bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abhängigkeit der formcharakteristischen Parameter Rundheit und Kompaktheit verschiedener Graphitmorphologien von der Vergrößerung
Authors: Magenreuter T. , Velichko A. , Mücklich F. 
Published: December 2013

Kurzfassung
Die Unterscheidung der verschiedenen Graphitmorphologien in Gusseisen wird schon seit einiger Zeit durch bildanalytische Untersuchungen erfolgreich vollzogen und ersetzt zunehmend den subjektiven Vergleich mit Richtreihenbildern gemäß den Normen ASTM A 247–67 bzw. DIN EN ISO 945.
In vorliegender Arbeit bildete die teilchenbasierte Methode die Grundlage für weitere Untersuchungen an reinen Proben aus Gusseisen mit Lamellen-, Vermikular- und Kugelgraphit (GJL, GJV bzw. GJS) sowie an Temperguss (GJM). Im Licht- (LM) und im Raster-Elektronen-Mikroskop (REM) wurden Gefügeaufnahmen gemacht und die beiden Formparameter Rundheit und Kompaktheit für verschiedene Vergrößerungen bestimmt. Die Abhängigkeiten der Formparameter von der Vergrößerung wurden dargelegt und diskutiert.
Weiterhin waren die gewonnen Messdaten Grundlage zum Aufbau eines Klassifikators, der für beliebige Vergrößerungen des zu untersuchenden Gefüges erstellt werden kann.
Dieser Klassifikator wurde darüber hinaus an verschiedenen Gefügebildern gestestet und seine Qualität in Bezug auf die Klassifizierung verschiedener Graphitmorphologien anhand der beiden formcharakteristischen Formparameter bewertet. Es ist vorstellbar, den Parameter Vergrößerung in eine Klassifizierungssoftware mit einzubauen.
Characterization of Q & T Steel Poleshoes Manufactured by Sand Casting
Authors: Asensio-Lozano J. , Álvarez-Antolín J. F. , Panta-Mesones J. T. , Vander-Voort G. F. 
Published: December 2013

Abstract
This paper presents a study of the microstructural and mechanical characterization of the GS 35 CrMoV 10 4 alloy employed in the manufacture of sand-cast poleshoes for 4-pole synchronous electric power generators working at a frequency of 60 Hz. In addition, the most appropriate treatment for ensuring compliance with the technical specifications defined in DIN Standard No. 1.7755 has been designed.
Quantification of the Impact of Strontium on the Solidification Path of the Aluminum-Silicon-Copper Alloys Using Thermal Analysis Technique
Authors: Djurdjevic Mile , Byczynski Glenn , Schechowiak Carola , Stieler Hagen , Pavlovic Jelena 
Published: December 2013

Abstract
The impact of strontium on the solidification path of the AlSi6Cu4 aluminium alloy was examined. Strontium levels up to 210 ppm have been considered. The purpose of this study is: (i) to optimize the amount of strontium additions in AlSi6Cu4 melt in order to achieve the necessary degree of silicon modification and (ii) to observe the effects of strontium level on the other characteristic solidification temperatures of this alloy, with special emphasis on the nucleation temperature of copper rich phases. This investigation showed that a strontium level of approximately 140 ppm was sufficient to modify eutectic morphology of silicon in thermal analysis test samples. Increasing the strontium levels up to 210 ppm raises the nucleation temperature of copper rich phases, leading also to the higher area fraction of those phases.
Elektronenmikroskopische Darstellung elektrolytischer Oxidschichten auf AA2214
Authors: Schneider Michael , Kübel Christian , Yezerska Olga , Viola Alain , Augros Myriam 
Published: December 2013

Kurzfassung
Die Legierung AA2214 gehört zu den mittel- bis hochfesten, aushärtbaren Knetlegierungen, die in der Luftfahrtindustrie eine wesentliche Rolle als Konstruktionswerkstoff spielen. Zum Zwecke des Korrosions- und Verschleißschutzes werden diese Legierungen sehr häufig anodisiert. Transmissionselektronenmikroskopische Untersuchungen an Schwefelsäureanodisierschichten zeigen deutlich den Einfluss der Anodisierspannung auf die Porengröße. Im Werkstoffgefüge auftretende intermetallische Phasen werden durch den Anodisierprozess weitgehend aufgelöst. Geringe Anteile an Legierungselementen sind jedoch im Oxid noch nachweisbar. Während des anschließenden Verdichtungsprozesses werden die offenen Poren verschlossen. Bereits nach 15 min ist dieser Vorgang weitgehend abgeschlossen. Dabei gibt es keine signifikante Gradierung der Verdichtung über die Oxidschichtdicke.
Mikrostrukturelle Beobachtungen bei der thermischen Ermüdung der Mg-Legierung AZ31
Authors: Krauß Martin , Scholtes Berthold 
Published: December 2013

Kurzfassung
Bei der thermisch-mechanischen Ermüdungsbeanspruchung von AZ31 werden in Abhängigkeit der Zyklenzahl sowie der Temperaturamplitude bzw. der Obertemperatur charakteristische Veränderungen der Mikrostruktur beobachtet. Bei niedrigen Lastspielzahlen steht hierbei die Bildung von Gleitbändern und Verformungszwillingen im Vordergrund, während bei mittleren und höheren Lastspielzahlen neben Erholungs- und Rekristallisationsvorgängen auch Texturänderungen zu beobachten sind. Rissbildungs- und Rissausbreitungsprozesse sind eher hohen Lastspielzahlen zuzuordnen. Es werden charakteristische Beispiele gezeigt, welche die Schädigungsentwicklung in der Mikrostruktur bis zum Versagen dokumentieren.
Effect of Different Heat Treatment Conditions on the Microstructure and Mechanical Properties of Inconel 718 Nickel Based Super Alloy Used in Petroleum Production
Authors: Nascimento Jôneo Lopes do , Barbosa Cássio , Fernandes José Luiz 
Published: December 2013

Abstract
The development of the oil and gas industry in Brazil in the last decades has led to petroleum extraction in deeper water and extremely corrosive environments, associated to the presence of H2S, CO2 and chlorides, as well as mechanical loads caused by the wave's movement and sea streams. In these adverse conditions the search for new materials with adequate properties for this kind of application is intense.
In the present work a study is carried out on the microstructure and mechanical properties of the super alloy Inconel 718 subjected to different temperatures and times of solution and aging heat treatments. This material, usually used in the fabrication of aircraft motor and energy generation turbines, in the present case is proposed for the fabrication of bolts used in the fixation of submarine pipes for oil extraction.
The use of techniques like optical microscopy, automatic image analysis, scanning electron microscopy (SEM) and hardness and tensile tests, allowed the identification of the ideal conditions for heat treating this material for this kind of application.
The Impact of Major Alloying Elements and Refiner on the SDAS of Al-Si-Cu Alloy
Authors: Djurdjevic Mile , Pavlovic Jelena , Byczynski Glenn 
Published: December 2013

Abstract
This paper investigates the effect of some major alloying elements (silicon and copper) and the effect of grain refiner (titanium boride) on the size of the secondary dendrite arm spacing (SDAS) in series of Al-Si-Cu alloys. It has been shown that both silicon and copper have significant influence on this solidification parameter. The addition of grain refining master alloys to aluminium alloys is common practice in many commercial foundries aiming to reduce the grain size of Al-Si alloys. However, it was shown in the present paper that master alloy based on TiB had an unexpected impact on the SDAS, decreasing the size of SDAS. In addition, there is a minimum of SDAS corresponding to the presence of 0.12 wt% of titanium in Al-Si alloy. Such findings could have important implications for Al-Si alloys in particular, due to their wide spread applications in the automotive industry.
The Investigation of Crystallization of a-Si Films Deposited on Different Orientations by Solid Phase Epitaxy Process
Authors: Lee Kyuyoul , Kim Chungkeun , Chang Youngchul , Gall Stefan , Rech Bernd 
Published: December 2013

Abstract
In the experiment of this study, amorphous silicon (a-Si) films deposited by electronbeam evaporation method on (100) p+, (110) p+ and (111) p+ Si wafer substrates were crystallized at 600 °C by the solid phase epitaxy method. The times for generating the nuclei were different from one another depending on crystallized directions of the substrates, because the number of dangling bonds existing on the surface of the substrates and also the intervals of lattices are different from one another depending on the direction of crystallization. The crystallized Si film showed lots of defects. With increasing annealing time, the number of defects decreased. Also, it included more cracks. However, crystallization of the a-Si film on the (111) Si substrate was not epitaxial growth. The crystallized Si film was composed of crystal grains smaller than 1 μm.
Nutzung des instrumentierten Kerbschlagbiegeversuches zur Bestimmung von Parametern der Bruchzähigkeit
Authors: Herold H. , Streitenberger M. , Cammarota G.P. , Casagrande A. , Morri A. , Garagnani G. 
Published: December 2013

Kurzfassung
Es gibt viele Ansätze zur Korrelation der Kerbschlagarbeit mit Bruchparametern. Die meisten davon liefern empirische oder halbtheoretische Gleichungen, die diesen Zusammenhang belegen.
In der vorliegenden Arbeit wird die dynamische Streckgrenze genutzt, um die Gültigkeit der Beziehung zwischen der an spitzgekerbten Proben ermittelten Kerbschlagarbeit KV [J] und der Bruchzähigkeit KIC [MPa √m] herzustellen. Dazu werden drei Bustähle (1.0570 – 1.0511 – 1.8900) und die Ti-Legierung Ti-AI6-V4 Vergleichend betrachtet.
Bei den Stählen stimmen die experimentell ermittelten Werte der Bruchzähigkeit mit denen anhand der abgeleiteten Gleichung berechneten überein. Für die Legierung Ti-Al6-V4 stimmen die Werte nicht überein, besonders nicht bei Raumtemperatur, wenn der Beitrag der α- Phase größer ist.
Mechanical Properties of Ferrochrome Based Hardfacing Layers Coated on AISI 1020 Steel Obtained by the Aid of Plasma Transfer Arc (PTA) Process
Authors: Çay Vedat Veli , Ozan Sermin , Topuz Polat , Kolukisa Sedat 
Published: December 2013

Abstract
Mechanical properties of ferrochrome based hardfacing layers coated on AISI 1020 steel obtained by the aid of Plasma Transfer Arc (PTA) was experimentally studied. Ferrochrome powders were mixed with sodium silicate gel to avoid spreading. The mixture was laid to 1.5 × 8 × 100 mm slots machined on AISI 1020 steel. Hardfacing layer was performed by PTA process under pure Argon as protective gas with 130 A/20 V power supply. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), micro hardness and abrasive tests were employed for the evaluation of ferrochrome alloyed coating. Hardfacing was successfully performed under given conditions. Microstructural changes and formations (phases) significantly improved hardness, abrasive wear resistance and integrity of hardfacing layer.
Embrittlement of 1.25 Ni-Cr Case Hardenable Steel Used for Gear Assembly
Authors: Jha Abhay K. , Sreekumar K. 
Published: December 2013

Abstract
1.25 Ni-1.0Cr-0.1Mo case hardenable steel of EN353 grade is used for manufacturing gears. One such gear assembly was used in the azimuth control gearbox of an antenna system. After about six months in operation, the gear failed with a big noise in the gearbox during operation. The gearbox when opened showed disintegrated teeth of both gear and pinion, which was found, crushed and resulted in multiple smaller pieces. Globular shaped metallic pieces were also found in the gearbox.
Detailed metallurgical investigation indicated that the fracture of the gear teeth occurred under impact of extraneous globular shaped metallic pieces of plain carbon steel entrapped in the gearbox. Inter-granular mode of fracture developed could be attributed to embrittlement of material.
Microstructural Features of AZ31 Deformed at High Temperatures
Authors: Poletti C. , Warchomicka F. , Okruch R. , Knoblich H. 
Published: December 2013

Abstract
An as-cast AZ31 magnesium alloy was investigated using light microscopy (LOM) and electron backscatter diffraction (EBSD) methods to quantify and describe the deformation mechanisms activated at high temperatures. Compression tests were carried out by means of a Gleeble®1500 device in the range of 320–500°C and 0.03–10 s-1 of strain rate. Deformed samples were simulated by finite elements method to correlate the microstructure with the local deformation parameters. EBSD measurements were used to distinguish and quantify the new recrystallized grains and to characterize the misorientation distribution. These results helped to determine the grain size distribution with the temperature and the strain rate by LOM pictures. Dynamic recrystallization is denoted by necklace microstructure, and twinning promotes the recrystallization nucleation. At high temperature and slow strain rate recovery takes place followed by continuous dynamic recrystallization.
Influence of Welding Speed on Microstructure and Mechanical Properties of AZ31 Magnesium Alloy Laser Weldments
Authors: Babu N. Kishore , Ashfaq M. 
Published: December 2013

Abstract
CO2 laser welds were prepared on 3 mm thick sheets of continuous cast and rolled AZ31 magnesium alloy, using different welding speeds (3 m/min, 4 m/min and 5 m/min). The microstructure and composition analysis of weld metal was examined using optical and scanning electron microscopy (HR-SEM, EPMA and EDS/X). Room temperature hardness and tensile properties of the weldments in the as-welded condition were studied and correlated with the microstructure. The microstructure of fusion zone consists of two parts: the equiaxed zone in the middle part and the columnar zone adjacent to fusion boundary. It has been shown that the average width of columnar grains in the fusion zone is increased with decreasing the welding speed. Microstructural examination showed that the equiaxed grain size in the fusion zone was the least in the welds made using 5 m/min welding speed. It has been shown that welds prepared with 5 m/min welding speed exhibited increase in hardness, yield strength and ductility when compared with other welds.
Grain Size Distributions in Normal Grain Growth
Authors: Zöllner Dana , Streitenberger Peter 
Published: December 2013

Abstract
An analytical distribution function characterising the grain sizes of polycrystalline microstructures is presented. Contrary to standard mathematical probability functions that are still often used for description of experimentally obtained size distributions, this one is based on a statistical mean-field theory of grain growth and is fully consistent with the fundamental physical conditions of total-volume conservation and the existence of a finite average grain volume. It is found that this distribution function describes the grain size distribution obtained by Monte Carlo Potts model simulations better than standard mathematical distributions. Additionally, two-dimensional plane sections from the simulated three-dimensional grain structures are considered and compared with experimental data, and the analytic size distribution function is also compared with an experimental grain size distribution for pure iron obtained by serial sectioning.
Lichtmikroskopische Auswertung der Wirksamkeit thermoplastischer Elastomere als Verarbeitungshilfsmittel in der Blasfolienextrusion von PE-LLD
Authors: Müller Marco , Wagner Manfred H. 
Published: December 2013

Kurzfassung
Der vorliegende Beitrag ist dem wissenschaftlichen Wirken von Herrn Dr.-Ing. Jörg Trempler gewidmet und ist gleichzeitig verbunden mit persönlichem Dank, den einer der Autoren für die eigene erhaltene Ausbildung an dieser Stelle ausdrücken möchte. Dieser Artikel diskutiert die Eignung thermoplastischer Elastomere als Kunststoffverarbeitungshilfsmittel in der Blasfolienextrusion von PE-LLD zur Verschiebung von Schmelzflussinstabilitäten in Richtung höherer Verarbeitungsgeschwindigkeit. Ziel ist es, Oberflächendefekte wie den sog. Sharkskin-Effekt zu verzögern, so dass höhere Verarbeitungsgeschwindigkeiten und damit eine höhere Produktivität erreicht werden können. Als Additive kommen verschiedene thermoplastische Elastomere sowohl auf Silicon- als auch auf Urethanbasis zum Einsatz.
Neben der lichtmikroskopischen Auswertung der Folienprodukte wird die Veränderung des rheologischen Verhaltens der Kunststoffschmelze durch die Additive anhand rheometrischer Verfahren (z. B. Kapillarrheometrie) untersucht. In diesem Zusammenhang kommt auch die Methode nach Mooney zur Bestimmung des Gleitanteils beim Durchströmen einer Kunststoffschmelze durch eine Düse zum Einsatz.
Chromium Grain-Boundary Segregation and Effect of Ion Beam Cleaning on Ni-Fe-Cr Alloys
Authors: Saraf L.V. 
Published: December 2013

Abstract
The grain boundaries play important role to control the mechanical strength of ternary alloys. From spacecrafts to naval vessels to nuclear reactors, stress corrosion cracking, brittleness, oxidation mostly originates at the grain boundaries and cause long term structural stability problems in most of the metallic structures [1]. Ni-Fe-Cr based ternary metal alloys have been widely studied for more than fifty years [2, 3]. Despite of vast amount of research, chromium diffusion in stainless steel or other Ni-Fe-Cr based ternary alloys is still an open scientific problem with challenges in structural stability and corrosion resistance [4]. Particularly, austenite Ni-Fe-Cr is looked upon favorably in space and jet engine industry for their improved resistance to stress corrosion cracking [5]. In solid oxide fuel cells (SOFC), Ni-alloys are frequently used as interconnects and seals [6]. In this communication, simultaneous energy dispersive spectroscopy (EDS) and electron backscatter diffraction (EBSD) mapping is utilized to study chemical and structural aspects of chromium segregation in Ni-Fe-Cr alloy. A focused Ga-ion beam is also utilized to study the effect of ion beam cleaning on EBSD image quality (IQ) and inverse pole figure (IPF) maps of Ni-Fe-Cr alloy
Metallographische Probenpräparation von verlöteten Solarzellen
Authors: Eberlein Dirk , Schmitt Peter , Voos Patrick 
Published: December 2013

Kurzfassung
Die Photovoltaik ist ein junger Industriezweig der stark wachsend auf innovative Technologien setzt. Nicht nur die Verbesserung der Solarzellwirkungsgrade, sondern auch der Einsatz neuer Modultechnologien ist von großer Bedeutung. Das Verschalten von mehreren Solarzellen wird standardmäßig via Weichlöten durchgeführt. Die vorliegende Arbeit stellt ein Verfahren dar, mit welchem die Qualität dieser Lötstellen auf Solarzellen untersucht werden kann. Dies stellt ein gutes Werkzeug in der Forschung und Entwicklung neuer Kontaktierungstechnologien, sowie in der Qualitätssicherung dar.
γ↔∊ Transformation Behavior of Austenitic-Martensitic FeMn(Cr) Steels
Authors: Weiß A. , Tranta F. , Scheller P.R. , Kovalev A. 
Published: December 2013

Abstract
Three differently alloyed austenitic FeMn(Cr) steels have been examined with a focus on the occurrence of ∊ martensite. Studies primarily focus on the detection of ∊ martensite by means of metallographic and X-ray methods as well as by means of dilatometric and DSC measurements. Dilatometric and DSC measurements have also been carried out to determine ∊ martensite formation and dissolution temperatures. Examination results including thermodynamic calculations serve to characterize the formation and dissolution of ∊ martensite in FeMn(Cr) steels.
The Characterisation of a Powder Metallurgically Manufactured TNM™ Titanium Aluminide Alloy Using Complimentary Quantitative Methods
Authors: Schloffer M. , Schmoelzer T. , Mayer S. , Schwaighofer E. , Hawranek G. , Schimansky F.-P. , Pyczak F. , Clemens H. 
Published: December 2013

Abstract
In order to be able to use intermetallic titanium aluminide in industrial applications, a quick and affordable method of quantitatively analysing their microstructures is required. In the presented work it was able to demonstrate on a powder metallurgical manufactured TNM™ alloy of nominal composition Ti-43.5Al-4Nb-1Mo-0.1B (at.%), that by electrolytic-polishing and colour etching a quick and cost effective quantitative microstructural analysis may be carried out via light-optical microscopic images. In doing so, the phase fractions and microstructural constituents of the various types of microstructures present are determined using complementary analysing techniques. Both light-optical and scanning electron microscopic images were captured from each of three different types of microstructures. These were then quantitatively evaluated using an image analysis program. The results were compared with those obtained from X-ray diffraction experiments. The possibilities and limits of the quantitative phase evaluation of light-optical microscopic images of colour etched microstructures are also explained and their relationship to the choice of parameters used for the colour etching and electro-polishing operations discussed.
Dynamic Recovery and Recrystallization during Hot-Working in an Advanced TiAl Alloy
Authors: Schmoelzer T. , Liss K.-D. , Rester M. , Yan K. , Stark A. , Reid M. , Peel M. , Clemens H. 
Published: December 2013

Abstract
Intermetallic TiAl alloys are light-weight high-temperature materials and intended to partly replace Ni based alloys in jet engines. Due to difficult forming operations, component prices are high and limit the possible field of application. During hot-working, recovery and recrystallization effects determine the microstructural evolution and thereby the mechanical properties of the finished part as well as its behavior during deformation. To study the occurring phenomena, in-situ diffraction experiments with high-energy X-rays were conducted. By means of this method, the dominating processes were identified. The results were validated through electron back scatter diffraction experiments.
Microstructure and EPR Studies of 13% Chromium Steels after Various Heat Treatments and the Influence of MnS on the EPR Test
Authors: Strobl S. , Haubner R. , Linhardt P. 
Published: December 2013

Abstract
Current collector rings (X12Cr13 stainless steel, Mat. No. 1.4006) exhibited different susceptibilities for staining, if provided from different manufacturers. The electrochemical potentiokinetic reactivation test (EPR test) revealed sensitisation as the reason for the insufficient corrosion behaviour. In the initial state, steel SS-1 shows a tempered structure and some ferrite with a sensitisation of max. 2.7%; steel SS-2 with a ferritic structure and carbides at the grain boundaries contains MnS and Ti(C,N) and exhibits sensitisation of ≈80%. After establishing a defined starting condition for both steels by solution annealing at 1050°C for 30 min, the steels were hardened in oil, air or cooled slowly in the furnace. Moreover, such oil-quenched samples were annealed at various conditions (800 or 750°C for 45 or 24 h), and the influence on sensitisation was determined via EPR test. The oil-quenched samples revealed the lowest degrees of sensitisation. Some unusual EPR results for SS-2 could be correlated with the dissolution of MnS during the test.