@article{64678,
abstract = {{One of the major topics in the modern automotive industry is reducing emissions and increasing the mileage
range. To tackle this challenge, on the one hand, modifying the powertrain system is a possibility, and on the
other hand, lightweight design offers various possibilities. Multi-Material Design (MMD) involves designing car
bodies that combine different materials that require joining. Given the variety of materials, mechanical joining
processes are preferred. Especially the current development of the Giga/Mega-casting process concerning
aluminium casting and the subsequent mechanical joining illustrates the challenges of this material group. In car
production, aluminium castings are mainly made from aluminium-silicon (AlSi) alloys. Ultimately, the alloy
system's insufficient ductility leads to crack initiation during mechanical joining. Cast parts are therefore often
used in areas of the car body that are exposed to high-pressure loads. For example, self-piercing riveting (SPR) is
used due to its high load-bearing capacity. In this study, improved joinability is demonstrated by influencing the
microstructure through tailored solidification rates and a developed heat-treatment chain strategy adapted for
hypoeutectic AlSi systems. Data on microstructure, mechanical, and joining properties are used to develop a
solidification-joining correlation for the SPR process across a range of Si contents and solidification rates. The
purpose is to develop the ability to produce suitable aluminium castings with sufficient joinability, thereby
improving versatility.}},
author = {{Neuser, Moritz and Kaimann, Pia Katharina and Stratmann, Ina and Bobbert, Mathias and Klöckner, Johann Moritz Benedikt and Mann, Moritz and Hoyer, Kay-Peter and Meschut, Gerson and Schaper, Mirko}},
journal = {{Journal of Manufacturing Processes}},
keywords = {{Mechanical joining, Aluminium, Self-piercing riveting, Casting, Microstructure, Joinability AlSi-alloys}},
publisher = {{Elsevier}},
title = {{{Solidification-joinability correlation of hypoeutectic aluminium casting alloys for self-piercing riveting (SPR)}}},
doi = {{https://doi.org/10.1016/j.jmapro.2026.02.040}},
volume = {{164}},
year = {{2026}},
}
@article{58163,
abstract = {{Fibre-reinforced polymers are increasingly used due to their high specific strength, making them suitable for local sheet metal reinforcement. This allows improved overall mechanical properties with reduced wall thickness of the sheet metal part and, thus, lower weight of the components. One of the main focuses of research into such hybrid structures is on the adhesive properties and the respective failure behaviour of the interfaces. Generally, the failure behaviour under the influence of mechanical loads can be divided into adhesive, cohesive and mixed-mode failure. The correlation between observed failure behaviour and adhesion properties of the hybrid composite materials is analysed in detail in this work. The hybrid composite consists of an aluminium sheet of the alloy EN AW‑6082 T6 and thermoset carbon fibre-reinforced plastic (CFRP) prepreg. The aluminium sheet was laser pretreated before hybrid production to improve the adhesion properties. The specimens studied were produced by the prepreg pressing process, in which the components are cured and joined simultaneously. The influences of the thickness of the CFRP part, the layup, the fibre orientation at the boundary layer, and the laser pretreatment parameters on the properties of the hybrid joints were investigated.}},
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 = {{Prepreg pressing process, hybrid joints, laser surface pretreatment, intrinsic manufacturing, CFRP, aluminium, materials engineering}},
pages = {{1--26}},
publisher = {{Informa UK Limited}},
title = {{{Correlation between interlaminar shear strength of CFRP and joint strength of aluminium-CFRP hybrid joints}}},
doi = {{10.1080/00218464.2024.2439956}},
year = {{2025}},
}
@article{59872,
abstract = {{Lightweight design is a driving concept in modern automotive engineering to minimize resource consumption over a vehicle's lifecycle through multi-material design, which relies on the use of joining techniques in car body fabrication. Multi-material design and the increasing trend towards producing large structural components using the megacasting process pose considerable challenges, particularly in the mechanical joining of aluminium-silicon (AlSi) castings. These castings typically exhibit low ductility and are prone to cracking when mechanically joined. Based on the excellent castability of hypoeutectic AlSi alloys, these are applied in sand casting and die casting as well as in megacasting. With a silicon content between 7 wt% and 12 wt%, these AlSi-alloys have a plate-like silicon phase that initiates cracks during mechanical joining. To enhance the joinability of castings, the research hypothesis is that improved solidification conditions enable a significant modification in the microstructure and therefore, increase the mechanical properties. During the manufacture of the castings using the sand casting process, the solidification conditions within the structural elements are varied to modify the microstructure to obtain castings with graded microstructure. The castings are evaluated using mechanical, microstructural and joining testing methods and finally, a microstructure-joinability correlation is established.}},
author = {{Neuser, Moritz and Schlichter, Malte Christian and Hoyer, Kay-Peter and Bobbert, Mathias and Meschut, Gerson and Schaper, Mirko}},
journal = {{44th Conference of the International Deep Drawing Research Group (IDDRG 2025)}},
keywords = {{Joining, Casting, Self-pierce riveting, Aluminium casting alloy}},
location = {{Lissabon (Portugal)}},
title = {{{Mechanical joinability of microstructurally graded structural components manufactured from hypoeutectic aluminium casting alloys}}},
doi = {{10.1051/matecconf/202540801081}},
volume = {{408}},
year = {{2025}},
}
@article{58807,
abstract = {{One of the most important strategies for reducing CO2 emissions in the mobility sector is lightweight construction. In particular, the car body offers several opportunities for weight reduction. Multi-material designs are increasingly being applied to select the most suitable material for the respective load and ultimately achieve synergy effects. For example, aluminium castings are used at the nodes of a spaceframe body. Subsequently, these are joined with profiles to form the bodyshell. To join different materials mechanical joining techniques, such as semi-tubular self-piercing riveting, are deployed. According to the current state of the art, cracks occur in the aluminium castings during the mechanical joining process as a result of the high degree of deformation. Although the aluminium casting alloys of the AlSi-system exhibit low ductility, these alloys reveal excellent castability. In particular, the ability to cast thin structural parts is enabled by the low liquidus point of the near eutectic aluminium casting alloys.
This study addresses the mechanical joining properties of the near eutectic aluminium casting alloy AlSi12, depending on different microstructures. These are achieved by annealing processes and modifying agents. Through an adapted heat treatment, the previously lamellar morphology can be transformed into a globular morphology, which leads to increased ductility and prevents the formation of cracks during the self-piercing riveting (SPR). The joinability is investigated using different die geometries, whereas the joint formation is analysed regarding crack initiation. To evaluate the increased ductility, microstructural and mechanical tests are performed and finally, a microstructure-joinability correlation is established.}},
author = {{Neuser, Moritz and Holtkamp, Pia Katharina and Hoyer, Kay-Peter and Kappe, Fabian and Yildiz, Safak and Bobbert, Mathias and Meschut, Gerson and Schaper, Mirko}},
journal = {{The Journal of Materials: Design and Applications, Part L}},
keywords = {{aluminium, casting, microstructure, joinability, self-piercing riveting}},
location = {{Porto, Portugal}},
publisher = {{Sage Publications}},
title = {{{Mechanical properties and joinability of the near-eutectic aluminium casting alloy AlSi12}}},
doi = {{10.1177/14644207251319922}},
year = {{2025}},
}
@inproceedings{60645,
abstract = {{Die Wandlungsfähigkeit einer Prozesskette erfordert Fügeverbindungen mit gezielt einstellbaren mechanischen, elektrischen, thermischen oder chemischen Eigenschaften. Dieser Beitrag beschreibt die Untersuchungen, inwiefern beim Clinchen zweier Bleche aus der ausscheidungshärtbaren Aluminiumlegierung EN AW-6014 bereits auf Basis der Prozessüberwachung des Kraft-Weg-Verlaufs bzw. des sich daraus ergebenden Energieeintrags auf die mechanischen und elektrischen Eigenschaften der Fügeverbindung geschlossen werden kann. An einer ausgewählten Fügeaufgabe werden im Stufenversuch die gegenseitigen Abhängigkeiten der einzelnen Einflussgrößen sowie des Wärmebehandlungszustands aufgezeigt. Dabei wird zwischen den Bindemechanismen Formschluss und Kraftschluss unterschieden. Die Formschlusskomponente wird anhand der geometrischen Kenngrößen wie Bodendicke, Halsdicke und Hinterschnitt in Mikroskopieuntersuchungen an Schliffbildern und den mechanischen Eigenschaften der Fügeverbindung untersucht, die im Scherzug- und Kopfzugversuch bestimmt werden. Dazu erfolgt zudem die Charakterisierung der Versagensbilder. Zur Quantifizierung der Kraftschlusskomponente der Fügeverbindung werden das Losbrechmoment im Torsionsversuch und der elektrische Widerstand mittels Vier-Leiter-Methode ermittelt und korreliert.}},
author = {{Lüder, Stephan and Kalich, Jan and Oesterle, Hannes and Schmale, Hans Christian}},
booktitle = {{Tagung Werkstoffprüfung 2024: Werkstoffe und Bauteile auf dem Prüfstand, Prüftechnik – Kennwertermittlung – Schadensvermeidung}},
editor = {{Krupp, Ulrich and Steller, Ingo}},
isbn = {{978-3-941269-97-2}},
keywords = {{Clinchen, Aluminium, Stufensetzversuch, Bindemechanismus, Formschluss, Kraftschluss, Zugversuch, Torsionsversuch, Widerstandsmessung}},
location = {{Krefeld}},
pages = {{205--210}},
title = {{{Prozessüberwachte Eigenschaftseinstellung beim Clinchen der ausscheidungshärtbaren Aluminiumlegierung EN AW-6014}}},
year = {{2024}},
}
@inproceedings{44036,
abstract = {{Abstract. In order to reduce global energy consumption in production and industry along with the associated CO2 emissions, existing resources must be used more efficiently. This includes the energy-efficient and comprehensive recycling of a wide range of metals. Especially for the production of aluminium, there is a large potential for saving energy using efficient recycling processes. With regard to the recycling of aluminium studies have shown that solid-state recycling processes are significantly more efficient considering the used energy and resources compared to the conventional, smelting-metallurgical recycling process. In this paper, the direct and energy-efficient friction-induced recycling process (FIRP) based on the conform process is further described and analysed in terms of the temperature-property relationships. For this purpose, the influence of the processing temperature on the microstructure and properties of the recycled semi-finished products is investigated using the toll system that enables an ECAP forming. Specific sections of the (in theory) infinite, recycled semi-finished product are taken and analysed at different process temperatures of the solid state recycling process. Based on these sections, the properties in terms of mechanical hardness, strength, ductility and grain size are analysed and a degressive relationship between process temperature and mechanical hardness up to a temperature of 270 °C can be shown. Applying the Hall-Petch relationship, it is analysed whether there is a correlation between the strength and the microstructure in the form of the grain size. }},
author = {{Borgert, Thomas and Homberg, Werner}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
keywords = {{Recycling, Aluminium, Friction-Induced, Energy Efficiency}},
location = {{Kraków}},
publisher = {{Materials Research Forum LLC}},
title = {{{Analysis of temperature effect on strength and microstructure in friction induced recycling process (FIRP)}}},
doi = {{10.21741/9781644902479-211}},
year = {{2023}},
}
@inproceedings{43044,
abstract = {{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. }},
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}},
}
@inproceedings{60647,
abstract = {{Das umformtechnische Fügeverfahren Clinchen ermöglicht ein energiearmes Fügen von Blechen und dient traditionell der Übertragung mechanischer Kräfte. Neue Einsatzgebiete erfordern eine elektrische oder thermische Leitfähigkeit, sodass es notwendig ist, das Clinchen entsprechend zu qualifizieren. Es wurden Untersuchungen an Aluminiumverbindungen durchgeführt, welche mit hohen Kurzzeitströmen belastet wurden. Der Einfluss verschiedener Oberflächenvorbehandlungen wurde betrachtet. Als Charakterisierungsmethode für die Bauteile und die geclinchten Fügeverbindungen wird die Messung des elektrischen Widerstandes herangezogen. Die untersuchten Clinchverbindungen sind fähig, die im Fehlerfall auftretenden Kurzzeitströme zu übertragen. Der Oberflächenzustand übt dabei einen signifikanten Einfluss auf die Clinchpunktausbildung und damit auf deren elektrische Eigenschaften aus. Durch Messung des elektrischen Widerstandes vor und nach dem Fügen sowie nach einer Bestromung mit Fehlerströmen, kann das Kontaktverhalten qualifiziert werden.}},
author = {{Reschke, Gregor and Kalich, Jan and Füssel, Uwe}},
booktitle = {{Tagung Werkstoffprüfung 2022: Werkstoffe und Bauteile auf dem Prüfstand, Prüftechnik – Kennwertermittlung – Schadensvermeidung}},
editor = {{Zimmermann, Martina}},
isbn = {{978-3-88355-430-3}},
keywords = {{Clinchen, Bindemechanismen, elektrische Eigenschaften, Aluminium, Kurzzeitbestromung}},
location = {{Dresden}},
pages = {{374--379}},
title = {{{Methoden zur Charakterisierung der Bindemechanismen bei geclinchten elektrischen Kontakten}}},
year = {{2023}},
}
@article{24589,
abstract = {{Additive manufacturing, e.g. by laser powder bed fusion (LPBF), is very attractive for lightweight constructions, as complex and stress-optimised structures integrating multiple functions can be produced within one process. Unfortunately, high strength AlZnMgCu alloys tend to hot cracking during LPBF
and thus have not so far been applicable. In this work the melting and solidification behaviour of
AlZnMgCu alloy powder variants with particle surface inoculation was analysed by Differential Fast
Scanning Calorimetry. The aim is to establish a method that makes it possible to assess powder modifications in terms of their suitability for LPBF on a laboratory scale requiring only small amounts of powder.
Therefore, solidification undercooling is evaluated at cooling rates relevant for LPBF. A method for the
temperature correction and normalisation of the DFSC results is proposed. Two ways of powder modification were tested for the powder particles surface inoculation by titanium carbide (TiC) nanoparticles:
via wet-chemical deposition and via mechanical mixing.
A low undercooling from DFSC correlates with a low number of cracks of LPBF-manufactured cubes. It
appears that a reduced undercooling combined with reduced solidification onset scatter indicates the
possibility of crack-free LPBF of alloys that otherwise tend to hot cracking.}},
author = {{Zhuravlev, Evgeny and Milkereit, Benjamin and Yang, Bin and Heiland, Steffen and Vieth, Pascal and Voigt, Markus and Schaper, Mirko and Grundmeier, Guido and Schick, Christoph and Kessler, Olaf}},
issn = {{0264-1275}},
journal = {{Materials & Design}},
keywords = {{Aluminium alloy 7075, Differential fast scanning calorimetry, Solidification, Undercooling, Additive manufacturing}},
title = {{{Assessment of AlZnMgCu alloy powder modification for crack-free laser powder bed fusion by differential fast scanning calorimetry}}},
doi = {{10.1016/j.matdes.2021.109677}},
year = {{2021}},
}
@phdthesis{37579,
abstract = {{Leichtmetalle mit einem breiten Eigenschaftsspektrum gewährleisten die Realisierung ressourcenschonender Produkte und ermöglichen die Intensivierung sortenreiner Kreislaufwirtschaften. Die vorliegende Arbeit untersucht einen wärmeunterstützten Ansatz zur Erhöhung der Formgebungsgrenzen stark kaltverfestigter AlMg4,5 Blechwerkstoffe bei gleichzeitiger Beschränkung des Festigkeitsverlustes durch Erholungseffekte. Experimentelle Untersuchungen stellen eine wissenschaftlich fundierte Erkenntnisbasis über die werkstofftechnischen Wirkzusammenhänge des untersuchten Prozesses dar. Gepaart mit an realen Bauteilgeometrien validierten numerischen Simulationsmodellen legt diese Arbeit einen methodischen Grundstein für die industrielle Umsetzung des hier untersuchten Blechumformprozesses. Die erzielte mittlere Dehngrenze des exemplarisch untersuchten Bauteils übersteigt die Dehngrenze eines konventionellen AlMg4,5 Werkstoffes um 190 %. Mit 320 MPa entspricht sie dem Festigkeitsniveau des walzharten Blechhalbzeuges im Lieferzustand, ein Wert, der nach dem aktuellen Stand der Technik auf Bauteilebene ausschließlich mit aushärtbaren AlMgSi Legierungen darstellbar ist. }},
author = {{Camberg, Alan Adam}},
isbn = {{978-3-8440-8271-5}},
keywords = {{Aluminium, Blechumformung, AlMg, Materialmodellierung, Duktiles Versagen, Halbwarmumformung, Automobil, Leichtbau, Uni-Alloy, 5000-Serie, 5182, GISSMO}},
pages = {{230}},
publisher = {{Shaker Verlag}},
title = {{{Festigkeitssteigerung von Aluminiumblechformteilen der 5000-Serie durch Erweiterung der Formgebungsgrenzen stark kaltverfestigter Ausgangswerkstoffe}}},
doi = {{10.2370/9783844082715}},
volume = {{2021,52}},
year = {{2021}},
}
@article{21436,
abstract = {{Ultrasonic wire bonding is a solid-state joining process, used in the electronics industry to form electrical connections, e.g. to connect electrical terminals within semiconductor modules. Many process parameters affect the bond strength, such like the bond normal force, ultrasonic power, wire material and bonding frequency. Today, process design, development, and optimization is most likely based on the knowledge of process engineers and is mainly performed by experimental testing. In this contribution, a newly developed simulation tool is presented, to reduce time and costs and efficiently determine optimized process parameter. Based on a co-simulation of MATLAB and ANSYS, the different physical phenomena of the wire bonding process are considered using finite element simulation for the complex plastic deformation of the wire and reduced order models for the transient dynamics of the transducer, wire, substrate and bond formation. The model parameters such as the coefficients of friction between bond tool and wire and between wire and substrate were determined for aluminium and copper wire in experiments with a test rig specially developed for the requirements of heavy wire bonding. To reduce simulation time, for the finite element simulation a restart analysis and high performance computing is utilized. Detailed analysis of the bond formation showed, that the normal pressure distribution in the contact between wire and substrate has high impact on bond formation and distribution of welded areas in the contact area.}},
author = {{Schemmel, Reinhard and Krieger, Viktor and Hemsel, Tobias and Sextro, Walter}},
issn = {{0026-2714}},
journal = {{Microelectronics Reliability}},
keywords = {{Ultrasonic heavy wire bonding, Co-simulation, ANSYS, MATLAB, Process optimization, Friction coefficient, Copper-copper, Aluminium-copper}},
pages = {{114077}},
title = {{{Co-simulation of MATLAB and ANSYS for ultrasonic wire bonding process optimization}}},
doi = {{https://doi.org/10.1016/j.microrel.2021.114077}},
volume = {{119}},
year = {{2021}},
}
@article{19973,
abstract = {{As a result of lightweight design, increased use is being made of high-strength steel and aluminium in car bodies. Self-piercing riveting is an established technique for joining these materials. The dissimilar properties of the two materials have led to a number of different rivet geometries in the past. Each rivet geometry fulfils the requirements of the materials within a limited range. In the present investigation, an improved rivet geometry is developed, which permits the reliable joining of two material combinations that could only be joined by two different rivet geometries up until now. Material combination 1 consists of high-strength steel on both sides, while material combination 2 comprises aluminium on the punch side and high-strength steel on the die side. The material flow and the stress and strain conditions prevailing during the joining process are analysed by means of numerical simulation. The rivet geometry is then improved step-by-step on the basis of this analysis. Finally, the improved rivet geometry is manufactured and the findings of the investigation are verified in experimental joining tests.}},
author = {{Uhe, Benedikt and Kuball, Clara-Maria and Merklein, Marion and Meschut, Gerson}},
journal = {{Production Engineering}},
keywords = {{Self-piercing riveting, Joining technology, Rivet geometry, Multi-material design, High-strength steel, Aluminium}},
pages = {{417--423}},
title = {{{Improvement of a rivet geometry for the self-piercing riveting of high-strength steel and multi-material joints}}},
doi = {{10.1007/s11740-020-00973-w}},
volume = {{14}},
year = {{2020}},
}