bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Characterization of Chemical Activated Fibers on Various Carbon Fibers
Authors: Moon Sook Young , Kim Myung Soo , Lim Yun Soo
Published: March 2009

OXI-PAN fibers, Kynol fibers, and rayon fibers were used as precursors for the
preparation of activated carbon fibers (ACFs) by chemical activation with KOH at 800°C. The effects of different precursor fibers and fiber/KOH ratios on the final ACFs are discussed. The precursor fibers used were appropriate for the ACFs in a single stage pyrolysis process. The OXI-PAN fibers, which were activated with KOH of 2.0M, showed a specific surface area of 2328m2/g, however, lost the fiber shape because of low yields. The Kynol fibers and Rayon fibers
showed the high yields, but lower specific surface areas of 900m2/g and 774m2/g, respectively, at KOH of 1.5M. The OXI-PAN fibers, which were activated with KOH of 1.5M, have a specific surface area of 1028m2/g and higher micro-pore volumes and lower yields rather than Kynol-1.5 and Rayon-1.5 samples. This phenomenon is attributed to higher chemical resistance of the Kynol and Rayon fibers rather than OXI-PAN fibers. However, the Kynol fibers were the best precursors
on KOH activation at 800°C when carbon yields, surface areas, and micropore volumes are condisered.
Oxidation Resistance of Nanocrystalline Microalloyed γ–TiAl Coatings under Isothermal Conditions and Thermal Fatigue
Authors: Wendler Bogdan , Kaczmarek Łukasz , Jachowicz M. , Rylski A.
Published: March 2009

γ-titanium aluminide a promising structural material for automotive and aircraft
applications at high temperatures suffers from poor gas corrosion resistance. It has been proved in this work by means of microthermogravimetry and SEM, EDS, EBSD and X-Ray diffraction carried out and under isothermal conditions and thermal cycling that a great improvement of the oxidation resistance of this material can be achieved due to magnetron sputtered coatings of γ-TiAl with vatious additions (Ag, Cr, Mo, Nb, Si or Ta) or their combinations. The oxidation rate of some of
these coatings is four orders of magnitude smaller than that of the bare γ-TiAl substrate.
The Design and Characteristics of a Novel Ultrasonic Motor
Authors: Lim Kee Joe , Kwon Oh Deok , Park Cheol Hyun , Lee Jong Sub , Kang Seong Hwa
Published: March 2009

In this paper, the design and characteristics of a novel ultrasonic motor which is
applicable to optical zoom or auto focusing operation of lens system for mobile phone are
investigated. Its design and simulation of performances are carried out by FEM (Finite Element
Method) commercial software. The shape of the motor is like square without one side, which is able
to insert optical lens. Two sheets of piezoelectric ceramic are fixed to both sides of the two legs of
an elastic body, respectively. To drive the ultrasonic motor, the voltage is applied to the two sheets
of piezoelectric ceramic bonded to one leg. The rotation direction can be easily changed by
switching the applied voltage to the piezoelectric sheets bonded to the other legs. The proto type of
motor is fabricated and its outer size is 10*10*2 mm3 including the camera lens of which the
diameter is 7.5 mm. Its power consumption is about 0.3 W and the rotation speed is adjustable from
10 to 200 rpm according to the applied voltage.
Concrete Products with Waste's Plastic Material (Bottle, Glass, Plate)
Authors: Pezzi L. , De Luca Pier Antonio , Vuono D. , Chiappetta F. , Nastro Alfonso
Published: March 2009

Plastic material is not easily biodegradable even after a long period, in fact a wide variety
of waste materials can be utilized as inert in matrix cement.
In this paper we have focused the attention on the use of plastic material particles incorporated as
aggregate in concrete and we have evaluated the chemical, physical and mechanical properties
The Ion Conducting Properties of Perovskite-Type Solid Solutions (La0.5Li0.5) [Ti1-x(M0.5Nb0.5)x]O3 (M = Al, Ga)
Authors: Fortalnova Elena A. , Mosunov Alexander V. , Safronenko Marina G. , Venskovskii Nikolay U. , Politova Ekaterina D.
Published: March 2009

The influence of B-site substitution on electroconducting properties of perovskite-type solid solutions (La0.5Li0.5)[Ti1-x(M0.5Nb0.5)x]O3 with M = Al, Ga, have been studied. A decrease in the conductivity due to the unit cell contraction with increasing x in case of M = Al has been revealed. In case of Ga and Nb substitutions for Ti the unit cell volume has been found to increase with increasing x while the conductivity decreases due to the impurity phases presence. The high
and low temperature anomalies on the temperature dependences of dielectric characteristic related to both the relaxation effect and phase transitions have been revealed.
Fatigue Notch Sensibility of Thermoplastic Glass Fibre Composites
Authors: Reis Paulo N.B. , Ferreira José A. Martins , Antunes Fernando , Costa José Domingos M.
Published: March 2009

This paper is concerned with a notch sensibility study of a thermoplastic composite
produced from a bi-directional woven E-glass fibres and polypropylene. Experimental tests were performed in three points bending using notched and unotched specimens of polypropylene glass fibres reinforced laminates to evaluate flexural properties and fatigue behaviour. Fatigue results were plotted as the stress range against the number of cycles to failure. The fatigue damage was
measured in terms of the stiffness loss. The testes carried out using notched specimens present lower values of both static and fatigue strengths than the unnotched specimens tests.
Foaming around Fastening Elements
Authors: Duarte Isabel M. A. , Banhart John , Ferreira Antonio , Santos Mário J.G.
Published: March 2009

The aim of this work was to improve the joining between the fastening elements and the aluminium alloys foams. The research work was carried out on joining fastening elements into aluminium alloy foams during the foaming process, i.e., foaming around fastening elements. The foamable precursor material was produced by hot pressing the powder mixture of metal and a small fraction of the blowing agent. A steel mould containing a foamable precursor material and the fastening elements were heated to temperatures above the melting point of metallic matrix of foamable precursor material in order to obtain the final specimens. Each aluminium foam specimen
(6061 and AlSi12) has 200x80x80mm and contains two fastening elements. The steel moulds design, the fastening elements geometry, the aluminium alloy composition, as well as the foaming parameters were studied in order to optimise the quality of the joints produced. The quality of the joints were determined by means of visual inspection and mechanical tests.
Narrow Diameter Carbon Nanotubes (CNTs) for Polymer Composite Reinforcement
Authors: Norani Muti Mohamed , Chech Tan Yee , Masrom Abdul Kadir
Published: March 2009

Strong and versatile carbon nanotubes are finding new applications in improving conventional polymer-based fibers. Nanotube-reinforced composites could ultimately provide the foundation for a new class of strong and lightweight fibers with properties such as electrical and thermal conductivity unavailable in current fibers. A recent research has discovered that the best type of nanotube for polymer composite reinforcement is the small diameter multiwalled nanotubes (MWNTs). Here, a catalytic technique has been developed to produce narrow diameter bulk multiwalled carbon nanotubes of less than 38 nm. Structural characterizations including scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), thermo gravimetric analysis (TGA) and Raman spectroscopy conducted on CNTs grown on three different catalysts, namely iron, cobalt and nickel have indicated that the catalyst used affects their sizes and crystallinity. Results showed that the smallest CNTs could be obtained by catalytic growth on Ni catalyst. The study has proven that with the skillful use of catalyst, a range of narrow sized nanotubes could be produced, providing the material needed to investigate the optimum diameter for the best mechanical reinforcement of polymer composites.
Surface Morphology of Anatase TiO2 Thin Film by Sol-Gel Method
Authors: Al-Jufairi N.
Published: March 2009

Sol-gel processing route has been used for the production of thin films from titanium isopropoxide (TIP). The surface properties and statistics results have been characterized by AFM; the coating process has been examined using SEM and optical microscope. The structure phase of TiO2 has been analyzed by XRD; the composition of TiO2 has been estimated through EDS; the thickness of film has been measured by polarized microscope in an interferometric technique. The coating films are always crystallined in the anatase structure with circular particles in nanometer size.
Temperature Variation Effects on Current-Voltage (i-v) Characteristics of n-GaN Schottky Diode
Authors: Munir Tarriq , Aziz Azlan Abdul , Abdullah Mat Johar , Mahmoud Ahmed Naser
Published: March 2009

We focus in this paper the temperature variation effects on the current – voltage ( I-V) characteristics of n-GaN schottky diode. The diode was doped with carrier concentration 1*1013cm-3 and Pt electrode was used. The simulated current were obtained at temperatures from 50K to 500K and voltage up to 2Volt. We use the Srh (Schokley read hall), Cvt (Lombardi Model), Auger (Auger), Fermi (Fermi Dirac), Impact, Bgn (Bandgap Narrowing), Complete ioniz model to get the schottky rectifying current – voltage (I-V) characteristics.. We find that by increasing the temperature from 50K to 500K, the forward schottky rectifying current decreases from 2.7187 Amp to 0.383 Amp. while the forward turn – on voltage decreases. In reverse bias at low temperature the current is high and we increase the temperature the current decreases. The breakdown voltage decreases at higher temperature.
Interfacial Structures Developed by Firing Metal-Ceramic Dental Systems
Authors: Daróczi Lajos , Hegedűs C. , Kökényesi V. , Beke Dezső L.
Published: March 2009

Metal-ceramic systems play very important role in the prosthetic dentistry. The most widely used metallic alloys are the Ni-Cr, Co-Cr, Au-based alloys and Ti. The bonding strength between the metal base and the ceramic covering layer can be very different in different systems and is strongly affected by the firing conditions as well. For the further improvement of the bonding properties the detailed knowledge of the microstructure of the metal–ceramic interlayer is essential. In this work our results, obtained by scanning and transmission electron microscopy on systems of commercial alloys and corresponding porcelains will be reviewed.
Rare Earth Doped Y2O3:RE3+ (RE= Eu, Tm and Tb) Powder Phosphors Prepared by Microwave Heating Technique
Authors: Ishak Izdihar , Daud Alias
Published: March 2009

A simple microwave heating system was designed for firing phosphor samples. An 800W magnetron operating at 2.45 GHz was used. The system is capable of reaching 1200oC in less than three minutes with the help of SiC succeptor. The synthesis technique prior to the microwave heating is described. The results indicate that the samples start to crystallize after 5 minutes. The X-Ray diffraction (XRD) data indicates that the sample is polycrystalline and acquires the host structure. The Photoluminescence (PL) and Photoluminescence Excitation (PLE) spectra for the powder phosphor prepared show similar results as those prepared using the conventional method. The Y2O3 powder samples doped with Eu show strong red emission at 630nm, the Tb doped samples show a strong green emission at 550nm and Tm doped samples shows blue emission at 460nm. The Scanning Electron microscope (SEM) picture taken show that the crystal size of the microwave irradiated samples was smaller in comparison to those prepared using the conventional method. This may be due to shorter heating time. These results indicate that the microwave heating technique is a reliable, fast and suitable technique to produce these powder phosphors. The characteristics of the phosphors are as good as those prepared using the conventional heating technique.
The Study of Thermal Treatment on Electrical Properties at Cr/p-GaN
Authors: Tan C.K. , Aziz Azlan Abdul , Zainuriah Hassan , Yam F.K. , Lim C.W. , Hudeish A.Y.
Published: March 2009

The barrier height of as-deposited Cr contacts was found to be ΦB= 0.87eV with the ideality of η=1.51 and remained almost unchanged after further annealing at 500 oC for 5 minutes. The barrier height of diodes were increased drastically after annealed at 600 oC where ΦB=1.01eV with η=1.69. Upon annealing at 700 oC for 5 minutes, the ΦB decreased to 0.61eV and the Cr diodes were degraded for higher temperature in this annealing duration. The ΦB remained in 0.80- 0.90eV respectively at 800 oC for 2 minutes and 900-1000 oC for 1 minute.
Photovoltaic Properties of Semiconductor (ZnSe)/Polymer (PEO - Chitosan Blend) Junction for Solar Cells Applications
Authors: Mohamad S.A. , Ali M.H. , Ibrahim Z.A. , Arof A.K.
Published: March 2009

The properties of ZnSe/PEO junction photoelectrochemical cells have been
studied under dark and illuminated conditions. ZnSe was electrodeposited onto an
indium tin oxide (ITO) glass and the polymer film of PEO-chitosan: NH4I (+I2) was placed
over it followed by another ITO glass. The polymer film was prepared by the solution
cast technique. The open circuit voltage (Voc) of the fabricated cells was between 300
mV to 400 mV. In the dark the device operates as a diode while under illumination it
operates as a photoelectrochemical cell.
Growth and Characterization of Ga2O3 Nanoribbons and Nanosheets
Authors: Kim Hyoun Woo
Published: March 2009

We have studied on the use of a GaN powders for growing gallium oxide (Ga2O3) nanoribbons and nanosheets by the thermal evaporation technique. We used x-ray diffraction, scanning electron microscopy, and transmission electron microscopy to characterize the samples. The results showed that the produced Ga2O3 nanomaterials had single crystalline monoclinic structures. The proportion of wider nanoribbons or nanosheets to nanoribbons increased by increasing the growth temperature and by employing the mixture of GaN and ZnO powders.
Structural Study of In2O3 Structures Grown by the Metalorganic Chemical Vapor Deposition
Authors: Kim Hyoun Woo , Myung Ju Hyun , Lee Chong Mu
Published: March 2009

We have synthesized the film-like and rod-like structures of indium oxide (In2O3) by metalorganic chemical vapor deposition (MOCVD) method. The structural morphology of the deposits changed from the film to the arrays of 1-dimensional (1-D) materials with increasing the deposition temperature. The 1-D materials with the serrated surfaces prepared at 350°C possessed a crystalline cubic structure and had preferentially grown along the [111] direction.
Annealing Effects on GaN/ZnO/Si Structures Prepared by RF Magnetron Sputtering
Authors: Kim Hyoun Woo , Shim S.H. , Lee C.
Published: March 2009

This study shows the effect of thermal annealing on GaN/ZnO/Si structures prepared by rf
magnetron sputtering. Thermal annealing tended to induce a different crystalline orientation from the
c-axis orientation observed with as-deposited films. The sample annealed at 900 oC under excitation
at 325 nm showed two emission bands centered at approximately 380 and 550 nm.
Analysis of SiO2 Thin Film Deposited by Reactive Sputtering
Authors: Radović I. , Serruys Yves , Limoge Yves , Jaoul Olivier , Romčević N.Ž , Poissonnet S. , Bibić N.
Published: March 2009

SiO2 layers were deposited by reactive d.c ion sputtering (using 1keV Ar+ ion gun) from a
high purity silicon target in an oxygen ambient. The base pressure in the deposition chamber was
4.7·10-9mbar, and the substrate temperature was held at 550 °C. The argon partial pressure during
ion gun operation was 1·10-3mbar. Structural characterization of the films was performed by
Rutherford backscattering spectrometry (RBS analysis), electron microprobe analysis, X-ray
diffraction (XRD analysis) and Raman spectroscopy. Reactive sputtering proved to be efficient for
the deposition of silica at an oxygen partial pressure of 2·10-4mbar and an electrical current on the
target of 5.5mA.
Advanced Ways and Experimental Methods in Self-Propagating High-Temperature Synthesis (SHS) of Inorganic Materials
Authors: Kuznetsov Maxim V. , Parkin Ivan P. , Kvick A. , Busurin S.M. , Shishkovskiy I.V. , Morozov Yuri G.
Published: March 2009

New experimental methods for investigations of phase formation during SHS have been established. First experiments using penetrating synchrotron radiation and energy dispersive detectors for different classes of complex inorganic materials were carried out at ESRF (Grenoble, France) and Daresbury (UK). A new and very sensitive thermal imaging method (Thermal Imaging Technique (TIT)) based on continuous registration of the whole combustion process by using highly sensitive IR-camera and software developed by MIKRON Instruments Co. (USA) was used for precise registration of the combustion parameters. SHS was performed on different types of pure and doped complex inorganic materials in pellet and powder form in a range of dc magnetic fields up to 20 T and in electrical field strengths up to ±220 kV/m. The dc magnetic field was applied during the reaction, supplied either by a permanent magnet (transverse, up to 1.1 T) or by an electromagnet (longitudinal, up to 20 T). The dc electrical field was applied along the direction of the combustion wave front propagation. The combined processes of SHS and SLS (Selective Laser Sintering) of 3D articles for different powdered compositions were optimized with laser irradiation power.
Mechanism of Consolidation of Nanoparticles in Diamond-Boron Oxide System at High Pressure and Temperature
Authors: Bykov A. , Oleynik G. , Ragulya A. , Timofeeva I. , Klochkov L. , Kovalev A.
Published: March 2009

The high pressure sintering process of nanocrystalline diamond powder was studied. The
influence of the liquid phase on the base of boron oxide was analyzed. The mechanism of
cooperative-diffusive coalescence, which acts during sintering of ultradisperse diamond powders, is
proposed.
Influence of External Factors on Amorphous and Nanocrystalline Soft Magnetic Alloys Studied by Mössbauer Spectroscopy
Authors: Degmová Jarmila , Sitek J. , Bednarčík J.
Published: March 2009

In this paper, a review of recent 57Fe Mössbauer spectroscopy (MS) studies of external
influence on the properties of amorphous and nanocrystalline Fe- and Co-based alloys is submitted.
Different types of alloys (FeCuNbZr, FeCuNbSiB, FeCoCuNbB, CoFeZrB and CoFeSiB) in the
form of original amorphous and nanocrystalline ribbons were subjected to different external factors:
different annealing atmospheres, mechanical stress (for example influence of ball-milling) and
tensile stress. It will be shown that the Mössbauer spectrometry is a suitable tool for such studies
because the measured spectral parameters are very sensitive to the changes in the vicinity of the
probe 57Fe-nuclei and thus, this technique provides a wide variety of information about structural
and magnetic behavior of Fe-containing materials.
Microscopic Studies of the GC/Poly-NiTMHPP/Nafion Electrochemical Nitric Oxide Sensor
Authors: Macherzynski M. , Kowal A. , Macherzynska B. , Gołas J.
Published: March 2009

Glassy carbon (GC) discs and platinum microcylindrical electrodes were modified with a
layer of nickel(II) tetrakis 3-methoxy-4 hydroxyphenyl porphyrin (poly-TMHPP-Ni) of different
loadings (Γ) between 0.6 and 10 nmol/cm2, and subsequently with a Nafion layer. The topography
and in some cases the thickness of films were measured by means of contact mode AFM. SEM and
optical microscopy observations were used for the comparative studies on a larger scale. The useful
range of the coverage with modifying polymer was investigated. The optimal value of loading for
the sensor was found to be in the range of 6-8 nmole of poly-TMHPP-Ni per cm2. We observed the
Nafion layer uniformity in nanometric scale.
Electrooxidation of Hydrogen on Nanostructured Pt/C Catalysts for Polymer Electrolyte Fuel Cells
Authors: Babić B. , Radmilović Velimir , Krstajić N. , Kaludjerović B.
Published: March 2009

Mesoporous carbon cryogel synthesized by sol-gel polycondensation and freeze-drying with specific surface area (BET) of 517 m2 g-1 was used as a catalyst support. Pt/C catalysts were prepared by a modified ethylene glycol method (EG). Transmission electron microscopy (TEM) images show that the dispersion of the catalyst is very uniform with a mean particle size of about 2.65 nm. Hydrogen oxidation reaction (HOR) was studied on Pt/C catalyst in 0.5 mol dm-3 HClO4 acid solution. It has been found that HOR appears as a reversible two-electron direct discharged reaction (Tafel slope for this reaction is ≈30mV dec-1) and that Pt/C catalyst exhibits a very high catalytic activity. However, the corresponding value of the exchange current density obtained by dividing the exchange current by the active surface area of Pt particles has the same order of magnitude as those for the HOR in acidic solution at single crystal and polycrystalline Pt.
Oxygen Reduction on Carbon Cryogel-Supported Pt Nanoparticles in Acid Media
Authors: Gajić-Krstajić Lj.M. , Trišović T.Lj. , Babić B. , Vračar Lj.M.
Published: March 2009

The kinetics of oxygen reduction (ORR) on carbon cryogel supported Pt nanoparticles (Pt
/ C) in acid solution was studied using the rotating disk electrode technique. This electrocatalyst
was prepared by a modified polyol synthesis method and characterized by transmission electron
microscopies. The kinetics of ORR shows a significant enhancement at Pt nanoparticle surfaces as
compared with the same reaction on polycrystalline Pt surface. The four-electron reduction, with a
first-charge transfer-rate determining step, has been found to be operative. However, the specific
activity of the Pt / C is similar to that of the polycrystalline Pt electrocatalyst.
Thermodynamic Modelling of Boron Nitride Formation in Thermal Plasma
Authors: Radić-Perić J.
Published: March 2009

The synthesis of solid BN in thermal plasma is investigated theoretically by computing the
equilibrium composition of a gas mixture containing boron, nitrogen, hydrogen and argon. The
calculations are done for the temperature range between 500 and 6000 K and the total pressure in
the system of 1 bar. They are based on the fact that thermal plasma is in local thermodynamic
equilibrium, which makes possible theoretical determination (by employing the Gibbs free energy
data for the compounds present in the system) of its equilibrium composition. From the calculated
compositions of investigated gas systems, the temperature zones with saturated and/or oversaturated
vapour of B and B2N are determined and the formation mechanism of BN in solid state is proposed.
Interpreting of XPS C1s Binding Energies in Silicon Containing Polymers and Nanoparticles
Authors: Hoffmann E.A. , Korugić-Karasz Lj.
Published: March 2009

A method for predicting XPS C1s binding energies in polymers has been developed
previously [1]. The calculation uses partial atomic charges determined quantum chemically (by the
semi-empirical AM1 Method), which are found to provide a linear correlation with the binding
energies corrected by the so-called Madelung intramolecular potential. We used this method
successfully for interpreting XPS spectra of partially degraded fluoropolymers [2]. In the current
contribution we investigate the possibility of developing a similar equation to describe siliconcontaining
polymers that are medically and technologically important, and also some nanoparticles
based on organo-silicon compounds.
Mechanical Oscillations and Charge Carriers in Nanostructures
Authors: Tošić B.S. , Šetrajčić J.P. , Sajfert V.D. , Vučenović S.M. , Mirjanić D.Lj. , Jaćimovski S.K.
Published: March 2009

The Green’s functions technique suitable for broken symmetry structure analysis was developed. With the help of this new technique the phonon subsystem was analysed in ultrathin films and in cylindrical nanotubes with finite height. The most interesting results of mentioned analyses are spatial dependence of thermodynamical characteristics, existence of phonon gap and extremely low specific heat and thermal conductivity at low temperatures. This promises wide application of films and finite nanotubes in technology. The same technique was applied to investigate electron subsystems in rectangular nanostructures of all dimensions as well as in simple and full nanotubes. The most interesting conclusion of these analyses is the presence of autoreduction effect being the consequence of nonisomorphic transition configuration – momentum space. This effect represents a qualitative difference between nano and macroscopic structures. The skin effect is present in all types of nanostructures except nano-parallelepiped where antiskin effect takes place. The latter is quite understandable, since in nano-parallelepiped nodes are on boundaries.
Influence of Fullerenol C60(OH)24 on Doxorubicin Induced Cardiotoxicity in Rats
Authors: Djordjević-Milić V. , Djordjević A. , Dobrić S. , Injac Rade , Vučković D. , Stankov Karmen , Dragojević-Simić V. , Suvajdžić Lj.
Published: March 2009

Earlier investigation of fullerenol, C60(OH)24, features, in vitro, showed that fullerenol
have strong antioxidative potential. In this work, we examined the influence of fullerenol as a
potential antioxidative protector on doxorubicin induced cardiotoxicity in rats. Experiments were
performed on adult Wistar rats, both gender. Animals were divided into six groups, each containing
eight individuals. Doxorubicin was administrated i.v. (tail vein) in single dose of 8mg/kg.
Fullerenol C60(OH)24 in treated animals was administrated i.p. (in doses 50, 100, 200 mg/kg) for 30
min. before application of doxorubicin. Control group (intact animals) was given saline (1 mL/kg).
One group was treated only with fullerenol (100 mg/kg i.p.). Cardiotoxicity of doxorubicin as well
as cardioprotective effects of fullerenol were evaluated following the heart function monitored by
ECG recording during adrenalin i.v. infusion, and pathomorphological examination of the heart
tissue. These evaluations were performed on the day 2 and 7 after doxorubicin administration. Both
functional and pathomorphological investigations revealed no heart damage two days after given
treatments. However, on the day 7 after doxorubicin injection, changes in cardiovascular reflexes to
adrenalin as well as structural damage were manifest. The time for appearance of adrenalin-induced
reflex bradicardia in ECG record was significantly longer in doxorubicin treated group in
comparison with the control one. Also, pathomorphological examination of the heart tissue showed
vacuolization of cardiomyocites. In fullerenol pretreated groups these described changes were
ameliorated and corresponded to the control values. These results suggest that fullerenol might be
potential cardioprotector in doxorubicin treated individuals.
Modeling of a Plasma Etcher for Charging Free Processing of Nanoscale Structures
Authors: Radmilović-Radjenović M. , Nina Aleksandra , Strinić A. , Stojanović V. , Nikitović Željka , Malović G.N. , Petrović Z.Lj.
Published: March 2009

Neutral beam etching is proposed as a candidate for reducing plasma-process-induced damage in nanoscale devices. In this paper, neutralization of ion beams due to both gas phase collisions and ion surface interactions based on a PIC (Particle in Cell) simulation of realistic Capacitively Coupled Plasma is presented. It was found that a satisfactory degree of neutralization might be achieved by a combined effect of charge transfer and surface collisions.
Ferricoxychloride and Hematite Nanoparticles: Synthesis and Phase Transformation
Authors: Marinović-Cincović M. , Wang Guillaume , Fedoroff Michel , Šaponjić Z.V. , Milonjić S.K. , Nedeljković J.M.
Published: March 2009

A synthetic procedure based on thermal hydrolysis of iron(III) chloride solutions for the
preparation of hematite (α-Fe2O3) and ferricoxychloride (FeOCl) colloids consisting of
nanoparticles (NPs) is described. Transmission electron microscopy indicated that both colloids
consisted of particles smaller than 10 nm. X-ray diffraction measurements revealed transformation
of FeOCl NPs into α-Fe2O3 NPs after a few months. The phase transformation was explained in
terms of redissolution – recrystallization process. UV-vis spectroscopy was used for precise
determination of the band gap of α-Fe2O3.
Experimental Analysis of Toughness in 6156 Al-Alloy Sheet for Aerospace Applications
Authors: Morgeneyer T.F. , Starink Marco J. , Sinclair I.
Published: March 2009

Analysis of toughness in 6156 Al-Mg-Si-Cu sheet has been performed using enhanced
Kahn tear tests on samples quenched at different rates, whilst microstructures of the samples have
been assessed using differential scanning calorimetry, scanning electron microscopy and
transmission electron microscopy. Crack initiation energies were unaffected by changing water
quench temperature from 20°C to 60°C, however a significant reduction was evident on air cooling.
Crack propagation resistance was reduced for both 60°C water quenched and air cooled materials.
The failure morphology of the air cooled material appears consistent with classical intergranular
ductile failure. Coarse voiding and shear decohesion was prevalent in the 20°C water quenched
material, whilst the 60°C water quenched material showed a mixture of transgranular and
intergranular fracture modes. Changes in microstructure and precipitation behaviour resulting from
reduced quenching rate were identified and related to the observed fracture behaviour, particularly
in terms of precipitate free zone formation and the simultaneous presence of coarse particles at
grain boundaries.
Influence of Strain Rate on Shear Localization during Deformation and Fracture of 5754 and 5182 Aluminium Alloy
Authors: Hadianfard Mohammad Jaffar , Worswick Michael J.
Published: March 2009

The effect of strain rate in the range of 10-4 to 10-1 s-1 on localization of deformation and
fracture behavior of 5754 and 5182 aluminum alloys is investigated. For this study, tensile tests,
interrupted tensile tests, shear band decoration, fractography and image analysis has been used. This
investigation is based on experimental work and observation of the material behavior. Results show
that strain rate has some effect on the mechanical properties and deformation stability of the alloys.
The area of localized plastic deformation and thickness of the shear bands were found to be
sensitive to the strain rate. It was also observed that localization of plastic deformation and shear
band formation is an important step in the damage propagation and final fracture of the alloys.
Detail of damage development, based upon micrographs of samples interrupted at different stages
of straining is presented
Interfacial Microstructure of Magnetic Pressure Seam Welded Al-Fe, Al-Ni and Al-Cu Lap Joints
Authors: Watanabe Mitsuhiro , Kumai Shinji , Aizawa Tomokatsu
Published: March 2009

A new welding method, magnetic pressure seam welding, was used to lap join dissimilar
metals (Al-Fe, Al-Ni and Al-Cu). The circuit for magnetic pressure seam welding consists of a
capacitor, an electric discharge gap switch, and a plate-type coil. The overlapped metal plates are
placed over the coil. When an impulse current from an energy-storage capacitor bank passes through
the coil, a high-density magnetic flux is suddenly generated around the coil. The generated
high-density magnetic flux lines cross the end of the overlapped plates. Eddy currents are induced
mainly inside the Al plate because it has a high electrical conductivity. Both the Joule heat generated
in the plates and the magnetic pressure applied from the Al side promote the joining of the lapped
plates. The welding is normally achieved within 10 μs. This results in very little microstructural
change in the parent plates aside from the area around the weld interface. Strong lap joints were
obtained for every metal combination and no tensile fracture took place in the weld region. A
characteristic wavy morphology was observed at the weld interface. An intermediate phase layer was
also observed at the weld interface. TEM observation revealed that the intermediate layer consisted of
fine Al grains and intermetallic compound particles dispersed among the Al grains. The growth
direction of the wave, the welding condition dependency of the wavelength and the amplitude of the
interfacial wave were intensively investigated in order to clarify the welding mechanism of this
method.
Epitaxial Grain Growth during Surface Modification of Friction Stir Welded Aerospace Alloys by a Pulsed Laser System
Authors: Ryan P. , Prangnell Philip B. , Williams Stewart W.
Published: March 2009

The liquid film re-growth behaviour resulting from pulsed laser surface melting (LSM)
has been investigated for typical 2xxx, and 7xxx aerospace alloys, both on parent plate and friction
stir welded (FSW) joints. In Zr free alloys, as a result of the high growth rate and steep thermal
gradient, the melted layer re-grew with a stable front, epitaxially, from the parent subsurface grains.
This caused a thin coarse grained solidified layer to form over the parent material, thermomechanically
affected zone (TMAZ) and heat affected zone (HAZ), and fine columnar grains to
develop over the FSW nugget zone of the same order in width as the nugget grain size. In the case
of the Zr containing alloys, a very fine columnar grain structure was found over the entire surface,
independent of the subsurface grain structure. This has been shown to occur by growth selection
from a band of nanoscale Al grains epitaxially nucleated on Al3Zr dispersoids, at the melt solid
interface, that had not fully dissolved in the melt.
Evaluation of Biaxial Forming Limits by Bulge Testing
Authors: MacEwen S.R. , Shi Y. , Hamstra P. , Mallory R. , Wu Pei Dong
Published: March 2009

Finite element modelling of sheet-forming operations, such as pressure-ram-forming,
(PRF™) requires knowledge of forming limits under biaxial strain conditions. In this work,
elliptical bulge tests have been used to evaluate the forming limits of an aluminum bodystock alloy,
X309, that is used for PRF™ applications. Limiting dome heights have been determined as a
function of pressure-rate and temperature. All tests have been done with the rolling direction, RD,
of the sheet aligned with the major axis of the bulge.
Self-Blowing Process of Al Foam Assisted by Exothermic Reaction
Authors: Kobashi Makoto , Kanetake Naoyuki
Published: March 2009

Aluminum foam is a class of porous materials; in which closed pores are produced by a
gas generation in liquid (or semi-liquid) aluminum. Aluminum foams are, generally, fabricated by
heating a foamable precursor (a powder compact consisting of aluminum and TiH2 powders).
Decomposition of TiH2, which is followed by a hydrogen gas release, produces bubbles in molten
aluminum. In this research, aluminum foam was fabricated with the help of a chemical
exothermic reaction. Titanium and boron carbide (B4C) powders were blended in the Al-TiH2
precursor as reactive powder elements. When one end of the precursor was heated, a strong
exothermic reaction between titanium and B4C took place (3Ti + B4C 􀃆 2TiB2 +TiC + 761KJ), and
the neighboring part of the precursor was heated by the heat of reaction. Hence, once the reaction
happens at the end of the precursor, it propagates spontaneously throughout the precursor. The
blowing process takes place at the same time as the reaction because aluminum melts and TiH2
decomposes by the heat of reaction. The advantage of this process is that the energy to make
aluminum foam is not necessarily supplied form the external source, but generated form inside of
the precursor. Therefore the blowing process is self sustainable (Self-Blowing Process). In this
work, the effect of processing parameters on the Self-Blowing Process was observed. The
processing parameters we focused on were blending ratio of the starting powders (aluminum, TiH2,
titanium, B4C) and heating methods.
In-Situ SEM Observations of Moving Interfaces during Recrystallisation
Authors: van der Zwaag Sybrand , Anselmino E. , Miroux A. , Prior David J.
Published: March 2009

To obtain further progress and a more detailed understanding of the mechanisms involved in recrystallisation, new and more accurate techniques such as in-situ observations are necessary. This innovative method has been used to monitor the recrystallisation process in a FEGSEM equipped with hot stage. Observations are done in backscatter mode with particular attention to orientation contrast. EBSD maps of the observed areas can be acquired before and after recrystallisation. Details of the movement of the interfaces between the recrystallised region and the parent structure are recorded and analysed. The results show that the grain boundaries observed do not move smoothly but with a jerky motion. The recrystallising front sweeps through small areas, corresponding to single sub-grains or small groups of them, very rapidly and then stops at other sub-grain boundaries for varying time before progressing to the following area.
The Influence of Grain Structure and Texture on Formability and Toughness of Extruded Aluminium Alloys
Authors: Furu Trond , Pedersen K.O.
Published: March 2009

The main focus in this work is to investigate the effect of crystallographic texture, grain
structure and dispersoids on formability and toughness in some industrial 6xxx and 7xxx series
alloys. Materials of these alloys showing strong cube textures or β-fibre deformation textures in as
extruded condition have been compared with the same alloys processed by rolling and heat
treatment to obtain a random texture. It is found that the formability depends on the temper and the
texture and that the effect of the latter is path dependent. Materials with a random texture have a
significant higher formability in terms of uniform elongation than materials with cube texture when
deformed in the W-temper condition. Forming in other deformation modes shows less difference
between the cube and random texture. However, a fibrous grain structure with a sharp β-fibre
texture shows an anomalous behaviour when deformed in the biaxial deformation regime.
Toughness, in terms of Charpy energy and local strains in the necking area, is significantly higher
for materials with a cube texture as compared to materials with random textures. This difference is
explained by variations in the dispersoid levels, grain structures (size and grain boundary
misorientation) and the texture.
Application of a Mathematical Model to Simulate Multi-Pass Hot Rolling of Aluminium Alloy AA5083
Authors: Ahmed H. , Wells Mary A. , Maijer Daan M. , van der Winden Menno
Published: March 2009

A mathematical model has been developed and validated to predict deformation, temperature and microstructure evolution during multi-pass hot rolling of an AA5083 aluminum alloy. The validated model was employed to examine the effect of changing the number of rolling passes and the strain partitioning during multi-pass rolling on the material stored energy and the resulting microstructure. Results indicate that the number of rolling passes has a significant effect on the material stored energy. In addition, the way the strain is partitioned in two-pass rolling cases affects the material stored energy with decreasing strain/pass providing the highest stored energy in the material after rolling and vice versa. The reason behind these results was further investigated indicating that the thermal evolution during rolling may significantly influence the material stored energy and subsequent recrystallization kinetics.
Effect of Hot-Extrusion Conditions on Mechanical Properties and Microstructure of P/M Al-Zn-Mg-Cu Alloys Containing Zr
Authors: Adachi Hiroki , Osamura Kozo , Kusui Jun , Okaniwa Shigeru
Published: March 2009

The effect of extrusion rate and ratio on the Al3Zr induced dynamic recrystallization
(DRX) that occurs during hot extrusion of RS-P/M Al-Zn-Mg-Cu-Zr alloys was investigated. An
increase in the logarithm of extrusion rate promoted DRX and lead to a monotonic increase in the
number of fine grains. Although DRX was also promoted and the grain size reduced by an increase in
extrusion ratio from 10 to 20, the DRX behavior hardly changed, even when the extrusion ratio
exceeded 20. However, with increasing extrusion ratio, the width of fibrous grain, i.e., the
unrecrystallized region, decreased and the tensile strength increased to 879 MPa.
When the extrusion rate and ratio exceeded 54 mm/min and 20, respectively, a marked grain
coarsening occurred upon solution treatment, and the tensile strength tended to decrease, because of
the high dislocation density induced by hot extrusion. By annealing at 563 K before solution
treatment, it was possible to prevent grain coarsening, and thus prevent the strength decrease.
Effect of Rolling Friction on the Development of {111} Texture in A1050 Aluminium Sheets
Authors: Sudo Masatoshi
Published: March 2009

Commercially pure aluminum (A1050) sheets have been cold- rolled in vacuum, to obtain high
friction between rolls and sheet. This cold-rolling in vacuum successfully introduced large shear deformation
near the sheet surface. The shear strain is the highest at the sheet surface, and rapidly decreased to zero at the
quarter thickness. These high shear strains are sufficient enough to produce {111} and {001} cold- rolling, or
shear texture. Conventional cold-rolling texture such as (001) [100], is naturally observed at the mid-thickness.
It is confirmed that a high shear strain and probably steep strain gradient through thickness have a sufficient
effect on the increase in {111} cold-rolling texture near the sheet surface. {111} cold-rolling texture is proved to
be effective in the evolution of {111} recrystallization texture. This development will be discussed based on the
cold-rolling texture change.
Softening of an AA3103 Alloy Analysed Using Gallium Enhanced Microscopy
Authors: Ekström Hans Erik , Mishin O.V. , Östensson Lars , Hagström Joacim
Published: March 2009

The softening behaviour during annealing was investigated in cold and hot rolled
AA3103 alloys after different heat treatments. It was found that the evolution of boundary spacing
determined using gallium enhanced microscopy gives a very good representation of the softening
behaviour. The results show that cold rolled Al-Mn alloys soften by continuous growth of the
subgrain structure, “continuous recrystallisation”, provided the pre-treatment of the ingots has been
made to avoid too high a density of dispersoids and the cold rolling reduction has been very large.
The very high strain creates a microstructure with a large fraction of high angle boundaries that are
mostly parallel to the sheet surface. A recently developed subgrain growth model which takes the
effect of solute drag into account, gives a good description of the softening kinetics. The solute drag
is controlled by bulk diffusion of Mn. The simultaneous precipitation of Mn from the solid solution
takes place by grain boundary diffusion of the Mn atoms mainly to pre-existing particles. The solute
concentration decreases as the inverse of the boundary spacing, which is due to the grain growth
mainly in the thickness (normal) direction.
A Comparative Study on the Softening Behaviour of Cold Rolled Ingot and Continuous Cast AA5754
Authors: Sarkar S. , Wells Mary A. , Poole Warren J.
Published: March 2009

An investigation was conducted on the softening behaviour of cold rolled continuous cast
(CC) AA5754 Al alloy and compared to the results for the ingot cast (IC) material. The present
study suggests that the CC material exhibits greater resistance to softening as compared to the IC
AA5754 for the same amount of cold deformation. The differences in the softening kinetics become
more noticeable with increasing level of cold deformation and from a processing point of view can
be attributed to the absence of the homogenization stage during the processing of the CC material.
Resistivity measurements were carried out during the annealing treatment of the CC materials to
examine the possibility of concurrent precipitation, which could potentially retard the softening
kinetics for these materials. In addition, the current research reveals that the CC material produces a
finer recrystallized grain size as compared to the IC material.
Tear Toughness Evaluation of High-Quality Squeeze-Cast and Rheocast Aluminium Alloy Castings
Authors: Kumai Shinji
Published: March 2009

Cast plates of A356 aluminum alloy with different thickness were fabricated by
rheocasting and squeeze casting. Tear tests were performed on the as-cast and heat-treated products
(T5 and T6), and effects of solidified structure and heat treatment on unit crack propagation energy
(UEp) were examined. Increased cooling rate (corresponding to a decrease in plate thickness)
resulted in refined solidified structure and enlarged UEp values for as-cast samples. For both rheocast
and squeeze-cast samples, both spheroidized eutectic Si particles and age-hardened α-Al matrix by
T6 treatment were effective for increasing UEp. UEp of the squeeze-cast sample was higher than that
of the rheocast sample. Observation of crack growth path and fracture surface revealed that the tear
toughness of the present cast alloy was controlled by distribution of eutectic solidified region in the
cast structure, which provided a preferential crack growth path. The discontinuous distribution for the
squeeze-cast sample is considered to be beneficial for increasing crack growth resistance rather than
the continuous arrangement of the network-like eutectic region for the rheocast sample. Relatively
small UEp was obtained for the T6 treated rheocast sample collected from the 6 mm thickness plate.
This is attributable to the volume fraction of the eutectic solidified region in the sample being larger
than others under the present experimental conditions.
Effects of High Frequency Electromagnetic Field on Improving Macro/Micro Structure and Reducing Segregation for Aluminium Alloy Billets
Authors: Hao Hai , Zhang Xing Guo , Park Joon Pyo , Kim Ho Young , Yao Shan , Jin Jun Ze
Published: March 2009

By imposing a high frequency magnetic field, the surface quality and macro/micro
structure of the direct chill cast billets are improved. The casting speed can also be improved by
simultaneous applying mold and electromagnetic coil, especially for the alloys with a wide freezing
range such as Al-Cu-Mg alloy. The extent of macrosegregation in the Al-Cu-Mg alloy is reduced by
application of the magnetic field. Moreover, the inverse segregation layer usually observed in the
direct chill cast billet is eliminated by the effect of the electromagnetic field. The microstructure of
the hot-rolled and heat treated billets cast under the high frequency field also show better
characteristics.
Confirming Computer Calculations of Phase Stability with the Experimental Observations in Automotive Alloy AA6111
Authors: Gupta A.K. , Marois P.H. , Lloyd David J.
Published: March 2009

AA6111 sheet alloy has been used in automotive panel applications in North America and Europe for several years. This alloy exhibits an excellent combination of strength, formability, ageing response and surface appearance following forming and painting operations. Such a combination of properties is obtained by carefully tailoring the processing route to obtain the desired microstructure of the alloy. In recent years, the ability to predict the phase stability in different alloys has improved significantly, and it is now relatively easy to predict the particles that could form in complex multi component alloys during different processing steps. The accuracy of the predictions is dependent on whether or not the free energy expressions used in the calculations are correct. In this study, the AA6111 alloy was subjected to various annealing treatments that are reflective of different phase fields computed by the Thermo-Calc software. The particles were extracted using the phenol extraction technique and were identified using energy dispersive analysis. The interrelation of the particle analyses with the computed phase stability in AA6111 is presented.