@article{66067,
abstract = {{Abstract
Mechanical joining processes have played an increasingly important role in the manufacturing of modern lightweight structures due to a greater variety of materials. The growing number of joining tasks requires a large number of joining elements. Friction spun joint connectors (FSJC) offer an innovative approach that meets the growing demand for flexibility. This process combines rotational movement and axial force to create targeted friction heating, enabling the production of FSJCs and the joining of various sheet metal materials. The shape of the FSJC can be optimally adapted to the joining situation in question, providing a significant advantage in terms of process chain versatility. This paper investigates FSJCs made of the steel grades C45E+C (1.1191) and 115CrV3 (1.2210), the effect of in situ quenching during the joining process. The influences of the essential parameters of rotational speed, feed rate, and FSJC length on the mechanical properties after quenching are being focused on and compared to similar conditions during joining without quenching. At the same time, the material change is analyzed to determine the effect of different alloy approaches on hardness profiles and strength characteristics in cross-tensile testing. For this purpose, systematic test series with varying process parameters are conducted and evaluated using hardness measurements and cross-tensile tests.}},
author = {{Nordieker, Ansgar Bernhard and Homberg, Werner}},
issn = {{0972-2815}},
journal = {{Transactions of the Indian Institute of Metals}},
number = {{6}},
publisher = {{Springer Science and Business Media LLC}},
title = {{{Quenching During Thermomechanical Joining Using Friction Spun Joint Connectors}}},
doi = {{10.1007/s12666-026-03846-5}},
volume = {{79}},
year = {{2026}},
}
@inproceedings{65706,
abstract = {{Abstract. Saving emissions and a circular economy are key aspects of sustainable production and compliance global climate change targets. Friction-induced solid-state recycling of aluminum scrap to production endless semi-finished products. Scrap is fed into a continuously rotating wheel. This requires less energy compared to heat-based recycling processes. Different sizes, shapes and surfaces of chips can be used as starting material in the process. The influence of this has been shown in past publications. A native oxide layer is a fixed component of aluminum surface. This layer is broken up during the forming process, allowing the aluminum to bond. In addition to the geometry, the surface finishes and the thickness of the oxide layer are therefore also important input variables in friction-induced solid-state recycling. The oxide layers on the chips were determined for the investigation. In addition, different layer thicknesses were produced to survey their influence. The resulting semi-finished products were evaluated on the basis of their tensile strength and microstructure. The main result of the investigations is the fact that semi-finished products made from chips with thicker oxide layers tend to be more brittle. In addition, thick oxide layers cause microstructural and surface defects.}},
author = {{Gabsa, Steffen and Homberg, Werner and Goller, Timothy and Nordieker, Ansgar Bernhard and Grundmeier, Guido}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Influence of different oxide thicknesses on the friction induced and continuous solid-state recycling of aluminum scrap}}},
doi = {{10.21741/9781644903599-272}},
volume = {{54}},
year = {{2025}},
}
@inproceedings{54650,
abstract = {{Abstract. Reducing the weight of vehicles can significantly lower the energy or fuel consumed and thus the emissions during operation. One possibility to assess this is the use of a property adapted multi-material systems containing high strength steel, light metals like aluminium or magnesium and fibre reinforced plastics. While expanding the number of materials used new challenges arise for the production and furthermore the joining technology to manufacture the vehicle made of the multi-material systems. One approach to overcome these challenges is to use innovative and adaptable joining techniques which allows the manufacturing of joints of different material combinations. Extensive research activities on the two stage thermo-mechanical joining process with adaptable joining elements was able to demonstrate the great potentials in terms of joining dissimilar materials with good strength. The previously kinematic and path-based fabrication of auxiliary joining elements is modified in this publication to a form-based approach with a perspective of establishing an efficient process chain using easily and cheaply available rods. Based on the new approach to produce the auxiliary joining elements, it can be demonstrated that a reproducible production of the geometry is possible for the investigated steel as well as aluminium material. }},
author = {{Borgert, Thomas and Nordieker, Ansgar Bernhard and Homberg, Werner}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
location = {{Toulouse}},
publisher = {{Materials Research Forum LLC}},
title = {{{Form-based manufacturing of aluminium and steel auxiliary joining elements as the basis for an efficient joining operation}}},
doi = {{10.21741/9781644903131-180}},
year = {{2024}},
}
@article{54649,
author = {{Borgert, Thomas and Nordieker, Ansgar Bernhard and Wiens, Eugen and Homberg, Werner}},
issn = {{2666-3309}},
journal = {{Journal of Advanced Joining Processes}},
publisher = {{Elsevier BV}},
title = {{{Investigations to improve the tool life during thermomechanical and incremental forming of steel auxiliary joining elements}}},
doi = {{10.1016/j.jajp.2024.100185}},
volume = {{9}},
year = {{2024}},
}