Five well-known Zr-based alloys of the systems Zr–Cu–Al–(Ni–Nb, Ni–Ti, Ag) (Cu 5 15.4–36 at.%) with the highest glass-forming ability were comparatively analyzed regarding their pitting corrosion resistance and repassivation ability in a chloride-containing solution. Potentiodynamic polarization measurements were conducted in the neutral 0.01 M Na₂SO₄ 1 0.1 M NaCl electrolyte and local corrosion damages were subsequently investigated with high resolution scanning electron microscopy (HR-SEM) coupled with energy dispersive x-ray spectroscopy (EDX). Both pitting and repassivation potential correlate with the Cu concentration, i.e., those potentials decrease with increasing Cu content. Pit morphology is not composition dependent: while initially hemispherical pits then develop an irregular shape and a porous rim. Corrosion products are rich in Cu, O, and often Cl species. A combination of low Cu and high Nb or Ti contents is most beneficial for a high pitting resistance of Zr-based bulk metallic glasses. The bulk glassy Zr₅₇Cu₁₅.₄Al₁₀Ni₁₂.₆Nb₅ (Vit 106) and Zr₅₂.₅Cu₁₇.₉Al₁₀Ni₁₄.₆Ti₅ (Vit 105) alloys exhibit the highest pitting resistance.

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Die kollaborative Teilebearbeitung mit Robotern und Werkzeugmaschinen wird in der Fertigung immer wichtiger. Durch die gleichzeitige Arbeit von Robotern und Werkzeugmaschinen kann eine noch effizientere Produktion erreicht werden. Mit der Entwicklung fortschrittlicher simulationsbasierter Lösungen können Hersteller jetzt die Zusammenarbeit von Robotern und Werkzeugmaschinen besser simulieren und überprüfen, um potenzielle Probleme zu erkennen und zu lösen, bevor sie in der realen Fertigung auftreten. Eine solche Lösung ist die NX-Offline-Simulation in Verbindung mit digitalen Zwillingen, mit der Hersteller ihre Teilebearbeitungsprogramme testen und optimieren können. Der Vortrag erläutert kurz das laufende Projekt 'RokoPro' und die Notwendigkeit des Einsatzes von Robotern in der Fertigung und der Simulation zur Überprüfung dieser Lösungen. / Collaborative part processing with robots and machine tools is becoming increasingly important in manufacturing. Even more efficient production can be achieved by having robots and machine tools work simultaneously. With the development of advanced Simulation-based solutions manufacturers can now better simulate and verify the collaboration of robots and machine tools to identify and solve potential problems before they occur in real manufacturing. One such solution is NX offline simulation along with digital twins, which allows manufacturers to test and optimize their part processing programs. The presentation briefly explains the ongoing project “RokoPro” and the need for use of robots in manufacturing and simulation to check those solutions.

The amount of aluminium sheets in future body-in-white concepts is still on the rise. There is a need for optimizing the joining techniques, caused by the different characteristics compared to the established steel components. Especially the electrode life for resistance spot welding as a reliable and established process needs to be improved. One reason for the short electrode life when welding aluminium is the insulating effect of the aluminium oxide layer. One possibility to reduce the electrode wear is the mechanical destruction of the oxide layer before the welding. This paper describes the influence of a translational and rotational electrode movement on the electrode wear. The oxide layer destruction is detected by resistance measurement. It could be shown that the destruction of the oxide layer already occurs at low movements. However, a homogeneous, large-area destruction is necessary for a wear reduction.

Strategies to increase sustainability are of growing relevance for supply chains and especially for the management of production processes. In this paper, we build on existing literature in closed-loop supply chain management and consider a two-period game-theoretic model in which product returns are reused in the manufacturing process. In all scenarios, we assume that the return rate of used products is random and not known to the players at the beginning of the planning horizon, thus, they have to deal with uncertainty in period 1. In contrast to existing literature, we will also address the circumstance that the players’ level of information in period 2, after the returns have been realized, can be linked to the collection mode in the supply chain. In Scenario A, the retailer is involved in the collection of the used products and transfers them to the manufacturer, so that symmetric information is available. In Scenario B, on the other hand, the used products reach the manufacturer directly from the customer, so that the manufacturer has an information advantage over the retailer. By comparing these scenarios and a vertically integrated supply chain benchmark case, it becomes clear that, depending on the actual return rate, the presence of private information can be either beneficial or detrimental to the manufacturer. The retailer, on the other hand, can compensate for information disadvantages in most cases over the multi-period planning period due to its position as a Stackelberg leader. Regardless of the amount of a transfer payment offered to it by the manufacturer, it prefers the collection of the goods by the manufacturer itself. These findings contribute to literature on symmetric information, where, for example, a retailer-led collection is preferred (Savaskan et al. Manage Sci 50(2):239–252, 2004) or the decision depends on the amount of the transfer payment (Modak et al. J Clean Prod 171:512–528, 2018). However, we show that cooperation between the players leads to the best results not only economically but also from an ecological point of view.

Die Diplomarbeit untersucht die Qualitätsbewertung von dynamischen Simulationsmodellen zur Prozessunterstützung in modernen Industrieanlagen. Es wird in Anlehnung an die ISO 25010 ein Qualitätsmodell zur Bewertung von Softsensormodellen zur Online-Prozessüberwachung erstellt. Methoden zur Bewertung von Softwarequalität werden auf die Qualitätsbewertung von Simulationsmodellen übertragen. Der Fokus liegt hierbei auf der Funktionalität und Zuverlässigkeit der Simulationsmodelle. Anhand des Qualitätsmodells wird ein Prototyp zur teilautomatisierten Qualitätsprüfung implementiert. Das wichtigste Merkmal des Prototyps ist die Ausgabe von Handlungsempfehlungen zur Evolution der Simulationsmodelle. Anhand eines Softsensormodells zur Überwachung der Biomassekonzentration in einem Fermentationsprozess und einer Fallstudie wird der Prototyp evaluiert. / This thesis investigates the quality assessment of dynamic simulation models for process support in modern industrial plants. Based on ISO 25010, a quality model for the assessment of soft sensor models for model-based process monitoring is developed. For this, methods for evaluating software quality are transferred to the quality of simulation models. The focus is on the functionality and reliability of the simulation models. The quality model is used to implement a prototype for semi automated quality testing. The most important feature of the prototype is the output of recommendations for the evolution of the simulation models. The prototype is evaluated using a soft sensor model for online estimation of biomass concentration in a fermentation process and a case study.

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