@inproceedings{56626,
  author       = {{Holzmüller, Maik and Gong, Yi and Bader, Fabian and Henke, Armin and Homberg, Werner}},
  booktitle    = {{Lecture Notes in Mechanical Engineering}},
  isbn         = {{9783031410222}},
  issn         = {{2195-4356}},
  publisher    = {{Springer Nature Switzerland}},
  title        = {{{Numerical Approach to Model a Novel Electrohydraulic Incremental Forming Process for the Manufacture of Pillow Plate Heat Exchangers}}},
  doi          = {{10.1007/978-3-031-41023-9_69}},
  year         = {{2023}},
}

@article{47536,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>Efforts 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.</jats:p>}},
  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{46483,
  abstract     = {{<jats:p>The demands on joining technology are constantly increasing due to the consistent lightweight construction and the associated increasing material mix. To meet these requirements, the adaptability of the joining processes must be improved to be able to process different material combinations and to react to challenges caused by deviations in the process chain. One example of a highly adaptable process due to the two-step process sequence is thermomechanical joining with Friction Spun Joint Connectors (FSJCs) that can be individually adapted to the joint. In this paper, the potentials of the adaption in the two-stage joining process with aluminium auxiliary joining elements are investigated. To this end, it is first investigated whether a thermomechanical forming process can be used to achieve a uniform and controlled manufacturing regarding the process variable of the temperature as well as the geometry of the FSJC. Based on the successful proof of the high and good repeatability in the FSJC manufacturing, possibilities, and potentials for the targeted influencing of the process and FSJC geometry are shown, based on an extensive variation of the process input variables (delivery condition and thus mechanical properties of the raw parts as well as the process parameters of rotational speed and feed rate). Here it can be shown that above all, the feed rate of the final forming process has the strongest influence on the process and thus also offers the strongest possibilities for influencing it.</jats:p>}},
  author       = {{Borgert, Thomas and Henke, Maximilian and Homberg, Werner}},
  issn         = {{2504-4494}},
  journal      = {{Journal of Manufacturing and Materials Processing}},
  keywords     = {{Industrial and Manufacturing Engineering, Mechanical Engineering, Mechanics of Materials}},
  number       = {{4}},
  publisher    = {{MDPI AG}},
  title        = {{{Investigations on the Influences of the Thermomechanical Manufacturing of Aluminium Auxiliary Joining Elements}}},
  doi          = {{10.3390/jmmp7040147}},
  volume       = {{7}},
  year         = {{2023}},
}

@inbook{46752,
  abstract     = {{Due to current global challenges regarding energy security as well as climate change the importance of preserving the nature and all available resources is steadily increasing. In order to achieve the energy-saving and climate targets, it is not only necessary to develop new processes and processing possibilities, but also to optimise known process chains with regard to energy and resource efficiency in the area of production technology. Here, the recycling of supposed production waste represents an opportunity to save energy. In addition to the conventional and smelting metallurgical recycling process, extensive research activities have therefore been carried out for alternative solid-state recycling processes. One example is the friction-induced recycling process, which has been used in past studies to demonstrate the energy- and resource-efficient production of semi-finished products from aluminium scrap such as chips. In addition, properties like chemical composition and strength can be adjusted locally and in terms of processing time. This can be used to improve the versatility of further processing steps.}},
  author       = {{Borgert, Thomas and Homberg, Werner}},
  booktitle    = {{Lecture Notes in Mechanical Engineering}},
  isbn         = {{9783031413407}},
  issn         = {{2195-4356}},
  publisher    = {{Springer Nature Switzerland}},
  title        = {{{Friction-Induced Recycled Aluminium Semi-finished Products in Thermo-mechanical Joining Technology}}},
  doi          = {{10.1007/978-3-031-41341-4_1}},
  year         = {{2023}},
}

@article{47535,
  abstract     = {{Consistent lightweight construction in the area of vehicle manufacturing requires the increased use of multi-material combinations. This, in turn, requires an adaptation of standard joining techniques. In multi-material combinations, the importance of integral cast components, in particular, is increasing and poses additional technical challenges for the industry. One approach to solve these challenges is adaptable joining elements manufactured by a thermomechanical forming process. By applying an incremental and thermomechanical joining process, it is possible to react immediately and adapt the joining process inline to reduce the number of different joining elements. In the investigation described in this publication, cast plates made of the cast aluminium alloy EN AC-AlSi9 serve as joining partners, which are processed by sand casting. The joining process of hypoeutectic AlSi alloys is challenging as their brittle character leads to cracks in the joint during conventional mechanical joining. To solve this, the frictional heat of the novel joining process applied can provide a finer microstructure in the hypoeutectic AlSi9 cast alloy. In detail, its Si is finer-grained, resulting in higher ductility of the joint. This study reveals the thermomechanical joining suitability of a hypoeutectic cast aluminium alloy in combination with adaptively manufactured auxiliary joining elements.}},
  author       = {{Borgert, Thomas and Neuser, Moritz and Hoyer, Kay-Peter and Homberg, Werner and Schaper, Mirko}},
  issn         = {{2504-4494}},
  journal      = {{Journal of Manufacturing and Materials Processing}},
  keywords     = {{Industrial and Manufacturing Engineering, Mechanical Engineering, Mechanics of Materials}},
  number       = {{5}},
  publisher    = {{MDPI AG}},
  title        = {{{Thermomechanical Joining of Hypoeutectic Aluminium Cast Plates}}},
  doi          = {{10.3390/jmmp7050169}},
  volume       = {{7}},
  year         = {{2023}},
}

@inproceedings{43031,
  abstract     = {{Requirements of multi-material construction involve adjustments to standard joining techniques. Especially the growing importance of integral cast components poses additional engineering challenges for the industry. One approach to achieve these goals are adaptable joining elements formed by friction spinning. This approach uses friction-induced heat to form customisable joining elements to join sheets for different boundary conditions, even for brittle cast materials. It is possible to react immediately to adapt to the joining process inline and reduce the amount of different joining elements. As the joining partner serve casting plates of the aluminium casting alloy EN AC–AlSi9, which is processed in the sand casting. Joining hypoeutectic AlSi alloys constitutes a challenge because the brittle character of these cause cracks in the joint during conventional mechanical joining. Furthermore, the friction-induced heat of the novel joining process causes a finer microstructure in the hypoeutectic AlSi9 casting alloy. In particular, the eutectic Si is more fine-grained, resulting in higher joint ductility. This study indicates the joining suitability of a hypoeutectic aluminium casting alloy in combination with adaptive manufactured additional joining elements. Here, various mechanical and microstructural investigations validate the influence of the thermomechanical joining technique. In conclusion, the potential of this joining process is presented regarding the joinability of cast aluminium components.}},
  author       = {{Borgert, Thomas and Neuser, Moritz and Wiens, Eugen and Grydin, Olexandr and Homberg, Werner and Schaper, Mirko}},
  booktitle    = {{Materials Research Proceedings}},
  issn         = {{2474-395X}},
  location     = {{Nürnberg}},
  pages        = {{187--194}},
  publisher    = {{Materials Research Forum LLC}},
  title        = {{{Influence of thermo-mechanical joining process on the microstructure of a hypoeutectic aluminium cast alloy}}},
  doi          = {{10.21741/9781644902417-24}},
  volume       = {{25}},
  year         = {{2023}},
}

@inproceedings{34001,
  author       = {{Arian, Bahman and Homberg, Werner and Kersting, Lukas and Trächtler, Ansgar and Rozo Vasquez, Julian}},
  booktitle    = {{36. Aachener Stahlkolloquium – Umformtechnik “Ideen Form geben“}},
  isbn         = {{978-3-95886-460-3}},
  pages        = {{333--347}},
  title        = {{{Produktkennzeichnung durch lokal definierte Einstellung von ferromagnetischen Eigenschaften beim Drückwalzen von metastabilen Stahlwerkstoffen}}},
  year         = {{2022}},
}

@inproceedings{34003,
  author       = {{Arian, Bahman and Oesterwinter, Annika and Homberg, Werner and Rozo Vasquez, Julian and Walther, Frank and Kersting, Lukas and Trächtler, Ansgar}},
  booktitle    = {{19th Int. Conference on Metal Forming 2022}},
  title        = {{{A flow forming process model to predict workpiece properties in AISI 304L}}},
  year         = {{2022}},
}

@article{33724,
  author       = {{Vieth, Pascal and Borgert, Thomas and Homberg, Werner and Grundmeier, Guido}},
  issn         = {{1438-1656}},
  journal      = {{Advanced Engineering Materials}},
  keywords     = {{Condensed Matter Physics, General Materials Science}},
  publisher    = {{Wiley}},
  title        = {{{Assessment of mechanical and optical properties of Al 6060 alloy particles by removal of contaminants}}},
  doi          = {{10.1002/adem.202201081}},
  year         = {{2022}},
}

@article{34216,
  abstract     = {{Mechanical joining technologies are increasingly used in multi-material lightweight constructions and offer opportunities to create versatile joining processes due to their low heat input, robustness to metallurgical incompatibilities and various process variants. They can be categorised into technologies which require an auxiliary joining element, or do not require an auxiliary joining element. A typical example for a mechanical joining process with auxiliary joining element is self-piercing riveting. A wide range of processes exist which are not requiring an auxiliary joining element. This allows both point-shaped (e.g., by clinching) and line-shaped (e.g., friction stir welding) joints to be produced. In order to achieve versatile processes, challenges exist in particular in the creation of intervention possibilities in the process and the understanding and handling of materials that are difficult to join, such as fiber reinforced plastics (FRP) or high-strength metals. In addition, predictive capability is required, which in particular requires accurate process simulation. Finally, the processes must be measured non-destructively in order to generate control variables in the process or to investigate the cause-effect relationship. This paper covers the state of the art in scientific research concerning mechanical joining and discusses future challenges on the way to versatile mechanical joining processes.}},
  author       = {{Meschut, Gerson and Merklein, M. and Brosius, A. and Drummer, D. and Fratini, L. and Füssel, U. and Gude, M. and Homberg, Werner and Martins, P.A.F. and Bobbert, Mathias and Lechner, M. and Kupfer, R. and Gröger, B. and Han, Daxin and Kalich, J. and Kappe, Fabian and Kleffel, T. and Köhler, D. and Kuball, C.-M. and Popp, J. and Römisch, D. and Troschitz, J. and Wischer, Christian and Wituschek, S. and Wolf, M.}},
  issn         = {{2666-3309}},
  journal      = {{Journal of Advanced Joining Processes}},
  keywords     = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}},
  publisher    = {{Elsevier BV}},
  title        = {{{Review on mechanical joining by plastic deformation}}},
  doi          = {{10.1016/j.jajp.2022.100113}},
  volume       = {{5}},
  year         = {{2022}},
}

@article{29719,
  author       = {{Borgert, Thomas and Homberg, Werner}},
  issn         = {{2352-4847}},
  journal      = {{Energy Reports}},
  keywords     = {{General Energy}},
  pages        = {{399--404}},
  publisher    = {{Elsevier BV}},
  title        = {{{Energy saving potentials of an efficient recycling process of different aluminum rejects}}},
  doi          = {{10.1016/j.egyr.2022.01.027}},
  volume       = {{8}},
  year         = {{2022}},
}

@inproceedings{30292,
  abstract     = {{The spinning process is a flexible incremental forming process for the manufacturing of axially-symmetric sheet metal or tubular components with functionally graded properties. It is characterized by the utilization of universal tooling geometries and quite low forming forces. The process has a high potential to reduce material waste, to extend the forming limits and to achieve more complex geometries as well as favorable part properties [1]. Current research work at the Chair of Forming Technology (LUF) is focused on innovative flow-turning processes that have a high potential for producing flat components with excellent geometrical and mechanical properties while keeping process times short [2]. In combination with process-integrated local heat treatment, the new spinning process is predestined for the efficient forming of ultra-high-strength steel or tailored materials. Due to the desired field of food industry only food-safe materials such as special stainless steels are being investigated. This paper presents an innovative machine layout as well as an adequate process design for the production of high-performance circular knives with optimized mechanical hardness. In this context, particular attention is paid to various areas of temperature control as well as process-related challenges during the process.}},
  author       = {{Engemann, David and Homberg, Werner}},
  keywords     = {{Cutting blades, Flow-forming, Incremental forming, Hot Forming, High strength steels}},
  location     = {{Braga - Portugal}},
  title        = {{{Hot Spinning of Cutting Blades for Food Industry}}},
  year         = {{2022}},
}

@article{31360,
  abstract     = {{<jats:p>The adaptive joining process employing friction-spun joint connectors (FSJC) is a promising method for the realization of adaptable joints and thus for lightweight construction. In addition to experimental investigations, numerical studies are indispensable tools for its development. Therefore, this paper includes an analysis of boundary conditions for the spatial discretization and mesh modeling techniques, the material modeling, the contact and friction modeling, and the thermal boundary conditions for the finite element (FE) modeling of this joining process. For these investigations, two FE models corresponding to the two process steps were set up and compared with the two related processes of friction stir welding and friction drilling. Regarding the spatial discretization, the Lagrangian approach is not sufficient to represent the deformation that occurs. The Johnson-Cook model is well suited as a material model. The modeling of the contact detection and friction are important research subjects. Coulomb’s law of friction is not adequate to account for the complex friction phenomena of the adaptive joining process. The thermal boundary conditions play a decisive role in heat generation and thus in the material flow of the process. It is advisable to use temperature-dependent parameters and to investigate in detail the influence of radiation in the entire process.</jats:p>}},
  author       = {{Oesterwinter, Annika and Wischer, Christian and Homberg, Werner}},
  issn         = {{2075-4701}},
  journal      = {{Metals}},
  keywords     = {{General Materials Science, Metals and Alloys}},
  number       = {{5}},
  publisher    = {{MDPI AG}},
  title        = {{{Identification of Requirements for FE Modeling of an Adaptive Joining Technology Employing Friction-Spun Joint Connectors (FSJC)}}},
  doi          = {{10.3390/met12050869}},
  volume       = {{12}},
  year         = {{2022}},
}

@article{30885,
  abstract     = {{High-speed forming processes such as electromagnetic forming (EMF) and electrohydraulic forming (EHF) have a high potential for producing lightweight components with complex geometries, but the forming zone is usually limited to a small size for equipment-related reasons. Incremental strategies overcome this limit by using a sequence of local deformations to form larger component areas gradually. Hence, the technological potential of high-speed forming can be exploited for large-area components too. The target-oriented process design of such incremental forming operations requires a deep understanding of the underlying electromagnetic and electrohydraulic forming processes. This article therefore analyzes and compares the influence of fundamental process parameters on the acting loads, the resulting course of deformation, and the forming result for both technologies via experimental and numerical investigations. Specifically, it is shown that for the EHF process considered, the electrode distance and the discharge energy have a significant influence on the resulting forming depth. In the EHF process, the largest forming depth is achieved directly below the electrodes, while the pressure distribution in the EMF depends on the fieldshaper used. The energy requirement for the EHF process is comparatively low, while significantly higher forming speeds are achieved with the EMF process.}},
  author       = {{Heggemann, Thomas and Psyk, Verena and Oesterwinter, Annika and Linnemann, Maik and Kräusel, Verena and Homberg, Werner}},
  issn         = {{2075-4701}},
  journal      = {{Metals}},
  number       = {{4}},
  title        = {{{Comparative Analysis of Electrohydraulic and Electromagnetic Sheet Metal Forming against the Background of the Application as an Incremental Processing Technology}}},
  doi          = {{10.3390/met12040660}},
  volume       = {{12}},
  year         = {{2022}},
}

@phdthesis{42813,
  author       = {{Wiens, Eugen}},
  isbn         = {{978-3-8440-8408-5}},
  title        = {{{Innendrückwalzen – Ein innovatives Umformverfahren zur inkrementellen Formgebung von wanddickenkonturierten Rohren mit lokal einstellbaren mechanischen Eigenschaften}}},
  year         = {{2022}},
}

@article{32412,
  abstract     = {{<jats:p>Friction-spinning as an innovative incremental forming process enables large degrees of deformation in the field of tube and sheet metal forming due to a self-induced heat generation in the forming zone. This paper presents a new tool and process design with a driven tool for the targeted adjustment of residual stress distributions in the friction-spinning process. Locally adapted residual stress depth distributions are intended to improve the functionality of the friction-spinning workpieces, e.g. by delaying failure or triggering it in a defined way. The new process designs with the driven tool and a subsequent flow-forming operation are investigated regarding the influence on the residual stress depth distributions compared to those of standard friction-spinning process. Residual stress depth distributions are measured with the incremental hole-drilling method. The workpieces (tubular part with a flange) are manufactured using heat-treatable 3.3206 (EN-AW 6060 T6) tubular profiles. It is shown that the residual stress depth distributions change significantly due to the new process designs, which offers new potentials for the targeted adjustment of residual stresses that serve to improve the workpiece properties.</jats:p>}},
  author       = {{Dahms, Frederik and Homberg, Werner}},
  issn         = {{1662-9795}},
  journal      = {{Key Engineering Materials}},
  keywords     = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
  location     = {{Braga, Portugal}},
  pages        = {{683--689}},
  publisher    = {{Trans Tech Publications, Ltd.}},
  title        = {{{Manufacture of Defined Residual Stress Distributions in the Friction-Spinning Process: Driven Tool and Subsequent Flow-Forming}}},
  doi          = {{10.4028/p-3rk19y}},
  volume       = {{926}},
  year         = {{2022}},
}

@article{29357,
  abstract     = {{<jats:p>Friction-spinning as an innovative incremental forming process enables high degrees of deformation in the field of tube and sheet metal forming due to self-induced heat generation in the forming area. The complex thermomechanical conditions generate non-uniform residual stress distributions. In order to specifically adjust these residual stress distributions, the influence of different process parameters on residual stress distributions in flanges formed by the friction-spinning of tubes is investigated using the design of experiments (DoE) method. The feed rate with an effect of −156 MPa/mm is the dominating control parameter for residual stress depth distribution in steel flange forming, whereas the rotation speed of the workpiece with an effect of 18 MPa/mm dominates the gradient of residual stress generation in the aluminium flange-forming process. A run-to-run predictive control system for the specific adjustment of residual stress distributions is proposed and validated. The predictive model provides an initial solution in the form of a parameter set, and the controlled feedback iteratively approaches the target value with new parameter sets recalculated on the basis of the deviation of the previous run. Residual stress measurements are carried out using the hole-drilling method and X-ray diffraction by the cosα-method.</jats:p>}},
  author       = {{Dahms, Frederik and Homberg, Werner}},
  issn         = {{2075-4701}},
  journal      = {{Metals}},
  keywords     = {{General Materials Science, Metals and Alloys}},
  number       = {{1}},
  publisher    = {{MDPI AG}},
  title        = {{{Manufacture of Defined Residual Stress Distributions in the Friction-Spinning Process: Investigations and Run-to-Run Predictive Control}}},
  doi          = {{10.3390/met12010158}},
  volume       = {{12}},
  year         = {{2022}},
}

@inproceedings{30263,
  abstract     = {{High-strength wire materials are usually available as strip material which is further processed in a forming process (e.g. punch-bending). For storage and transport of the semi-finished wire to the customer, the material is wound onto coils. The manufacturing and coiling process introduces plastic deformations into the wire, which lead to undesirable residual stresses and wire curvature of the semi-finished product. These residual stresses and curvatures cause variations in the material properties of the semi-finished product, which have a negative impact on the subsequent product quality. Straightening machines are used to compensate the residual stresses and the curvature in the wire. At the beginning of the straightening process, the straightening machines must be set up in such a way that residual stresses and curvatures are optimally compensated. This setup process is usually a manual and iterative process, where a lot of material is wasted until the optimal settings for the straightening machine are found.In order to reduce the amount of material waste, the operator must be supported in the setup process. In this context, a new and innovative setup assistance system was developed to support the operator during the setup process. The setup assistant system automatically detects the wire curvature by means of an optical measuring system. Based on the optically detected measuring points, the wire curvature is determined by a robust calculation algorithm. Based on a database built up through the carried out experimental and numerical research work, the optimum setting parameters for the straightening machine are suggested to the operator without lengthy trial and error. After confirmation by the operator, the roller settings are automatically adjusted by the mechatronic straightening machine. With the presented method, the conventional iterative setup procedure can be made more resource-efficient and a high straightening quality can be reproducibly achieved. }},
  author       = {{Bathelt, Lukas and Bader, Fabian and Djakow, Eugen and Henke, Christian and Trächtler, Ansgar and Homberg, Werner}},
  location     = {{Braga / Portugal}},
  title        = {{{Innovative assistance system for setting up a mechatronic straightening machine}}},
  doi          = {{https://doi.org/10.4028/p-vs07w9}},
  year         = {{2022}},
}

@inproceedings{30265,
  abstract     = {{Due to increasing globalization and rising quality requirements, the steel and metal processing industry is facing growing cost and innovation pressure. Not least because of their high lightweight potential, high-strength steel materials are meeting the growing material requirements of steel and metal processing in areas such as aerospace and medical technology. In particular, the tight tolerance limits of applicable shape and dimensional accuracies pose a challenge in the processing of high-strength steel strip materials. Improving the processability of high-strength steel materials through the use of straighteners with set-up assistance systems significantly increases the potential for competing with other materials such as aluminum or magnesium alloys. }},
  author       = {{Bader, Fabian and Bathelt, Lukas and Djakow, Eugen and Henke, Christian and Homberg, Werner and Trächtler, Ansgar}},
  location     = {{Braga / Portugal}},
  title        = {{{An approach for an innovative 3d steel strip straightening machine for curvature and saber compensation}}},
  doi          = {{https://doi.org/10.4028/p-87wvu0}},
  year         = {{2022}},
}

@inproceedings{33978,
  author       = {{Bathelt, Lukas and Bader, Fabian and Djakow, Eugen and Henke, Christian and Trächtler, Ansgar and Homberg, Werner}},
  booktitle    = {{Fachtagung VDI MECHATRONIK 2022 }},
  location     = {{Darmstadt}},
  pages        = {{19--24}},
  title        = {{{Mechatronische Richtapparate: Intelligente Richttechnik von hochfesten Flachdrähten}}},
  year         = {{2022}},
}