bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure of Rapidly Solidified Ti-46Al-2Cr-2Nb-xY Alloys
Authors: Chen Yu Yong , Liu Zhi Guang , Chai L. , Kong Fan Tao , Davies Hywel A.
Published: March 2009

In this paper, a rapid solidification (RS) method was employed to produce
yttrium-containing TiAl based alloy ribbons. The microstructure evolution was investigated in terms
of yttrium addition and RS parameters. For comparison, the conventionally cast counterpart alloys
were studied as well. It was found that the microstructure of as cast alloys is sensitive to the Y
content. The alloys with addition of 0 to 1.0at.% Y were of lamellar microstructures, but the alloy
samples with 1.5 and 2.0at.% Y additioin were of strip-like microstructure. The yttrium-free alloy
exhibited full γ phase, while the Y-bearing alloys contain γ phase, a small amount of α2, and yttrium
containing phases. With increasing Y content, the secondary dendritic arm spacing (SDAS)
gradually reduced. In the case of the rapidly solidified alloys, the microstructure was refined
evidently when compared with the as cast counterparts. The fine Y-rich precipitates were
homogeneously distributed in the matrix with a particle size of several tens of nanometers. A bcc
phase (a=0.314 nm) was found in the alloys containing more than 1.5at.% Y, which was attributed
to the extension of the solubility of Y in the matrix by rapid solidification.
Studies on Porous Titanium Alloy Implant Manufactured by Three Dimensional Solid Freeform Fabrication System
Authors: Lim K.K. , Cheang P. , Chandrasekaran M.
Published: March 2009

Titanium (Ti) alloys have emerged to become valuable biomaterials for biomedical and
orthopedic applications due to their high strength to weight ratio, excellent biocompatibility and
corrosion resistance. In this study, the authors utilized Solid Freeform Fabrication (SFF), also
commonly known as a rapid prototyping technology to investigate a new porous three-dimensional
(3D) Ti alloy implant. Elemental powders for producing a Ti-Al-Fe-Zr alloy were mechanically
alloyed and blended with water soluble binder material. The blended powders were manufactured
by Three Dimensional Printer (3DP), followed by debinding and sintering in an inert environment.
The effects of process parameters on structural and geometrical requirements were assessed. Results
from these investigations demonstrated that Ti alloys are promising biomaterials for near net shape
fabrication of porous 3D implants, which retained their interconnected pore network. As an
illustration, complex geometries of porous 3D Ti alloy specimens were manufactured as a
demonstration of 3D SFF System.
Microstructural Modification of Metallic Materials by Electromagnetic Processing and the Theoretical Interpretation
Authors: Zuo Liang , Zhang Yu Dong , Hu Zhuo Chao , Faraoun H.I. , Zhao Xiang , Esling Claude
Published: March 2009

The recrystallization behaviors of cold rolled aluminum alloys in electric field up to 400kV/mm and the phase transformation processes of proeutectoid steels under magnetic field up to 14 Tesla have been experimentally examined. It has been found that both the electric field and the magnetic field have influence on the evolution of texture and microstructure characteristics. During the recrystallization annealing under the electric field of the cold-rolled 3104 aluminum alloy sheets, the electric field postpones the recovery and recrystallization progress. First principle calculation was performed to study the electric structures of aluminum atoms and vacancies. It shows that vacancies that are helpful for recovery are electrically negative. As the sample worked as anode during electric field annealing, it was covered with positive surface charges that attract the electronegative vacancies in the vicinity of the free surface and annihilate them. In this way, the recovery and then the recrystallization are postponed. The magnetic field applied changes the precipitation sequence of transitional carbides during low temperature tempering that makes the relatively high-temperature monoclinic χ-Fe5C2 carbide precipitated without following the usual precipitation sequence, i.e. by skipping the precipitation of the usual orthorhombic η-Fe2C carbide. To reveal the working mechanism of this phenomenon, first principle calculations were performed to study the formation energies of the two iron-carbide systems and their electronic and magnetic structures and properties. Calculation results show that η-Fe2C has lower formation energy, which is proved by the formation sequence observed during the usual low temperature tempering process. However, χ-Fe5C2 has the higher magnetic moment, which enhances the stability under the magnetic field through magnetization. Therefore, under the magnetic field its precipitation tendency is increased.
Approaches to the Design and Processing of Novel Titanium Alloys
Authors: Bettles Colleen J. , Lapovok Rimma , Ng H.P. , Tomus Dacian , Muddle Barry C.
Published: March 2009

The range of commercial titanium alloys available is currently extremely restricted, with one alloy (Ti-6Al-4V), and derivatives of it, accounting for a very large proportion of all applications. High performance alloys are costly to fabricate and limited to low-volume applications that can sustain the cost. With the emergence of new processing technologies that promise to reduce significantly the cost of production of titanium metal, especially in powder form, there is an emerging imperative for cost-effective near net shape powder processing techniques to permit the benefit of reduced metal cost to be passed on to higher-volume applications. Equally, there is a need for the design and development of new alloys that are intrinsically low-cost and lend themselves to fabrication by novel cost-effective net shape processing. The approaches that might be used to select, design and process both conventional alloys and novel alloy systems will be reviewed, with a focus on innovation in design of low-cost alloys amenable to new processing paths and increasingly tolerant of variability in composition.
Syntactic Foams Consolidated with Starch: Mixing Behaviour for Post-Mould Processing
Authors: Islam M.M. , Kim Ho Sung
Published: March 2009

The mixing required for post-mould gelatinisation of syntactic foams using starch as
binder was studied. It was found that starch particles tend to adhere to hollow microspheres during
mixing, forming agglomerates. A transition in the buoyancy of microsphere-starch phases was
found at a particular volume fraction of starch. The transitional point was close to a volume fraction
of starch at which a calculated relative density for a system consisting of multiple starch particles
per microsphere was unity. Starch-microsphere inter-distance appears to be an important parameter
affecting starch content in an agglomeration.
New Strategy toward Novel Hyperbranched Phenol-Formaldehyde Resin: Synthesis, Characterization and Curing Study
Authors: Ghosh Samaresh
Published: March 2009

Novel hyperbranched phenol-formaldehyde (HBPF) resin 1 has been prepared for the first time.
Thorough characterizations (FT-IR, NMR, HPLC, MALDI-TOF MS and elemental analyses and
rheological flow behavior) were performed to ascertain the structure of HBPF 1. The condensationcuring
event of HBPF with diglycidylether of bisphenol-A (DGEBA) has been studied by
differential scanning calorimetry (DSC) technique.
The Use of Aqueous Urea as Chemical Denaturant in Processing CGM into a Biodegradable Polymer Material
Authors: Viljoen C. , Verbeek C.J.R. , Pickering K.L.
Published: March 2009

Corn gluten meal (CGM) has potential as a bioderived polymer for use in composite
materials. Previous work to improve the processability of CGM has focused on the use of
plasticisers including water, polyethylene glycol, glycerol and octanoic acid, however, a common
problem is that these leach from the material subsequent to processing [1]. It has been raised that a
certain degree of denaturation must occur in order to make proteins processable [2]. The current
work explores the use of aqueous urea as chemical denaturant in processing CGM into a
biodegradable polymer material. Consolidated materials were obtained which showed increased
resistance to cracking with higher urea concentration. FTIR analysis revealed that processing CGM
with increased concentrations of aqueous urea resulted in the progressive transformation of the
protein secondary structure from an ordered, clustered conformation to that of extended chains.
Aqueous urea is assumed to promote protein-solvent interactions which stabilise the extended chain
conformations.
Production of High Purity Alumina and Zeolite from Low-Grade Kaolin
Authors: Meor Yusoff Meor Sulaiman , Masilana M. , Choo T.F. , Julie A.M.
Published: March 2009

Malaysia mainly produced low quality kaolin and the paper describes the development
of a chemical process to produce high purity alumina and zeolite from this mineral. Selective
leaching technique was applied to remove 45% of the Al2O3 content in kaolin. The high purity
alumina produced shows similar characteristic to the commercial product. An alkaline fusion stage
was then carried to transform the kaolin mineral into zeolite. Identification of the crystalline phase
by XRD shows that it consists of both zeolite P and hydroxysodalite.
Polycondensation of Urea and Boric Acid to Give Polyborate Ester, a Precursor for Boron Nitride
Authors: Mondal S. , Banthia A.K.
Published: March 2009

Polycondensations (condensation polymerization) are stepwise reactions between
bifunctional or polyfunctional compoents, with elimination of simple molecules such as water or
alcohol and the formation of macromolecular substances. Polyborate ester , formed by this process,
gives ceramic materials during pyrolysis. Polymer pyrolysis offers an attractive alternative to the
typical high temperature powder processing approach in the fabrication of high-performance
ceramics. This approach might also prove to be useful in the fabrication of fibers, coatings, and
composites. It is within this framework that the present study was undertaken; its aim is the
preparation of boron-containing oligomeric precursors which gives boron nitride after
pyrolysis. The precursor was synthesized by the condensation reaction between boric acid
and urea (or other N-containing reactive multifunctional compounds). The oligomeric precursor
and its pyrolysed products were thoroughly characterized by elemental analysis, IR, NMR,
XRD, Thermal Analysis and Transmission Electron Microscopy(TEM). The elemental analysis
results of the oligomer are---- C-13.40%, H-5.97%, N-32.44% and B-17.09%. X-ray diffraction
and TEM studies showed that boron nitride obtained from this system possess tetragonal structure.
Highly c-Axis Oriented Al-Doped ZnO Thin Films Grown in Premixed H2/Ar Sputtering Gas
Authors: Lee Eun Soo , Wibowo Rachmat Adhi , Kim Kyoo Ho
Published: March 2009

Al-doped ZnO (AZO) thin films were grown on Corning 1737 glass by RF Magnetron
Sputtering under premixed hydrogen-argon (H2/Ar) sputtering gas. It is found that the introduction of
various H2 concentrations during sputtering deposition altered the properties of Al-doped ZnO films.
The presence of H2 during AZO growth at low deposition temperature leads to the growth of a-axis
preferential orientation crystal whereas c-axis preferential orientation occurred only at higher
deposition temperature. Highly oriented c-axis (002) crystal has been successfully grown under 3%
H2 concentration at 200°C deposition temperature. Film’s resistivity is appeared to be a function of H2
concentration. Additional H2 concentration in sputtering gas increased of film’s transmittance up to
85% at visible-near infra red spectra while it caused the Burstein-Moss shift toward the blue region at
350 nm wavelength.
Thermal, Mechanical and Morphological Performance of BisGMA/TiO2 Nanocomposite
Authors: Behera D. , Banthia A.K.
Published: March 2009

Vinyl ester BisGMA [Bisphenol-A-glycidyldimethacrylate] resin has been modified by
incorporating Titanium dioxide(TiO2)nanoparticles (0.5%-2% by weight). An ultrasonic mixing
process was employed to disperse the particles into the resin system prior to casting and curing test
specimens. From TEM investigation, it is found that the particles are nano size (5-60nm) and
dispersed throughout the entire volume of the resin. Dynamic mechanical analysis was conducted
for both the neat resin and nanocomposite. In dynamic mechanical analysis, nanocomposite shows
increase in storage modulus (6%), and glass transition temperature (5.8%) from neat resin system.
Thermogravimetric analysis shows 7.5% better thermal stability. In addition, the nanocomposite
shows enhance in the stiffness by 5% in flexural loading. The Tg and flexural modulus of the
nanocomposites were enhanced as the particle volume fraction was enhanced and than decreased.
Fabrication of Al-Si-Cu-Mg-Zn Alloy Matrix Composite Reinforced with Submicrometer Sized Al2O3 Particles Formed by Displacement Reaction
Authors: Woo Kee Do , Lee I.B. , Kim I.Y. , Zhang De Liang
Published: March 2009

The displacement reaction (in situ reaction) is an effective process to solve the interfacial problem between Al matrix and ceramic particles in Al alloy matrix composites. In this study, an Al alloy matrix composite powder containing nanometer was produced by using high energy ball milling, and a bulk Al alloy matrix composite reinforced with nanometer and submicrometer sized Al2O3 particles was obtained by sintering the ball milled composite powder at 950 °C for 2h. It was found that the Al2O3 particles were homogeneously distributed in the Al matrix after sintering. Some of the Si particles have lots of fine Al2O3 particles distributed homogeneously in the Al matrix. The hardness of the sintered specimen produced using as-milled composite powder is higher than that of the sintered specimen produced using as-mixed powder.
Thermal, Morphological and Dynamic Mechanical Characterization of Melt Blended PC Nanocomposites
Authors: Samal S.K. , Mohanty S. , Nayak S.K.
Published: March 2009

Polycarbonate (PC) nanocomposites were prepared by melt intercalation technique in an
intermeshing co-rotating twin-screw extruder. Both unmodified (Na+MMT) and organo-modified
(Cloisite 10A & OMMT) clays were used for the preparation of nanocomposites. The effect of
addition of clays on the morphological and dynamic mechanical properties of PC matrix has been
studied. The wide angle X-ray (WAXD) studies reveal a dominated exfoliated morphology of the
nanocomposites at a clay content of 5%. The intercalated morphology is predominated upto clay
content of 3%. Transmission electron microscopy (TEM) demonstrated the co-existance of
intercalated/exfoliated morphology in all the composites. Dynamic mechanical analysis (DMA)
shows an increase in storage modulus indicating higher stiffness in case of organomodified clay
filled composites as compared to unmodified & virgin matrix.
Improving Hygrothermal Performance in Epoxy-Biofibre Composites
Authors: Newman Roger H. , Thumm Armin , Clauss E.C. , Guen M.J.L.
Published: March 2009

Confocal microscopy and water diffusivity measurements were used to characterise the
development of defects in biofibre-reinforced composite materials. Biofibres swelled more than the
matrix when the specimen was immersed in water, but the associated distortion of the matrix rarely
caused defects. The biofibres shrank faster than the matrix when the specimen was dried in air,
causing debonding at the fibre-matrix interfaces and microcracks within the fibres. We started with
coarse technical fibres from the leaves of harakeke (Phormium tenax), treated a portion with 1%
NaOH, and pulped a portion at 170 °C. Water diffusivities for the corresponding composites
increased over the first 3 wet-dry cycles, particularly for the composite made with untreated fibre,
but were too small to be of concern for the composite made from pulped fibre.
MWNT Polymer Nanocomposites Based on P3HT
Authors: Musumeci A.W. , Silva G.G. , Liu J.W. , Rintoul L. , Waclawik E.R. , George G.A.
Published: March 2009

Thin and short multi walled carbon nanotubes (MWNTs) were used to prepare nanocomposites based on poly(3-hexylthiophene) (P3HT). The MWNTs were characterized by TEG, SEM, TEM and Raman spectroscopy following deposition of films from stable dispersions of MWNT in chloroform. Non-covalent interaction between MWNT and P3HT dissolved in chloroform allowed the preparation of solution-cast composite films. Composite thermal events such as glass transition, melting temperature and heat of fusion were investigated by DSC and compared with pure polymer. Conductivity of composite bulk films was measured as a function of temperature by 2-point probe DC-resistance measurements. Loadings of MWNTs above 0.1 weight percent (wt%) in the conjugated polymer significantly increased the conductivity of P3HT composites. Interplay between charge transport through the semiconductor polymer and carbon nanotube network allowed the increase of conductivity after percolation to values close to 10-2 S cm-1, an improvement of four orders of magnitude over that of films cast from pure P3HT.
On Feasibility of Ply-Layup Orientation in CF/Epoxy Composite Laminates Using Rayleigh Probes
Authors: Park Jae Woung , Im Kwang Hee , Hsu David K. , Heo Uk , Lee K.S , Kim Y.H. , Kim Sun Kyu , Yang In Young
Published: March 2009

A nondestructive technique would be very beneficial, which could be used to test the
CF/Epoxy composite laminates. A new method for nondestructively determining the ply layup in a
composite laminate is presented. A one-sided pitch-catch setup was used in the detection and
evaluation of flaws and material anomalies in the composite laminates. Two Rayleigh wave
transducers were joined head-to-head and used in the pitch-catch mode on the surface of the
composites. The pitch-catch signal was found to be more sensitive than normal incidence
backwall echo of longitudinal wave to subtle flaw conditions in the composite. Also the other
method employs a normal-incidence longitudinal ultrasound to perform C-scan of ply interfaces of
the laminate, and extracts fiber orientation information from the ultrasonic reflection in the laminate.
Using two-dimensional spatial Fourier transform, interface C-scan images were transformed into
quantitatively angular distribution plots to show the fiber orientation information therein and to
determine the orientation of the ply. Therefore, it is found that the efficiency of developed system
shows between the one-sided pitch-catch testing and C-scan images in characterizing ply-layup
orientation of the laminates.
Overview of Current International Magnesium Research and Recent CAST CRC Developments
Authors: StJohn David H.
Published: March 2009

This paper provides an overview of the key areas of magnesium research and
development being undertaken internationally and consideration of the future challenges
confronting the further implementation of magnesium components. This paper will also include a
description of some of the technologies that the CAST Cooperative Research Centre has developed
and licensed for commercialisation which address some of the future challenges. There will also be
a brief overview of the extent of Australia’s commitment to magnesium alloy research through the
CAST CRC, the Centre of Excellence for Design in Light Metals and the CSIRO including their
Light Metals Flagship program.
Numerical Study of Functionally Graded Materials
Authors: Naryanappa K.M. , Krishna M. , Sharma S.C. , Murthy H.N. Narasimha
Published: March 2009

One-dimensional comprehensive mathematical model coupling particle movement and thermal conduction in the casting mould system is developed. A formula for pressure in liquid metal during the centrifuge process is derived. The model takes into consideration the propagation of solidification front and movement of particles due to centrifugal acceleration which takes place either in the same or in opposite direction to that of the solidification front depending on the relative density difference between the particles and melts. In the force balance expression, repulsive force term is incorporated for the particles that are at the vicinity of the solid/liquid interface to calculate the particle segregation pattern in the casting region The effects of various process parameters such as, rotational speed of the mold, size of the reinforcing material, relative density difference between the particle and melt, initial pouring temperature of the liquid melt, mold pre-heating temperature, heat transfer coefficient between the casting/mold interface are studied. It is noted that for a given set of operating conditions, the thickness of the particle rich region in the composite decreases with increase in rotational speed, particle size, relative density difference between the particle and melt, initial pouring temperature and initial mold temperature. With decrease in the heat transfer coefficient between the casting/mold interface, the solidification time increases which, in turn, results in more intense segregation of solid particulates. Again, with increase in the initial volume fraction of the solid particulates, both the solidification time as well as the final thickness of the particulate rich region increase.
Influence of Alkali Treatment on the Interfacial Bond Strength of Industrial Hemp Fibre Reinforced Epoxy Composites: Effect of Variation from the Ideal Stoicheometric Ratio of Epoxy Resin to Curing Agent
Authors: Islam M.S. , Pickering K.L.
Published: March 2009

Industrial hemp fibre was treated with alkali and the influence of this treatment on
interfacial shear strength (assessed using the single fibre pull-out test) and composite strength with
an epoxy resin, over a range of epoxy resin to curing agent ratios, was investigated. Scanning
electron microscopy was conducted to assess the fracture behaviour of the composite tensile test
specimens. It was found that alkali treatment increased the interfacial shear strength and composite
tensile strength, Young’s modulus and elongation at break. The highest tensile strength was
obtained with an epoxy resin to curing agent ratio of 1:1 while the best Young’s modulus was
achieved with a resin to curing agent ratio of 1:1.2.
Optimising the Model of Gas-Jet Quenching of a Carburised Gear
Authors: Stratton Paul
Published: March 2009

Extensive CFD modelling of cooling using nitrogen jets showed that an array of high
velocity gas jets close to its surface could cool the part at a similar speed to oil. The optimum
conditions were: an approximately uniform nozzle field with the jets four to eight times their own
diameter apart, at a distance from the part to be quenched of a quarter of the diameter of the jets;
and a jet velocity of 100 m/s. When these optimised conditions were applied to an idealised gear
form, the model suggested that it could be fully hardened if a nitrogen/hydrogen mixture was used.
The model was validated by comparison with physical experiments under exactly the same
conditions. Unfortunately, although close to the physical results, the model results had some
important differences.
Part of the difference was explained by the exclusion of radiation losses from the model and part by
the use of values for specific heat that were derived from static, rather than dynamic, experiments.
When the model was modified to correct these there was closer, but by no means perfect,
agreement. The finite element model used at this stage was thought to model the heat transfer
accurately, but not the steel. The heat transfer data was therefore applied to a metallurgical model.
The results from this model were superior in some respects, particularly regarding the phase changes
occurring, although again not perfect, perhaps because of the experimental technique used.
Multifarious Fracture Features of CuZrAlGd(Ag) Bulk Metallic Glasses
Authors: Fu H.M. , Zhang Hai Feng , Wang H. , Zhang Ming Xing , Hu Zhuang Qi
Published: March 2009

Multifarious fracture features, such as coarse rive-like, micro holes, rugged and flat
fracture surface, were systematically investigated in the monolithic Cu46-xZr45Al7Gd2Agx (x=0, 0.5)
bulk metallic glasses. The fracture planes presented different angles with the loading direction.
These fracture features were completely different from the typical fracture characteristics of
amorphous alloys, i.e. vein-pattern and fracturing approximately along the maximum shear stress
plane. On the other hand, some tiny strips with about 50 nm intervals were also detected on the flat
fracture plane. The preliminary discussions on the formation mechanisms of these exceptional
features were presented.
The Effect of Additives and Substrate Conditions on the Copper Electrodeposition for Thin Film Applications
Authors: Woo T.G. , Seol Kyeong Won , Park Il Song , Lee H.W. , Woo K.N. , Jeon W.Y.
Published: March 2009

The effect of surface states of substrate and additives on copper electrodeposition for thin
film applications was investigated. Titanium substrate states were mechanically and chemically
moderated and several additives such as Arabic gum, hydroxyl ethyl cellulose, and chlorine were used
during electrodeposition process under a constant current condition with current density of 500
mA/cm2. Results obtained using SEM, X-ray, and AFM for early stage of copper nucleation and
growth revealed that substrate conditions and additives appear to be effective in producing
uniformly-distributed copper nuclei and their subsequent growth in a regulated manner of surface
leveling. The shape of copper nuclei was clearly affected by the surface state of the substrate. It seems
to be related with dislocations produced on the titanium cathode during surface moderating. Hardness,
growth direction, and resistivity of copper deposits changed with the kind of additives.
Surface Characteristics of the Anodized and Hydrothermally Treated Titanium Affected by the Current Density, Voltage, and Time
Authors: Park Il Song , Woo T.G. , Lee Min Ho , Bae Tae Sung , Seol Kyeong Won
Published: March 2009

This study examined the effect of the current density, anodizing voltage and time on the
surface characteristics of titanium during anodic spark oxidation. Anodic spark oxidation was
performed at different concentrations of electrolyte composed of DL-α-glycerophosphate (DL-α-GP)
and calcium acetate (CA). The specimens were anodized at various conditions (current density,
anodizing voltage, and duration) in a fixed electrolyte concentration. Anodized specimens were
treated hydrothermally under high pressure steam using an autoclave. Homogeneous anodic oxide
films were produced by anodic spark oxidation on the titanium surface with 1~4 μm diameter pores,
and the breakdown voltage was changed by the electrolyte concentration. After the hydrothermal
treatment, hydroxyapatite crystals formed as an enlarged polygonal shape in the higher concentration
of DL-a-GP group and as thin needles in higher concentration of CA group. The bioactivity and
osteoblast growth was good for the anodized surface at 340V compared with the groups applied other
parameters.
Surface Characterization of an Extruded 6060 Al Alloy
Authors: Zhang Wei , Metson Jim , Nguyen C.L. , Chen S.
Published: March 2009

The surface characteristics of an extruded 6060 aluminium alloy were investigated with
X-ray Photoelectron Spectroscopy (XPS). The results revealed that the extruded surface was covered
by oxides of aluminium and magnesium. The thickness of aluminium oxide was found to change
along the extrusion direction with the thinnest and thickest oxide at the beginning and end of the
extrudate, respectively. Magnesium segregation was found on the surface of the extrusion with the
highest and lowest Mg concentration at the beginning and end of the extrudate, respectively. This is
the inverse result of that expected where increasing Mg content was believed to be associated with
film instability and thicker films.
Growth and Properties of Stannite-Quaternary Cu2ZnSnSe4 Thin Films Prepared by Selenization of Sputtered Binary Compound Precursors
Authors: Wibowo Rachmat Adhi , Kim W.S. , Munir Badrul , Kim Kyoo Ho
Published: March 2009

Cu2ZnSnSe4 (CZTSe) thin films were grown on Corning glass 1737 by sequential methods
of sputtering deposition and selenization process. As-grown films showed that elemental Cu, Zn, and
Sn were in the nearly CZTSe stoichiometric ratio with Se-deficiency as detected by Energy Dispersive
X-Ray spectrometry (EDX). In order to attain film stoichiometry, as-deposited films were subjected
to selenization process in tube furnace under Ar ambient at different selenization temperatures for
10-60 min. It was found that compositions of binary compound in the sputtering target as well as
selenization are critical for the growth of the CZTSe films. The structural characteristics of the
selenized CZTSe films revealed a highly oriented stannite CZTSe phase with (112), (220/204) and
(312/116) growth orientations and a CuSe secondary phase. By using 0.5% KCN solution, CuSe
secondary phase could be totally etched from the CZTSe film surface.
Titania/Ormosils Organic-Inorganic Hybrid Thin Films Doped with Azobenzene Small Molecules for Optical Switch Applications
Authors: Que Wen Xiu , Sun M. , Jia C.Y. , Cheng L. , Sun Zhuo , Wang L.L. , Hu X.
Published: March 2009

Titania/organically modified silanes (ormosils) organic-inorganic hybrid thin films doped with azobenzene small molecules are prepared by a low temperature sol-gel spin-coating process for optical switch applications. Acid-catalyzed solutions of γ-glycidoxypropyltrimethoxysilane and methyltrimethoxysilane mixed with tetrapropyl orthotitanate are used as matrix precursors. Atomic force microscopy is used to study the morphological properties of the hybrid thin films. Results indicate that crack-free thin films with a thickness of about 1.3μm can be obtained by a single spin-coating process after a low heat treatment temperature. The propagation mode properties of the hybrid thin films are also studied by employing a prism coupling technique. The photo-responsive properties of the hybrid films baked at different temperatures are induced by an irradiation with UV light and subsequent visible light.
The Gas Sensitvity Character of WO3 Nanosized Material
Authors: Huang Shi Zhen , Lin Wei , Chen Wen Zhe
Published: March 2009

By thermal decomposition, WO3 nanosized material was prepared as sensitive material and
doped SiO2 nanosized material has been prepared using Sol-Gel process. NO2 gas-sensing elements
have been manufactured with prepared material. The element is sensitive to NO2 with fairly good
selectivity. Micro-structure of the material was analyzed by SEM, and the sensing mechanism was
discussed.
Effect of Oxygen Flow Rate and Temperature on the Structure of DC Sputtered Nanocrystalline Copper Oxide Films
Authors: Chiang M.J. , Wu C.W. , Cheng H.E.
Published: March 2009

Copper oxide, a direct band gap semiconductor with band gap about 1.21-1.51 eV, has been
regarded as a promising material for photovoltaic. Nanocrystalline copper oxide films have been
synthesized on Si by dc sputtering method. The effects of oxygen flow rate and deposition
temperature on the microstructure of nanocrystalline copper oxide films were investigated. X-ray
diffraction analysis shows that a broaden peak of Cu2O (111) at 36.720 was observed at the deposition
condition of DC power 150 W, pressure 2*10-2 Torr, substrate temperature 100 °C, Ar flow rate 15
sccm and O2 flow rate 1sccm. With increasing the oxygen flow rate to 3 and 5 sccm, CuO (-111) could
be observed at 36.58o. The increase of oxygen flow rate resulted in the film formation from Cu2O to
CuO. SEM pictures show that copper oxide films exhibit nanosize grains. X-ray diffraction patterns
of CuO films deposited at 50~200 °C show that only (-111) plane is obtained. The SEM pictures show
that the grain size increases with the deposition increases.
Preparation and Characterization of Zn-Se Bilayer Structure
Authors: Singh M. , Arora J.S. , Awasthi Kamlendra , Nathawat R. , Vijay Y.K.
Published: March 2009

The Zn-Se bilayer structure prepared using thermal evaporation method at pressure 10-5 Torr. These films annealed in the vacuum for two hours on different constant temperatures. The optical band gap was found to be varying with annealing temperature due to removal of defects and increase in grain size. It was also observed by the X-ray diffraction pattern the grain size of the film increase with annealing temperature. The lattice constant of hexagonal structure of these films is found to be a =b=4.42Å and c=5.68Å. The dominant peaks to be at 23.2°,28° and 43.9° having values (100), (002) and (111) respectively. The Rutherford back scattering data of these films confirmed the mixing of elements with time.
Population Dynamics of Excitons in Silicon Nanocrystals Structures under Strong Optical Excitation
Authors: Shalygina Olga A. , Zhigunov Denis M. , Palenov Dmitrii A. , Timoshenko Victor , Kashkarov Pavel K. , Zacharias M. , Koenraad Paul M.
Published: March 2009

We report on the experimental and theoretical studies of population/depopulation
dynamics of excitons in the structures with Si nanocrystals in SiO2 matrix (nc-Si/SiO2) under strong
optical excitation. The experimental results are explained using a phenomenological model based
on rate equations for coupled system of energy donors (excitons) and energy acceptors (erbium
ions). Exciton luminescence is found to exhibit superlinear dependence for Er-doped samples. At
the same time the Er-related luminescence at 1.5 μm shows a saturation of the intensity and
shortening of the lifetime, which are attributed to the population inversion of the Er ions states. The
obtained results demonstrate that nc-Si/SiO2:Er systems can be used for applications in Si-based
optical amplifiers and lasers, compatible with planar Si-technology.
Study of Thermal-Anneal-Induced Rearrangement of N-Bonding Configurations in GaInNAs/GaAs Quantum Well
Authors: Dixit V. , Liu H.F. , Xiang N.
Published: March 2009

Blueshifts of photoluminescence (PL) peak wavelength from GaInNAs/GaAs quantum
well (QW) at various annealing temperatures have been studied. Our results indicate that as-grown
GaInNAs/GaAs QW sample has N-Ga3In1
phase, which changes to a mixture of N-Ga3In1 and NGa2In2
after annealing. The activation energy characterized for short range order is 2.38 eV, which is
smaller than that for the diffusion process (3.196 eV). This indicates that the short range order is the
dominant mechanism for PL blueshift at relatively low annealing temperature and for short time
annealing.
Novel Passivation Method in the Fabrication of Submicron InGaAsP/InP Ridge Waveguide Lasers
Authors: Lim Ee Leong , Teng Jing Hua , Chua Soo Jin , Dong J.R. , Ang Norman Soo Seng , Chong Lip Fah
Published: March 2009

One challenge for the realization of electrically drive nano-photonic devices is the
formation of metal contacts and passivation. In this paper, we report a novel self-aligned method
suitable for the formation of the metal contact and passivation for submicron photonic devices. Two
different dielectric materials with high selectivity in wet chemical etching and a wet etching of
semiconductor to create an undercut are involved. The whole process is completely compatible with
existing compound semiconductor process. As a demonstration of this method, the fabrication and
characterization of an InGaAsP/InP submicron-ridge waveguide lasers is presented. The method is
extendable to high aspect ratio-submicron ridge waveguide and other device fabrication.
Optical Reﬂection from a Monolayer of Embedded Nano-Objects Covered by a Thick Capping Layer
Authors: Wijers C.M.J. , Voskoboynikov O.
Published: March 2009

In a hybrid discrete-continuum description the optical response of a capped monolayer of nano-objects has been determined. The monolayer emits a summation of partial plane waves obeying traditional reflection and transmission, enabling solution of the monolayer dipole strength. For thick capping layers the resulting reflection coefficients could be approximated by analytical expressions. These results have been used to investigate the feasibility of experimental detection of the optical response of nano-object monolayers.
Visible Light Emission from Ordered Nanopatterned InP Surface
Authors: Mohanta S.K. , Soni R.K. , Tripathy S. , Chua Soo Jin
Published: March 2009

The InP nanostructures have been fabricated by low-energy Ar+-ion of dose 1 × 1018 cm-2
and energy 50 keV, at normal incidence. The InP nanodot size varies from 50 to 90 nm.
Photoluminescence spectra show blue shifted visible emission band at 1.98 eV, and quenching of
the band edge emission from the nanopatterned surface. The blue-shifted emission band arises due
to size convoluted band-to-band emission form the surface nanodots while the defects formation in
the irradiated surface leads to the quenching of band edge emission. Thermal annealing results in
clustering of the patterned surface and enhancement of the band edge emission accompanied with
absence of visible band. Our results show that the origin of visible emission is from the surface
nanodots and not from the nanocrystallites in the implanted surface region. This is corroborated by
the wavelength dependence of photoluminescence measurement by probing different depth of the
disordered region.
Photoluminescence and Fractal Properties of Diverse Carbothermal Zinc Oxide Nanostructures
Authors: Magdaluyo Eduardo R. , Arellano Ian Harvey J. , Tapia Alvin Karlo G. , Samargo Roland V. , Payawan Leon M.
Published: March 2009

The photoluminescence of the diverse nanostructures of nonstoichiometric ZnO grown via carbothermal reduction at 900°C was investigated. Various formations of different structures like wires, rods, tubes and tetrapods resulted from the inhomogeneity of the boundary diffusion layer associated with vapor current induced in the set-up. The band gap emission of these structures was observed at around 390 nm, which corresponds to energy of 3.20 eV. The study was extended to measure changes of crystal habit of ZnO nanostructures in terms of its fractal dimension.
Band Structure and Optical Gain of 1.3 um GaAsSbN/GaAs Compressively Strained Quantum Well Laser
Authors: Dong B. , Fan W.J. , Dang Y.X.
Published: March 2009

The band structures and optical gain spectra of GaAsSbN/GaAs compressively strained
quantum well (QW) were studied using 10-band k.p approach. We found that a higher Sb and N
composition in the quantum well and a thicker well give longer emitting wavelength. The result also
shows a suitable combination of Sb and N composition, and QW thickness can achieve 1.3 μm lasing.
And, the optical gain spectra with different carrier concentrations will be obtained.
Manufacturing and Testing of High Performance Sheet Moulding Compound
Authors: Hou Meng , Ye Lin
Published: March 2009

The paper describes the manufacture of thin composite panels using high performance
sheet moulding compound (SMC). Topics discussed within the paper include characterisation of
curing and flow behaviour of SMC material, tooling design concept and determination of suitable
processing conditions for compression moulding. A Full scale “Burst test” was carried out to evaluate
the mechanical performance of SMC panels. The overall performance of the SMC panels was
satisfactory with all panels failed beyond the specification value. The main failure mode was a
through-thickness cracking. In addition, a geometrical non-linear numerical analysis was also carried
out to investigate the stress distribution and deflection behaviour of SMC panel during “Burst
testing”.
High Performance Composites Using Nanotechnology
Authors: Bauer Monika , Kahle O. , Landeck S. , Uhlig C. , Wurzel R.
Published: March 2009

Lightweight design, using high performance composites, which directly yields a reduced
need for fuel is in the focus of new developments for traffic engineering. The increased substitution
of traditional, metal based materials by fibre-reinforced composites in the aviation industry
exemplifies this trend. In addition to mechanical properties, e.g. an increase in strength, that leads to
direct weight savings, or improved dynamical performance, which translates into longer
maintenance intervals, i.e. longer service-life. In the field of fibre-reinforced polymer matrix
composites possible contributions from nanotechnology are currently reviewed. The modification of
the matrix by introducing a “nanophase” has attracted most attention up-to-date. Additional
approaches include modification of traditional reinforcements, as well as the development of new
reinforcing materials. Desired improvements include mechanical properties, interlaminar shear
strength, reinforcement in z-direction, fiber-matrix adhesion, and obtaining new functionalities.
Starting from a summary of the most important effects of nano-modifiers in polymeric matrices, the
presentation will review published results on the modification of thermoset matrix fiber-reinforced
composites by using nanotechnology, as well as some of our own work in that field. Furthermore,
applications of such modified composites in component parts are discussed.
Rheology of Magnetorheological Shear Thickening Fluids
Authors: Li Wei Hua , Zhang Xian Zhou
Published: March 2009

This paper presents fabrication and characterizing of a new functional material,
magnetorheological shear thickening fluid (MRSTF), by mixing micron-sized magnetizable
particles with nano-sized silica particle based shear thickening fluid. Dynamic properties of the
MRSTF were characterized by using a parallel-plate rheometer. The effects of steady-state shear
rate and magnetic field on MRSTF rheological properties were addressed. The suspension shows an
abrupt increase in complex viscosity beyond a critical dynamic shear rate and a magnetic field
controllable characteristic, as well as reversible.
Investigation of Bimodal Particles Based Magnetorheological Elastomers
Authors: Zhang Xian Zhou , Li Wei Hua
Published: March 2009

This paper presents the study of rheological and mechanical properties of MR elastomers
fabricated using small and large particle. Analysis indicated that MR elastomers fabricated with
bimodal particles at a specific particle ratio ingredient show enhanced MR effect compared with
those fabricated with monoparticles. MR elastomer samples were fabricated by using small and
large particles with sizes of 5m and 50m respectively. Their rheological and mechanical
properties were characterized with a MR rheometer. Experimental results agree well with the
analysis.
Finite Element Analysis of a New Custom Made Orthotropic Post Material for Dental Applications
Authors: Khanal Manoj , Zheng Ying , Chen Zeng Tao
Published: March 2009

Effects of cement properties on stress distributions at the dentin-cement-post interfaces
have been studied using 3D explicit finite element simulations. The mastication and horizontal
loadings are simulated with titanium and glass fiber posts. Different type of cements (moduli 2,8,18
and 22 GPa) is considered to study the interface stresses. The interface stresses are evaluated at
dentin-cement-post interfaces and along the surface of the post and cement. The element deletion
technique from finite element analysis has been used to predict the cement failure. The simulation
results suggest that the cement with similar modulus as dentin is preferable to avoid the stress
concentration at the dentin-cement interface. The types of cement do not affect the failure initiation
location on the cement. Under the simulated conditions, the failure initiation is located at 1.7 to 2.2
mm from the post apex.
Reduced Gravity Testing and Research Capabilities at Queensland University of Technology’s New 2.0 Second Drop Tower
Authors: Steinberg Ted
Published: March 2009

Reduced gravity experimentation is important to many research groups working in various
fields investigating both fundamental and applied aspects of diverse physical phenomena. Very few
terrestrial or extra-terrestrial experimental facilities are currently available that allow researchers
access to reduced gravity environments. The Queensland University of Technology’s has recently
fabricated a purpose built, stand alone 2.0 second drop tower specifically to accommodate reduced
gravity experimentation. The specifications and operational procedures of this new research facility
are presented. Information concerning current and future areas of research is also presented and
discussed. These research areas include: 1) cellular biology, 2) fluid dynamics and multiphase flow,
3) nanomaterial production including silica sol-gels and carbon nanotubes, and 4) heterogeneous
combustion with a focus on bulk metallic materials burning in oxygen enriched atmospheres
performed in collaboration with NASA and industry partners. Discussion on the use of the new
research facility in the production of advanced materials for earth-based applications will be
presented. Opportunities will also be discussed regarding both collaborative research and the
provision of reduced gravity test services.
A Data-Constrained 3D Model for Material Compositional Microstructures
Authors: Yang Sam , Furman Scott , Tulloh Andrew
Published: March 2009

A mathematical model has been developed for predicting material compositional
microstructures using measured data as constraints. Examples of measured data include 3-D sets of
tomography data, 2-D sets of compositional data on surfaces and sections, and material absorption
and interaction properties. The model has been partially implemented as a MS-Windows application.
Reasonable agreement has been obtained between the numerical predictions from the software and
the simulated data. The predicted microstructures could be used to study various material properties
such as porosity distribution, diffusion and corrosion.
Guided Wave Propagation and Interaction with Damage in Tubular Structures
Authors: Lu Ye , Ye Lin , Wang Dong , Meng Guang
Published: March 2009

A piezoelectric active sensor network is configured to collect the wave scattering from a throughthickness
hole on an aluminium rectangular tube. It is found that guided waves are capable of
propagating across the tube edges, while keeping the sensitivity to the damage even not on surfaces
where the actuator and sensor are located. Signal correlation between the intact and damaged
structure is evaluated and the probability distribution of damage is thus achieved on the unfolded
tube surface.
Deposition and Properties Studies of Superfine TiN Films with Magnetic Filter
Authors: Chen Ling , Zeng De Chang , Qiu Wan Qi , Shi Xin Wei , Liu Zheng Yi
Published: March 2009

Arc ion plating(AIP) has higher deposition rates, whereas macro-particles (MPs) make
the film properties decreasing. In this paper, AIP with or without magnetic filter (MF or AIP) and
composition of AIP followed with magnetic filter (MFAIP) were designed to deposit TiN films on
silicon (Si) and high-speed steel(HSS), respectively. Scanning electron microscope (SEM),
nanoindentation and microscratch tests were investigated. SEM showed that both the MF and the
MFAIP films had a superfine layer among the columnar crystals grown vertically against substrate
surface. However, the columnar crystals of MF films were leptosomatic and well-orientational,
while MFAIP ones were coarse and short, and even ragged in size and orientation. Nanoindentation
test results showed the highest hardness for MF films and the lowest one for AIP films. A new
parameter Scratch Crack Propagation Resistance (CPRs) was introduced to evaluate the film
adhesion properties in a scratch test. MF films had the highest adhesion. AIP films were most
susceptible to failure as the CPRs was the lowest, although the Lc1 was higher than MFAIP ones. It
was proposed that the MPs were effectively removed with the MF, and the MF layers were
superfine to improve the properties of the films.