@article{59510,
  abstract     = {{<jats:p>The use of organo-catalysis in continuous-flow reactor systems is gaining attention in medicinal chemistry due to its cost-effectiveness and reduced chemical waste. In this study, bioactive curcumin (CUM) derivatives were synthesized in a continuously operated microfluidic reactor (MFR), using piperidine-based polymeric networks as catalysts. Piperidine methacrylate and piperidine acrylate were synthesized and subsequently copolymerized with complementary monomers (MMA or DMAA) and crosslinkers (EGDMA or MBAM) via photopolymerization, yielding different polymeric networks. Initially, batch reactions were optimized for the organo-catalytic Knoevenagel condensation between CUM and 4-nitrobenzaldehyde, under various conditions, in the presence of polymer networks. Conversion was assessed using offline 1H NMR spectroscopy, revealing an increase in conversion with enhanced swelling properties of the polymer networks, which facilitated greater accessibility of catalytic sites. In continuous-flow MFR experiments, optimized polymer gel dots exhibited superior catalytic performance, achieving a conversion of up to 72%, compared to other compositions. This improvement was attributed to the enhanced swelling in the reaction mixture (DMSO/methanol, 7:3 v/v) at 40 °C over 72 h. Furthermore, the MFR system enabled the efficient synthesis of a series of CUM derivatives, demonstrating significantly higher conversion rates than traditional batch reactions. Notably, while batch reactions required 90% catalyst loading in the gel, the MFR system achieved a comparable or superior performance with only 50% catalyst, resulting in a higher turnover number. These findings underscore the advantages of continuous-flow organo-catalysis in enhancing catalytic efficiency and sustainability in organic synthesis.</jats:p>}},
  author       = {{Killi, Naresh and Rumpke, Katja and Kuckling, Dirk}},
  issn         = {{2310-2861}},
  journal      = {{Gels}},
  keywords     = {{flow chemistry, heterogeneous catalysis, sustainable synthesis, organo-catalysis, polymeric gel dots}},
  number       = {{4}},
  publisher    = {{MDPI AG}},
  title        = {{{Synthesis of Curcumin Derivatives via Knoevenagel Reaction Within a Continuously Driven Microfluidic Reactor Using Polymeric Networks Containing Piperidine as a Catalyst}}},
  doi          = {{10.3390/gels11040278}},
  volume       = {{11}},
  year         = {{2025}},
}

@inproceedings{59907,
  abstract     = {{<jats:p>Abstract. Flow forming is recognized for its precision in producing rotationally symmetric components, but the use of metastable austenitic stainless steel (AISI 304L) introduces challenges due to uncontrolled strain-induced α’ martensite formation. Variations in factors such as eccentricity and batch inconsistencies lead to unpredictable microstructural profiles, limiting reproducibility [1,2]. This study addresses these issues by incorporating thermal actuators for cryogenic cooling and induction heating to regulate forming temperatures, enabling control of the α’-martensite content. Experimental investigations demonstrate that local tempering during thermomechanical reverse flow forming produces discernible variations in microstructure, affecting mechanical and magnetic properties [3]. Controlled local adjustments of α’-martensite content allow for customization of properties in seamless tubes, advancing manufacturing capabilities for complex, defect-free components. The results presented demonstrate promising strategies for implementation within the context of closed-loop property control in flow forming.</jats:p>}},
  author       = {{Arian, Bahman and Homberg, Werner and Kersting, Lukas and Trächtler, Ansgar and Rozo Vasquez, Julian and Walther, Frank}},
  booktitle    = {{Materials Research Proceedings}},
  editor       = {{Carlone, Pierpaolo and Filice, Luigino and Umbrello, Domenico}},
  issn         = {{2474-395X}},
  keywords     = {{Flow Forming, Thermomechanical Forming, α’-Martensite, Property Control}},
  location     = {{Paestum, Italy}},
  publisher    = {{Materials Research Forum LLC}},
  title        = {{{Advanced thermomechanical flow forming: A novel approach to α’-martensite control for enhanced material properties}}},
  doi          = {{10.21741/9781644903599-127}},
  volume       = {{54}},
  year         = {{2025}},
}

@article{60299,
  abstract     = {{Non-rotationally symmetrical joints can have different properties that can be controlled by the joint orientation. This hypothesis is tested using a Reuleaux triangle joint geometry. A tool design is carried out, followed by a numerical sensitivity analysis of the tool geometry. Initial tools were manufactured for experimental investigations and then adapted based on the findings of the sensitivity analysis. The joints are characterized by micrographs, 3D scans, shear tensile tests, head tensile tests and three-point bending tests and compared with a round geometry. The analysis confirms the hypothesis. Thus, joints with adaptable properties can be produced with one tool set.}},
  author       = {{Steinfelder, Christian and Acksteiner, Clemens and Brosius, Alexander}},
  issn         = {{0007-8506}},
  journal      = {{CIRP Annals}},
  keywords     = {{Joining, Forming, Property adjustment}},
  publisher    = {{Elsevier BV}},
  title        = {{{A new joint with versatile properties based on a Reuleaux triangle geometry}}},
  doi          = {{10.1016/j.cirp.2025.03.002}},
  year         = {{2025}},
}

@article{51122,
  author       = {{Al-Lami, Abbas J.S. and Kenig, Eugeny Y.}},
  issn         = {{2214-157X}},
  journal      = {{Case Studies in Thermal Engineering}},
  keywords     = {{Fluid Flow and Transfer Processes, Engineering (miscellaneous)}},
  publisher    = {{Elsevier BV}},
  title        = {{{New pressure drop and heat transfer correlations for turbulent forced convection in internally channeled tube heat exchanger ducts}}},
  doi          = {{10.1016/j.csite.2024.103993}},
  year         = {{2024}},
}

@inproceedings{49430,
  abstract     = {{Within the current energy and environmental crisis, new material- and energy-saving processes are needed. For this reason, this study focuses on the development of a new forming technology for Ti-6Al-4V sheet metal. It is based on combination of solution treatment by resistive heating with rapid tool-based quenching and subsequent annealing. This new “TISTRAQ” process is comparable with press-hardening already known for steels and hot die quenching known for aluminium alloys. One of the main influencing factors for this process is the heat transfer coefficient (HTC). It is an important driver for adjustment of basic parameters, as selection of tool material or the forming speed but also plays an important role while elaborating temperature distribution in the numerical model. Therefore, a new and unique test rig was developed to determine the HTC and to perform tool-based heat treatment at specimen level under laboratory conditions. The test rig was used to investigate the influence of the titanium-tool-lubricant system on HTC and cooling rate. Further the effect of heat treatment in the test rig and tool-based quenching on microstructure and mechanical properties was studied. To improve the prediction of the temperature distribution of the titanium during cooling, the HTC was integrated into the numerical process simulation}},
  author       = {{Kaiser, Maximilian Alexander and Höschen, Fabian and Pfeffer, Nina and Merten, Mathias and Meyer, Thomas and Marten, Thorsten and Rockicki, Pawel and Höppel, Heinz Werner and Tröster, Thomas}},
  booktitle    = {{IOM3. Chapter 14: Forming, Machining & Joining [version 1; not peer reviewed]}},
  keywords     = {{Interfacial heat transfer coefficient, Ti-6Al-4V, nonisothermal forming, thermomechanical processing, TISTRAQ process}},
  location     = {{Edinburgh}},
  title        = {{{The new TISTRAQ process: Solution treatment with rapid quenching and annealing for Ti-6Al-4V sheet metal part forming - investigation on heat transfer coefficient and influence on cooling rates}}},
  doi          = {{doi.org/10.7490/f1000research.1119929.1}},
  year         = {{2024}},
}

@inproceedings{49437,
  abstract     = {{The phase and TTT diagrams of the Ti-6Al-4V system allow the development of a new forming process for a more energy- and materialefficient production of sheet metal parts. This new “TISTRAQ” process is composed of two steps. In terms of process technology, the first step is comparable to a direct press-hardening process already well known for steels. In this step, the Ti-6Al-4V sheet material is resistively heated to a temperature below β-transus Tβ and, after a very short holding time, simultaneously formed and quenched by use of water cooled tools. Thereby, the β phase undergoes a martensitic transformation. The second step is a subsequent short-time annealing, which leads to a hardening of the material. In this work, a new test rig using resistive heating technique was used in order to produce
different solution treated and tool quenched (STQ) and subsequently annealed (STA) states. In this paper, the effects of heating rate, solution treatment temperature and holding time on microstructure and mechanical properties are addressed. For the characterisation, tensile testing and scanning electron microscopy were used. By the systematic variation of applied processing parameters, dominating effects on microstructure and mechanical properties were evaluated. For example, the solution treatment temperature was found to have a significant effect on microstructural features and characteristic strength and strain values. The obtained results reveal a high potential for future technical applications.}},
  author       = {{Pfeffer, Nina and Kaiser, Maximilian Alexander and Meyer, Thomas and Göken, Mathias and Höppel, Heinz Werner}},
  booktitle    = {{IOM3. Chapter 14: Forming, Machining & Joining [version 1; not peer reviewed]}},
  keywords     = {{Ti-6Al-4V, thermomechanical processing, resistive heating, quench-forming, process parameter-microstructure-properties relationship}},
  location     = {{Edinburgh}},
  title        = {{{The new TISTRAQ process: Solution treatment with rapid quenching and annealing for Ti-6Al-4V sheet metal part forming - the effect of processing parameters on microstructure and mechanical properties}}},
  doi          = {{https://doi.org/10.7490/f1000research.1119929.1}},
  year         = {{2024}},
}

@article{60300,
  abstract     = {{This study focuses on the phenomenological change in material strength caused by a specific heat treatment and the subsequent analysis of the influence on the clinching process and the resulting joint properties. For this purpose, three series of tests were performed. In the first series of tests, the influence of heat treatment up to 340 °C on the mechanical properties of an age-hardenable AlMgSi alloy was investigated. Holding time and temperature were varied and the material strength was evaluated by tensile and hardness tests. Two strength-increasing and two strength-reducing heat treatment parameters were identified. In the second series of tests, selected heat treatment parameters were applied to a larger number of specimens and the joint strength was investigated by shear and head tensile tests. In the shear tensile test, mainly the properties of the punch-side material have an influence on the resulting joint strength. A change in strength of the die-side material can be neglected. In contrast, the properties of both sheets are important in the head tensile test. The strength of the joint will only increase if the strength of both sheets is increased. In general, a strength increasing heat treatment resulted in higher joint strength. In the third series of tests, the factor of punch displacement was considered, which was demonstrated to directly influence the formation of the clinched joint geometry.}},
  author       = {{Steinfelder, Christian and Rempel, Dennis and Brosius, Alexander}},
  issn         = {{2666-3309}},
  journal      = {{Journal of Advanced Joining Processes}},
  keywords     = {{Joining by forming, Clinching, EN AW-6014, Heat treatment, Load-bearing capacity}},
  publisher    = {{Elsevier BV}},
  title        = {{{Influence of the material properties on the clinching process and the resulting load-bearing capacity of the joint}}},
  doi          = {{10.1016/j.jajp.2024.100263}},
  volume       = {{10}},
  year         = {{2024}},
}

@article{43457,
  abstract     = {{The production of hydrogen and the utilization of biomass for sustainable concepts of energy conversion and storage require gas sensors that discriminate between hydrogen (H2) and carbon monoxide (CO). Mesoporous copper–ceria (Cu–CeO2) materials with large specific surface areas and uniform porosity are prepared by nanocasting, and their textural properties are characterized by N2 physisorption, powder XRD, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The oxidation states of copper (Cu+, Cu2+) and cerium (Ce3+, Ce4+) are investigated by XPS. The materials are used as resistive gas sensors for H2 and CO. The sensors show a stronger response to CO than to H2 and low cross-sensitivity to humidity. Copper turns out to be a necessary component; copper-free ceria materials prepared by the same method show only poor sensing performance. By measuring both gases (CO and H2) simultaneously, it is shown that this behavior can be utilized for selective sensing of CO in the presence of H2.}},
  author       = {{Baier, Dominik and Priamushko, Tatiana and Weinberger, Christian and Kleitz, Freddy and Tiemann, Michael}},
  issn         = {{2379-3694}},
  journal      = {{ACS Sensors}},
  keywords     = {{Fluid Flow and Transfer Processes, Process Chemistry and Technology, Instrumentation, Bioengineering}},
  number       = {{4}},
  pages        = {{1616 -- 1623}},
  publisher    = {{American Chemical Society (ACS)}},
  title        = {{{Selective Discrimination between CO and H2 with Copper–Ceria-Resistive Gas Sensors}}},
  doi          = {{10.1021/acssensors.2c02739}},
  volume       = {{8}},
  year         = {{2023}},
}

@inproceedings{43044,
  abstract     = {{<jats:p>Abstract. The combination of incremental sheet metal forming and high-speed forming offers new possibilities for flexible forming processes in the production of large sheet metal components of increased complexity with relatively low forming energies. In this paper, the general feasibility and process differences between the pulse-driven high-speed forming technologies of electrohydraulic and electromagnetic forming were investigated. An example component made of EN AW 6016 aluminum sheet metal was thus formed incrementally by both processes and the forming result evaluated by an optical 3D measurement system. For this purpose, a forming strategy for electromagnetic incremental forming (EMIF) was developed, tested and adapted to the electrohydraulic incremental forming process (EHIF). The discharge energy, the tool displacement and the pressure field of the forming zone were determined as relevant parameters for the definition of an adequate tool path strategy. It was found that the EHIF process is less affected by larger distances between the tool and the blank, while this is a critical variable for force application to the component during EMIF. On the other hand, the more uniform pressure distribution of the EMIF process is advantageous for forming large steady component areas. </jats:p>}},
  author       = {{Holzmüller, Maik and Linnemann, Maik and Homberg, Werner and Psyk, Verena and Kräusel, Verena  and Kroos, Janika}},
  booktitle    = {{Materials Research Proceedings}},
  issn         = {{2474-395X}},
  keywords     = {{Incremental Sheet Forming, Aluminium, High-Speed Forming}},
  location     = {{Nürnberg}},
  pages        = {{11--18}},
  publisher    = {{Materials Research Forum LLC}},
  title        = {{{Proof of concept for incremental sheet metal forming by means of electromagnetic and electrohydraulic high-speed forming}}},
  doi          = {{10.21741/9781644902417-2}},
  volume       = {{25}},
  year         = {{2023}},
}

@article{43045,
  abstract     = {{<jats:p>The pressure fields generated by two simultaneous discharges have not been investigated on any notable scale for the electrohydraulic impulse forming method. In this study, the synchronicity of two discharges is ensured by the sequential connection of two wires mounted in two spark gaps in a common volume of liquid. The objective is to experimentally confirm the equilibrium of the energies evolved in two spark gaps by means of pressure measurements. In addition, multipoint membrane pressure gauges demonstrated the feasibility of easily recording detailed pressure maps. Based on the membrane deformation mechanism and material strengthening under static and impulse conditions, the processing procedure is further developed so as to achieve better accuracy in the determination of pressure field parameters. The practical equality of the pressure fields on the left and right halves of the flat-loaded area confirms the equality of energies evolved in the two spark gaps. The direct shock waves create zones with the most intensive loading. These results provide a basis for the development of new electrohydraulic technologies involving the application of two simultaneous discharges with equal energy and pressure parameters.</jats:p>}},
  author       = {{Knyazyev, Mykhaylo and Holzmüller, Maik and Homberg, Werner}},
  issn         = {{2504-4494}},
  journal      = {{Journal of Manufacturing and Materials Processing}},
  keywords     = {{impulse, forming, electrohydraulic, discharge, wire, pressure gauge, pressure field}},
  number       = {{1}},
  publisher    = {{MDPI AG}},
  title        = {{{Investigation of Pressure Fields Generated by Two Simultaneous Discharges in Liquid Initiated by Wires}}},
  doi          = {{10.3390/jmmp7010040}},
  volume       = {{7}},
  year         = {{2023}},
}

@article{34223,
  abstract     = {{In this study, quasi-unidirectional continuous fiber reinforced thermoplastics (CFRTs) are joined with metal sheets via cold formed cylindrical, elliptical and polygonal pin structures which are directly pressed into the CFRT component after local infrared heating. In comparison to already available studies, the unique novelty is the use of non-rotational symmetric pin structures for the CFRT/metal hybrid joining. Thus, a variation in the fiber orientation in the CFRT component as well as a variation in the non-rotational symmetric pins’ orientation in relation to the sample orientation is conducted. The created samples are consequently mechanically tested via single lap shear experiments in a quasi-static state. Finally, the failure behavior of the single lap shear samples is investigated with the help of microscopic images and detailed photographs. In the single lap shear tests, it could be shown that non-rotational symmetric pin structures lead to an increase in maximum testing forces of up to 74% when compared to cylindrical pins. However, when normalized to the pin foot print related joint strength, only one polygonal pin variation showed increased joint strength in comparison to cylindrical pin structures. The investigation of the failure behavior showed two distinct failure modes. The first failure mode was failure of the CFRT component due to an exceedance of the maximum bearing strength of the pin-hole leading to significant damage in the CFRT component. The second failure mode was pin-deflection due to the applied testing load and a subsequent pin extraction from the CFRT component resulting in significantly less visible damage in the CFRT component. Generally, CFRT failure is more likely with a fiber orientation of 0° in relation to the load direction while pin extraction typically occurs with a fiber orientation of 90°. It is assumed that for future investigations, pin structures with an undercutting shape that creates an interlocking joint could counteract the tendency for pin-extraction and consequently lead to increased maximum joint strengths.}},
  author       = {{Popp, Julian and Römisch, David and Merklein, Marion and Drummer, Dietmar}},
  issn         = {{2076-3417}},
  journal      = {{Applied Sciences}},
  keywords     = {{Fluid Flow and Transfer Processes, Computer Science Applications, Process Chemistry and Technology, General Engineering, Instrumentation, General Materials Science}},
  number       = {{10}},
  publisher    = {{MDPI AG}},
  title        = {{{Joining of CFRT/Steel Hybrid Parts via Direct Pressing of Cold Formed Non-Rotational Symmetric Pin Structures}}},
  doi          = {{10.3390/app12104962}},
  volume       = {{12}},
  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{34224,
  abstract     = {{Crack growth in structures depends on the cyclic loads applied on it, such as mechanical, thermal and contact, as well as residual stresses, etc. To provide an accurate simulation of crack growth in structures, it is of high importance to integrate all kinds of loading situations in the simulations. Adapcrack3D is a simulation program that can accurately predict the propagation of cracks in real structures. However, until now, this three-dimensional program has only considered mechanical loads and static thermal loads. Therefore, the features of Adapcrack3D have been extended by including contact loading in crack growth simulations. The numerical simulation of crack propagation with Adapcrack3D is generally carried out using FE models of structures provided by the user. For simulating models with contact loading situations, Adapcrack3D has been updated to work with FE models containing multiple parts and necessary features such as coupling and surface interactions. Because Adapcrack3D uses the submodel technique for fracture mechanical evaluations, the architecture of the submodel is also modified to simulate models with contact definitions between the crack surfaces. This paper discusses the newly implemented attribute of the program with the help of illustrative examples. The results confirm that the contact simulation in Adapcrack3D is a major step in improving the functionality of the program.}},
  author       = {{Joy, Tintu David and Weiß, Deborah and Schramm, Britta and Kullmer, Gunter}},
  issn         = {{2076-3417}},
  journal      = {{Applied Sciences}},
  keywords     = {{Fluid Flow and Transfer Processes, Computer Science Applications, Process Chemistry and Technology, General Engineering, Instrumentation, General Materials Science}},
  number       = {{15}},
  publisher    = {{MDPI AG}},
  title        = {{{Further Development of 3D Crack Growth Simulation Program to Include Contact Loading Situations}}},
  doi          = {{10.3390/app12157557}},
  volume       = {{12}},
  year         = {{2022}},
}

@article{44041,
  author       = {{Ahmadov, A. I. and Nagiyev, Sh. M. and Aydin, C. and Tarverdiyeva, V. A. and Orujova, M. Sh. and Badalov, S. V.}},
  issn         = {{2190-5444}},
  journal      = {{The European Physical Journal Plus}},
  keywords     = {{General Physics and Astronomy, Fluid Flow and Transfer Processes}},
  number       = {{9}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Bound state solutions of Dirac equation: spin and pseudo-spin symmetry in the presence of the combined Manning–Rosen and Yukawa tensor potentials}}},
  doi          = {{10.1140/epjp/s13360-022-03255-9}},
  volume       = {{137}},
  year         = {{2022}},
}

@article{30213,
  abstract     = {{<jats:p>Requirement changes and cascading effects of change propagation are major sources of inefficiencies in product development and increase the risk of project failure. Proactive change management of requirement changes yields the potential to handle such changes efficiently. A systematic approach is required for proactive change management to assess and reduce the risk of a requirement change with appropriate effort in industrial application. Within the paper at hand, a novel method for Proactive Management of Requirement Changes (ProMaRC) is presented. It is developed in close collaboration with industry experts and evaluated based on workshops, pilot users’ feedback, three industrial case studies from the automotive industry and five development projects from research. To limit the application effort, an automated approach for dependency analysis based on the machine learning technique BERT and semi-automated assessment of change likelihood and impact using a modified PageRank algorithm is developed. Applying the method, the risks of requirement changes are assessed systematically and reduced by means of proactive change measures. Evaluation shows high performance of dependency analysis and confirms the applicability and usefulness of the method. This contribution opens up the research space of proactive risk management for requirement changes which is currently almost unexploited. It enables more efficient product development.</jats:p>}},
  author       = {{Gräßler, Iris and Oleff, Christian and Preuß, Daniel}},
  issn         = {{2076-3417}},
  journal      = {{Applied Sciences}},
  keywords     = {{Fluid Flow and Transfer Processes, Computer Science Applications, Process Chemistry and Technology, General Engineering, Instrumentation, General Materials Science}},
  number       = {{4}},
  publisher    = {{MDPI AG}},
  title        = {{{Proactive Management of Requirement Changes in the Development of Complex Technical Systems}}},
  doi          = {{10.3390/app12041874}},
  volume       = {{12}},
  year         = {{2022}},
}

@inproceedings{20125,
  abstract     = {{Datacenter applications have different resource requirements from network and developing flow scheduling heuristics for every workload is practically infeasible. In this paper, we show that deep reinforcement learning (RL) can be used to efficiently learn flow scheduling policies for different workloads without manual feature engineering. Specifically, we present LFS, which learns to optimize a high-level performance objective, e.g., maximize the number of flow admissions while meeting the deadlines. The LFS scheduler is trained through deep RL to learn a scheduling policy on continuous online flow arrivals. The evaluation results show that the trained LFS scheduler admits 1.05x more flows than the greedy flow scheduling heuristics under varying network load.}},
  author       = {{Hasnain, Asif and Karl, Holger}},
  booktitle    = {{2021 IEEE 18th Annual Consumer Communications & Networking Conference (CCNC)}},
  keywords     = {{Flow scheduling, Deadlines, Reinforcement learning}},
  location     = {{Las Vegas, USA}},
  publisher    = {{IEEE Computer Society}},
  title        = {{{Learning Flow Scheduling}}},
  doi          = {{https://doi.org/10.1109/CCNC49032.2021.9369514}},
  year         = {{2021}},
}

@article{35327,
  author       = {{Wortmann, Martin and Viertel, Klaus and Welle, Alexander and Keil, Waldemar and Frese, Natalie and Hachmann, Wiebke and Krieger, Philipp and Brikmann, Johannes and Schmidt, Claudia and Moritzer, Elmar and Hüsgen, Bruno}},
  issn         = {{0017-9310}},
  journal      = {{International Journal of Heat and Mass Transfer}},
  keywords     = {{Fluid Flow and Transfer Processes, Mechanical Engineering, Condensed Matter Physics}},
  publisher    = {{Elsevier BV}},
  title        = {{{Anomalous bulk diffusion of methylene diphenyl diisocyanate in silicone elastomer}}},
  doi          = {{10.1016/j.ijheatmasstransfer.2021.121536}},
  volume       = {{177}},
  year         = {{2021}},
}

@inproceedings{23465,
  abstract     = {{One of the main objectives of production engineering is to reproducibly manufacture (complex) defect-free parts. To achieve this, it is necessary to employ an appropriate process or tool design. While this will generally prove successful, it cannot, however, offset stochastic defects with local variations in material properties. Closed-loop process control represents a promising approach for a solution in this context. The state of the art involves using this approach to control geometric parameters such as a length. So far, no research or applications have been conducted with closed-loop control for microstructure and product properties. In the project on which this paper is based, the local martensite content of parts is to be adjusted in a highly precise and reproducible manner. The forming process employed is a special, property-controlled flow-forming process. A model-based controller is thus to generate corresponding correction values for the tool-path geometry and tool-path velocity on the basis of online martensite content measurements. For the controller model, it is planned to use a special process or microstructure (correlation) model. The planned paper not only describes the experimental setup but also presents results of initial experimental investigations for subsequent use in the closed-loop control of α’-martensite content during flow-forming.}},
  author       = {{Arian, Bahman and Homberg, Werner and Riepold, Markus and Trächtler, Ansgar and Rozo Vasquez, Julian and Walther, Frank}},
  isbn         = {{978-2-87019-302-0}},
  keywords     = {{Flow-forming, Spinning, Process Strategy, Martensite Content, Property Control, Micromagnetic Measurement, Metastable Austenitic Stainless Steel}},
  location     = {{Liège, Belgium}},
  publisher    = {{ULiège Library}},
  title        = {{{Forming of metastable austenitic stainless steel tubes with axially graded martensite content by flow-forming}}},
  year         = {{2021}},
}

@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}},
}

@proceedings{19976,
  abstract     = {{The aim to reduce pollutant emission has led to a trend towards lightweight construction in car body development during the last years. As a consequence of the resulting need for multi-material design, mechanical joining technologies become increasingly important. Mechanical joining allows for the combination of dissimilar materials, while thermic joining techniques reach their limits. Self-piercing riveting enables the joining of dissimilar materials by using semi-tubular rivets as mechanical fasteners. The rivet production, however, is costly and time-consuming, as the rivets generally have to be hardened, tempered and coated after forming, in order to achieve an adequate strength and corrosion resistance. A promising approach to improve the efficiency of the rivet manufacturing is the use of high-strength high nitrogen steel as rivet material because these additional process steps would not be necessary anymore. As a result of the comparatively high nitrogen content, such steels have various beneficial properties like higher strength, good ductility and improved corrosion resistance. By cold bulk forming of high nitrogen steels high-strength parts can be manufactured due to the strengthening which is caused by the high strain hardening. However, high tool loads thereby have to be expected and are a major challenge during the production process. Consequently, there is a need for appropriate forming strategies. This paper presents key aspects concerning the process design for the manufacturing of semi-tubular self-piercing rivets made of high-strength steel. The aim is to produce the rivets in several forming stages without intermediate heat treatment between the single stages. Due to the high strain hardening of the material, a two stage forming concept will be investigated. Cup-backward extrusion is chosen as the first process step in order to form the rivet shank without forming the rivet foot. Thus, the strain hardening effects in the area of the rivet foot are minimized and the tool loads during the following process step can be reduced. During the second and final forming stage the detailed geometry of the rivet foot and the rivet head is formed. In this context, the effect of different variations, for example concerning the final geometry of the rivet foot, on the tool load is investigated using multistage numerical analysis. Furthermore, the influence of the process temperature on occurring stresses is analysed. Based on the results of the investigations, an adequate forming strategy and a tool concept for the manufacturing of semi-tubular self-piercing rivets made of high-strength steel are presented.}},
  editor       = {{Kuball, Clara-Maria and Uhe, Benedikt and Meschut, Gerson and Merklein, Marion}},
  keywords     = {{high nitrogen steel, self-piercing riveting, joining by forming, bulk forming, tool design}},
  pages        = {{280--285}},
  title        = {{{Process design for the forming of semi-tubular self-piercing rivets made of high nitrogen steel}}},
  doi          = {{10.1016/j.promfg.2020.08.052}},
  volume       = {{50}},
  year         = {{2020}},
}