bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical properties of a single gecko seta
Authors: Huber Gerrit , Orso Steffen , Spolenak Ralph , Wegst Ulrike G. K. , Enders Susan , Gorb Stanislav N. , Arzt Eduard 
Published: February 2009

Abstract
Measurements of the stress – strain response of hairlike gecko setae are presented. These setae have diameters in the micron range and are part of the attachment organs that enable lizards to cling to surfaces. Three test methods were employed: (a) applying tension with a piezoresistive cantilever inside a focused ion beam microscope under vacuum conditions, (b) three-point bending in air using an atomic force microscope, and (c) nanoindentation tests on the circumference of the seta. Elastic moduli were found to depend strongly on the method of testing: Tensile testing in vacuum yielded an elastic modulus of 7.3 ± 1.0 GPa which was roughly five to six times higher than in bending and in nanoindentation tests at ambient conditions. The results are discussed in terms of the anisotropic nanostructure of the setae and humidity effects. They constitute valuable input parameters for optimizing the performance of artificial attachment devices.
A model to calculate the viscosity of silicate melts
Authors: Grundy A. Nicholas , Liu Honqin , Jung In-Ho , Decterov Sergei A. , Pelton Arthur D. 
Published: February 2009

AbstractA model has been developed that links the viscosities of silicate melts to their thermodynamic properties. Over the past several years, through critical evaluation of all available thermodynamic and phase equilibrium data, we have developed a quantitative thermodynamic description of multicomponent silicate melts using the Modified Quasichemical Model for short-range ordering. The local structure of the liquid, in terms of the bridging behavior of oxygen, calculated using our thermodynamic model allows us to characterize the structure of the liquid semi-quantitatively using the concepts of Q-species and connectivity of Q-species. The viscosity is modeled by optimizing viscosity parameters that are related to the structure of the liquid. The viscosity of pure liquid silica is modeled using four model parameters and every other unary liquid is modeled using two. The viscosity of all binary liquids is reproduced within experimental accuracy by optimizing one or at most two binary viscosity parameters for each system. In the present article the equations for the viscosity model are derived and analyses for the experimentally well-established systems CaO – SiO2MgO – SiO2, NaO0.5– SiO2, KO0.5– SiO2and AlO1.5– SiO2are presented. This is the first step in the development of a predictive model for the viscosity of multicomponent silicate melts that will be presented in part II.
A note on the application of the phase rule
Authors: Chen Shuang-Lin , Schmid-Fetzer Rainer , Chou Kuo-Chih , Chang Y. Austin , Oates William A. 
Published: February 2009

Abstract
When an equilibrium state contains degenerate phases, the number of independent phases must be considered in applying Gibbs' Phase Rule. This number can be derived from the rank of the matrix containing the coefficients of the Gibbs – Duhem equations. This provides a quantitative determination of the degrees of freedom even under such conditions of degeneracy.
Thermodynamic properties of liquid silver–indium–tin alloys determined from emf measurements
Authors: Jendrzejczyk-Handzlik Dominika , Gierlotka Wojciech , Fitzner Krzysztof 
Published: February 2009

Abstract
The thermodynamic properties of liquid Ag – Sn – In alloys were determined using solid oxide galvanic cells with zirconia electrolyte. The following galvanic cells were employed:
Re + kanthal, Ag
x
– In
y
– Sn(1−x−y
),(In2O3)s.s//ZrO2 + (Y2O3)//NiO, Ni, Pt(I)
in the temperature range from 973 to 1273 K, and in the range of indium mole fraction from 0.3 to 0.8.
This limitation was imposed by the side reaction between tin in the liquid alloy and solid In2O3. It was also found that the liquid is in equilibrium with the solid solution of oxides. Calorimetric measurements of the heat of mixing were also carried out at constant temperature 1003 K and along one isopleth with XAg/XSn = 1/1.
The thermodynamic properties of the liquid phase were described by the Redlich – Kister – Muggianu formula and the phase relations in the ternary system were calculated. The results of calculations were compared with the experimental data which are available from different literature sources.
Elastic properties of braided ceramic matrix composites
Authors: Tushtev Kamen , Koch Dietmar , Grathwohl Georg 
Published: February 2009

Abstract
Fibre reinforced ceramic components are most efficiently produced by the braiding technique. Since the braiding angle can be adjusted during the preform fabrication process in a wide range as required by the loading situation of the composite, the evaluation and prediction of the elastic properties as a function of variable braiding angles is of high importance. Based on the classical laminate theory an inverse method for the determination of the elastic properties of an equivalent unidirectional ply is elaborated and applied to predict the effect of variable braiding angles. Orthogonal and non-orthogonal braided carbon/carbon composites were tested under in-plane tensile and shear loading in order to validate the analytical concept. A very good correlation between theoretical and experimental results was obtained.
Hardfacing behavior of Cr–Ni stainless steel with Co-based super alloys
Authors: Nursoy Mustafa , Yaz Mehmet , Celik Halis 
Published: February 2009

Abstract
In this study, the hardfacing behavior of Cr – Ni stainless steel was studied by depositing of Stellite 1, Stellite 6, and Stellite 12 superalloys on Cr – Ni stainless steel specimens using electric arc welding and tungsten inert gas welding. The cobalt base alloys were hardfaced on stainless steel plates as a single layer. The samples taken from the hardfaced materials were studied by optical microscopy, scanning electron microscopy, X-ray diffraction, and microhardness measurements. The hardness and wear resistance values of the layer obtained after the hardfacing processes are satisfactory and the process seem to be suitable for application.
Development of SMD 32.768 kHz tuning fork-type crystals
Authors: Lee Sungkyu , Moon Yangho , Ahn Jae-Hwan , Chung Hyungsik 
Published: February 2009

Abstract
Taguchi' design of experiment method and statistical F-test were used to optimize design of tuning forks for use in Qualcomm® mobile station modem (MSM)-3000TM series central processing unit chips of code division multiple access, personal communication system, and global system for mobile communication systems. Design parameters for motional capacitance C1 was further optimized after much trial and error so that as-fabricated resonance frequency values of a tuning fork blank remain almost the same prior to final frequency adjustment plating of the mounted crystals, regardless of packaging pressure change from ambient to designated 6 × 10– 5 Torr. Finite element method modeling was used in conjunction with Taguchi' design of experiment method and, after much trial and error, this enabled selection of essential design parameters to effectively manufacture tuning fork test samples using photolithography with subsequent photoresist spray coating. The tuning fork test samples thus fabricated were characterized and analyzed using Taguchi' method and statistical F-test to evaluate sensitivity of motional capacitance C1 and as-fabricated resonance frequency for various design parameters at ambient to designated packaging pressure of 6 × 10– 5 Torr. Motional capacitance C1 is most sensitive to tine width and tine surface electrode width. Unlike as-fabricated resonance frequency values, motional capacitance values do change with vacuum level of the package. However, tine width asymmetry, electrode thickness and tine tip electrode thickness could be freely adjusted for crystal impedance level without affecting resonance frequency and motional capacitance value. Other design parameters could be adjusted to best suit the manufacturing process.
Quantification of ∊-martensite after thermocycling in Fe-(17∼25)Mn alloys
Authors: Murasov Mykhaylo , Duprez Lode , Van Humbeeck Jan 
Published: February 2009

Abstract
Fe-(17∼25)Mn alloys have been systematically investigated by means of X-ray diffraction, optical microscopy, differential scanning calorimetry and dilatometry. Such parameters of martensitic transformation as transformation temperatures, enthalpy, phase composition and microstructural changes are discussed taking into account the effect of thermocycling. A special focus is laid on the incompleteness of the γ → ∊ transformation that is attributed mainly to the antiferromagnetic → paramagnetic transition of austenite. The volume fraction of epsilon martensite has been determined using the results from X-ray diffraction and dilatometry tests.
Far infrared spectroscopy of Pb0.85Sn0.15Te alloy doped with Ni
Authors: Nikolić Pantelija M. , Vujatović Stevan S. , Golić Danijela Lukovic , Labus Nebojša J. , Paraskevopoulos Konstantinos M. , Zorbas Kostas T. , Nikolić Maria Vesna , Bojičić Aleksandar , Blagojević Vladimir , König Wolfgang 
Published: February 2009

Abstract
Far infrared reflectivity spectra of single crystal Pb0.85Sn0.15Te doped with Ni were measured in the temperature range between 10 K and 300 K. Analysis of the experimental spectra was made using a fitting procedure based on the modified model of plasmon-phonon interactions and the optical parameters were calculated. Two local modes were observed and their origin was discussed.
Experimental study on gallium activity in the liquid Ga-Bi-Sn alloys using the EMF method with zirconia solid electrolyte
Authors: Katayama Iwao , Živković Dragana , Novaković Rada , Yamashita Hiromi 
Published: February 2009

Abstract
The EMF of galvanic cells with zirconia solid electrolytes was measured to determine the activity of gallium in liquid Ga-Bi-Sn alloys in the temperature range of 1000–1250 K along three pseudo-binary lines of (Bi
y
, Sn1−y)-Ga where y = 0.25, 0.50 and 0.75. A mixture of Ga and Ga203 was used as a reference electrode. The activity curves of Ga show positive deviations from ideality in the whole composition range. The excess free energies of mixing for Ga-Bi-Sn alloys have been calculated using the general solution model in the same temperature range and along same pseudo-binary lines. The gallium activities obtained by the EMF method and calculated using the general solution model at 1100 K were compared with literature data.
Achieving ultra-fine grains in AZ61 Mg alloy by friction stir processing
Authors: Du Xinghao , Zhang Erlin , Wu Baolin 
Published: February 2009

Abstract
In order to obtain fine-microstructure magnesium alloys with superior mechanical properties, AZ61 alloy is processed by friction stir processing combined with rapid heat sinking in this study. Ultrafine-grain microstructure with average size less than 300 nm was observed in the resultant AZ61 alloy. The mean microhardness of the ultrafine-grain region reached 120 ∼ 130 HV, twice that of the AZ61 substrate. All these results demonstrate clearly that under a cooling rate high enough, ultrafine-grain structure in AZ 61 alloy with superior mechanical properties can be produced by one pass friction stir processing via dynamic re-crystallization.
The role of solidification conditions on the microstructural features of AA6111 aluminum strips cast on a horizontal single belt caster
Authors: Shabestari S. G. , Li D. , Isac M. , Guthrie R. I. L. 
Published: February 2009

Abstract
The effect of the thickness of strips and cooling rates on the macro- and micro-structural features such as grain size, secondary dendrite arm spacing, and intermetallic phases, were studied for AA6111 aluminum alloy cast on a simulator of a horizontal single belt strip casting process. Different strips were investigated. As strip thickness decreased from 2.49 mm to 0.55 mm, the grain size decreased about 56 % and secondary dendrite arm spacing decreased about 56.7 %. An equation was developed based on the results obtained via thermal analysis which relates secondary dendrite arm spacing to cooling rate in this process. The formation and behavior of various complex intermetallic compounds in AA6111 were studied using scanning electron microscopy. The compositions of the precipitates were analyzed using electron probe microanalysis and their most likely stoichiometries determined.
Thermographic analysis of AlSi12 during crystallisation as a function of cooling rate
Authors: Wulf Eric , Krause Christian , Bormann Dirk , Schaper Mirko , Becker Jörg August , Becker Verena , Bach Friedrich-Wilhelm 
Published: February 2009

Abstract
At the Institute of Materials Science of the Leibniz University of Hannover, investigations were carried out to better understand the crystallisation processes of the cast alloy AlSi12. Here, the influence of different cooling rates was investigated in-situ and ex-situ. The temperatures of the geometric specimens were determined during the experiment with the aid of a near-infrared camera and thermocouples. The aim was to both determine a function between the specimen' cooling rate and the speed of the solid – liquid interface as well as establish a relationship between the thermographic images and the solidification' morphology.
Correlation between heat treatment, microstructure and mechanical properties of a hot-work tool steel
Authors: Mayer Svea , Scheu Christina , Leitner Harald , Siller Ingo , Clemens Helmut 
Published: February 2009

Abstract
The mechanical properties of the hot-worked and tempered tool steel grade X37CrMoV5-1 were studied as a function of the heat treatment and, thus, microstructure. Based on the continuous cooling transformation diagram, different hardening processes had been chosen to achieve fully martensitic and mixed martensitic-bainitic microstructures with different amounts of bainite. Mechanical tests demonstrate that the fully martensitic microstructure exhibits the highest toughness and ductility over the entire temperature range, whereas the strength remains constant. Microstructural investigations, performed using scanning and transmission electron microscopy, show that the degraded mechanical properties are related to the presence of the bainitic microstructure as well as carbides at former austenite grain boundaries.
A combined microtensile testing and nanoindentation study of the mechanical behavior of nanocrystalline LIGA Ni–Fe
Authors: Schwaiger Ruth , Reszat Jan-Thorsten , Bade Klaus , Aktaa Jarir , Kraft Oliver 
Published: February 2009

Abstract
In this work, we studied nanocrystalline LIGA Ni-2.6 at.% Fe and Ni-5.6 at.% Fe with an average grain size of 10 nm. Microtensile samples were produced by the LIGA process including direct current electrodeposition. Microstructures and mechanical properties were investigated in the as-deposited state as well as after annealing at different temperatures. Results from tensile testing were compared to nanoindentation experiments with a particular emphasis on the strain rate sensitivity of the alloys. The Ni – Fe alloys were confirmed to be suitable LIGA materials for applications that require high hardness combined with microstructural stability and low internal stresses. For both alloys with 10 nm grain size, tensile yield strength and corresponding hardness values of the order of 2 GPa and 6 GPa, respectively, were found. After annealing at moderate temperatures (200 °C), strength and hardness increased although some grain growth was observed.
Microstructure evolution during a liquid–liquid decomposition under the common action of the nucleation, growth and Ostwald ripening of droplets
Authors: Zhao J. Z. , Li H. L. , Zhang X. F. , He J. , Ratke L. 
Published: February 2009

Abstract
The kinetic details of the microstructure evolution during a liquid – liquid phase transformation under the common action of the nucleation, diffusional growth and Ostwald ripening of the minority phase droplets are investigated numerically. The results demonstrate that the cooling rate during the nucleation period of the minority phase droplets has an overwhelmingly strong effect on the microstructure formation compared with the cooling rate after the nucleation period. Generally, the effect of the Ostwald ripening of the minority phase droplets is weak in an alloy cooled continuously all through the miscibility gap and the average radius of the minority phase particles shows an inverse square root dependence on cooling rate. An obvious coarsening of the minority phase droplets occurs and the exponential varies towards – 1/3 only when the cooling rate decreases by more than two orders of magnitude after the nucleation of the precipitated droplets.
Bainite orientation in plastically deformed austenite
Authors: Shirzadi A. A. , Abreu H. , Pocock L. , Klobčuar D. , Withers P. J. , Bhadeshia H. K. D. H. 
Published: February 2009

Abstract
Experiments have been conducted to see whether specific crystallographic variants of bainite form in polycrystalline steel when transformation occurs from plastically deformed austenite which is otherwise free from externally applied stress. It is demonstrated by studying both overall and microtexture that there is no perceptible variant selection as bainite forms. Indeed, the texture is found to weaken on transformation.
Oxidation behaviour of experimental Co–Re-base alloys in laboratory air at 1000°C
Authors: Klauke Michael , Mukherji Debashis , Gorr Bronislava , da Trindade Filho Vicente Braz , Rösler Joachim , Christ Hans-Jürgen 
Published: February 2009

Abstract
The oxidation behaviour of experimental Co – Re-based alloy at 1000 °C was studied. A set of binary, ternary and quaternary alloys from the Co – Re – Cr – C system was used as model alloys to understand the role each alloying element plays on oxidation. The morphology and composition of the oxide scale that formed was analysed by X-ray diffraction, energy dispersive spectroscopy and scanning electron microscopy. It was found that the present Co – Re alloys with 23 at.% and 30 at.% Cr additions behaved very similarly to Co – Cr binary alloys with equivalent Cr content. The oxide scale was multilayered, consisting of a dense CoO outer layer, a porous mixed oxide layer containing Co-oxide and Co – Cr spinel, and a discontinuous and non-protective Cr3O2 layer. The binary Co – Re alloy behaved differently in oxidation, and it formed only a monolithic CoO scale. However, Re in combination with Cr promotes Cr – Re-rich phase formation, which oxidises preferentially compared to the Co matrix. Carbon ties up part of the Cr to form Cr23C6 type carbides. However, these carbides are not stable at 1000 °C and dissolved with time, therefore C had only a minor role in the oxidation behaviour. In general, increasing Cr content in the alloy improved oxidation resistance.
High-speed Melt Spinning of Nanoparticle-filled High Molecular Weight Poly(ethylene terephthalate)
Authors: Jang K. H. , Kim B. C. , Hahm W. G. , Kikutani T. 
Published: February 2009

Abstract
High molecular weight poly(ethylene terephthalate) (HMW-PET) (intrinsic viscosity of 0.809 dL/g) and its nanocomposites with 1 wt.% organoclay C12PPh-Cl− and 1 and 2 wt.% trisilanol isobutyl-poly(hedral oligomeric silsesquioxane) (POSS) were high-speed melt spun over the range of take-up speeds 1 to 4.5 km/min, and the effects of nanoparticle type on the fiber properties were investigated. The clay and POSS nanocomposites exhibited quite different melt spinning behaviors. The neat PET and PET/POSS nanocomposites showed a neck-like deformation distinctly from the take-up speed of 3.5 and 3 km/min while PET/clay nanocomposites did not show any neck-like deformation over the entire spinning speed range. In comparison with nanocomposite chips clay gave rise to re-aggregation of nanoparticles whereas POSS made little change in dispersion. Clay suppressed the crystallization of PET during high-speed spinning although it had more effective nucleation effects at the static state than POSS. Clay nanocomposite fibers gave lower modulus and higher elongation at break than PET fibers. On the other hand, the mechanical properties of POSS nanocomposite fibers were almost equal or slightly better than PET fibers.
Investigation of the Effects of Formulation and Processing Parameters on Properties of PA 6 Nanocomposites using Taguchi Method of Experimental Design
Authors: Moghri M. , Garmabi H. 
Published: February 2009

Abstract
In this work, the effect of processing conditions and nanoclay (NC) content on formation and various properties of polyamide 6 (PA 6) nanocomposites was studied by means of Taguchi method of experimental design. PA 6/organoclay nanocomposites were prepared by melt mixing of PA 6 at different organoclay loadings using a co-rotating twin-screw extruder. In order to investigate the effects of both processing conditions and organoclay content on silicate dispersion (exfoliation) and thermal and mechanical properties of the nanocomposites, different extrusion rates, processing temperatures and feeding rates at various NC loadings were used. X-ray diffraction (XRD) was used to characterize the formation of nanostructure and clay dispersion. The thermal properties of PA 6 nanocomposites were studied through TMA tests. XRD results revealed the formation of nanocomposite and evidenced that the samples exhibit mixed intercalated / exfoliated morphology and verified that, the extent of exfoliation increases with both clay content and extrusion rate used. The mechanical properties of PA 6 nanocomposites were studied using tensile tests. The strength and modulus of PA 6 nanocomposites were improved significantly by increasing the clay concentration and shear rate level.
A Two-level Decomposition Method for Cooling System Optimization in Injection Molding
Authors: Yu D. , Wang X. , Wang Y. 
Published: February 2009

Abstract
The cooling system of a plastic injection mold plays a crucial role in determining both the productivity of the injection molding process and part quality. The cooling process is an important phase of injection molding, which could account for more than three-fourths of the total molding cycle time. Thus, an efficient cooling will significantly improve productivity by reducing the cooling time, and uniformity and balanced cooling can ensure part quality by preventing sink marks, different shrinkage, internal thermal residual stress and warpage.
In this paper, the geometric parameters (i. e., radius and location of each cooling channel) and process parameters (i. e., inlet coolant temperature, volumetric flow rate of each cooling channel, packing time, and cooling time, etc.) are considered systematically in the cooling system design of injection molding. A two-level decomposition method for the cooling system optimization is proposed. The optimization problem is divided into two subproblems (cooling channel design and process design) on the basis of the different effects on refrigerant behaviour of different kinds of design variables. By combining the Kriging model and CAE technology, a mold cooling system for a 15-inch display was optimized. The results show that the method can efficiently improve the temperature distribution and the part quality.