}},
publisher = {{Springer Science and Business Media LLC}},
title = {{{Corrosion fatigue behavior of electron beam melted iron in simulated body fluid}}},
doi = {{10.1038/s41529-022-00226-4}},
volume = {{6}},
year = {{2022}},
}
@article{30923,
abstract = {{Additive manufacturing (AM) processes are not solely used where maximum design freedom meets low lot sizes. Direct microstructure design and topology optimization can be realized concomitantly during processing by adjusting the geometry, the material composition, and the solidification behavior of the material considered. However, when complex specific requirements have to be met, a targeted part design is highly challenging. In the field of biodegradable implant surgery, a cytocompatible material of an application-adapted shape has to be characterized by a specific degradation behavior and reliably predictable mechanical properties. For instance, small amounts of oxides can have a significant effect on microstructural development, thus likewise affecting the strength and corrosion behavior of the processed material. In the present study, biocompatible pure Fe was processed using electron powder bed fusion (E-PBF). Two different modifications of the Fe were processed by incorporating Fe oxide and Ce oxide in different proportions in order to assess their impact on the microstructural evolution, the mechanical response and the corrosion behavior. The quasistatic mechanical and chemical properties were analyzed and correlated with the final microstructural appearance.}},
author = {{Torrent, Christof J. J. and Krooß, Philipp and Huang, Jingyuan and Voigt, Markus and Ebbert, Christoph and Knust, Steffen and Grundmeier, Guido and Niendorf, Thomas}},
issn = {{2674-063X}},
journal = {{Alloys}},
number = {{1}},
pages = {{31--53}},
publisher = {{MDPI AG}},
title = {{{Oxide Modified Iron in Electron Beam Powder Bed Fusion—From Processability to Corrosion Properties}}},
doi = {{10.3390/alloys1010004}},
volume = {{1}},
year = {{2022}},
}
@article{29947,
author = {{Schall, Christoph Wilhelm Theodor and Schöppner, Volker}},
journal = {{Polymer Engineering and Science}},
keywords = {{Computing Resources Provided by the Paderborn Center for Parallel Computing}},
number = {{3}},
pages = {{815--823}},
title = {{{Measurement of material degradation in dependence of shear rate, temperature, and residence time}}},
doi = {{10.1002/pen.25887}},
volume = {{62}},
year = {{2022}},
}
@misc{31789,
author = {{Hopp, Matthias and Tölle, Lisa}},
booktitle = {{Journal of Applied Polymer Science}},
pages = {{1--13}},
title = {{{Influence of process parameters on the formation of inhalable fiber dust during shredding for mechanical recycling of fiber‐reinforced organo sheets}}},
year = {{2022}},
}
@misc{31788,
author = {{Hopp, Matthias and Tölle, Lisa and Bünger, J. and Westphal, G. and Rosenkranz, N. and Monsé, C.}},
booktitle = {{ Kunststoffe international}},
pages = {{12--15}},
title = {{{Fiber Dust Formation during the Recycling of FRP}}},
year = {{2022}},
}
@misc{31787,
author = {{Hopp, Matthias and Tölle, Lisa and Bünger, J. and Westphal, G. and Rosenkranz, N. and Monsé, C.}},
booktitle = {{Kunststoffe}},
pages = {{52--55}},
title = {{{Faserstäube beim FVK-Recycling}}},
year = {{2022}},
}