bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of the Influence of the Pre-Aging Process on the Hardness of 6082 and 7075 Aluminum Alloys
Authors: Şahin Salim , Durmuş Hülya , Yüksel Nilay 
Published: December 2013

Abstract
In this study, the effect of pre-aging time and temperature on mecha­nical properties of aluminium alloys 6082 and 7075 has been investigated. Pre-aging has been applied at 50, 60, 70 and 80 °C for 24, 72, 144 hours after solution treatment process at 560 °C for 1 hour. Then these samples have been subjected to an aging process at 180 °C and 125 °C. The hardness of samples has been measured during aging process regularly. Eventually, it was determined that if pre-aging process is performed at low temperature, an increase of hardness occurs and hardness decreases with increasing temperature during aging.
X-ray Residual Stress Analysis of Nitrided Low Alloyed Steels
Authors: Hoffmann Joachim Ernst , Zgani Marouan , Scholz Dirk , Altendorfer Margit , Clemens Helmut , Kübler Ralf 
Published: December 2013

AbstractResidual stress analyses were performed on nitrided, low alloy steels by varying the measuring conditions. The measurements were carried out in the compound layer on ∊-Fe2–3N and γ′-Fe4N as well as in the diffusion layer on α-Fe. By considering different criteria, tensile residual stresses of up to 300 MPa produced, {111}-interference, for ∊-Fe2–3N using CuKα radiation on the specimen's surface. After removing 5 μm from the surface, compressive residual stresses occur in this phase. On employing the CrKα and CuKα radiation, relatively high compressive stresses are obtained of up to above −1000 MPa for γ′-Fe4N. For measurements using CrKα radiation, compressive residual stresses result in the diffusion layer for α-Fe, which have a maximum value below the surface. Here, the measurements of the {211}-interference give lower residual stress magnitudes than measurements of the {110}- and {200}-interferences. By verifying the phase superpositions, the linear distributions of line positions or the comparable loading stress analysis using XRD or strain gauges, the results determined at the {211}-interference appear to be realistic. Attention should be paid to the high penetration depth of CrKα radiation. Here, no gradients of the investigated stress states may exist which are too large. The steel possessing a higher content of nitride forming elements such as Al, for example, mainly exhibit the highest compressive residual stresses. In the diffusion layer of 34CrAlNi7-10, maximum compressive residual stresses of −800 MPa result at {211}-interference in α-Fe.
Evaluation and Optimization of Operating Parameters Affecting the Davis Tube Magnetic Tester by Using 2ndFactorial Design
Authors: Abdel Haffez Gamal S. , Abu-Ali Mohamed Hussein 
Published: December 2013

AbstractThe current practice of assessing the efficiency of recovery of magnetite is represented by Davis tube tests based on magnetic induction. 2ndfactorial design is used for the parametric study of the magnetic separation, because the classical approach is a tedious method. Factorial design is the most efficient way to explore the combinations of variables, because it considers every observation and uses only the most necessary observations. The results of the factorial experiments were used to identify the variables having a significant effect on magnetic recovery. The main objective of this work is to upgrade the iron ore using the Davis tube magnetic tester. It is also intended to study the most important operating parameters affecting the separation process. Among these are the feed size (μm), current intensity (A), tube oscillation (rpm), tube inclination (degree) and wash water rate (l/min). Consequently, the best fit relation can be expressed mathematically as: Y = 58.99 + 7.25X + 4.56I — 1.49O — 2.19W — 1.84S.
Terahertz Time Domain Spectroscopy for Non-Destructive Testing of Hazardous Liquids
Authors: Chrzanowski Lars S. von , Beckmann Jörg , Marchetti Barbara , Ewert Uwe , Schade Ulrich 
Published: December 2013

Abstract
Hazardous liquids, liquid explosives and flammable liquids are characterized by means of terahertz time domain spectroscopy (THz-TDS) in analogy to existing non-destructive testing (NDT) strategies. Various polar liquids (alcohols, acetone, hydrogen peroxide, nitro methane) and non-polar aircraft and automobile fuels as well as organic solvents are characterized in the practically relevant, non-contact and non-destructive reflection geometry in the time domain. Absorption coefficients and indices of refraction of a representative set of these liquids are investigated in the spectral range between 0.1 THz and 1.1 THz in transmission configuration by two different set-ups either suitable for strongly or weakly absorbing liquids.
Schwingfestigkeitsanalyse struktureller Klebverbindungen unter Belastung mit variablen Amplituden*
Authors: Schmidt Halvar , Bruder Thomas , Hanselka Holger 
Published: December 2013

Kurzfassung
Das Fügeverfahren Kleben gewinnt unter dem Gesichtspunkt Leichtbau aufgrund seiner Eigenschaften wie erhöhte Steifigkeit, verbessertes Crash-Verhalten und Fügbarkeit nichtmetallischer Werkstoffe (beispielsweise GFK oder CFK) stetig an Bedeutung. Der vorliegende Beitrag beschreibt die Entwicklung einer neuartigen, bauteilähnlichen Probenform zur Schwingfestigkeitsanalyse struktureller Klebverbindungen. Deren Schwingfestigkeitsverhalten unter Belastung mit variablen Amplituden wird aufgezeigt. Reihenfolgeeffekte wurden festgestellt. Basierend auf diesen Erkenntnissen wird neben der für die rechnerische Lebensdaueranalyse benötigten Schadensakkumulation auf die Energie­freisetzungsrate zur Abschätzung einer Versagensgrenze eingegangen.
Mechanische Kurzzeitprüfung zur Bewertung des Verhaltens von PE-Rohrwerkstoffen beim langsamen Risswachstum*
Authors: Langer Beate , Berthold Anja , Grellmann Wolfgang , Enderle Hans-Friedrich 
Published: December 2013

Kurzfassung
Die Kenntnis der Deformations- und Schädigungsmechanismen beim langsamen Risswachstum in Polyethylen (PE)-Rohrwerkstoffen ist im Hinblick auf ihre Lebensdauervorhersage von besonderer Bedeutung. Eine etablierte Möglichkeit der Simulation und Vorhersage des langsamen Risswachstums ist der Full-Notched Creep Test (FNCT), der besonders bei den heute verwendeten PE-Rohrwerkstoffen durch sehr lange Prüfzeiten gekennzeichnet ist. Aus diesem Grund wurde in der vorliegenden Arbeit nach Korrelationen gesucht, die zwischen Methoden der Kurzzeitprüfung und dem Full-Notched Creep Test bestehen. Als Methoden der Kurzzeitprüfung wurden die für Kunststoffe etablierten bruchmechanischen Konzepte “Essential Work of Fracture” und “Risswiderstandskurve” gewählt.
Neues aus der Normung auf dem Gebiet der mechanisch-technologischen Prüfverfahren*
Authors: Blum Jenny 
Published: December 2013

Kurzfassung
In diesem Beitrag werden die neuesten Entwicklungen in der Normung auf dem Gebiet der Werkstoffprüfung folgender Gebiete vorgestellt: mechanisch-technologische Prüfverfahren (Härteprüfung, Zugversuch, Kerbschlagbiegeversuch) und Kalibrierung von Werkstoffprüfmaschinen.
Instrumentierte Eindringprüfung zur Bestimmung lokaler Festigkeitskennwerte an Punktschweißverbindungen
Authors: Brauser Stephan , Subaric-Leitis Andreas , Ullner Christian , Rethmeier Michael 
Published: December 2013

Kurzfassung
Die lokalen Festigkeiten im Bereich einer Schweißverbindung sind maßgebend für deren Widerstandsfähigkeit gegenüber mechanischen Beanspruchungen. Im Gegensatz zu anderen präparationsaufwendigen Methoden, z.B. die Untersuchung von Mikro-Zugproben, liefert die instrumentierte Eindringprüfung mit deutlich geringerem Aufwand Verläufe von Festigkeiten mit sehr guter Ortsauflösung. Im Rahmen dieser Arbeit werden wahre Spannungs-Dehnungskurven aus zyklischen Eindringversuchen mittels Auswertungen auf der Basis repräsentativer Spannungen und Dehnungen und auf der Basis neuronaler Netze an Punktschweißverbindungen aus hochfesten Stählen, jeweils im Bereich des Grundwerkstoffs und der Schweißlinse, bestimmt. Die Ergebnisse werden exemplarisch für einen Stahltyp mit Ergebnissen von Zugversuchen am Grundwerkstoff und am thermisch behandelten Werkstoff mit Schweißgut ähnlicher Struktur verglichen und diskutiert.
Influence of Heat Treatment Parameters on the Microstructure and Mechanical Properties of Boron-Alloyed Steels
Authors: Güler Hande , Ertan Rukiye , Özcan Reşat 
Published: December 2013

Abstract
This paper focuses on the effect of heat treatment parameters on the microstructure and mechanical properties of quenchable 22MnB5 steel sheets with an Al–Si layer. Heat treatment parameters such as temperature and cooling rate from the solid solution temperature were investigated. For this purpose, the heat treatment was conducted within the temperature range from 700°C to 950°C, and two different cooling techniques were applied to the specimens: air cooling and water quenching. The microstructures of the specimens were then studied using optical microscopy. Additionally, tensile and hardness tests were performed at room temperature. The results show that the effects of heat treatment were obviously influenced by the original microstructure of the 22MnB5 sheet. With the increase of heat treatment temperature, the martensite proportions increased, and the hardness and tensile strength also increased, especially after the 850°C quenching. Moreover, quenching after 900°C has been reached was determined to be an ideal process for hot forming 22MnB5 steel sheets.
Tribological Properties of Sn-Pb Based SnPbAlZn Journal Bearings
Authors: Ünlü Bekir Sadik , Pinar Ahmet Murat , Özdin Kamil 
Published: December 2013

Abstract
Tin and lead based alloys are widely used as journal bearing materials in tribological applications. If Al or Zn with their sliding property will be added to such materials the tribological properties of journal bearings can be improved once more. In this study, wear properties of these journal bearings manufactured from SnPbAlZn, pure Sn, pure Pb, pure Al, and pure Zn bearings were investigated. Experiments were carried out in every 30 min for the total of 150 min by using radial journal bearing wear test rig. As a result wear properties can be improved by variation of SnPbAlZn material.
The Effect of Plasma Arc Process Parameters on the Properties of Dissimilar AISI 1040/AISI 304 Steel Plate Welds
Authors: Kiliç Musa , Kirik İhsan , Celik Ferkan , Orhan Nuri 
Published: December 2013

Abstract
In this study, 10 mm thick AISI 1040 and AISI 304 steel plates were welded in the butt position without pretreatment by plasma transferred arc (PTA) welding technique. Therefore, mechanical behaviour, microstructure, penetration depth and length were investigated. After welding, microstructural changes in the interface regions of the welded specimens were examined by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). Micro-hardness as well as V-notch Charpy tests were performed to determine the mechanical properties of the welds. The influence of the welding parameters on the dimension and shape of the joints has been found out. From the results, it was derived that with the parameters used, a partly keyhole weld bead formed with a penetration depth of 10 mm and a width of 11 mm in butt position.
Glimmentladungsanalyse (GD-OES) buntgehärteter Stahloberflächen
Authors: Schnapp Jürgen Dieter , Weber Heike , Schilling Jörg , Wilke Marcus 
Published: December 2013

Kurzfassung
Das Bunthärten wird traditionell zur hochwertigen, ästhetischen Oberflächenveredelung ferritisch-perlitischer Stähle vor allem für Komponenten von Jagd- und Sportwaffen verwendet. Diese weltweit von wenigen Werkstätten praktizierte Technologie war bisher empirisch orientiert und wurde weitgehend geheim gehalten. Die Struktur der buntgehärteten Randschichten wird hier mit der relativ neuen Methode der Glimmentladungsanalyse (GD-OES) untersucht und mit den Herstellungsparametern korreliert. Eine hochwertige Bunthärtung mit gewünschter marmorierter Farbstruktur und guten mechanischen und chemischen Eigenschaften ist an die Bildung von mehreren charakteristischen Randschichten mit typischen Kennwerten der chemischen Zusammensetzung, Struktur, Gefüge und deren Tiefenprofilen gebunden. Die untersuchten unlegierten und niedriglegierten Stähle haben vergleichbare Schichten, die durch technologie- und werkstoffspezifische Parameter erreicht werden.
A New Approach to Iznik Tiles
Authors: Sarigüzel Meryem , Günay Esin 
Published: December 2013

Abstract
Traditional Iznik ceramics (tile and pottery) are known as “unproducible” due to their high quartz content and unique processing steps. During the course of this study, a comparison of traditional and modern Iznik tiles in colour and brightness carried out. As latest insights of recent studies showed that the production techniques and the size of pigments are crucial parameters for the quality of colours of ceramics. Therefore, Iznik tiles were shaped by dry press without changing their quartz content. Secondly, paints to be applied in the decor stage were prepared with both traditional and nanometersized pigments and used in production process. Finally, characterization techniques were used in order to understand and compare the results and also the effects of nanometer sized pigments on Iznik tiles.
Innovative Ultrasonic Testing Facility for Fatigue Experiments in the VHCF Regime*
Authors: Heinz Stefan , Balle Frank , Wagner Guntram , Eifler Dietmar 
Published: December 2013

Abstract
At the Institute of Materials Science and Engineering of the University Kaiserslautern an ultrasonic testing facility was developed to perform fatigue tests in the VHCF regime. The individual design of the ultrasonic testing facility allows to control the process parameters and to measure relevant data with a frequency of up to 500 kHz in reasonable time. This permits a high-resolution measurement of the ultrasonic oscillation and the dissipated energy as well as a determination of microstructural reactions inside the specimens. With the described ultrasonic testing facility constant amplitude tests and load increase tests were carried out with the alloy Ti6Al4V. The results show that the innovative test and measuring techniques are best suited to describe the fatigue behaviour of Ti6Al4V. Additionally, for the first time high resolution 3D scanning laser vibrometry were carried out to determine the oscillation behaviour of specimens under ultrasonic cyclic load.
Assessment of the Residual Strength Thresholds of Composite Pressure Receptacles – Criteria for Hydraulic Load Cycle Testing
Authors: Mair Georg W. , Hoffmann Martin 
Published: December 2013

Abstract
The current practice of periodic retesting of composite pressure receptacles primarily based on the hydraulic pressure test has to be evaluated as critical. This is justified by micro damages caused to the specimen by the test itself and by a lack of informative values. Thus, BAM Federal Institute of Materials Research and Testing uses a new validation approach in the case of retest periods of more than 5 years. It enables the description of the condition of a specific design type series based on destructive tests parallel to operation. With respect to this approach it is explained how the statistical evaluation of sample tests and their extrapolation to end of life or at least to the time of next retesting can be achieved. In addition, it is explained how the reliability limits may be linked to the size and pressure level of the respective composite pressure receptacle. The frame of this safety approach includes the influence of the maximum working pressure on the safety assessment. One topic of this approach is the introduction of the working diagram essential for safety assessments that allows graphical evaluation of load cycle strength by mean value, scatter and survival rate of samples as well as instruction how to use it. For this, it is explained how the number of filling cycles and the reduction of the respective hydraulic residual cycle strength interacts with the newly introduced value of specific filling sensitivity.
Ferroelektret-Prüfköpfe für die zerstörungsfreie Prüfung mit Luftultraschall
Authors: Döring Joachim , Bartusch Jürgen , Gaal Mate , Kreutzbruck Marc , Erhard Anton , Bovtun Viktor 
Published: December 2013

Kurzfassung
Für die luftgekoppelte Ultraschall-Prüfung wird der Prototyp eines neuartigen Prüfkopfes vorgestellt. Statt eines piezokeramischen Ultraschall-Wandlers mit einer λ/4-Anpassschicht wird eine Ferroelektret-Folie aus schaumförmigem Polypropylen eingesetzt. Durch die außerordentlich geringe akustische Impedanz der Folie reduzieren sich die Reflexionsverluste an den Grenzschichten zur Luft so stark, dass bei diesem Prüfkopf auf eine λ/4-Anpassschicht verzichtet werden kann. Außerdem ist die Folie hochspannungsfest. Sie konnte mit Spannungen von mehr als 3500 V angesteuert werden und erlaubte eine Vorspannung am Ultraschall-Wandler des Empfangsprüfkopfes von 2000 V. Mithilfe der hohen Anregungsspannung stieg die Amplitude des akustischen Prüfimpulses auf das 11,2-Fache. Die Empfindlichkeit des Empfängers erhöhte sich durch die Vorspannung weiter um den Faktor 4,3. Insgesamt steigt die Amplitude am Empfänger also auf das 48-Fache, bei gleichbleibendem Rauschpegel. Ein abschließender Vergleich mit kommerziellen Luftultraschall-Prüfköpfen belegt die Überlegenheit der Folien-Prüfköpfe. Damit rückt der Einsatz einer vollwertigen Impuls-Echo-Technik auch bei der luftgekoppelten Ultraschallprüfung deutlich näher.
The Effect of the Inclination Angle on Inverse Z Joints in Composite Materials Bonded with Adhesives
Authors: Adin Hamit , Turgut Aydın 
Published: December 2013

Abstract
The improvements in physical and mechanical properties of industrial adhesives show that adhesive bonding techniques can be successfully applied to the most engineering fields. Due to some of their advantages in comparison to fastening methods, adhesively bonded joints have been researched by many researchers. In this study, the effect of the inverse Z joints angle (IZJs) was both experimentally and numerically analyzed. Vinylester Atlac 580 and Flexo Tix were used as adhesives. Two different composite materials were the adherends. In order to identify the mechanical properties of the adhesives, the bulk specimen method was used. Finite Element Analysis (FEA) was performed with software Ansys (V.10.0.1). Experimental results were compared with numerical results and the comparisons were found to be reasonable. The results showed that angle of the specimen with the increase of the stresses increase as well. The stresses in the middle of the overlap length were also higher than those at the edge of the overlap length.
Materials Testing under Mechanical Stress, Pressure and Turbulent Flow of Impure Supercritical CO2
Authors: Ruhl Aki Sebastian , Göbel Artur , Kühn Hans-Joachim , Kranzmann Axel 
Published: December 2013

Abstract
The climate change necessitates measures to reduce carbon dioxide (CO2) emissions in the atmosphere, one of which is carbon dioxide capture and storage (CCS). Transmission of pressurized liquid or supercritical CO2 containing residual flue gas constituents in pipelines is an important component of CCS systems. Material testing under conditions as close as possible to real conditions is a prerequisite for reliable and safe implementation of CCS. A novel pipeline corrosion test facility was developed, accounting for major mechanical, physical and chemical influencing factors: elastic deformation, pressure, temperature, gas composition and flow velocity can be independently adjusted. Radial and tangential stress distributions on a round sample were experimentally investigated, indicating a good accordance with expected theoretical values. In this contribution the idea of the novel corrosion test facility and the assembled equipment as well as first results are presented and discussed.
Experimental Investigations on Yttrium Borate Phosphate Phosphors with Codoped Ce3+ and Tb3+ Ions
Authors: Limin Dong , Yanlong Sun , You Li , Chao Guo , Qin Li , Zhidong Han , Xianyou Zhang 
Published: December 2013

Abstract
Green phosphor of Y(BO3, PO4): Ce, Tb was synthesized by means of sol-gel and conventional solid state methods. The thermal formation process was characterized by thermogravimetric analysis (TG) and differential thermal analysis (DTA). The effects of synthesis conditions on the crystalline and morphological structures were investigated using the X-ray diffraction (XRD) and Scanning Electronic Microsocpy (SEM). The results revealed that Y(BO3, PO4): Ce, Tb phosphors with the monocline structure and high purity were successfully prepared by the sol-gel method. Furthermore, the products synthesized by the sol-gel method showed a well developed crystal structure, small particle size, narrow size distribution, and high luminescent performance. The product synthesized at 1050 °C in 2 h had better emission intensity than the others.
Human Factors Perspective on the Reliability of NDT in Nuclear Applications
Authors: Bertovic Marija , Fahlbruch Babette , Mueller Christina 
Published: December 2013

Abstract
A series of research studies have been conducted over the course of five years venturing into the fields of in-service inspections (ISI) in nuclear power plants (NPPs) and inspection of manufactured components to be used for permanent nuclear waste disposal. This paper will provide an overview of four research studies, present selected experimental results and suggest ways for optimization of the NDT process, procedures, and training. The experimental results have shown that time pressure and mental workload negatively influence the quality of the manual inspection performance. Noticeable were influences of the organization of the working schedule, communication, procedures, supervision, and demonstration task. Customized Failure Mode and Effects Analysis (FMEA) was used to identify potential human risks, arising during acquisition and evaluation of NDT data. Several preventive measures were suggested and furthermore discussed, with respect to problems that could arise from their application. Experimental results show that implementing human redundancy in critical tasks, such as defect identification, as well as using an automated aid (software) to help operators in decision making about the existence and size of defects, could lead to other kinds of problems, namely social loafing and automation bias that might affect the reliability of NDT in an undesired manner. Shifting focus from the operator, as the main source of errors, to the organization, as the underlying source, is a recommended approach to ensure safety.