bluuebunny/crossref_metadata_2025_split huggingface dataset:
Untersuchung verschiedener Verfahren der Probenentnahme für die Wasserstoffanalyse bei Kaltwalzenschäden
Authors: Merzlikin Sergiy V. , Hassel Achim Walter , Steinhoff Karl , Wildau Monika 
Published: December 2013

Kurzfassung
Beim Kaltwalzen ist seit langem eine typische Art von Ausschalungsbrüchen der Walzen bekannt. Es wird angenommen, dass eine Wasserstoffversprödung der gehärteten Walzen für die Schäden verantwortlich ist. Atomarer Wasserstoff kann beim Walzvorgang durch eine galvanische oder eine chemische Reaktion entstehen und in die Walze eindringen.
Bei jedem Verdacht auf wasserstoffinduzierten Walzenbruch muss der gesamte Wasserstoffgehalt bestimmt werden, um die Ursache des Schadens genau festzustellen. In dieser Arbeit wurde die Abhängigkeit der Ergebnisse der Wasserstoffanalysen von den jeweiligen Probenentnahmeverfahren untersucht, um dadurch mögliche Verfälschungen auszuschließen und eine Richtlinie für diese Prozedur für die Zukunft zu erarbeiten.
Influence of Surface Quality on the Biaxial Strength of Silicon Nitride Specimens
Authors: Harrer W. , Danzer R. , Supancic P. 
Published: December 2013

Abstract
Details of surface finish affect significantly the surface quality of ceramic specimens (e.g. surface roughness, residual stress). To analyse the influence of surface quality on strength five samples of silicon nitride specimens were machined applying different surface finishing procedures. Then they were strength tested using the biaxial Ball-on-three Balls (B3B) test. The test results were compared to those of conventional bending tests. A fractographic analysis was performed on selected specimens to identify the fracture origins. It could be shown that a better surface quality leads to an increased strength but increases the scatter of strength data too.
Defects and Fracture Statistics in Low-Pressure Injection Moulded Alumina Components
Authors: Lube T. , Kraleva I. 
Published: December 2013

Abstract
The strength and the defects responsible for failure occurring in tubular alumina components were investigated. Strength testing was performed on machined components in 3-point and 4-point bending. Weibull statistics were applied to describe the strength distributions. Fracture surfaces were investigated using stereo-microscopy and SEM. Fractography revealed that three different types of defects were responsible for failure of the 3-point as well as the 4-point bend specimens. Using an iterative procedure, a separate Weibull distribution for each defect type was evaluated using the data of the two different specimen types.
Microstructural Changes during Vacuum Carburizing of Steels
Authors: Bruncko Mihael , Anzel Ivan , Kneissl Albert C. 
Published: December 2013

Abstract
Vacuum carburizing is a modern, very efficient and environmentally friendly process for case hardening of steels. Nowadays the technology has replaced atmosphere carburizing in many cases due to better repeatability and uniformity of heat treated samples. The process of vacuum carburizing is performed under oxygen free hydrocarbon gas atmosphere (usually pure acetylene) at partial pressure lower than 20mbar and in conditions which are far from thermodynamic equilibrium. The process consists of the cycles of active (saturation) and passive (diffusion) stages. Desired case depth and corresponding target concentration profile of carbon can be supervised by controlling the duration of these two stages.
A New Tint to Obtain Coloured Metallographic Structures of Tempered Cast Iron, Carbon Steel and Alloys
Authors: Sánchez L. García , Dietz C. , Valenzuela F. Penco , García J. A. Martínez , Portal A. J. Criado 
Published: December 2013

Abstract
A new method for preparation of metallographic samples, based on application of phthalocyanine blue diluted with nitrocellulose resin, is presented. A thin layer of the dye was applied onto cast iron or carbon steel samples and alloys prior to observation under optical microscopy. Highly resolved coloured micrographs were obtained for quenching structures or isothermal phase transformation of carbon iron alloys.
Evaluation of Diffusion Bonding (Welding) Process Temperatures of AISI 1010 Plain Carbon Steel with AISI 430 Ferritic and AISI 420 Martensitic Stainless Steels
Authors: Çay V. 
Published: December 2013

Abstract
Characterization and evaluation of diffusion bonding process temperatures of AISI 1010 plain carbon steel (PCS) with AISI 430 ferritic and AISI 420 martensitic stainless steels were experimentally studied. The diffusion bonding of AISI 1010 with AISI 430/420 steel couples were held for 40 min, at 800°C–900°C–1000°C– 1100°C, under protective atmosphere, with 10 MPa load blow those that would cause macroscopic deformation to the contacting surfaces. Microstructure morphologic evaluations were carried out with the help of SEM. Shear tests and weld efficiency were calculated at interface for mechanical properties characterization. Test results and morphologic evaluations showed that under given diffusion bonding conditions, welding/bonding integrity were slightly increased at elevated temperatures and highest values were traced at 1000°–1100°C process temperatures.
Analysis of the Crack Initiation at Non-Metallic Inclusions in High-Strength Steels
Authors: Grad P. , Reuscher B. , Brodyanski A. , Kopnarski M. , Kerscher E. 
Published: December 2013

Abstract
High-strength steels exhibit different fracture surface characteristics under cyclic load when failure is initiated by non-metallic inclusions depending on the lifespan. These can be attributed to different crack propagation mechanisms. These characteristics are correlated with the short and long crack propagation. As far as the short crack is concerned, the mechanism of the discontinous decohesion of carbides in the immediate vicinity of the inclusions and the merging of the resulting microcracks to form a macrocrack is discussed. This postulated mechanism is investigated by means of a combination of scanning electron microscope (SEM) analyses of the fracture surface and target preparation by means of focused ion beam (FIB) by a detailed resolution of the local microstructure around the crack-initiating inclusion and the crack path.
The Kinetics of Individual Grains in Polycrystalline Materials
Authors: Zöllner D. , Streitenberger P. , Fielden I. 
Published: December 2013

Abstract
Based on a mean-field approach a 3D grain growth model is presented which predicts the growth history of individual grains of a grain ensemble in terms of linear grain size and time. The analytical results are compared with the results of numerical simulations using the Monte-Carlo-Potts model. In addition, based on a stochastic model of grain growth, the diffusivity of the very discontinuous movements of individual quadruple and triple junctions is set in relation to the rate of growth. This allows the calculation of the average growth law of an ensemble of grains solely from the measurement of the stochastic growth kinetics of individual grains. The results from simulation and theory are compared with experimental results of in-situ scanning electron microscopy observations of grain growth in polycrystalline metals.
Analysis and 3D-Modelling of Open-Pore Metal Foams Using Binarized Light-Optical Microscopy In-Depth Microsections
Authors: Matz A. M. , Jost N. 
Published: December 2013

Abstract
Open-porous metal foams are cellular structures that can be defined, in simplified terms, as interwoven networks of metal ligaments that are surrounded by a fluid (liquid or gaseous). They are characterized by a very low relative density of usually 4 to 12% of the density of a solid composed of an identical base material. As such they have a small volume along with a very large surface area, providing for numerous interesting physical properties with resulting practical applications.
A detailed description of the physical properties of these materials essentially requires a characterization of their geometric structure. Within the scope of this work, microsections of these foam structures are captured in a defined depth distance of sz
≤0,5 mm. In the course of the experiment, these microsections are software-converted to binary images. They are optimized in a way that artifact characteristics, which would have a negative effect on the analysis, converge to a minimum. Based hereon, it is now possible to generate realistic 3D models of individual microsections, allowing for a three-dimensional measurement of the material. Furthermore, binary format microsections allow for determining miscellaneous statistical characteristic values of the examined foam structures. Based on these results, it is consequently very easy to draw conclusions on the geometry of large-dimensional foam structures. When varying individual characteristic parameters, such a database also provides the possibility to generate differing geometric structures, which, in turn, provide for a sound basis in order to create scalable simulation models.
Liquid Metal Induced Crack Formation in Molten Zinc – a Damage Mechanism Driven by Diffusion and Stress
Authors: Körber D. , Landgrebe R. , Adelmann J. , Hoche H. , Oechsner M. 
Published: December 2013

Abstract
Tests have been performed on hot-dip galvanized four point bend specimens to investigate how different levels of compressive stresses and tensile loads under simultaneous thermal activation below the melting temperature of the zinc coatings affect liquid metal assisted cracking (LMAC). While the material volumes under tensile stress developed intergranular cracking, areas under compressive stress – even using a tin and lead alloyed zinc melt – did show no signs of damage. The flat specimens tested without superimposed loading did only show intergranular edge defects in the order of several grain layers when ageing during several hours in differently alloyed zinc melts. Moreover, in the context of the tests, the dominating effect of the alloying elements lead and tin could be confirmed for the intergranular crack formation. Furthermore, the particular importance of the material condition for the occurrence of the damage by LMAC could be shown by means of the progression of the crack formation in the microstructure.
Microstructural Characterization of Carbides in a Cast High-Speed Steel Using Different Metallographic Techniques
Authors: Gümüş S. , Atapek Ş. H. , Polat Ş. , Erişir E. , Alkan A. 
Published: December 2013

Abstract
High-speed steels are mostly manufactured by casting and they exhibit a characteristic dendritic microstructure with primary carbides. In this study, the morphology of carbides in a cast high-speed steel is investigated using light and scanning electron microscopes. The morphology and structure of the carbides were revealed by means of different metallographic techniques such as chemical and electrolytic etching and color metallography. The combination of these metallographic techniques gives different approaches to how different primary carbide morphologies can be observed in the martensitic structure. Besides, microanalysis was carried out to determine the chemical composition of primary carbides using SEM/EDX.
Moving Blade Failure in the Low-Pressure Turbine of a Steam Turbo Set
Authors: Mundt G. , Neidel A. , Matijasevic-Lux B. 
Published: December 2013

Abstract
The rivet spigots by means of which the shroud bands of steam turbine vanes are attached to the blades failed because of corrosion fatigue cracking. The result was that the blades underwent increased dynamic stresses and, consequently, sustained fracture by cyclic loading.
Grain Size Measurements Using Circular or Rectangular Test Grids
Authors: Voort G.F. Vander 
Published: December 2013

Abstract
Experiments were conducted to determine the influence of the number of grains counted using the Jeffries planimetric procedure of ASTM E 112 with a single test circle compared to the number counted using rectangles as suggested by Saltykov. Both planimetric methods produced similar estimates of the ASTM grain size number when the counts per field placement were high. The Saltykov rectangle method is a viable test method and produced good data down to low count numbers. Bias was not observed at low counts, only data scatter. The intercept count method, using only a single test circle per field, yielded slightly higher estimates of the ASTM grain size number, but the difference was relatively insignificant.
The Quantitative Metallographical Characterisation of Hot Formed Duplex Steels
Authors: Weidig C. , Schepanski N. , Rettenmayr M. 
Published: December 2013

Summary
Image analysis investigations into the quantitative characterisation of hot formed duplex steel microstructures are presented. The shape parameters Feret diameter, Feret angle and roundness are used to describe the morphology of the microstructures. High temperature compression tests were carried out at 1 150 °C, 1 200 °C and 1 250 °C and the microstructures produced compared with that of the initial un-deformed material. The technical yield strength were also correlated with the temperatures and strain rate used. This revealed that the technical yield strength doubled by reducing the temperature of deformation from 1 250 °C to 1 150 °C and by increasing the strain rate by an order of magnitude. It is also shown that the pronounced preferential direction of the phases present in the initial un-deformed material is no longer quantitatively discernable above a temperature of deformation of 1 200 °C.
Growth Kinetics of CrC Coating Layers on AISI D3 Obtained by Thermo-Reactive Diffusion Technique
Authors: Kurt B. , Onder E. , Carboga C. , Demirel B. , Karagoz M. 
Published: December 2013

Abstract
In this study, the characterization and growth kinetics of chromium carbide layer coated on AISI D3 cold-work tool steel by pack method thermo-reactive diffusion process in solid medium were carried out. Coatings were performed by using ferro-chromium powder as Cr source at 950, 1 000, 1 050 and 1 100 °C for 2 and 4 h. The carbide layers were evaluated based on microstructure, thickness, hardness, energy dispersive X-ray facility and X-ray diffraction analysis. Chromium carbide layer thickness on the coated specimens has been in the 4.2–17 μm range depending on treatment time and temperature. Growth kinetics of the carbide layers were analyzed by measuring the depth of carbide layer as a function of temperature and time. The activation energy was estimated to be 180.13 kJ/mol. The microhardness values of the coating layers are range of 1 200–1 600 HV. Ball rotating micro-abrasion technique was used to carry out wear tests on the thin coating layers.
Quality Control of Thermal Spray Coatings in Diesel Engines
Authors: Carstensen J. V. , Lindegren M. 
Published: December 2013

Abstract
Thermal spraying is a method, which is suitable for coating of large components. The coatings can e. g. improve the wear, friction and/or corrosion properties of components so that they can withstand the increased loads. The quality of the coatings is essential to ensure reliable operation of the components. However, quality control of thermally sprayed coatings is indeed nontrivial and sample preparation is a key issue. This paper shows examples of thermal spray coated components in large diesel engines and provides insight into the methods used in preparing samples for quality control.
Influence of Viscosity-interface Modifier Interactions on Performance and Processability of Rice Hull PE Composites
Authors: Dixit N. , Sain M. , Kortschott M. T. , Gulati D. 
Published: December 2013

Abstract
Interface modifiers and viscosity modifiers are added to wood plastic composites to improve interfacial adhesion and processing rate respectively. However, because of the chemically reactive nature of interface modifiers and viscosity modifiers, there is a high possibility of interactions between them, influencing the mechanical properties and processabilty of the composites. To evaluate this point, interactions between three different interface modifiers and a viscosity modifier were investigated in this study. Concurrently, the effectiveness of three different interface modifiers in improving mechanical properties of the composites was also studied. The results indicated that there was a significant improvement in the tensile strength, flexural strength, flexural modulus and impact properties of the composites with all the three maleated polyethylene based coupling agents. Moreover, presence of an amide carboxylic acid based viscosity modifier along with a maleated polyolefin based interface modifier reduced the mechanical properties of the composites as compared with that of the composites having only maleated polyolefin based interface modifiers.
Single and Multi Objective Optimization for Injection Molding Using Numerical Simulation with Surrogate Models and Genetic Algorithms
Authors: Zhou J. , Turng L.-S. , Kramschuster A. 
Published: December 2013

Abstract
The objective of this study is to develop an integrated computer-aided engineering (CAE) optimization system that can quickly and intelligently determine the optimal process conditions for injection molding. This study employs support vector regression (SVR) to establish the surrogate model based on executions of three-dimensional (3D) simulation for a selected dataset using the latin hypercube sampling (LHS) technique. Once the surrogate model can satisfactorily capture the characteristics of simulations with much less computing resources, a hybrid optimization genetic algorithm (GA) or a multi-objective optimization GA is then used to evaluate the surrogate model to search the global optimal solutions for the single or multiple objectives, respectively. The performance and capabilities of other surrogate modeling approaches, such as polynomial regression (PR) and artificial neural network (ANN), are also investigated in terms of accuracy, robustness, efficiency, and requirements for training samples. Experimental validations and applications of this work for process optimization of a special box mold and a precision optical lens are presented.
Correlations between Injection Molding Parameters, Morphology and Mechanical Properties of PPS Using Artificial Neural Networks
Authors: Lotti C. , Bretas R. E. S. 
Published: December 2013

Abstract
The processing conditions of injection molding have a complex influence on the morphology and on the mechanical properties of a semicrystalline polymer. Therefore, to establish correlations between processing conditions, morphology and mechanical properties constitutes a difficult task; finding these correlations is one of the goals of a materials engineer.
The purpose of this work was to study the influence of the injection molding conditions on the morphology and mechanical properties of poly(p-phenylene sulphide), PPS, using artificial neural networks, ANNs. First, a statistical analysis was done to find the more influential processing parameters that affect the morphology and mechanical properties of the PPS. Second, ANNs were applied to establish correlations between processing conditions, morphology and properties.
It was found that the variables with the highest influence on the morphology and the mechanical properties were the injection and mold temperatures (Tinj and Tmold, respectively), as they showed a straight relationship with the crystallinity index of the injection molded part.
Three different ANNs were built to predict the correlations. The ANN-1 predicted the crystallinity gradient along the thickness of the injection molded part from Tmold, Tinj, and flow rate, Q; the ANN-2 predicted the elastic and flexural modulus, E, and the yield stress from the crystallinity gradient, while the ANN-3 predicted the mechanical properties directly from the processing conditions. All ANNs were built with only fifteen experimental data and were trained with the group cross-validation method, GCV and with a training-test set method. Both methods showed similar and excellent performance. Thus, it can be concluded that ANNs can be used as a powerful tool in the learning of these complex correlations.
Tip-clearance Effect on Mixing Performance of Twin Screw Extruders
Authors: Ishikawa T. , Nagano F. , Kajiwara T. , Funatsu K. 
Published: December 2013

Abstract
In order to evaluate the tip-clearance effect on mixing, 3-D numerical simulations were applied to kneading block section of co-rotating twin screw extruders. The software we used was originally developed for non-Newtonian and non-isothermal flow analysis based on the finite element technique. The marker-particle tracking analysis was also developed in order to estimate the particle path, residence time distribution, stress and strain history, and so on.
The stress distribution obtained by the above-mentioned simulations suggested the following mixing mechanisms. The kneading block with the small tip-clearance (TC) caused the bimodal stress distribution which had peaks in both high and low stress level. The marker-particles which overpassed the TC formed the peak at the high stress level and the other particles contributed to the peak at the low stress level. In other words, a large number of particles evaded the TC and it caused heterogeneous stress induced mixing. On the other hand, the large tip-clearance caused the narrow and sharp stress distribution because most of the particles passed over the TC. The stress level was not high, however, homogeneous stress induced mixing was expected. Since the tip-clearance applied a significant effect to the dispersive mixing, it should be optimised in accordance with the material design.
Effects of Take-up Speed of Melt Spinning on the Structure and Mechanical Propertiesof Maximally Laser Drawn PA9-T Fibers
Authors: Uddin A. J. , Ohkoshi Y. , Gotoh Y. , Nagura M. , Endo R. , Hara T. 
Published: December 2013

Abstract
A new semiaromatic polyamide, PA9-T, was melt-spun at take-up speeds from 200 to 1000m min−1. The as-spun fibers were drawn with CO2 laser-heated drawing to their maximal draw ratio (DRmax). The drawing stress was recorded during this process. The effects of take-up speed of melt-spinning on maximally drawn fibers were characterized through measurements of density, birefringence, wide-angle X-ray diffraction, crystal orientation, tensile testing, and dynamic viscoelastic analysis. All as-spun fibers were essentially amorphous and their birefringence and density increased slightly with the increase of take-up speed. Lower take-up speeds yielded higher DRmax values, and fibers drawn to their DRmax exhibited superior structure and mechanical properties. The tensile strength and Young's modulus achieved were the highest reported to date for PA9-T: 737 MPa and 5.8 GPa, respectively.