@proceedings{22453, editor = {{Wiens, Eugen and Wischer, Christian and Homberg, Werner}}, title = {{{Development of a novel adaptive joining technology employing Friction-Spun Joint Connectors (FSJC)}}}, doi = {{10.25518/esaform21.4682}}, year = {{2021}}, } @article{21444, author = {{Heggemann, Thomas and Homberg, Werner and Sapli, Hüseyin}}, issn = {{2351-9789}}, journal = {{Procedia Manufacturing}}, pages = {{36--42}}, title = {{{Combined Curing and Forming of Fiber Metal Laminates}}}, doi = {{10.1016/j.promfg.2020.04.118}}, year = {{2020}}, } @inproceedings{21522, author = {{Sapli, Hüseyin and Heggemann, Thomas and Homberg, Werner}}, location = {{Karlsruhe}}, title = {{{Combined Curing and Deep Drawing of Fiber Metal Laminates to Spherical Hybrid Components}}}, year = {{2020}}, } @inproceedings{22965, author = {{Rozo Vasquez, Julian and Arian, Bahman and Riepold, Markus and Homberg, Werner and Trächtler, Ansgar and Walther, Frank}}, booktitle = {{ 54. Metallographie-Tagung}}, pages = {{75--81}}, title = {{{Microstructural investigation on phase transformation during flow forming of the metastable austenite AISI 304 }}}, year = {{2020}}, } @article{30713, author = {{Rostek, Tim and Wiens, Eugen and Homberg, Werner}}, journal = {{Procedia Manufacturing}}, pages = {{395--399}}, publisher = {{ Elsevier Ltd}}, title = {{{Joining with Versatile Friction-Spun Joint Connectors}}}, doi = {{10.1016/j.promfg.2020.04.313}}, volume = {{47}}, year = {{2020}}, } @inproceedings{21447, abstract = {{Even though the spectrum of parts is expected to shift over the long term as a result of increasing e-mobility, there is still an extremely high demand for complex components made of high-strength materials which can only be produced by hydroforming technologies. The innovative combination of hydroforming processes with other forming processes, as well as the improvement of the processes themselves, offers considerable potential for improvement. A number of promising ways of improving the hydroforming process chain are therefore the subject of this contribution. The focus of the article is on possible approaches for combining (incremental) pre- and post-forming operations, which can permit considerable improvements in both quality and features at a reduced cost. Furthermore, a novel combination of quasi-static and high-speed forming processes is presented, leading to an improved overall forming process (with a high application potential) for the production of complex parts. }}, author = {{Wiens, Eugen and Djakow, Eugen and Homberg, Werner}}, booktitle = {{Nebu/Nehy 2020}}, keywords = {{Hydroforming, Incremental Forming, Internal Flow-turning, High-speed Forming}}, title = {{{Some ideas for the further development of hydroforming process chains}}}, year = {{2020}}, } @article{21443, abstract = {{Current challenges in the automotive industry are the reduction of fuel consumption and the CO2 emissions of future car generations. These aims can be achieved by reducing the weight of the car, which further improves the driving dynamics. In most currently mass-produced cars, the body accounts for one of the largest parts by weight, and hence designing a lightweight car body assumes great importance for reducing fuel consumption and CO2 emissions. Extremely lightweight designs can be achieved by using purely composite materials, which are very light but also highly cost intensive and not yet suitable for large scale production due to the necessity of manual processing. A promising approach for the automated, large-scale production of lightweight car structures with a high stiffness to weight ratio is the combination of high strength steel alloys and CFRP prepregs in a special hybrid material/fiber metal laminate (FML) – which can be further processed by forming technologies such as deep drawing. In current research work at the Chair of Forming and Machining Technology (LUF) at the University of Paderborn, innovative manufacturing processes are being developed for the production of high strength automotive structural components made of fiber metal laminates. This paper presents the results of technological and numerical research that is currently being performed at the LUF into the forming of hybrid fiber metal laminates. This paper focuses on the results of basic research and the individual measures (tool, process and material design) necessary for achieving the desired part quality. }}, author = {{Heggemann, Thomas and Homberg, Werner}}, issn = {{0263-8223}}, journal = {{Composite Structures}}, pages = {{53--57}}, title = {{{Deep drawing of fiber metal laminates for automotive lightweight structures}}}, doi = {{10.1016/j.compstruct.2019.02.047}}, year = {{2019}}, } @inproceedings{15024, abstract = {{Abstract. Within the scope of this study, an intrinsically lubricated deep drawing die fabricated via laser beam melting (LBM) is investigated. In contrast to the common objective of generating highly dense LBM components, this work endeavors to achieve intended micro-scale porosity. By utilizing permeable structures, in-process closed-loop control of lubrication during the forming operations is feasible. Based on a modified AM scan strategy, the required filigree, porous structures can be generated. Thus, in the present work three permeable specimens are additively generated from the maraging steel 1.2709. The cylindrical specimens are then analyzed via light microscopy (LM), microcomputer tomography (microCT), and with regard to the oil throughput rate. Subsequently, an intrinsically lubricated, AM deep drawing tool die is manufactured and experimentally tested. The findings reveal interesting results for deep drawn specimens with AM deep drawing dies.}}, author = {{Bader, Fabian and Hengsbach, Florian and Hoyer, Kay-Peter and Homberg, Werner and Schaper, Mirko}}, booktitle = {{PROCEEDINGS OF THE 22ND INTERNATIONAL ESAFORM CONFERENCE ON MATERIAL FORMING: ESAFORM 2019}}, title = {{{Intrinsically lubricated tool inserts for deep drawing applications generated by selective laser melting}}}, doi = {{10.1063/1.5112720}}, year = {{2019}}, } @article{15028, abstract = {{Friction-spinning is an incremental forming process, which is accompanied by complex thermal and mechanical loads in the tool and the formed part. To influence the process temperature, two main process parameters, i.e. the rotation speed and the feed rate, can be adapted. With the objective to improve the tool performance and the quality of the workpiece, this study focuses on a coating concept for friction-spinning tools made of high speed steel (HS6 5 2C, 1.3343). On the one hand, atmospheric plasma sprayed (APS) Al2O3 and ZrO2-8Y2O3 coatings serve as a thermal insulator, and, on the other hand, physically vapor deposited (PVD) TiAlSi7.9N and CrAlSi7.5N films are applied to increase the hardness and wear resistance of the tools. In addition, duplex coatings, combining the APS and PVD technique, are synthesized to influence both the heat transfer and the tribological properties of friction-spinning tools. Subsequently, all coated tools are tested in a friction-spinning process to form flanges made of AW-6060 (AlMgSi 3.3206) tube materials. The tool temperatures are determined in-situ to investigate the impact of the tool coating on the process temperature. Compared to an uncoated tool, the alumina and zirconia coatings contribute to a reduction of the tool temperature by up to half, while the PVD films increase the hardness of the tool by 20 GPa. Furthermore, it is shown that the surface quality of thermally sprayed (TS) or PVD coated tools is directly related to the surface roughness of the resulting workpiece. }}, author = {{Tillmann, Wolfgang and Fehr, Alexander and Stangier, Dominic and Dildrop, Markus and Homberg, Werner and Lossen, Benjamin and Hijazi, Dina}}, issn = {{0944-6524}}, journal = {{Production Engineering}}, pages = {{449--457}}, title = {{{Al2O3/ZrO2-8Y2O3 and (Cr,Ti)AlSiN tool coatings to influence the temperature and surface quality in friction-spinning processes}}}, doi = {{10.1007/s11740-019-00899-y}}, year = {{2019}}, } @phdthesis{15030, abstract = {{Working-media-based forming processes (WMBF) represent a great potential regarding the production of complex sheet-metal lightweight components with excellent surface quality, shape accuracy and dimensional stability. The working-media-based forming processes characterize the sheet-metal forming process, where the sheet metal blank is formed during the forming process by means of a (quasi-)static or dynamic working media pressure into a contouring forming tool. Although the WMBF offers improved utilization of the formability of the used materials compared to conventional sheet metal forming processes, there are limits in the production of complex deeper or sharp edged components with (quasi-)static and dynamic WMBF processes, which can not be overcome by using these methods alone. In order to overcome this, multi-level WMBF process sequences for components with spherical and stepped geometries are developed in this work. Here the developed strategies combine the advantages of (quasi-)static and dynamic WMBF processes. Furthermore, based on analytical, experimental and numerical investigations, innovative process management strategies were derived, which completely compensate the local wall thickness changes, make better use of existing material resources and thus enable the safe production of mentioned geometries.}}, author = {{Djakow, Eugen}}, keywords = {{High Speed Forming}}, pages = {{188}}, publisher = {{Shaker}}, title = {{{Ein Beitrag zur kombinierten (quasi-)statischen und dynamischen Umformung von blechförmigen Halbzeugen}}}, doi = {{ISBN 978-3-8440-6723-1}}, year = {{2019}}, } @article{15031, author = {{Linnemann, M. and Psyk, V. and Djakow, Eugen and Springer, R. and Homberg, W. and Landgrebe, D.}}, issn = {{2351-9789}}, journal = {{Procedia Manufacturing}}, pages = {{21--26}}, title = {{{High-Speed Incremental Forming – New Technologies For Flexible Production Of Sheet Metal Parts}}}, doi = {{10.1016/j.promfg.2018.12.038}}, year = {{2019}}, } @article{15036, author = {{Piper, M. and Zibart, A. and Djakow, Eugen and Springer, R. and Homberg, W. and Kenig, E.Y.}}, issn = {{1359-4311}}, journal = {{Applied Thermal Engineering}}, pages = {{142--146}}, title = {{{Heat transfer enhancement in pillow-plate heat exchangers with dimpled surfaces: A numerical study}}}, doi = {{10.1016/j.applthermaleng.2019.02.082}}, year = {{2019}}, } @phdthesis{42789, author = {{Djakow, Eugen}}, isbn = {{978-3-8440-6723-1}}, title = {{{Ein Beitrag zur kombinierten (quasi-)statischen und dynamischen Umformung von blechförmigen Halbzeugen}}}, year = {{2019}}, } @phdthesis{42810, author = {{Tabakajew, Dmitri}}, isbn = {{978-3-8440-6647-0}}, title = {{{Simulationsgestützte Analyse und Optimierung der Umformung geschlossener Stahlprofile mittels Hamburger Verfahren}}}, year = {{2019}}, } @phdthesis{42809, author = {{Schmidt, Hans Christian}}, title = {{{Ein Beitrag zum stoffschlüssigen Fügen durch plastische Deformation: partielles Kaltpressschweißen durch inkrementelles Walzen}}}, year = {{2019}}, } @phdthesis{42799, author = {{Lossen, Benjamin}}, isbn = {{978-3-8440-6729-3}}, title = {{{Ein Beitrag zur Herstellung von hybriden Bauteilen mittels Reibdrücken}}}, year = {{2019}}, } @inproceedings{21451, author = {{Rostek, Tim and Homberg, Werner}}, booktitle = {{AIP Conference Proceedings 2113, 170018}}, number = {{1}}, publisher = {{AIP Publishing}}, title = {{{Improved set up strategies for steel strip straightening machines}}}, doi = {{10.1063/1.5112734}}, volume = {{2113}}, year = {{2019}}, } @inproceedings{15068, author = {{Wiens, Eugen and Homberg, Werner}}, booktitle = {{PROCEEDINGS OF THE 22ND INTERNATIONAL ESAFORM CONFERENCE ON MATERIAL FORMING: ESAFORM 2019}}, title = {{{Forming analysis of tailored tubes with an internal contoured wall thickness and external axial ribs manufactured by internal flow-turning}}}, doi = {{10.1063/1.5112535}}, year = {{2019}}, } @inproceedings{21457, abstract = {{This paper presents the finite element model developed for the simulation of pipe elbow production by the so-called ‘Hamburg process’ in order to improve productivity and resource efficiency. To optimize the tooling design, a sensitivity analysis of the tool parameters that influence the quality of pipe elbows, such as mandrel height and length, is conducted. Different materials data sets including damage models were considered. Using numerical simulations, it is possible to determine an optimized tool geometry for the production of specific pipe elbow dimensions. Furthermore, as a result of the experiments and numerical simulations conducted, it is possible to increase the production velocity of the serial plant. Along with deformation, damage models are included in simulations in order to identify the right process boundaries. Finally, an experimentally validated model is developed for increasing resource efficiency in pipe elbow fabrication.}}, author = {{Diekmann, Uwe and Homberg, Werner and Prehm, Jens and Rostek, Tim and Schönhoff, Nils and Tabakajew, Dmitri and Trasca, Andreea and Uysal, Haris}}, booktitle = {{Materials Science Forum}}, issn = {{1662-9752}}, pages = {{159--164}}, publisher = {{Trans Tech Publications Ltd}}, title = {{{Optimization of Tooling Design for Hot Mandrel Bending of Pipe Elbows}}}, doi = {{10.4028/www.scientific.net/msf.918.159}}, volume = {{918}}, year = {{2018}}, } @inproceedings{21458, author = {{Rostek, Tim and Homberg, Werner}}, booktitle = {{AIP Conference Proceedings 1960, 100013}}, number = {{1}}, publisher = {{AIP Publishing}}, title = {{{Grading Technologies for the Tanufacture of Innovative Cutting Blades}}}, doi = {{10.1063/1.5034953}}, volume = {{1960}}, year = {{2018}}, }