Integration von Sach- und Dienstleistungen – Ausgewählte Internetquellen zur hybriden Wertschöpfung

The article presents results of an internet research on product-service systems. Web sites showing interesting practical examples and studies available online are presented to point out the practical relevance of innovative combinations of products and services. The multiplicity of research projects found on the internet shows that this phenomenon is also discussed intensively in research. These projects have been categorized by analyzing their web sites. Furthermore, the results of the internet research highlight a high diversity of terms for describing the concept of product-service systems. As a consequence, orientation in this subject area is hindered.     

Magnetic Behaviour of O2 Confined in Nanopores

The static susceptibility of solid oxygen condensed into nanoporous matrices is measured as a function of temperature and pore diameter. The drastic changes of the qualitative behaviour are interpreted as a cross-over from three- to one-dimensional behaviour.     

Dynamical Quantum Phase Transitions

A sweep through a quantum phase transition by means of a time-dependent external parameter (e.g., pressure) entails non-equilibrium phenomena associated with a break-down of adiabaticity: At the critical point, the energy gap vanishes and the response time diverges (in the thermodynamic limit). Consequently, the external time-dependence inevitably drives the system out of equilibrium, i.e., away from the ground state, if we assume zero temperature initially. In this way, the initial quantum fluctuations can be drastically amplified and may become observable—especially for symmetry-breaking (restoring) transitions. By means of several examples, possible effects of these amplified quantum fluctuations are studied and universal features (such as freezing) are discussed.     

Influence of the Gas Atmosphere on the Composition and Phase Development of Polymer-Derived SiOC-Ceramics

Silicon oxycarbide (SiOC)-based ceramics were synthesized by pyrolysis of a commercial polysiloxane containing MoSi₂ and ceramic filler particles. The influence of different gas atmospheres on the chemical composition and on the phase formation of the filled Si–O–C ceramic during the pyrolysis process up to elevated temperatures of above 1200°C has been studied. The pyrolysis gas composition in the furnace during pyrolysis was measured with an in situ gas analyzer. Both the core and the surface of bulk samples were investigated with respect to composition in order to take the changes on the rim area of the specimens into account. The influence of hydrogen gas on the compositional gradient of the resulting ceramic material was derived from samples investigated by polarization microscopy, X-ray diffraction (XRD), and micro-XRD (μ-XRD).     

Versuchsmethodik für Laboruntersuchungen zum Zusammenhang zwischen Herstellungsbedingungen,Gefüge und Werkstoffeigenschaften

Wegen ihrer großen Bedeutung unter den heutigen Herstellungsverfahren wurden thermomechanische Behandlungen durch Warmflachstauchversuche mit dem Warmumformsimulator (Wumsi) des Max-Planck-Instituts für Eisenforschung durchgeführt. Die gegenüber anderen Simulationsverfahren vergleichsweise großen Wumsi-Proben erlaubten erstmalig mit aus ihnen entnommenen 1/2 CT-Proben auch die Durchführung von Bruchmechanikversuchen an im Labor thermomechanisch behandeltem Stahl. Hierbei wurden die Meßwerte mit einem Laborrechnersystem für die spätere Auswertung gespeichert. Die beschriebene Versuchsmethodik wird exemplarisch mit Versuchsergebnissen an dem Vergütungsstahl 50 CrMo 4 illustriert. Neben einer thermomechanischen Behandlung mit vier simulierten Walzstichen wurde eine konventionelle Vergleichsvariante erzeugt; die Proben wurden bei verschiedenen Temperaturen angelassen. Sowohl bei den Ergebnissen der Zug- und Kerbschlagbiegeversuche, als auch bei den bruchmechanischen Kennwerten Rißzähigkeit K_Ic und J_R-Rißwiderstandskurven zeigte sich die Verbesserung der Werkstoffeigenschaften durch die thermomechanische Behandlung gegenüber denen nach der konventionellen Behandlung.     

Influence of processing parameters on quality factors of one-shot hybrid structures made by RTM

This paper is dealing with the influence of processing parameters for manufacturing of steel–carbon-fiber-reinforced-plastic (CFRP) hybrid plates by using the one-shot-hybrid resin-transfer-moulding (OSH-RTM) process. A design of experiments study was carried out. The quality of the manufactured parts was quantified by the bending modulus, the apparent interlaminar shear strength (ILSS), the maximum deflection and the density of the CFRP. The following changeable processing parameters were chosen: mould temperature, resin temperature, change in mass flow and maximum injection pressure. It is shown that the mould temperature and the change in mass flow show significant impact on the flexural modulus, density and maximum deflection of the plate while there is no significant impact on the apparent ILSS. Furthermore, the interaction between the mould temperature and resin temperature is having an influence on the flexural modulus and density.     

Influence of textile parameters on the in‐plane permeability characteristics of non‐crimped fabric preforms

Material parameters such as the permeability of dry reinforcing textiles are key variables for modern composite production using liquid composite molding (LCM) technique. Nowadays numerical filling simulations are required for predicting the mold filling behavior. Inaccurate predictions can lead to a high risk of air inclusion and corresponding need for cost‐intense revision of the mold design. Permeability values of the textiles used in the process are basic requirements for a numerical filling simulation, since the permeability is directly linked to the filling behavior. Nevertheless, the permeability values of non‐crimped fabrics (NCF) which are used for aerospace and automotive structures are rare. In this study the influence of textile parameters of NCF on the in‐plane permeability has been investigated using a capacitive in‐plane permeability measurement technology. The results show the influence of the roving filament number as well as the used stitch length on the in‐plane permeability. It is confirmed that the textile grammage is not affecting the in‐plane permeability of NCF reinforcements. The results of this study are valuable for textile selection with specific permeability data as well as for numerical filling simulations. POLYM. COMPOS., 37:1854–1863, 2016. © 2015 Society of Plastics Engineers