bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tribologische Untersuchungen an PEEK- und Bronze-Basis-Werkstoffen
Authors: Tas Zakir 
Published: December 2013

Kurzfassung
Das Ziel der diesem Beitrag zugrunde liegenden Untersuchungen ist, das Reibungs- und Verschleißverhalten der Peek- und Bronze-Basis-Materialpaarungen in trockenen und geschmierten Zuständen zu untersuchen, um die Werkstoffe mit günstigen Reibungs- und mit geringsten Verschleißkennzahlen zu ermitteln und damit geeignete Materialkombinationen auswählen zu können. Als Grundkörper wurden zwei verschiedene Kunststoffe (Arlon 1330 und 1555) aus PEEK-Basis sowie Deva-Metall aus Bronze-Basis gewählt und ihre Reibungs- und Verschleißverhalten experimentell untersucht. Dabei wurde als Gegenkörper das Hartmetall WC/Co verwendet. Bei allen Versuchen wurden die Beanspruchungsparameter konstant gehalten, damit die Ergebnisse untereinander verglichen werden können. Drehmoment, Temperatur und Längenabnahmen der Proben wurden gemessen. Mithilfe der gemessenen Größen wurden die anderen tribologischen Kenngrößen ermittelt. Gemessene und experimentell ermittelte Daten wurden statistisch ausgewertet und grafisch dargestellt. Bei der grafischen Darstellung wurde darauf geachtet, dass sie neben der Erleichterung der Auswahl der geeigneten Werkstoffpaarung auch zur Analyse des tribologischen Verhaltens dient. Detaillierte Untersuchung der Reiboberflächen erfolgte durch SEM-Aufnahmen und EDX-Analyse. Nach den Oberflächenanalysen wurden festgestellt, dass die Materialübertragung aus der Gegenlauffläche bei Peek-Basis- Werkstoffen stattfindet.
The Dynamics of Loading and Growth of Fatigue Cracks in the Proximity to Rolling Contact of Elements with Defects on Their Surface*
Authors: Pietrzyk Mariusz , Bogdański Stanisław 
Published: December 2013

Abstract
This paper highlights the analysis of the development of fatigue cracks under loading in the region of rolling contact. A surface defect is taken as an irregularity of a convex circular profile on an otherwise regular contact track, on which a rolling element is moving. 2D numerical models with different lengths of cracks were analysed. The results provided an estimation of the influence of the irregularity height and the length of a crack on the stress intensity factors (SIF) at the crack tip, and, as a consequence, on the crack growth rate and direction. A simplified model of contact was used in which the rolling element was replaced by the distribution of displacements equivalent to its interaction. It was assumed that an element in a contact pair having a large mass and moving with a high velocity would not deviate from its initial path while rolling over the irregularity on the track. This allowed the dynamic contact interaction and corresponding crack tip loading to be estimated, despite the use of a quasi—static model for the analyses.
Damage Identification in Strongly Loaded Carbon-Reinforced Composite Using the Electric Resistance Change Procedure*
Authors: Gadomski Jacek , Pyrzanowski Paweł 
Published: December 2013

Abstract
Composite materials are often used as primary structures in important devices, like transport facilities. However, prediction of their work and damage propagation is not easy. Operating of the structure causes delaminations and fibers cracking which are difficult to detect by visual investigation. The paper presents an experiment in which an electrical resistance change method was used for investigating damage in strongly loaded carbon-fiber reinforced plastic composites, where the conducting carbon fiber was used as a sensor for defect detection. The method is shown by which the electric potential difference was measured at the carbon/epoxy composite beam type specimen exposed to the action of pure bending moment.
Zur Auswertung von Schwingfestigkeitsversuchen im Zeitfestigkeitsbereich —
Authors: Martin Andreas , Hinkelmann Karsten , Esderts Alfons 
Published: December 2013

Kurzfassung
Die Auslegung schwingend beanspruchter Bauteile setzt häufig experimentell ermittelte Wöhlerlinien voraus. Diese werden aus Einstufenschwingversuchen bestimmt. Die Auswertung solcher Versuche erfordert statistische Verfahren. Neben der mittleren 50%-Wöhlerlinie muss auch das Streuverhalten der Experimente analysiert werden. Der vorliegende Beitrag gibt Hinweise zur Abschätzung der Standardabweichung aus einer Stichprobe von Wöhlerversuchen. Zur Korrektur der systematischen Unterschätzung der Standardabweichung bei geringen Stichprobenumfängen werden Näherungslösungen angegeben. Dabei wird zwischen Versuchen nach dem Horizonten- und dem Perlenschnurverfahren unterschieden.
EN ISO 6892-1:2009 Tensile Testing: Initial Experience from the Practical Implementation of the New Standard*
Authors: Aegerter Johannes , Kühn Hans-Joachim , Frenz Holger , Weißmüller Christian 
Published: December 2013

Abstract
With the publication of EN ISO 6892-1:2009 [1], the harmonisation of tensile testing at room temperature in Europe was achieved by combining EN 10002-1:2001 [2] with ISO 6892:1998 [3]. Essential changes are the introduction of the strain rate and the strain rate control as the significant testing rate or control mode, respectively, referred to as “Method A”. By using this method in the correct way it is guaranteed that in the moment of determination of properties comparable resulting strain rates at the test piece in smaller ranges of specified strain rates are adopted — also if different stiffnesses of the testing equipment are present. This leads especially for strain rate sensitive materials to better comparable results. In this paper it is documented the need for the implementation of method A, methods for the realisation — also by the use of older testing systems — and an example of the comparability of results of the methods for a strain-rate-sensitive-steel.
Arbeitswalzen aus Keramik zum Walzen von dünnen Stahlfolien im 20-Walzen-Sendzimirgerüst
Authors: Goryany Vyacheslav , Mauk Paul Josef , Giersbach Jörg 
Published: December 2013

Kurzfassung
Die Walzversuche von dünnen Stahlfolien in einem 20-Walzen-Sendzimirgerüst mittels Arbeitswalzen aus Hochleistungskeramik ergaben durchweg eine hervorragende Anwendbarkeit dieser Werkstoffe, bei denen zu erwarten steht, dass die Anwendung von keramischen Walzen wegen erhöhter Standzeit deutlich günstiger sein wird.
Magnesium Applications for Fuel Economy and Energy Production
Authors: Kulekci Mustafa Kemal , Yelken Tugba , Esme Ugur , Kazancoglu Yigit 
Published: December 2013

Abstract
In this study, the properties, applications, technological barriers, and future projection of magnesium and magnesium based materials in fuel economy and energy production were evaluated. Mg lowers fabrication and joining costs, substitution by lightweight materials enable weight savings, in addition lifetime fuel costs and CO2 emission are reduced. Studies state that reducing the automotive weights by a certain amount will result in a similar reduction in fuel consumption and CO2 emissions. Most power systems, either renewable or nuclear, provide solutions for electricity production, but to date, there is no satisfactory substitute for liquid fossil fuel for use in transportation (cars, airplanes, and the like) due to environmental reasons or security of supply. A resent approach to this problem is to use hydrogen as fuel. Researches on Magnesium-Air Fuel Cell (MAFC) Technology resulted in new and improved technologies which have advanced the magnesium-air fuel cell to commercialization. The MAFC approach to an alternative energy source is the development of a powerful, reliable and environmentally friendly non-toxic fuel cell that generates energy using magnesium. From the results of the resarches it is concluded that magnesium applications reduce CO2 emission, and fuel costs.
Prüfung und Überwachung von Komponenten intralogistischer Anlagen
Authors: Zielke Reiner , Tillmann Wolfgang , Rademacher Hans-Georg , Sievers Norman , Siebrecht Tobias , Walther Frank 
Published: December 2013

Kurzfassung
Der Sonderforschungsbereich (SFB) 696 Forderungsgerechte Auslegung von intralogistischen Systemen – Logistics on Demand wurde im Juli 2006 an der Technischen Universität Dortmund eingerichtet, um analytische Methoden und Technologien zur anforderungsgerechten Gestaltung und Organisation intralogistischer Systeme zu entwickeln. In zwölf Teilprojekten ging es darum, die heutigen und zukünftigen Anforderungen der Anwender, darunter auch den produktbegleitenden Service, stärker in den Mittelpunkt der Produktentwicklung intralogistischer Systeme zu rücken. Vision ist es, die methodische und technische Basis für flexible, auf Veränderungen automatisch reagierende, sich selbst kontrollierende und reparierende zuverlässige Intralogistiksysteme zu schaffen.
Service Life Estimation for a Reformer Tube against Creep Dominated Failure
Authors: Baydogan Murat , Kayali Eyup Sabri , Cimenoglu Huseyin 
Published: December 2013

Abstract
Remaining service life of a petrochemical plant reformer tube, which has been exposed to water vapour at 540° C for 22 years under an internal pressure of 88 bar, was analysed via the Larson-Miller approach. Samples machined from the exposed and the original tubes were subjected to stress rupture tests at various stress levels and temperatures to determine the variation of the Larson-Miller parameter with the applied stress. At a service temperature of 540° C, the remaining service life decreased with increasing applied stress. For the stress of 42 MPa, which corresponded to the hoop stress generated on the tube during service, it was estimated that the tube has completed about 50 % of its actual service life.
Laser-Speckle-Photometry – A Method for Non-Contact Evaluation of Material Damage, Hardness and Porosity
Authors: Cikalova Ulana , Bendjus Beatrice , Schreiber Jürgen 
Published: December 2013

Abstract
The Laser Speckle Photometry is a newly developed non-contact non-destructive testing method which is based on the detection and analysis of thermal or mechanical activated characteristically speckle dynamics. The determination of the material damaged state is based on the understanding of structural changes on different scaling levels given by the physical mesomechanics. The hierarchical behavior of the mesomechanical structures (meso-structures) leads to the hypothesis of the fractal nature of the deformation structure. The fractal dimension D
F
is a suitable parameter to characterize the fatigued material state. In the case of the laser speckle photometry method the modified auto-correlation function from the pixel intensity changes of the speckles images was used for the computation of Parameter D
F
. The hardness or porosity of materials is defined by micro-structural variation and is combined with several thermal properties of the material. Therefore the speckle thermal diffusivity parameter K was determined using thermal conduction equation from the pixel intensity of speckle images changes during thermal activation. Afterwards correlation between the norm K and hardness and porosity, respectively was found. Results of this research will be presented in the present contribution.
Influence of Heat Treatment and Thermochemical Processes on the Properties of the Steel X 38 CrMoV 5 3
Authors: Kisasoz Alptekin , Karaaslan Ahmet 
Published: December 2013

Abstract
In this study, the effects of heat treatments and cooling rates on the properties of the steel X 38 CrMoV 5 3 were investigated. Heat treatments and cooling rates during the steel fabrication processes are critical parameters for the properties of tool steels, since the phases and the lattice structures change respectively. In the experiments, four different heat treatment processes and also, nitriding and carbonitriding processes were applied to specimens made from the investigated steel. For such experiments, two different austenitising temperatures with three different cooling rates were selected and the effects of the process para­meters on the mechanical strength were investigated. Microstructure evaluations were carried out by image analysis and by using a scanning electron microscope. To determine and compare the mechanical properties, Vickers hardness tests and three-point bending tests were applied.
Development of Vibration Isolation Mounts of a Vehicle Using Static and Dynamic Analysis
Authors: Korkmaz İbrahim 
Published: December 2013

Abstract
In automotive industry, rubber mounts are widely used to cushion the loads and isolate vibration in passenger vehicle compartments. In this study an engine rubber mount and strut bushing are analysed. The static and dynamic characteristics of the rubber specimen as well as the viscoelastic and hyperelastic properties are obtained by static and dynamic testing. The material properties coefficients in the finite element analysis have been implemented accordingly to the test data. The dynamic and static characteristics of the strut bushing and the engine mount are predicted with finite element analysis. The solutions show satisfactory agreement between predicted and experimental results. According to the authors, this work on the development of vibration isolation mounts using physical tests and simulations for verification of the final product, and providing the static and dynamic design factors represents pioneer work in open literature.
Mechanical Properties of A6063/SiC Composites Produced Using the Lost Foam Casting Process
Authors: Güler Kerem Altug , Kisasoz Alptekin , Yuksel Caglar , Karaaslan Ahmet 
Published: December 2013

Abstract
Aluminum matrix composites have a long history and they are still in the focus of interest. Molten metal processes are basic and the most common techniques of these kind of materials. Using lost foam casting process (LFCP) for aluminum matrix composite production is a new approach. LFCP is a special casting method, and it has flexibilities and advantages under complexity, material, and production aspects. It was considered that, reinforcement materials (SiC particles, etc) can be added to molten aluminum within the expanded polystyrene (EPS) foam patterns. Successful experiments were performed; SiC particles and molten aluminum were mixed with lost foam casting (LFC) technique. And this current study was carried out to determine the mechanical properties of A6063/SiC cast composites. The microstructures of the castings were investigated with optical and scanning electron microscopy (SEM). Archimedes density test, tensile, impact, and Brinell hardness tests were performed, and the results are consistent to those generally observed for metal matrix composites. Hardness, especially yield strength of matrix was increased with reinforcement addition, however ductility and toughness were decreased. Also, the respective production technique has a significant effect on the mechanical properties.
Statistical Optimization of Gold Recovery from Difficult Leachable Sulphide Minerals Using Bacteria
Authors: Ahmed H. A. M. , El-Midany A. A. 
Published: December 2013

Abstract
Some of refractory gold ores represent one of the difficult processable ores due to fine dissemination and interlocking of the gold grains with the associated sulphide minerals. This makes it impossible to recover precious metals from sulphide matrices by direct cyanide leaching even at high consumption of cyanide solution. Research to solve this problem is numerous. Application of bacteria shows that, some types of bacteria have great affect on sulphides bio-oxidation and consequently facilitate the leaching process. In this paper, leaching of Saudi gold ore, from Alhura area, containing sulphides before cyanidation is studied to recover gold from such ores applying bacteria. The process is investigated using stirred reactor bio-leaching rather than heap bio-leaching. Using statistical analysis the main affecting variables under studied conditions werde identified. The design results indicated that the dose of bacteria, retention time and nutrition K2SO4 are the most significant parameters. The higher the bacterial dose and the bacterial nutrition, the better is the concentrate grade. Results show that the method is technically effective in gold recovery. A gold concentrate containing >100 g/t gold was obtained at optimum conditions, from an ore containing < 2 g/t gold i.e., 10 ml bacterial dose, 6 days retention time, and 6.5 kg/t K2SO4 as bacteria nutrition.
Characterization of Eutectic Sn-Cu Solder Alloy Properties Improved by Additions of Ni, Co and In
Authors: Piyavatin Pitinan , Lothongkum Gobboon , Lohwongwatana Boonrat 
Published: December 2013

Abstract
Recently, the cost factor of raw materials has emerged continuous improvement of tin-copper solder alloys. This work aims to improve the microstructural and mechanical properties of the eutectic tin-copper solder alloys by addition of nickel, cobalt and indium. The temperature profile of reflow soldering in surface-mount assembly was simulated to produce realistic joint microstructures. Key properties for electronic soldering were characterized, i.e. melting behaviour, solidification beha-viour, wettability, electrical resistivity, microstructures and mechanical properties. The results showed that addition of Ni, Co and In can effectively improve the mechanical properties of Sn-0.7Cu solder alloy i.e. microhardness and shear strength by providing preferred interfacial morphology and formation of intermetallic compound precipitates. The new solder alloys also showed reduced liquidus and solidus temperatures whereas no significant degradation of other key properties were seen.
Abgestimmte Testumgebung aus dem Baukasten für Betriebsfestigkeitsversuche an Cabrioverdecken*
Authors: Mawick Gregor , Gries Christian , Schmiedt Stefan , Kuttner Thomas 
Published: December 2013

Kurzfassung
Ein flexibler Shakerbock für Cabrioverdecke mit einstellbaren Massen und Steifigkeiten ist entwickelt und für den Einsatz auf einer 4-Stempelanlage erprobt worden. Damit wird der Versuchsaufbau bestmöglich in der Geometrie, den Eigenfrequenzen und Eigenformen dem zum Zeitpunkt des Versuches nicht verfügbaren Gesamtfahrzeug angepasst. Durch den modularen Aufbau kann der flexible Shakerbock an verschiedene Fahrzeuge angepasst werden und ermöglicht den Aufbau aller üblichen Dachsysteme.
Exploiting the Property Profile of High Strength Steels by Damage Mechanics Approaches*
Authors: Münstermann Sebastian , Sharaf Mohamed , Lian Junhe , Golisch Georg 
Published: December 2013

Abstract
Although high strength low alloy steels offer the potential for lightweight design, their application is often rather limited due to existing design rules. A further development of these standards requires precise prediction of realistic limit states. The damage model of Bai and Wierzbicki has been extended in order to improve the description of the ductile failure behaviour of steels, especially when crack initiation in dynamic loading is to be simulated. Application examples of the extended model are given in order to show that it can be used for limit state analysis. An outlook presents the application of the model to derive improved safety factors for probabilistic safety concepts.
Microstructure and Mechanical Properties of Dual Matrix Aluminium-Fly Ash Composites Processed via Cryomilling, Cold Compaction and Hot Extrusion
Authors: Mindivan Harun , Vatansever Recep , Sabri Kayali Eyup 
Published: December 2013

Abstract
AA6061/Al alloy chips of different size and fly ash particles have been recycled using the solid state process. The effect of chip size and fly ash content on the microstructure, mechanical and wear properties of the recycled AA6061/Al two phase composites were investigated. Microstructural characterization revealed a uniform distribution of fly ash particles in recycled composites with fine chips and a good interface between fly ash particulates and AA6061/Al two phase matrixes. According to mechanical and wear results, the incorporation of fly ash particles in the AA6061/Al two phase matrix caused reasonable increase in hardness, compressive strength, and wear resistance. On the recycled composites fine chips, the destructive action of the steel ball was very limited compared to that of the Al 2O3 ball.
Innovative Prüfmethodik zur Ermittlung der thermomechanischen Ermüdung an Zylinderköpfen
Authors: Bischoff Tobias , Rödling Steffen , Stauder Bernhard 
Published: December 2013

Kurzfassung
Im Auslegungsprozess von Zylinderköpfen spielt die Bewertung der thermomechanischen Ermüdung eine wesentliche Rolle. Der IABG- Zylinderkopfprüfstand basiert auf einer innovativen Methode, die eine Beurteilung und Optimierung von Zylinderköpfen hinsichtlich thermomechanischer Ermüdung bereits in einem sehr frühen Entwicklungsstadium erlaubt. Durch die im Vergleich zu konventionellen Prüfmethoden deutlich kürzeren Versuchszeiten bietet der Prüfstand die Möglichkeit, die Entwicklungszeiten neuer Zylinderkopfkonzepte bei gleichzeitiger Reduzierung der Versuchskosten erheblich zu verkürzen. Der offene Aufbau des Prüfstandes ermöglicht zudem erstmals eine In-situ-Detektion des Anrisses sowie eine Verfolgung des Rissfortschrittes im Brennraumdach. Der vorliegende Artikel stellt das Prüfkonzept und die Ergebnisse eines Variantenvergleichs von konstruktiv identischen Zylinderköpfen mit unterschiedlichen Aluminium-Gusslegierungen vor.
How to Deal with Very High Cycle Fatigue (VHCF) Effects in Practical Applications?*
Authors: Bacher-Hoechst Manfred , Issler Stephan 
Published: December 2013

Abstract
Fatigue designing of high-stressed engine components is a key factor for reliable power train systems in automotive industry. In this context load assumptions are very important since this is attended with a pre-designing of important machine elements. Load analyses are usually performed by using experimental methods since the accuracy of load simulations are often not precise enough. An example for VHCF problems occurs in modern high pressure pumps for gasoline direct injection systems, which have load spectra with a large amount of cycles up to 109 including a very powerful shape of the spectra. At the same time it is necessary to consider the properties of fuels in service since they might affect the fatigue strength significantly. For example, ethanol-based gasoline fuels are used in a lot of countries worldwide and especially their additives may lead to significant corrosion fatigue effects. In addition, it is well known that material inclusions play an important role for the VHCF behaviour especially for high-strength steels. This paper deals with possibilities to avoid VHCF problems of components in service to maintain reliable systems.
Drilling Template Used to Produce Cellular EPS Patterns for the Lost Foam Casting Process
Authors: Guler Kerem Altug , Uster Ates , Cigdem Mustafa 
Published: December 2013

Abstract
Cellular metals differ from the other materials by a lower density which is their characteristic property. Besides, they show unusual physical, mechanical, thermal, acoustic and electrical properties. Even though they have lots of pores compared to solid materials they can show a unique combination of several properties that cannot be obtained in a conventional material at the same time. There are several kinds of production methods for cellular materials. Nowadays, lots of researches have been carried out with respect to new production methods. The lost foam process, which bases on evaporating the polystyrene foam model, reduces the process steps of investment casting and can be an alternative method to many production methods. In this study, open cell samples were produced with two different aluminium alloys by using the lost foam casting technique. A413 as a casting alloy and A6063 as a wrought alloy were selected for casting experiments. After production of these two aluminium alloys, the decrease in weight, compression strengths, deformation ratios were determined and compared to each other.