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Aufsatz
Prozessintegration von induktiver Wärmebehandlung und Festwalzen – sichere und zuverlässige Komponenten mit hoher Schwingfestigkeit
(2017-02-08)
Mechanische Oberflächenbehandlungen, beispielsweise das Festwalzen, spielen in der technischen Praxis eine bedeutende Rolle und tragen wesentlich zur Steigerung der Zuverlässigkeit hochbeanspruchter Komponenten bei. In einer Reihe von Fällen wurde gezeigt, dass eine Erhöhung der Prozesstemperatur die Wirksamkeit der Verfahren noch steigert, weil dies zu einer besseren Stabilisierung der eingebrachten Druckeigenspannungen führt. Eine wesentliche Voraussetzung zur Einführung dieser Verfahren in die Praxis ist allerdings, ...
Aufsatz
Bend Straightening of a Carbonitrided Gear Shaft – Consequences on Residual Stresses and Retained Austenite near the Surface
(2017-06-20)
Carbonitriding of shafts in drive technology is strongly connected with distortion. Bend straightening is an important process step in order to eliminate distortion without removing the hardened surface layer. As shown in several investigations, even for simple part geometries, bending induced stresses and plastic deformations have a strong impact not only on the residual stress state but also on the microstructure after straightening. As gear shafts become increasingly filigree and complex in their geometry, the ...
Aufsatz
Climatic Ageing of Components of Polymer Based Electrochromic Devices
(2013-09-09)
Combining a shading function and a polycarbonate window displays an attractive alternative to the currently employed glass roof in vehicles. However, the ageing of such a device must be investigated before any application. Therefore, our investigations focus on the ageing of the components of a polycarbonate based electrochromic device. The optical, electrical, mechanical and electrochemical properties of the ion storage layer as well as the substrate will be assessed after storage in a climate with a high humidity ...
Aufsatz
Spatio-temporal resolution studies on a highly compact ultrafast electron diffractometer
(2015)
Time-resolved diffraction with femtosecond electron pulses has become a promising technique to directly provide insights into photo induced primary dynamics at the atomic level in molecules and solids. Ultrashort pulse duration as well as extensive spatial coherence are desired, however, space charge effects complicate the bunching of multiple electrons in a single pulse.Weexperimentally investigate the interplay between spatial and temporal aspects of resolution limits in ultrafast electron diffraction (UED) on our ...
Aufsatz
Ordoliberalism Out of Order? The Fragile Constitutionality of Greek Austerity (Part Two)
(2020-06)
This is the second part of a two-part post. The first part, available here, considered the historical background of the concept of constitutional order and its relation to the ordoliberal project. Judicial independence was examined in parallel with central bank independence, with each understood as a means of insulating policy from social and democratic pressures and also as a means of enacting and maintaining fiscal discipline and market-conforming order. It also included some preliminary observations on the relation ...
Aufsatz
Characterization of Anisotropic Properties of Hot Compacted Self-Reinforced Composites (SRCs) via Thermal Diffusivity Measurement
(2019-11-01)
The mechanical properties of self-reinforced composites (SRCs) produced in a hot compaction process significantly depend on the process parameters. Only a little deviation of the process temperature or pressure causes the component to act differently under mechanical load. This is a chance and a challenge at the same time, since this process is difficult to handle but by properly controlling the process parameters, the mechanical properties can be adjusted, even locally for one component. In this research SRC are ...
Aufsatz
Joining of Contact Pins and Conductive Compounds via Injection Molding – Influence of the Flow Situation on the Electrical Contact Resistance
(2020-04-09)
While a lot of research can be found in the field of bulk resistance of carbon filled polymers, comparatively few papers focus on contact resistance between compound and metal contacts. Due to that small number of researches that deal with contact resistances, studies of the influence of injection molding conditions and parameters on the contact resistance are also very rare. In contradiction to that, these influences on bulk resistance have been studied. The objective of this work was to investigate the electrical ...
Aufsatz
A Closer Look at the Bonding Capacity of Thick Metal-Plastic Hybrids
(2019-03-01)
Metal-plastic hybrids have a lot of advantages compared to purely metal or purely plastic parts. A good design for metal-plastic hybrids can help to save weight, for example in automotive applications. Therefore, it is important to understand the joining mechanisms between both materials. Aluminum AlSi9Cu3(Fe) and polyamide 6.6 with 35 % glass fibers were used as joining partners. The materials were joined by enclosing the metal part at least partially with plastic right inside the injection molding tool. Afterwards, ...
Aufsatz
UV Pre-Treatment for Polycarbonate for Bonding LSR in a Multi-Component Injection Molding Process
(2019-03-01)
In this study, the influence of UVC radiation and the influence of ozone on the surface energy of specimens made of polycarbonate were investigated. In an additional step, the peeling resistance of silicone flaps, which were overmolded, onto pre-treated PC plates of multicomponent specimens were analyzed. For this purpose, the samples were exposed to UVC radiation for different lengths of time, ranging from 5 s to 3 600 s. To further evaluate the influence of the ozone created by the UVC in the presence of oxygen, ...
Aufsatz
Characterization of wood-based multi-material systems under dynamic impact stress
(2018)
Due to its naturally grown properties, wood has played a rather subordinate role as a material for technical applications up to now. In this paper, multi-material systems based on veneers of beech (Fagus sylvatica) with different reinforcing variants were investigated. In addition to the influence of different adhesive systems (urea formaldehyde and polyurethane), the effect of reinforcing by aramid fiber fabric and stainless steel foil in different climates was examined. At the center of the investigations were ...