bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Materialographic Preparation and Microstructure Characterization of Lithium Ion Accumulators
Authors: Hafner C. , Bernthaler T. , Knoblauch V. , Schneider G. 
Published: December 2013

Abstract
Lithium ion accumulators are widely used already in numerous electronic devices. However, a great deal of research will still be required as to their use as a reliable and efficient energy storage unit in the automotive industry. Their characterization using physical and electrochemical methods has made great progress and was published already. In contrast, the classical materialographic characterization of their microstructure by means of microscopy is applied only to a small extent nowadays. Access by the public to relevant results is scarcely possible.
Properties like capacity and power as well as safety und stability also depend very much on the cell design (e. g. geometry, layer thicknesses) and microstructure (e. g. volume fraction, grain size) of the materials employed. A microstructure analysis by microscopy is intended to provide for a more profound comprehension of the connection between the basic parameters and function here. A challenge is posed by the preparation of a microsection to reveal a representative image of the microstructure without artefacts. The process of materialographic preparation and the potential of various microscopy techniques for visualizing and quantifying the cell components and ageing effects are presented here. The opportunities of characterizing the basic parameters specific to the cells furnishes new knowledge on the properties of battery materials and, hence, will be of great utility for future examinations and further developments of the lithium ion technology.
The Phase and Microstructural Analysis of Protective Oxide Coatings on Molybdenum
Authors: Traxler H. , Jörg R. , Zabernig M. , Sigl L.S. 
Published: December 2013

Abstract
Due to their high sensitivity to oxygen, the use of refractory metals requires an effective protection against oxidation. In the case of molybdenum this is achieved by using a silicon and boron based coating commercially marketed under the trade name SIBOR®. In the moduction of a SIBOR®-coating, a mixture of Si, B and C is plasma sprayed in air onto the Mo-surface to be protected and subsequently annealed in hydrogen. Previous investigations have shown that in doing so a stationary coating of Mo-borides and Mo-silicides is formed. However, the exact phase arrangement and composition has until now remained unclear.
Energy dispersive X-ray spectroscopy (EDS) in the scanning electron microscope (SEM) is able to analyse the silicides in SIBOR®, although due to the overlapping of the Mo- and B-spectral partial a clear identification of the borides was not possible. Using a combination of electron back scatter diffraction (EBSD) and wavelength dispersive X-ray spectroscopy (WDS) it is, however, shown that SIBOR® is made up of a series of sub-layers of Mo2B and MoB followed by Mo5Si3 and MoSi2, and that the other phases of the Mo-Si-B ternary system, i.e. Mo3Si and Mo5SiB2(T2), do not occur.
Notably, the two borides and the Mo5Si3 exhibit a structure which is polycrystalline in the lateral direction yet normal to the surface forms of only a single layer of crystallites. In contrast, the final MoSi2-layer has a polycrystalline structure both in the lateral and in the normal directions. Furthermore, Mo5Si3 and MoSi2 both exhibit marked textures.
Investigations on High Temperature MgB2 Superconductor Wires and Tapes with New Sheath Materials and the Correlation of Their Microstructures and Properties
Authors: Schubert Margitta , Häßler Wolfgang , Rodig Christian , Herrmann Marco , Kario Anna Urszula , Scheiter Juliane , Prescher Heiko , Holzapfel Bernhardt , Schultz Ludwig 
Published: December 2013

Abstract
Long superconducting MgB2 wires and tapes were produced by the “powder in a tube” method (PIT) using a mechanically alloyed nano-powder consisting of Mg, B and MgB2 as the precursor material. Both single-core (SC) and multi-core (MC) conductors were made by swaging and wire drawing the powder contained within a new type of sheath material (ODS-Cu) which, amongst others, also has the advantage of thermally stabilising the conductor.
Metallographic investigations on specimens of the conductors in the as-drawn condition and after heat treatment were carried out both to monitor the manufacturing process as well as to gain information regarding important parameters such as the changes in hardness and ductility of the sheath and filament occurring during the forming process and the effect which they have on the final properties of the conductors. The metallographic and scanning electron microscopic (SEM) investigations of the microstructures were carried out on longitudinal (LS) and cross (XS) sections of the conductors which made it possible to understand the correlation between the microstructures and properties of the conductors and to draw important conclusions in order to be able to achieve the optimum design and best electrical properties for the finished conductors. By heat treating the cold formed conductor in the temperature range 500–650°C, very good superconducting properties were able to be produced with critical temperatures (Tc) of 36 K and critical current densities (jc) of 104 A/cm2 in fields of 11 T (parallel to the tape surface), measured at 4.2 K. Using this new sheath material, a conductor of over 100 m in length was able to be manufactured.
Effect of Austempering Temperature and Time on the Kinetics and Microstructure of Austempered Compacted Graphite Cast Irons
Authors: Teymourian M. , Boutorabi S.M.A. 
Published: December 2013

Abstract
After starting the austempering nucleation of bainitic ferrite was observed within a very short time. Samples that austempered for 2 min.showed martensite in the microstructure. By increasing the austempering time from 30 min to 90 min the retained austenite decomposes and X-ray diffraction observations revealed the greatest volume fraction of retained austenite up to 17.3 and 23.8 percent when austempered for 30 min. Micro-hardness of the bainitic ferrite increased up to 370 and 500 HV and micro-hardness of the retained austenite increased up to 300 and 400 HV at the austempering temperatures of 300°C and 400°C respectively. In comparison to austempered ductile iron, the austempered compacted graphite cast iron shows higher rate of bainitic reaction. Bainite formation driving force and consequently the rate of austempering process are higher in compacted graphite cast irons.
Vibratory Polishing of a Nickel-Based Superalloy (MAR 247) Using VibroMet 2
Authors: Watermeyer P. 
Published: December 2013

Abstract
Preparation artifacts such as scratches, surface deformation and smearing are often difficult to remove by conventional grinding and polishing.
Vibratory polishing is a mechanical process. It provides a very gentle polishing treatment. This final preparation step provides for a removal of ground specimen surfaces without causing deformations. The sample surface was examined on the basis of different mechanical and chemical/mechanical preparation steps with regard to its suitability for subsequent examinations using a scanning electron microscope (for example EBSD measurements).
Examination of the Microstructure and Properties of Low-Frequency Electromagnetic Casting 6060 Aluminum Alloy Billets and Bars
Authors: Markovic S. , Stakic M. , Manasijevic S. , Kamberovic Z. , Radisa R. , Korac M. 
Published: December 2013

Abstract
This study investigated the advantages of using low-frequency electromagnetic casting (LFEC) process compared to conventional direct chill DC casting of aluminum alloy and considered possible energy savings. The obtained results have indicated that casting in low-frequency electromagnetic field offers a series of advantages regarding the quality of aluminum billet, such as smooth billet surface, uniform grain size on the cross section, finer macrostructure and balanced distribution of intermetallic phases in the alloy. This guarantees their good properties in further processing, i.e. pressing, drawing, anodizing, plasticization etc. If the material is properly prepared for melting and for the technological process of casting and if primary aluminum is used as the basic raw material, the 6xxx-series billets can be extruded with no or minor prior thermal homogenization. This is a significant argument for using low-frequency electromagnetic casting (LFEC) process, which allows for significant savings in energy and labor and simplifies the manufacturing process as well.
Preparation and Etching Methods for a Light-Optical Microscopy Analysis of Extrusion Seams and Microstructural Contrasting for Aluminum Alloys EN AW-6063 and EN AW-6082
Authors: Reeb A. , Ohl A. , Poser K. , Kloppenborg T. , Brosius A. , Tekkaya A.E. , Weidenmann K.A. 
Published: December 2013

Abstract
To begin with, a visualization of the seam location as well as of the microstructure of the entire profile cross-section is necessary in order to evaluate the stability of extrusion processes and the resulting relationships between process, microstructure, and properties of extrusion profiles characterized by an extrusion seam. The investigations aim at determining appropriate preparation and etching methods for a light-optical microscope analysis of the longitudinal as well as the transversal extrusion seam in the alloys EN AW-6063 and EN AW-6082 and – in the best case – a simultaneous microstructural contrasting. For this purpose, different chemical etching techniques have been applied. A reliable uncovering of the seam was possible for both alloys using a HF solution. Etching with Weck's reagent after NaOH pre-etching turned out to be a promising method for microstructural contrasting of the EN AW-6063 alloy. The transversal extrusion seam could not be rendered visible by means of conventional etching methods. In this context, extrusion of both alloys (EN AW-6082 and EN AW-6063) applying the billet-to-billet extrusion method in line with visioplastic analyses allowed for an indirect representation of the extrusion seam.
Microstructural Investigation of Melt-Spun NiTi Based Ribbons
Authors: Mehrabi K. , Bruncko M. , Kneissl A.C. 
Published: December 2013

Abstract
In order to get small-dimensioned shape memory alloys (SMAs) with good functional and mechanical properties, a rapid solidification technique was employed. This paper discusses the use of different melt-spinning procedures for the preparation of proper thin NiTi ribbons.
Metallographic characterization of SMAs is an important way to evaluate material properties, therefore the effect of alloy composition and different conditions of melt-spinning process (crucible, melting time and temperature) on the various inclusions and microstructure of NiTi alloys was investigated. Specimens for metallographic studies were cut from the longitudinal cross sections of melt-spun ribbons. The microstructures and different phases were examined by optical, scanning and transmission electron microscopy and the influence of the processing methods on microstructures of ribbons will be discussed.
The Joint Application of Various Microscopy Techniques for the Evaluation of Area Fraction of Structural Components – Theoretical Assumptions and Practical Aspects
Authors: Richter J. 
Published: December 2013

Abstract
The paper discusses employing a variety of microscopical techniques and their limitations in the context of the evaluation of the area fraction of structural components. The idea of the joint application of several types of microscopes to area fraction assessment depending on the sizes of objects being evaluated is introduced. The relevant measuring schemes and formulae for the correct calculation of the total area fraction in two, three, four or five stage analyses using light and electron microscope techniques are presented together with practical examples and results. In this joint approach the advantages of each microscope type are utilized while avoiding the drawbacks. A concept of the local area fraction is suggested and applied in the quantitative evaluation of a carbide phase in an economical niobium high-speed steel. The appropriate variants of the joint method are recommended for various size scales and size distributions of objects to be analyzed. The methods described enable an accurate evaluation of area fraction in cases where the possibilities of single microscope techniques are insufficient.
Structural Changes in Cobalt Solid-Solution Crystals Due to Milling
Authors: Podlesak H. , Gläser C. , Wielage B. , Hösel D. , Neugebauer R. 
Published: December 2013

Abstract
A detailed microstructural study was carried out using a field emission-scanning electron microscope with the aim of analysing the effect of surface work-hardening which occurs when milling the cobalt based hard facing alloy ”Stellite 12“. The strengthening was determined to be caused by the formation of two-dimensional structural defects in the cobalt solid-solution matrix. The assumption that a stress induced martensitic transformation of the crystalline areas of the cubic cobalt phase into thin hexagonal cobalt platelets occurs was confirmed by X-ray diffraction phase analysis. In addition, it was assumed that stacking faults would be formed. For the microscopic investigation, the channeling effect achieved by imaging using a conventional ring-shaped back scattered electron detector proved most useful. Because of needed high quality of polished sections, an optimised method of preparation was developed.
Metallographic Analysis of the Dead Metal Zone In Metal Cutting With a Rounded-Edge Tool
Authors: Öztürk S. , Uysal A. , Altan E. 
Published: December 2013

Abstract
The experimental results show that a small dead region is seen in front of the rake face during cutting with a rounded-edge cutting tool. Although this fact was accepted, metallographic analysis of the dead metal zone had never been conducted. A quick stop device was used to obtain chip root samples that are representative of the deformation taking place during dynamic (actual) cutting conditions. A metallographic analysis was performed on selected specimens to identify the microstructure and formation. The photomicrographs were analyzed and an effort made to explain the dead metal zone microstructure.
Quantitative Analysis of Microstructure in Low Carbon Steel after Thermomechanical Process in (α+γ) Region
Authors: Kolan C. , Wrońska A. , Lis A. , Golański G. 
Published: December 2013

Abstract
This paper presents results of quantitative analysis of ferrite grains in low carbon steel C15V with microalloying addition of vanadium. Thermomechanical treatment in the intercritical (α+γ) region was performed using the dilatometer DIL805A. On the basis of dilatometric researches the critical temperatures of α ↔ γ transformation for C15V steel during heating with v5−8=0.5 K/s and cooling with v8−5=1 K/s were estimated. The steel deformation was carried out with application of two different variants: deformation in (α+γ) region after cooling from full austenitization temperature and deformation in (α+γ) region after heating from ambient temperature (ferritic-bainitic microstructure). The effects of these treatments were observed by means of a light optical microscope in bright and polarized field.
The quantitative analysis of microstructure was investigated using Image Pro Plus (IPP) program. Characteristic parameters for ferrite grains such as: field area, average diameter, shape factor were estimated. For each of these parameters, histograms and maps of average grain diameter distribution were performed using STATISTICA 9 and IPP programs. It was observed that deformation in the intercritical range (α+γ) promotes the occurrence of many ferrite nucleus in the obtained structures, especially at grain boundaries. For low carbon steel this results in formation of very fine microstructure.
Evaluation of Porosity of Precision Castings Made of High-Temperature Creep Resisting Nickel Superalloys
Authors: Roskosz S. 
Published: December 2013

Abstract
The subject matter of the paper is the quantitative evaluation of gaseous and shrinkage porosity in construction elements of a low-pressure aircraft engine turbine using quantitative metallography methods. The research material consisted of blades and blade segments with a polycrystalline structure made of IN 713C and MAR M247 superalloys.
One of the major problems that occur in the precision castings is their porosity: gaseous, which is the result of emission of dissolved gases from the superalloy during solidification, and shrinkage, being the result of shrinkage of the superalloy and from a lack of feeding of the interdendritic space.
The comprehensive procedure of porosity evaluation includes: an automatic decimal-to-binary conversion of pores, a selective quantitative evaluation of gaseous and shrinkage porosity, the development of measuring conditions of quantitative metallography parameters, and the application of structural maps showing the varied porosity distribution over the cross-sections of castings of blades and blade segments.
The developed practical procedure of selective measurement of gaseous and shrinkage porosity in the examination of precision castings made of high-temperature creep resisting nickel superalloys is presented.
Effect of Growth Velocity on Solute Distribution and Electrical Conductivity in a Directionally Solidified Cu–8 %Ag Alloy
Authors: Lee W.-H. , Kang B.-H. , Kim K.-Y. , Cho H. 
Published: December 2013

Abstract
A Cu–8 %Ag alloy was directionally solidified at different growth velocities to investigate the relationship between the solute distribution and the electrical conductivity of the material. The temperature gradient was fixed at 6.1 K/mm, and the growth rate was varied from 1 µ m/s to 200 µ m/s The planar interface was not observed in this experimental range, although cellular and dendritic interface morphologies were observed. As the growth velocity was increased, the initial silver content decreased, while the silver content near the dendrite boundary increased. The lattice parameter of the Cu – Ag alloy increased with increases in the number of silver sites in the copper lattice as measured via a calculation using the VASP (Vienna Ab-initio Package Simulation) code. The lattice parameter also decreased with increases in the growth velocity due to the decrease in silver content in the matrix. Higher electrical conductivity was obtained with higher growth velocities.
Mechanical Milling Behavior and Characteristics of Bi2Te3 Thermoelectric Materials
Authors: Babu M. , Kim H.-S. , Kim H.-Y. , Hong S.-J. 
Published: December 2013

Abstract
In this paper, starting from the gas atomization powders, n-type Bi2Te3 thermoelectric alloys prepared via high energy ball milling and subsequently consolidated by hot extrusion. The effect of ball milling on the microstructure of Bi2Te3 alloys was studied. With increasing the milling time, from 3 min to 90 min, the particles were coarsening due to the agglomerated because of the high surface energy of the fine particles adhesive each other during the high energy ball milling. The preferential orientations of grains indicate that the extrusion process has the significant method to forcing the basal plane to orient preferentially in the extrusion direction were clearly observed by the TEM micrograph. The maximum electrical conductivity 6675.567 Ω−1m−1 measured at 100 °C temperature owing to the increasing of carrier concentration due to the donor defect formation and contamination occurred during the high energy ball milling at longer milling time (90 min).
Characterization of Oxidation Resistance of Stainless Steels at High Temperature by Metallographic Examinations and In-Situ Electrical Resistance Measurements
Authors: Bruncko M. , Rudolf R. , Mehrabi K. , Kneissl A. C. , Anzel I. 
Published: December 2013

Abstract
Practically all metals and alloys survive high-temperature exposure by growing oxide scales and/or by precipitation of the oxide particles in the matrix. Formed products can grow in shape of external oxide layers on surfaces, or as discrete oxide particles precipitated in a metal matrix. The first case represents external oxidation, and the other case is called internal oxidation. These processes are very important, because they determine the properties and applicability of metallic materials. Generally, they are undesired, because they cause deterioration of the mechanical properties and decomposition of metallic material. On the other side, the controlled process of external oxidation could be used for formation of protective coatings and the internal oxidation for dispersion strengthening of materials.
In this paper we present monitoring of high-temperature oxidation of X12Cr13 stainless steel by in-situ electrical resistance measurements at different annealing temperatures in the air atmosphere. We determined the kinetics of oxide scale formation and its morphology with additional metallographic examination made by optical and scanning electron microscopy. The results of this research work show that in-situ monitoring and characterization of high-temperature oxidation present a strong tool that will contribute to a better fundamental understanding of the phenomena that occur during high-temperature oxidation of metallic materials.
Analysis of Stray Grain Formation in Single Crystal CMSX-4 Superalloy
Authors: Chmiela B. , Szeliga D. , Sozańska M. , Jarczyk G. , Cwajna J. 
Published: December 2013

Abstract
Modern single crystal (SX) turbine blades are fabricated by directional solidification using a grain selector. The grain selection process was investigated by numerical simulation and verified by the experiment. A coupled ProCAST and cellular automaton finite element (CAFE) model was used in this study. According to the latest literature data, we designed the grain selector. Simulation confirmed an optimal grain selection efficiency of the applied selector geometry. The obtained experimental results reveal the possibility of stray grain formation in SX castings with a designed selector, in contrast to the simulation results.
X-Ray Computed Tomography as Supporting Technology in The Failure Analysis of Press-In Connections for Electronic Assemblies
Authors: Rauer M. , Schreck T. , Kaloudis M. 
Published: December 2013

Abstract
Besides its original field of application–the characterization of microstructures–the metallography is often referred to when analyzing failures of electronic components and assemblies. In this context, the cause of the failure is analyzed by means of a metallographic section. At this point, the precondition and difficulty is the right choice of the section plane. If it is not optimally selected, there is a risk of overlooking the defect and therefore of not recognizing important correlations. The X-ray computed tomography is an efficient method which helps making the right choice and facilitates a targeted metallographic preparation. Conspicuous features inside the damaged component can be detected in advance by means of a three-dimensional volume model established by computed tomography. Based on this information, an appropriate cutting plane can be chosen in the volume model and a targeted metallographic section can be prepared. In the following, it is possible to view the conspicuous spot with high resolution and to analyze its microstructure in selected areas. In order to demonstrate the use of computed tomography as a supporting technology in the target preparation, the following article establishes a link between both testing technologies and their application to the press-fit technology which serves as joining technology when assembling electronic components.