bluuebunny/crossref_metadata_2025_split huggingface dataset:
TEM-Untersuchungen an Erosionskratern, die durch elektrische Entladungen erzeugt werden
Authors: Soldera Flavio , Ilic Nenad , Mücklich Frank 
Published: December 2013

Kurzfassung
Durch elektrische Plasmaentladungen wurden Krater an der Materialoberfläche einer Pt-Probe erzeugt. Mittels FIB wurden TEM-Lamellen der Kraterquerschnitte präpariert, um die Gefügeänderung nach dem Entladungseinschlag zu beobachten. Das Material, das im flüssigen Zustand zum Kraterrand verschoben wurde, konnte identifiziert werden. Unter diesem Kraterrand bilden sich Mikroporen. Die Körner unter dem Krater erstrecken sich bis an die Krateroberfläche durch epitaxiales Wachstum.
FIB-Präparation und TEM-Analytik an AlSi1-Bondkontakten
Authors: Geißler Ute , Engelmann Hans-Jürgen , Urban Ingrid , Rooch Heidemarie 
Published: December 2013

Kurzfassung
Bei der Untersuchung der Verbindungsbildung von Bondkontakten sehr geringer Ausdehnung (25 μm-AlSi1-Draht auf Cu/Ni/Au-Metallisierung einer Leiterplatte) steht mit der Methode des Fokusierten Ionenstrahles (FIB) für die TEM-Zielpräparation ein sehr effektives Verfahren zur Verfügung, das die genaue Entnahme einer Lamelle aus dem interessierenden Probenbereich ermöglicht. Dabei gelingt es mit dem in-situ-lift-out-Verfahren im Vergleich zum ex-situ-lift-out-Verfahren dünnere Folien zu präparieren (ca. 40 nm), an denen im Bereich der Grenzfläche zwischen Bonddraht und dem Metallisierungschichtsystem EFTEM-Mappings und HRTEM-Untersuchungen möglich werden. Diese Untersuchungen liefern zusammen mit der Anwendung des FIB als Rasterionenmikroskop neue Erkenntnisse zum Gefüge der Bondkontakte und zum Aufbau der Grenzfläche und erweitern das Verständnis der Verbindungsbildung beim Drahtbonden.
Gemeinschaftsversuch an ausgewählten Magnesium-Legierungen
Authors: Carle Veronika , Täffner Ulrike , Kopp Wolf-Ulrich 
Published: December 2013

Kurzfassung
Über einen Gemeinschaftsversuch des Arbeitskreises “Probenpräparation” im Fachausschuss Materialographie der DGM wird berichtet. Von 10 Teilnehmern wurden eine Magnesium-Gusslegierung AZ 61, sowie 2 Magnesium-Knetlegierungen ZM 21 und AM 50 präpariert und qualitativ ausgewertet. Die von den Teilnehmern durchgeführten Präparationsschritte werden beschrieben, Bilder einzelner Gefüge gezeigt und Details erläutert. Ein Vorschlag zur Präparation wird gegeben.
Mechanical and Memory Properties of CuAlNi by Directional Solidification
Authors: Zhiping Liu , Woguang Li , Zhanhua Yin 
Published: December 2013

Abstract
Cu-Al-Ni shape memory alloy was fabricated under directional solidification in heated mold continuous casting equipment. The results show that it has distinct textures. Due to these strengthened textures, it has excellent mechanism, fatigue and memory performances.
The Ø 1.5 mm wire has a tensile strength of 910 MPa, elongation of 18.76%. Under 4% strain, the repeat tensile fatigue was up to 38560 circles and the recovery rate is 100%.
Wear/Friction Behaviour of FeB and FeB/h-BN Coatings Sprayed by Atmospheric Plasma Spraying
Authors: Ozdemir Ismail 
Published: December 2013

Abstract
The crushed and rounded ferroboron (FeB) powders of Fe-18.8B-0.2C-0.5Si-0.8Al (wt.%) were deposited onto an aluminum substrate by atmospheric DC plasma spraying to improve its tribological properties. Hexagonal boron nitride (h-BN) powders which have excellent lubricating properties similar to graphite were incorporated into the boride powders as a solid lubricant by a sintering process to obtain protective coatings with a low friction coefficient. As-sprayed coatings are composed of mainly FeB, iron matrix supersaturated with boron owing to the rapid solidification of molten droplets flattened on a substrate. The friction and wear behaviour of each coating were evaluated using a ring-on-disk type wear tester in paraffin based oil with an air atmosphere. It was found that sintering of iron boride powder with h-BN powder (5 wt.%) is an acceptable method for producing a protective composite coating against friction and wear. The evaluation of friction and wear results shows that iron boride coatings exhibit high seizure load and good anti-wear performance.
Metallographische Untersuchungen an Bauteilen
Authors: Stets Wolfram , Tschöpe Jörg 
Published: December 2013

Kurzfassung
Im Zuge der immer schnelleren Verfügbarkeit von Maschinen und Anlagen steigt die Bedeutung der Bauteilmetallographie als Werkzeug der Schadensanalyse und Qualitätskontrolle. Das Institut für Gießereitechnik arbeitet auf diesem Gebiet mit einem tragbaren Auflichtmikroskop mit bis zu 500-facher Vergrößerung. Die Bilder werden mit Hilfe einer Digitalkamera aufgenommen. Anhand von verschiedenen Untersuchungsfällen wird die Leistungsfähigkeit des Systems demonstriert. Es wurden bis zu 37 t schwere Gussstücke aus Gusseisen mit Kugelgraphit sowie Pumpengehäuse aus Duplexstahl untersucht. Auf der Grundlage der Untersuchungsergebnisse konnten Expertisen für die weitere Verwendbarkeit der Gussstücke erstellt werden.
Boride Layer Growth Kinetics of the Borided Hypoeutectoid Plain Carbon Steels by the Powder-Pack Method
Authors: Çelik Osman Nuri , Aydinbeyli Nedret , Gasan Hakan 
Published: December 2013

Abstract
In the present work, kinetics of boriding of hypoeutectoid plain carbon steels has been studied. Boriding of the AISI 1010, 1020, 1040 and 1060 test materials has been performed by means of a powder-pack method using EKabor 2 ® powders. Boriding heat treatments were performed at 1173 K, 1223 K, 1273 K and 1323 K for 2, 4 and 6 h. The borided materials were characterised by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and optical microscopy in order to determine the phase contents (FeB and Fe2B). Boride layer thickness was determined by optical microscopy and hardness by microhardness testing. The thickness of borided layers measured ranged from 71 to 362 μm. It was found that the effect of boriding time and temperature on the increasing boride layer thickness was more significant than the effect of increasing the carbon content. The hardness of the boride layers ranged from 1243 to 1740 HV. The kinetics of the reactions, K=K0exp(-Q/RT), were determined by varying the boriding temperature and time for the materials. A correlation between the C content and activation energy has been established by this study.
Quantitative 3D-Gefügeanalyse — Stereologie oder Tomographie
Authors: Velichko Alexandra , Mücklich Frank 
Published: December 2013

Kurzfassung
In der Materialforschung ist die dreidimensionale Ausprägung des Gefüges der Schlüssel zum Verständnis des Zusammenhanges zu den Herstellparametern einerseits und den Eigenschaften des Werkstoffs andererseits. Die prinzipielle Frage ist, ob es unbedingt nötig ist, alle Gefügemorphologien in 3D zu untersuchen, oder ob es ausreicht, bei den Gefügen die viel praktischere 2D-Bildanalyse zu nutzen und die 3D-Parameter nach stereologischen Beziehungen zu berechnen. Erwartungsgemäß gibt es bei der Vielfalt der Gefüge und den entsprechend komplexen Zusammenhängen keine generelle und einfache Antwort darauf. In diesem Beitrag wird am Beispiel der Korngrößenbeschreibung und damit verbundener Kennzahlen reflektiert, wann die 2D-Bildanalyse mit stereologischen Schätzungen zur 3D-Situation praktikable Ergebnisse liefert und wann die Gefügetomographie unbedingt nötig ist, um geeignete Informationen über das räumliche Gefüge zu gewinnen. Ausgehend von den bildfeldbezogenen vier Grundparametern des Gefüges wird dazu die Korngrößenbestimmung unter der Annahme von Kornformen mit zunehmender Komplexität (Kugel — äquiaxiale Polyeder — nichtäquiaxiale Polyeder — nichtkonvexe Kornformen) diskutiert. Es wird gezeigt, dass bei nicht konvexen unregelmäßigen Kornformen die 3D-Charakterisierung für sichere Klassifikationen und auch die Quantifizierung räumlicher Kenngrößen wie der Konnektivität oder der Teilchenzahl im Volumen unverzichtbar ist.
Properties of Alumina Coating Formed by Microarc Oxidation Technique on 6061 Aluminum Alloy
Authors: Polat Aytekin , Usta Metin , Makaraci Murat , Ata Ali , Tas Zakir 
Published: December 2013

Abstract
In this study, thick and hard alumina coatings were produced on 6061-T6 Al alloy substrates for different oxidation times and current densities by using of microarc oxidation (MAO) technique in an alkali-silicate electrolytic solution. The influence of oxidation time and current density on the kinetics, phase composition, hardness, surface roughness and structure of the coating were investigated. It is found that the kinetics of coating mainly depends on applied current density and oxidation time. The XRD results revealed that the coatings are composed of mainly α-Al2O3, γ-Al2O3 and mullite phase. The relative ratio of harder and denser α-Al2O3 phase increases with increasing current density and oxidation time. For the same coating time, the position of maximum hardness of coatings moves away from the substrate-coating interface to the coating surface with increasing current density. The surface roughness of coating is a function of coating thickness and increases with increasing deposition time and current density. The surface micro hardness of Al 6061-T6 alloy substrate was increased up to 2200 HV hardness after the coating.
Particle Distribution and Tool Wear in Friction Stir Processed Al-SiCp Coatings
Authors: Rao Kalvala Prasad , Patil Anand , Rangaraju RaghuRaj , Raja K.S. , Misra M. 
Published: December 2013

Abstract
Al-Mg alloy was friction stir processed (FSP) incorporating two different sized SiC particles. Reduction of particle size after FSP was very significant with coarser SiC particles than finer. The density of SiC particles in FSP nugget was found to be uniform from top to bottom with coarser SiC particles, whereas it was more at the bottom than the top with finer. Tool wear after FSP was found to be relatively more with coarser particles than finer.
A Procedure for in situ Identification of the Intermetallic AlTMSi Phase Precipitates in the Microstructure of the Aluminum Alloys
Authors: Warmuzek M. , Regulski K. 
Published: December 2013

Abstract
In this work, the results of the examinations of morphology and chemical composition of the primary AlTMSi intermetallic phases precipitates observed in the Al–Si cast alloys microstructure have been presented. A procedure for the treatment of EDS X-ray microanalysis results (selection and classification) using fuzzy logic concept has been developed and then tested in application for AlTMSi phase identification. Statistically significant differences in the chemical composition have been revealed between the analyzed groups of precipitates of both α- and β-AlTMSi phases formed in hypo- and eutectic Al-Si alloys with the same content of transition metals. The range of the measured Mn solubility in the precipitates of different crystal lattices has been statistically estimated.
Failure Analysis on a Ruptured Petrochemical Pipe
Authors: Harun M. , Shamsudin S. R. , Kamardin A. 
Published: December 2013

Abstract
The failure took place on a welded elbow pipe which exhibited a catastrophic transverse rupture. The failure was located on the welding HAZ region, parallel to the welding path. Branching cracks were detected at the edge of the rupture area. Deposits of corrosion products were also spotted. The optical microscope analysis showed the presence of transgranular failures which were related to the stress corrosion cracking (SCC) and were predominantly caused by the welding residual stress. The significant difference in hardness between the welded area and the pipe confirmed the findings. Moreover, the failure was also caused by the low Mo content in the stainless steel pipe which was detected by means of spark emission spectrometer.
Gefügecharakterisierung von Aluminium-Silicium Gusslegierungen
Authors: Kuhnke Katrin 
Published: December 2013

Kurzfassung
Die Ausbildung des Gussgefüges hat einen signifikanten Einfluss auf die mechanischen Eigenschaften von Gussteilen. Durch eine gezielte Einstellung der Abkühlgeschwindigkeit wie z.B. durch die Wahl des Gießverfahrens und durch Schmelzebehandlungsmaßnahmen lassen sich positive Effekte erreichen.
Die vorliegende Arbeit gibt einen Überblick über die Gefügeausbildung von Aluminium-Silicium-Gusslegierungen und über den Einfluss verschiedener Parameter wie Abkühlgeschwindigkeit, Gießverfahren, Veredelung und Kornfeinung.
Microstructural Characteristic of Co-Cr-Mo Powder Alloy Coating on Stainless Steel by Plasma Transferred Arc Weld Surfacing
Authors: Somunkiran İlyas , Kurt Bulent , Buytoz Soner , Orhan Nuri 
Published: December 2013

Abstract
In this study, Co-Cr-Mo powder was coated on the surface of AISI 304 stainless steel by the plasma transfer arc (PTA) process at 80, 90 and 100 A current values and argon gas was used for both plasma and protective. Deposition layers were examined with optical microscopy, SEM, EDX, XRD analysis and microhardness test. The thickness of the coating increased with current density. No cracks or pores were detected in the interface and coating layer. Higher current levels resulted in higher dilution levels and also in melting/burning of the substrate.
EBSD-Gefügeuntersuchungen an Aluminiummatrix-Verbundwerkstoffen
Authors: Heimann Sebastian , Knyazeva Marina , Pohl Michael 
Published: December 2013

Kurzfassung
Die Darstellung des Gefüges von Aluminiumlegierungen bereitet immer wieder Probleme. So kommt es z.B. häufig zu Fehlinterpretationen bei der Unterscheidung von Korngrenzen und Subkorngrenzen wegen deren unterschiedlichen Reaktionen auf die verschiedenen möglichen Ätzmittel. Aber auch die Vorbereitung durch Schleifen und Polieren kann bei nur wenig veränderten Randbedingungen zu unterschiedlichen Ergebnissen nach dem Ätzvorgang führen.
In den hier beschriebenen Untersuchungen wurden die Aluminiumlegierung EN AW-6061 und zwei Aluminiummatrix-Verbundwerkstoffe auf Basis von EN AW-6061 mittels Rückstreuelektronen-Kikuchi Beugung (EBSD; electron back scattering diffraction) untersucht.
Es konnte eine eindeutige Zuordnung von Groß- und Kleinwinkelkorngrenzen vorgenommen werden. So gelang eine genaue Analyse des Gefüges sowohl hinsichtlich des Einflusses der Fertigung als auch der Verstärkungsphase in den Verbundwerkstoffen.
SEM and TEM Investigations of Recovery and Recrystallization in Technically Pure Molybdenum
Authors: Primig Sophie , Leitner Harald , Lorich Alexander , Knabl Wolfram , Clemens Helmut , Stickler Roland 
Published: December 2013

Abstract
Beside traditional applications of refractory metals, e.g. in high temperature furnace construction, lighting or glass industry, one of the most important molybdenum products nowadays are large plates which are frequently used as targets for the sputtering of molybdenum layers in thin-film transistor liquid crystal displays. For the hot rolling of the sintered pre-material, the control over the recovery and recrystallization behavior is of particular importance. Molybdenum tends to a very recovery controlled behavior during hot deformation, at which the dislocations arrange into subcell boundaries instantaneously. These pronounced recovery processes seem to consume a large amount of the stored deformation energy for the actual recrystallization. On the other hand, recovery provides the future recrystallization nuclei. For a comprehensive characterization of these microstructural processes, electron microscopy appears to be the most proper means. The aim of this study is to evaluate the significance of electron channeling contrast imaging, electron back scatter diffraction and transmission electron microscopy with regard to recovery and recrystallization processes in molybdenum. Furthermore, appropriate specimen preparation procedures for scanning and transmission electron microscopy are described.
The Metallurgical Causes of Structural Inhomogeneities in Hot Rolled Bars of Martensitic 12% Chromium Steels
Authors: Neidel A. , Fischer B. , Leggemann S. 
Published: December 2013

Abstract
Signs of segregation found during the goods inwards inspection by the users of hot rolled bars of X20Cr13 turbine blade steel led to difficulties in the customer – supplier relationship, due to their unknown effect on the strength and reliability of the finished component. The aim of this investigation was to characterise the micro structural inhomogeneities metallographically, to discuss the metallurgical causes and possible consequences, and to suggest possible corrective of action.
A Step-By-Step Analysis of the Polishing Process for Tungsten Specimens
Authors: Manhard A. , Matern G. , Balden M. 
Published: December 2013

Abstract
The different stages of the polishing process of polycrystalline tungsten samples were investigated by scanning electron microscopy of both the sample surface and of cross-sections prepared with the help of a focused ion beam. It is shown that a distortion layer is present at the sample surface after mechanical fine grinding and even after polishing with diamond suspension, although the sample has a mirror-like finish. A sufficiently long chemo-mechanical polishing step using an alkaline colloidal silica suspension was able to remove this distortion layer. Although electropolishing produced an even smoother surface, the microstructure quality after chemo-mechanical polishing is comparable to that of an electropolished sample.
EBSD- und TEM-Investigations of the Deformation Induced Martensitic Transformation in the Austenitic Steel X6CrNiNb18–10 under Cyclic Loading
Authors: Soppa E. , Willer D. , Kuppler D. , Maile K. 
Published: December 2013

Abstract
As part of an existing research project [1] the fatigue behaviour at room temperature of the austenitic steel X6CrNiNb18–10 was investigated. From a combination of interrupted low cycle fatigue tests and EBSD-measurements in the scanning electron microscope (SEM) the deformation induced transformation of austenite into α'-martensite occurring was able to be observed over the life of the specimen. From TEM-investigations carried out on thin metal foils prepared from the fatigue specimens, the presence of body centred cubic (bcc) α'-martensite was confirmed within the austenitic matrix. This phase transformation affects the crack initiation mechanism. Fatigue cracks often form within the microstructure at the phase boundary between the austenite and the martensite and in the martensitic areas where they grow into the martensitic phase formed at the crack tip.
Microstructural Origins of Variability in the Tensile Ductility of Tilt-Pour Permanent Mold Cast Al Alloy at a Warm Temperature
Authors: Gokhale A. M. , Patel G. R. 
Published: December 2013

Abstract
Light-alloy castings often exhibit variability in the fracture sensitive properties such as ductility that does not necessarily correlate to the global average microstructural parameters such as dendrite cell size and porosity volume fraction in the three-dimensional microstructure. Nonetheless, in numerous such cases, the variability in the fracture sensitive properties does correlate to the variability in the local distributions of microstructural features and processing defects because the fracture path preferentially goes through the regions containing large concentrations of the defects and/or microstructural extrema. This paper presents the results of a detailed quantitative metallography and quantitative fractography based investigation of the relationships between microstructure and variability in uniaxial tensile ductility of the tensile test specimens drawn from very large size Al alloy automotive component castings fabricated using tilt-pour permanent-mold casting process. The percent tensile ductility e shows strong quantitative correlation with the area fraction of the porosity f in the corresponding fracture surfaces, which can be represented by the following power-law relationship, where e0 and n are empirical constants.
Measuring the Grain Size of Specimens with Non-Equiaxed Grains
Authors: Voort G. F. Vander 
Published: December 2013

Abstract
If a specimen has been cold worked, or it did not recrystallize after hot working, the grains will not be equiaxed and extra care must be taken when assessing the specimen's grain size. Always test a longitudinally oriented plane first to determine if the grains are, or are not, equiaxed. In this work, a low-carbon sheet steel was tested in the as-received condition (reportedly annealed), and after cold reductions in thickness of 12, 30 and 70 %. Above 70 % reduction, it can be quite difficult to reveal the ferrite grain boundaries well enough to get a precise measurement. Measurements were made on the three principal planes using the Jeffries planimetric method, the Abrams three-circle intercept method and the intercept method using directed parallel test lines. Grain elongation was assessed using the simple anisotropy ratio and the Saltykov degree of orientation method.
Microstructure Evolution and Mechanical Properties Investigation of Al-6 %Cu Alloy Laser and GTA Welds
Authors: Talari M. K. , Babu N. Kishore 
Published: December 2013

Abstract
Microstructural development, post-weld ageing response and mechanical properties of gas tungsten arc and CO2 laser welded Al-6 %Cu (AA2219) alloy were investigated in the present study. The fusion zone of laser weld consists of three parts: the fine grains in the middle part, the columnar zone and equiaxed zone adjacent to fusion boundary. In contrast, fusion zone of gas tungsten arc weld consists of two parts: the columnar zone in the middle part and the equiaxed zone adjacent to fusion boundary. The size of the equiaxed grains in the fusion zone was the least in the laser welds when compared to gas tungsten arc welds. Laser welds have exhibited higher hardness, post weld ageing response, yield strength, ductility and fatigue strength when compared with gas tungsten arc welds. Fine equiaxed grain morphology and discontinues eutectic distribution in the laser weld fusion zone could be attributed to the improved tensile and fatigue properties of laser welded samples. ‘Thermal pinning effect’, due to non isothermal conditions, has arrested grain growth in heat affected zone in spite of temperatures close to the melting point of aluminum in heat affected zone.
Practical Limitations to Carrier Layer Formation on Inclined Planes
Authors: Ikin J. B. , Thompson H. M. , Gaskell P. H. , Noakes C. J. 
Published: December 2013

Abstract
Two important instabilities associated with carrier layer formation on the inclined plane of slide-fed coating processes are explored, with a two liquid layer prototype configuration employed to mimic the slide-bead process as used by industry. The work relates to both slide-bead and curtain coating methods. Experiments first reveal how broad diffuse bands, that destroy the quality of the final coating, are formed as the carrier layer flow rate is reduced. The bands are found to be exacerbated by either decreasing the viscosity or flow rate of the carrier layer or by increasing the viscosity of the upper layer. As the flow rate of the carrier layer is reduced further, the upper layer begins to invade the carrier layer delivery slot. Flow visualisations reveal that a parallel sided delivery slot is superior to a chamfered one in terms of robustness against invasion of the interface and that reducing the slot width increases robustness further. Experiments and complementary numerical simulations confirm the existence of a recirculating eddy near the top of the downstream wall as the carrier layer flow rate is reduced and this insight is used to propose an instability mechanism for the onset of the bands. Further experiments expose the mechanism for the formation of cross bars. These can develop downstream of the carrier layer delivery slot and arise because the merging of the layers there becomes increasingly influenced by the flow, demonstrating that the sensitivity of cross bars to pump induced disturbances grows rapidly as the critical carrier layer flow rate for instability is approached and then collapses as the flow rate is reduced to a value where the layer is no longer effective in lubricating the flow of adjacent layers.