The use of 7000 aluminum alloys has an important role in future lightweight structures in the field of mobility due to the low density and high strength. However, these alloys can only be fusion welded to a limited extent because welding defects can rarely be prevented. For this reason, investigations are carried out to identify the most suitable welding parameters for two processes: laser beam and magnetic pulse welding. Herein, laser beam welding is successfully used to manufacture a roll‐formed and longitudinally welded pipe made of AA7075 and joined by magnetic pulse welding with a 3D‐printed lug‐tube made of AlSi10Mg. The fatigue strength of these pipe joints and of laser beam welded butt joint specimens is determined using load‐controlled fatigue tests. For the characterization of the specimens, cross sections are prepared and examined metallographically, which reflect the local weld seam geometry in the joining area. A fatigue assessment is made using linear‐elastic approaches. The reference radius concept is applied to map the influence of geometric notches on the fatigue strength, assuming linear‐elastic stress–strain behavior. It is shown that the recommended notch stress fatigue class FAT 178 (von Mises stress) can be applied for a safe and reliable fatigue assessment.

The present study provides an overview of previous studies on the welding of the AA7075-T6 aluminum alloy, followed by an investigation of the influence of short-time solution annealing on the mechanical properties of the weld. Conventional laser welding of Al-Zn-alloys leads to a low weld strength, which makes a post weld heat treatment (PWHT) favorable. The PWHT includes solution annealing, quenching and subsequent aging. For solution annealing, different holding times and cooling rates are investigated in this study. The focus of the investigation is on a short solution annealing time, which on the one hand is ecological and economically favorable and on the other hand offers great potential for inline heat treatments. The shortest solution annealing time of 10 s shows a significant increase in weld strength (joint efficiency of 72%), compared to the non-heat treated weld (joint efficiency of 52%). The microstructural analysis reveals that the cooling rate after solution heat treatment affects the formation of precipitates in the microstructure of the welded AA7075 alloy. Moreover, the enhancement of mechanical properties is related to the formation of Mg-Al-Cu and Mg-Zn rich precipitates.

In this paper, the potential of directional ultrasonic wave superposition by moving sound generators for laser beam welding of high-strength steel alloys 1.5528 (22MnB5) is studied. Steel sheets of identical thickness and in form of tailored blanks were joined in butt joint configuration. The influences of the various excitation parameters of the moving sound generators on the ultrasonic coupling and their influence on the distribution of the AlSi coating components within the melting zone and the weld seam characteristics are investigated. Etched cross-sections, scanning electron microscopy, energy dispersive X-ray spectroscopy, and electron backscattering measurements were used as the investigation methods to determine the AlSi distribution in the weld as well as its microstructure. The results presented a series of experiments which show that a suitable superposition of ultrasonic waves by the moving sound generators lead to a more homogeneous distribution of AlSi particles in the melt as well as to a finer microstructure within the weld, which improves the mechanical–technological properties.

A strong connection between research and teaching at a university is crucial to offer students a unique opportunity to put in practice the concepts taught in theoretical lectures. At the University of Stuttgart, several hands-on training courses have been offered for eight years within the module “Selected hands-on training for space”. Those are adapted to the current research at the Institute of Space Systems. During one semester, students participate in two of the offered courses and are evaluated through an exam or a report. Three ECTS for the space specialization in the aerospace engineering Master are granted after successful completion. The limited places offered are usually filled up in matter of hours and the students’ feedback has been very positive every year. The module includes up to five different courses, depending on the semester. The Life Support Systems seminar is focused on the cultivation of microalgae, linked to the institute’s ISS Experiment photobioreactor PBR@LSR. After learning the basic life support system concepts, the students build and conduct their own microalgae photobioreactor experiment. In the Missions Analysis practical seminar, based on the work of several PhD candidates, the participants learn and put in practice aspects of mission planning with the help of the Astos Solutions software as well as the SPICE toolkit. During the Rendezvous and Docking practical training, students learn about the operation and handling of a spacecraft. Besides theoretical lectures, guided sessions in the simulator allow to put into practice the handling of common complex procedures, audio-visual perception and motor skills. This seminar is linked to the research carried out in the SIMSKILL experiment. In the Earth Remote Sensing seminar, students learn how to handle payload data for Earth observation and their scientific evaluation. The Flying Laptop, a satellite fully built at the institute and launched in 2017, is used for this course. Finally, the research carried out in the field of electrolysers and fuel cells for space applications at the institute prompted the establishment of a training course. After deepening their knowledge on both electrolysers and fuel cells, the students prepare, carry out and evaluate various experiments. This paper presents the different training courses from our institute and their link to the current research.

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