bluuebunny/crossref_metadata_2025 huggingface dataset:
Wear on SAE 52100 with Nanocoating Al2O3 by MOCVD Process
Authors: Bressan J.D. , Battiston G.A. , Gerbasi R. , Daros D.P.
Published: March 2009

Present work investigates the wear resistance of SAE 52100 steel coated with
nanocoating Al2O3 by the Metal-organic Chemical Vapor Deposition (MOCVD) process. The wear
tests by sliding and abrasion were performed in a ball-on-disc apparatus whose ball substrate was
SAE 52100 steel. The MOCVD nanocoating processes were carried out in a research laboratory
apparatus at 240oC under N2 + O2+ H2O atmosphere. The counterface discs were ABNT 1008 steel
sheet used in the Brazilian fridge industry. The wear resistance of the nanocoated steel spheres were
evaluated through the ball-on-disc test, using a sliding velocity 0.6 m/s, normal loads of 20 N and
30 N, total sliding distance up to 2400 m and controlled conditions of temperature and humidity at
25oC and 42% respectively. The balls material substrates were submitted to two distinct coating
procedures: direct Al2O3 film deposition on substrate, or phosphatizing and then Al2O3 deposition
via MOCVD. The discs were tested as received. From the plotted graphs of cumulative lost volume
versus sliding distance, lower wear rates were observed for the nanocoated SAE 52100 sphere
compared to the sphere without coating, i.e., nanocoating with Al2O3 increases the sphere wear
resistance. This is probably due to a reasonable film adhesion. The balls phosphatized and coated
with Al2O3 showed similar wear resistance but a spherical micro-grain film of Al2O3 . The wear
mechanisms were also examined by scanning electron microscopy.
Second Generation High-k Gate Insulators
Authors: Li M. , Zhang Z. , Yu D. , McCarthy Ivana , Shamuilia Sheron , Afanas'ev Valeri V. , Campbell S.A.
Published: March 2009

Very high (k>25) permittivity materials have been investigated as a second step high-k
gate insulator. These are all formed by adding other materials to the basic HfO2. Hafnium titanate
thin films were deposited by chemical vapor deposition (CVD). It was observed that both the
interfacial layer (IL) EOT and the permittivity increase with Ti content and that films with higher Ti
content are also more immune to crystallization. Permittivities as high as 50 were achieved. In the
MOSFET devices with the hafnium titanate films, normal transistor characteristics were observed,
including electron mobility degradation. In SrHfO3 films, deposited by physical vapor deposition
(PVD), a permittivity as high as 35 was achieved. These films appear to be highly stable upon high
temperature annealing, but show a thick, anomalous interfacial layer.
Hot Pressing of cBN Ceramics with Al Binder
Authors: Sithebe H.S.L. , McLachlan David S. , Sigalas I.J. , Herrmann Mathias
Published: March 2009

Al-cBN cermets have been hot pressed at temperature between
800oC and 1100oC and pressure of 50MPa in vacuum. The
effect of particle size of the starting powders as well as the
effect of starting compositions and temperature was
investigated. The materials could only densify up to 84-92%
of theoretical density. After hot pressing at 800oC only Al and
cBN could be observed by XRD, whereas higher hot pressing
temperature result in the formation of AlN and AlB2 which
retard the densification. The microstructure of the hot pressed
material was studied using scanning electron microscopy. It
was observed that oxide layers exist at the interface between
Al and cBN phases. The presence of these oxide layers
resulted in blocking the Al from spreading and therefore
preventing full densification.
The Wear of Alumina Matrix Particulate Composites at Different Environments
Authors: Pędzich Zbigniew , Cheliński Rafał
Published: March 2009

Paper presents the results of investigation on wear of alumina and alumina-basing
particulate composites by hard abrasive particles in different environments. The results of two tests
(The Dry Sand Test and the Miller Test in pulp) were compared. As an abrasive medium coarse
silicon carbide grains were used in both cases. The alumina microstructure was modified by
different inclusions: zirconia, tungsten carbide, metallic tungsten and their mixtures. The results
indicate that the optimal wear susceptibility in given work environment could be achieved by the
addition of different type of additives.
Characterisation of Carbon Fibre Kaolin Matrix Composites
Authors: Papargyri S. , Tsipas D.N. , Botis A. , Spiliotis X. , Papargyris A.
Published: March 2009

Although structural kaolin based ceramics are attractive and useful materials, having
good mechanical characteristics, low density, good corrosion and high temperature resistance, their
use is restricted by their brittle behaviour. In order to improve their properties and mainly strength,
toughness and high temperature performance, fibre composite ceramics have been developed. In the
present work a series of kaolin-short random dispersed Grafil carbon fibre composites were
produced and sintered in an inert atmosphere of Argon at 1000oC and 1300oC and characterised
using various techniques. XRD analysis of the kaolin matrix at 1000oC showed that the crystalline
phases were decomposed without the formation of mullite a fact which also reconfirmed by SEM
examination. However at 1300oC mullite formation was well evidenced. XRD analysis of the fibres
in “as received” showed that they have graphite structure which was also retained, as SEM
examination revealed, after sintering. Examination of the Grafil fibres showed that they were quite
uniform in length and diameter and retained their integrity after sintering at the examined
temperatures. Examination the fractured composite surfaces showed only a weak bond between
fibres and matrix and at the pull out areas the fibres were replicated in the matrix.
Impact Testing on Al2O3 and Al2O3/ZrO2 Laminated Composites
Authors: Ioakimidis Christos S. , de Portu Goffredo
Published: March 2009

This study presents an investigation about the damage characteristics and mechanical
properties of Al2O3/ZrO2 laminate composites under low velocity biaxial and transient loading (BLTL).
These multilayer laminates have different layer thickness therefore residual stresses and are
compared to a 13-layer alumina specimen. Impact tests were conducted using a drop-weight test
facility with impact energies ranging from 0.033-0.160 kgm. Optical microscopy was used to
observe the damage characteristics of the impacted specimens. The load-time and energy-time
histories produced by the impact tests in conjunction with the observation of the optical
photographs give a good view of the behaviour that characterize the multilayers of Al2O3 (A) and
Al2O3/ZrO2 (AZ) ceramics under the selected experimental conditions.
Percolation Analysis of Electrical Conductivity and Mechanical Properties for CNT-Dispersed Y-TZP Nanocomposites
Authors: Sekino Tohru , Ukai T. , Kim Seung Ho , Kusunose Takafumi , Niihara Koichi
Published: March 2009

Multi-wall carbon nanotubes (MWCNTs) with a diameter of 20-30 nm were dispersed as
a conductive phase into yttria stabilized tetragonal zirconia polycrystalline (3Y-TZP) to add
electrical conductivity. The 3Y-TZP/MWCNT nanocomposites were fabricated by pressureless
sintering under inert atmosphere. Electrical conductive function was successfully introduced by
small amount of CNT addition. Critical volume fraction of the conductive phase for the percolation
was analyzed and was found to be 0.390 vol% of CNT, which was much smaller than that for
nano-sized carbon black dispersed 3Y-TZP (2.55 vol%). Microstructural investigation revealed that
dispersed CNTs formed continuous 3-dimensional nano-network within the 3Y-TZP matrix, that
contributed to the excellent conductive properties. Fracture strength was not improved much, while
fracture toughness was increased by the CNT addition, due mainly to its crack bridging and/or
pull-out mechanisms. It was considered that the use of anisotropic nano-sized conductive phase is
advantageous to obtain electrically functionalized nanocomposite ceramics.
Layered Interphases in Ceramic Matrix Composites and Relation with Interfacial Behaviour
Authors: Rouby Dominique , Kaflou A. , Reynaud Pascal , Jacques Sylvain , Rapaud O.
Published: March 2009

Unidirectional SiC/SiC minicomposites were produced by infiltration of a Hi-Nicalon
fibre tow by using pulsed chemical vapour deposition (P-CVD). The sequence of precursor gazes
inlet steps determines the structure of the Pyrocarbon/TiC layered interphase deposited first on the
filaments. The SiC matrix is then deposited with a given thickness. The different interphase
structures will be described. The interface behaviour was characterized by indentation method. The
load is applied on the fibre-end at a polished cross-section of the composite, and the displacement of
that fibre-end is measured. The push-in test on thick specimens shows that the fibre debonds at a
given fibre stress and then slides under a certain frictional shear stress. Both parameters increase
when the TiC layers become discontinuous, like aligned TiC clusters in a Pyrocarbon matrix. The
load-displacement behaviour is in very good agreement with theory when the interfacial shear stress
is kept constant, non depending on relative slip displacement. The push-through test on thin
composite slices gives directly access to sliding resistance because the fibre is less compressed. The
load displacement curves obtained will be described and analysed. For example, sliding velocity
jumps revealed a slight increase in sliding resistance with velocity. During push-back, a seating drop
was recorded as the fibre returns in its initial position, illustrating a certain effect of roughness.
Measurement and Simulation of the Oxidation of Carbon Fibers and C/SiC Ceramic
Authors: Meinhardt Jürgen , Woyke Tobias , Raether Friedrich , Kienzle Andreas
Published: March 2009

The fracture toughness increases but the long-term oxidation resistance of carbon short fiber
reinforced C/SiC composites decreases if the volume fraction of carbon fibers is high. To
understand the oxidation kinetic and their dependence from the C/SiC microstructure the
composites and also the used carbon short fiber bundles were investigated by a thermo balance and
by scanning electron microscopy. Additionally the oxidation of single carbon short fibers was
measured in situ by a hot stage light microscope. To simulate oxidation kinetics a software program
using Finite Element methods was developed. Below 800 °C oxidation resistance can be improved
by increasing the degree of graphitization of the carbon material within the short fiber bundles.
Above 800 °C the number of junctions between the short fiber bundles has to be reduced.
Nanostructured Carbon and Graphite – Ultra Lightweight Engineering Materials
Authors: Kern Frank , Gadow Rainer
Published: March 2009

Fine grain graphite has been an important material for tribologically loaded components
such as seals and bearings for almost a century. Requirements are becoming more severe and
complex concerning miniaturization, higher normal loads and toxicological restrictions. Today
state-of-the-art production of high quality fine grain graphite from binder and filler begins to reach
its technical and economic limits and manufacturers face some pressure that their products are
suppressed by other materials like silicon carbide. Nanostructured carbon and graphite derived from
sinterable carbon such as pretreated petrol-, coal-tar- as well as synthetic pitch precursors offers the
opportunity to improve the material properties, simplify the production processes and reduce the
environmental and workplace protection requirements. To achieve this objective raw materials and
compounds were adapted to near net-shape ceramic manufacturing technologies. The feedstocks
were formed and shaped. Post treatment and sintering technologies were developed in order to
obtain carbon components with superior mechanical strength, and both very high hardness and self
lubricating tribological behaviour even at high normal loads.
Micro- and Nano-Scale Wetting of Reactive Metal at Metal/Ceramic Interface
Authors: Mihailovic Marija , Volkov-Husović Tatjana , Raic Karlo
Published: March 2009

The wetting as a multi scale phenomenon, including micro- and nano-scale aspects, is
considered to be the essential step in the evaluation of the transport phenomena during
metal/ceramics joining with active filer metal. Micro-scale aspect deals with diffusivity at the
interface and into the bulk, as well as mass transfer around the grain boundary grooves (GBG) of
the ceramic surface. In that sense, the explanation of mass transport mechanism around the GBG’s
is presented. Mathematical analysis is based on experimental values taken from literature. Nanoscale
wetting aspect is an atomistic approach, which includes the investigation of phase boundary
structure. The mathematical model, which enables the contact angle calculation depending on the
features of crystal lattice and interactions between atoms and molecules of the liquid and solid
phases, is proposed.
Wetting/Dewetting Phenomena in the CaF2/Ga and CaF2/Ge Systems
Authors: Barzilai Shmulik , Lomberg M. , Froumin Natascha , Frage N.
Published: March 2009

The wettability of calcium fluoride by liquid Ga and Ge was studied. The initial contact
angles indicate that pure liquid Ge and Ga do not wet CaF2. Different spreading kinetics during the
experiments was observed. The contact angle in CaF2/Ge system increases with time, while the
contact angle in CaF2/Ga system decreases. The same differences were also observed for
temperature dependences of the contact angle. It was suggested that these wetting/dewetting
tendencies are related to the ratio of the vapor pressure values for the melt and for the substrate.
The experimental observations were confirmed by a thermodynamic analysis.
Residual Stresses in Cast Ni-Cr Alloys-Ceramics Joints with an Intermediate Layer
Authors: Jurasz Zbigniew , Juraszek Janusz
Published: March 2009

The results of residual stresses in biocompatible cast Ni-Cr alloys-ceramics joints with an
intermediate layer with thickness of about 10μm are discussed. To the experiment were used
specimens with dimensions of 45×3×10 mm and 45×4×10 mm made of Cr-Ni alloys-ceramics joint
both with and without of application of an intermediate layer. The examinations were carried out by
means of metallographical microscope, testing machine and X-ray diffractometer. The measurement
of residual macrostresses was carried out by using sin2ψ method. The obtained experimentally
values of residual macrostresses are in good agreement with results of numerical simulation
performed by means of FEM ANSYS package.
The researches have been shown that application of an intermediate ceramics layer influence on
increase of strength properties of Ni-Cr alloys-ceramics joints.
Corrosion of Glazes Coated with Functional Films in Detergent Solutions
Authors: Piispanen Minna , Fröberg Linda , Kronberg Thomas , Areva Sami , Hupa Leena
Published: March 2009

The goal of this work was to establish the compatibility of mat glazes with functional
films known to render the surfaces with self-cleaning or easy-to-clean properties. Glazes with
wollastonite, pseudowollastonite, diopside and zircon as the main crystalline phases in the surfaces
were coated with fluoropolymer as well as ceramic, sol-gel derived titania and zirconia films. The
glazes were soaked in typical detergent solutions used in everyday life up to four days. The surface
roughness was measured with confocal optical microscope and the surface was imaged and
analyzed with SEM/EDXA. When applied on wollastonite and pseudowollastonite containing
glazes the functional films readily reacted in water solutions by pitting of the surface in the vicinity
of the crystals. The ceramic titania and zirconia films showed better chemical resistance on
wollastonite –free glazes, while the fluoropolymer film corroded in the most alkaline environments.
The results indicate that functional films could be used also on rough surfaces without markedly
affecting the surface topography. However, the films should be applied only on glazes with an
excellent chemical resistance.
New Glass Sealing Method with Lead-Free Solders
Authors: Sakaguchi Koichi , Domi Shinjiro , Suganuma Katsuaki
Published: March 2009

We have developed a novel technique of joining a pair of glass substrates. In
the process, molten solder penetrates the gap between the glass substrates while the
solder-glass interfaces are being activated by friction. The activation is given by a metal
plate, which slides through the gap along the edge of the paired glass substrates and
brings in the molten solder by capillary-action. A Ti-doped Sn-Zn eutectic solder
showed good hermetic sealing of glass. A eutectic In-Sn solder also yielded good
joining, especially at low sealing temperatures.
Nickel Aluminides as a “Filler” for Joining Ceramics and Metals
Authors: Kalinski D. , Chmielewski M. , Krajewski A. , Kozłowski M.
Published: March 2009

Reactive sintering of liquid Al with solid Ni resulting in the formation of intermetallic
compounds was used for joining parts made of heat-resistant steel and parts made of ZrO2 ceramic.
The constituents of the binding layer (the ‘filler’) were introduced in the form of foils (e.g. in the
Al/Ni/Al sequence) in-between the two parts to be joined. The heat-resistant steel joints (steel-
/NiAl/-steel) were bonded in vacuum within the temperature range from 1023K to 1323K, at a
pressure of 6MPa for 30 to 60min. The ceramic joints of the ZrO2-/NiAl/-ZrO2 type were produced
in an argon atmosphere within the temperature range from 1373K to 1723K at a pressure of 6MPa
for a time from 30 to 60min. The joints of both types produced under these conditions had a
required structure and were suitable for exploitation at high temperatures in air. Based on the results
obtained for these joints, we experimented successfully with joining zirconium ceramics with heatresistant
steel by using the reactive sintering of Ni-Al intermetallic compounds.
High Temperature Plastic Flow and Ductility in Polycrystalline Oxide Ceramics: Doping Effect and Related Phenomena
Authors: Yoshida Hidehiro , Morita Koji , Kim Byung Nam , Hiraga Keijiro , Yamamoto Takahisa , Ikuhara Yuichi , Sakuma Taketo
Published: March 2009

High temperature creep and superplastic flow in high-purity oxide ceramics such as
alumina and tetragonal zirconia polycrystals is very sensitive to a small amount of doping by various
oxides. High-resolution transmission electron microscopy and an energy-dispersive X-ray
spectroscopy analysis revealed that grain boundaries in high-purity oxide ceramics are free from
amorphous phase, and that the doped cations tend to segregate along the grain boundaries. Since the
high temperature plastic flow in oxide ceramics takes place mainly by grain boundary matter
transport by atomic diffusion, the grain boundary nano-structure control must be a useful way to
develop new high-performance functional ceramics in the near future.
R-Curve Behaviour of Alumina Matrix Ceramics with Long Cracks
Authors: Szutkowska Magdalena , Boniecki Marek , Bućko Mirosław M.
Published: March 2009

The R-curve (KR versus crack length c) behavior has been examined in alumina-10 wt%
zirconia ceramics with 3 mol% yttria stabilized zirconia, alumina-10 wt% zirconia ceramics with 12
mol% nano ceria stabilized zirconia and Al2O3-30 wt% Ti(C,N) ceramics. An observation of in situ
microscopic long-through thickness crack growth during three point bending (3PB) of a single edge
notched beam (SENB) enabled measurement of the R-curve. It was found that both aluminazirconia
ceramics with yttria or ceria stabilized zirconia exhibit a rising R-curve while for Al2O3-30
wt% Ti(C,N) ceramics such relationship was not observed. Moreover the slow crack growth
parameters (n, logA) were determined by means of load-relaxation technique for tested alumina
matrix ceramics.
In Situ Investigation of Debinding of Non-Oxide Ceramic
Authors: Klimera Andreas , Raether Friedrich , Schulze Horn P.
Published: March 2009

Binder removal in small and large green compacts of AlN ceramic was investigated by
combining different in situ measuring techniques. Dimensional changes, wetting behaviour
and weight loss were measured by a thermooptical measuring device (TOM). Thermal
diffusivity was measured by the laser-flash technique and evolved gas species were identified
by FTIR analysis. The properties of the binder changed with increasing temperature. Wetting
properties drastically improved between 150°C and 350°C. The activation energy for the rate
determining step of binder decomposition was derived from weight loss data using the kinetic
field method. It was 180 kJ/Mol up to a temperature of 350°C, where it strongly increased.
The binder enhanced thermal conductivity of the green compacts – especially in the last stage
of binder removal - which was explained by its location in the vicinity of the contacts between
the AlN particles. With large samples and high heating rate a superposition of weight loss
reactions which could be clearly separated in other experiments was observed. This was
attributed to the effect of the high partial pressure of evolved gases in the pore system of the
green compacts.
Production of Si3N4-Based Articles and their Application in Aerospace Industry
Authors: Vikulin V.V.
Published: March 2009

As required by the purpose and operating conditions of the articles, Si3N4-based
ceramic materials must have a combination of properties ensuring their serviceability, while their
manufacturing process must afford the manufacture of complex-shaped products. The paper
deals with the technology of making complex-shaped articles from reaction-bonded, densified
silicon nitride in the system Si3N4, Si3N4-BN, Si3N4-Al2TiO5, Si3N4–Si by thermoplastic slip
casting of a fine high-purity silicon powder comprising additives or sintering aids with
subsequent nitridation at temperatures up to 1500°C or additional sintering up to 1750-1800°C.
In the process of making reaction-bonded silicon nitride, consideration is given to the exothermal
effect of reaction, to the influence of additives on the properties of ceramics and the
manufacturing process. Methods of oxidation protection of porous Si3N4-based ceramics and
adaptation of these methods to protection of porous SiC- or SiC-C – based ceramics are
discussed. Upon densification of reaction-bonded silicon nitride at temperatures up to 1750-
1800°C, consideration is also given to the effects of diffusion processes of the additives, used as
sintering aids, on ceramics microstructure. The mechanisms of dissolution – recrystallization of
α- and β-Si3N4 in the course of forming the self-reinforced ceramic structure are discussed. The
peculiarities of making Si3N4-Si – based material having unusual properties including the
mechanism of forming, oxidation resistance, electrical conductivity and high impact resistance
are covered. The paper presents the results of testing of the ceramic components and units of gasturbine
engines, bearings and attachments of the spacecraft Buran, and it also gives test data with
reference to the ceramic parts tested at temperatures above 2000°C.
Porous Ceramic Humidity Sensors Using Sol-Gel Processed ZrTiO4 Nanoparticles
Authors: Cosentino Ivana Conte , Muccillo E.N.S. , Vichi Flávio M. , Muccillo R.
Published: March 2009

Ceramic ZrTiO4 powders were prepared by a sol-gel method using zirconium
oxychloride and titanium tetraisopropoxide. In situ high temperature X-ray diffraction results show
that crystallization of the amorphous gel starts at 400°C. Single-phase ZrTiO4 nanoparticles of 46
nm average particle size, determined by nitrogen adsorption analysis, were obtained after heat
treatment at 450°C for 1 h. After pressing these sinteractive powders, pellets with controlled pore
size distribution were obtained by sintering at temperatures as low as 400°C. The analysis of pores
by mercury porosimetry gives an average porosity of 45%. The electrical resistivity, determined by
impedance spectroscopy measurements at 24°C under different humidity environments, shows the
ability of these pellets to adsorb water vapor in the porous surfaces.
Ceramic Chemical Sensors: An Overview
Authors: Weppner Werner
Published: March 2009

Electrostatic potential drops across interfaces caused by the exchange of ions together
with electrons may be used in various ways to measure the concentration of chemical species.
Potentiometric sensors make use of thermodynamic equilibration between the gas and the solid
electrolyte (type I and II) or the gas and a predominantly electronically conducting mixed
conducting electrode in combination with a junction at the electrode/electrolyte interface (type III).
Kinetic sensors make use of the transfer of ions across interfaces under non-equilibrium conditions
and relate the rate determining process to the concentration of the gas. Response time, selectivity
and sensitivity effects are discussed.
Sensor Sensitivity Study of the Thin and Thick WO3 Films to Ozone
Authors: Borisov A. , Ivanova O. , Krutovertsev S. , Pislyakov A.
Published: March 2009

Comparative study of WO3 thick film sensing features obtained by two different methods
to ozone content in the air is presented. The thin films of 0.1-0.3 μ were obtained at evaporation
temperature of 1100°C and pressure in chamber 1,33x10-8 bar. Films were formed by thick film
technology from WO3 based paste. The films sensitivity to ozone is determined by working
temperature of sensors. At the same time the characteristic stability depends on time and magnitude
of temperature impulse. It was shown, that measurement sensor samples have high sensitivity to 70
ppb of ozone in the air.
Microstructural Control of Composite Anode for Anode Supported Intermediate Temperature Solid Oxide Fuel Cells
Authors: Sato Kazuyoshi , Uemura Masayasu , Kondo Akira , Abe Hiroya , Naito Makio , Nogi Kiyoshi
Published: March 2009

Appropriate mechanical milling in dry ambient can improve the mixing state of two
powder materials as well as produce their composite particles. In this study the
influences of milling on microstructure and performance of anode supported SOFCs
was investigated. First, NiO and YSZ powder mixture was milled using an attrition type
apparatus for 5 and 30 min. The SOFCs were made through conventional ceramic
processing with the milled powder mixtures. The different milling time brought to
significant change in power density of the SOFCs. When the powder mixture milled for
5 min was applied, maximum power density of the cell was 0.44 W·cm-2 at 800 °C.
Contrarily, 0.75 W·cm-2 was obtained at the same operation temperature when the
powder mixture milled for 30min was applied. Structural analysis revealed that the
different power density was strongly related to the different anode microstructure.
Prolonged milling resulted in homogeneous porous composite layer with fine Ni and
YSZ grains, indicating larger triple phase boundary (TPB). It was demonstrated that the
appropriate mechanical milling followed by ceramic processing improves the
microstructure, and therefore enhances electrochemical activity of the anode.
Correlation of Electrochemical Properties and Pore Structure for Carbon Nanoarchitectures with Ultrathin, Conformal Poly(o-Methoxyaniline) Coatings
Authors: Long Jeffrey W.
Published: March 2009

We use carbon aerogels and nanofoams as conductive, ultraporous platforms onto which
ultrathin (<5-nm thick) conformal poly(o-methoxyaniline) coatings are applied using self-limiting
electrodeposition. The electroactive polymer coating is incorporated to increase the overall chargestorage
capacity of the resulting hybrid electrode structure. Nitrogen-sorption techniques are used
to characterize the carbon nanoarchitecture pore structure before and after application of the
polymer coating. The subtle modifications of the carbon nanoarchitecture with the polymer coating
are correlated with the resulting electrochemical properties, as determined by cyclic voltammetry
and electrochemical impedance spectroscopy.
Reassembled Octatitanate/Carbon-Fiber Composites as High-Rate Lithium Insertion Electrode
Authors: Suzuki Shinya , Miyayama Masaru
Published: March 2009

Composites of octatitanate and carbon-fibers were prepared through reassembling
tetratitanate nanosheets, synthesized through exfoliation / reassembly process, by the reaction with
HCl in colloidal suspension mixed with carbon- fibers, followed by heat treatment. High-rate lithium
intercalation properties were examined for the reassembled octatitanate / carbon-fiber composites,
and compared with those of reassembled octatitanate simply mixed with carbon-particles. The
reversible capacity and the energy efficiency of the reassembled octatitanate / carbon-fiber
composites were 190 mAh/g and 94 %, respectively, larger than those of a conventional octatitanate
or a reassembled octatitanate. Relatively large capacity of 135 mAh/g still remained at a large
current density of 10 A/g, which corresponds to about 70 % of the discharge capacity at a relatively
small current density of 100 mA/g. Reassembled octatitanate / carbon- fiber composites exhibited an
excellent performance as a high-rate lithium insertion electrode.
Thermodynamic Study of Al-Li-O-Zr: Experimental Results and Thermodynamic Assessment
Authors: Drouelle I. , Chatain Sylvie , Guéneau Christine , Zeller Philippe , Hamon Didier , Toffolon-Masclet Caroline
Published: March 2009

To better understand the formation of solid, liquid and gas phases between the Al-Li-O
ceramics and zirconium (Zr) at temperatures above 1273 K, we built a thermodynamic database on
the Al-Li-O-Zr quaternary system using the CALPHAD method. An accurate knowledge of both
phase diagram and thermodynamic data of all the binary and ternary sub-systems is necessary to
understand the phase relations in the quaternary. The thermodynamic descriptions of both Al-Li-Zr
and Al-O-Zr ternary systems are presented. In addition, the Li-Al-O-Zr system was experimentally
investigated using diffusion couples made of [ Zr / AlxLiyOz ] and [ ZrO2 / AlxLiyOz ] between 1373
K and 1573 K. The experimental results are compared with activity diagrams calculated with the
thermodynamic database.
Mixed Lithium-Boron Materials
Authors: Joy Jonathan S.
Published: March 2009

The blending of lithium hydride with both crystalline and amorphous boron has been investigated in
order to create single, stable inorganic materials. Loadings up to 20% have been achieved in order
to ascertain the ability to evenly distribute the particles throughout the lithium hydride matrix. Initial
X-ray data suggests that amorphous boron is more evenly distributed throughout the lithium hydride
owing to its smaller particle size but pressing the material results in a lower overall density than the
corresponding crystalline boron / lithium hydride mix.
Electrical Conductivity of Proton Conductive Ceramics under Reactor Irradiation
Authors: Shikama Tatsuo , Tsuchiya Bun , Nagata Shinji , Toh Kentaro
Published: March 2009

Electrical charges may be transported in ceramics by not only electrons but also by
electron-holes, ions, and protons. Especially in nuclear fusion environments, electrical conductivity
by proton migration (protonic conduction) will play an important role, as supply of hydrogen isotopes
is sufficient and working temperature for ceramics will be in general high. In the present paper,
radiation effects on the electrical conductivity of perovskite-type oxides will be reviewed,
emphasizing radiation effects on transport behaviors of hydrogen and on reducing behaviors of oxide
ceramics. Some perovskite-type oxides are known to have large protonic conductivity and an
electrical charge state of some atomic elements composing them can be studied easily by
spectroscopic techniques.
Reducing Hydrogen Penetration through Corrosion Layer Formed on Zirconium Alloys by Iron Addition
Authors: Kakiuchi Kazuo , Okubo Kazutoshi , Itagaki Noboru , Miyazaki Akihiro , Ishii Yoshiaki , Suzuki Shunichi , Terai Takayuki , Yamawaki Michio
Published: March 2009

Latest post-irradiation experiment results of Zry-2 and HiFi alloy (0.4%Fe-Zry2) showed that iron
addition reduces the hydrogen pickup by these alloys compared to oxidation amount. In order to clarify
the mechanism of reduced hydrogen absorption rate, (1) autoclave test, (2) surface potential
measurement and (3) hydrogen absorption test of the intermetallic compound were carried out.
Based on these results, a tentative mechanism for hydrogen absorption by zirconium alloys is proposed,
taking into account of both the electrical potential gradient over the oxide film as well as the SPP
window for hydrogen absorption.
Synthesis and Characterisation of BaMIV(PO4)2 in the View of Conditioning of the Actinides
Authors: Popa Karin , Konings Rudy J.M. , Bouëxière Daniel , Popa A. Florin , Geisler T.
Published: March 2009

We present here a systematic study on the BaMIV(PO4)2 double phosphates. We
successfully synthesized the compounds with MIV = Ti, Zr, Hf, Ge, Sn and Th. Several attempts to
obtain the compounds with MIV = Pb, Re, Ce, U and Np have been also performed and the
preliminary findings are discussed here. In agreement with previous studies, the BaMIV(PO4)2 (MIV
= Ti, Zr, Hf, Ge and Sn) compounds crystallize in the C1 2/m 1 space group (yavapaiite structure),
while BaTh(PO4)2 exhibit a different structure. The results on the stability of the BaZr(PO4)2 and
BaHf(PO4)2 yavapaiite-like compounds upon heating and cooling are presented.
Immobilization of Hafnium Surrogates in Fluorapatite
Authors: Fong Shirley K. , Gerrard Lee A. , Metcalfe Brian L. , Donald Ian W.
Published: March 2009

To immobilize the halide and actinide ions present in four Intermediate Level Waste (ILW)
waste-streams the following process has been developed at AWE. The waste streams are
initially calcined with CaHPO4 to yield apatite which is then sintered with a sodium
aluminophosphate glass to produce a monolithic wasteform. As each waste stream
composition is expected to vary widely it is necessary to determine the safe limits of waste
loading at which the actinides will be adequately immobilized via this solid state synthesis
route.
In these initial non-active studies hafnium was used as a surrogate for plutonium. Samples
having nominal composition (Ca10-2xHfx)F2(PO4)6 (x = 0, 0.125, 0.25, 0.5, 0.75, 1.0 and
1.25) were prepared at 850 and 1050 °C. These were studied by XRD to determine the
phase assemblage and solid solution limits in the apatite phase.
Phase pure fluorapatite (Ca10F2(PO4)6) was obtained at 1050 °C (x = 0). At x = 0.125, on
XRD patterns, additional reflections assigned to HfO2, Ca0.5Hf2(PO4)3 and Ca3(PO4)2 were
observed. Proportions of these phases increased with x.
Synthesis at 850°C (x = 0), yielded a two phase mixture of Ca10F2(PO4)6 and β-Ca2P2O7.
At x ≥ 0.250 HfO2 was detectable by XRD, thereafter proportions of HfO2 and β-Ca2P2O7
increased with x.
TiO2 Nanopowders for Sensing Applications; A Comparison between Traditional and Hydrothermal Synthesis Way
Authors: Nagliati Marco , Carotta M.C. , Gherardi S. , Lesci Isidoro Giorgio , Martinelli G.
Published: March 2009

Aim of the work is to compare the morphological properties of TiO2 powders obtained by
different methods. The microstructure of powders is a fundamental parameter to judge if the
material is suitable for gas sensing. Materials for chemical sensors have to be composed by
nanometric and spherical shaped grains sintered in controlled conditions aimed to obtain Schottky
barriers. We investigated a traditional sol-gel (SG) and an hydrothermal (HY) approach to obtain
titanium dioxide powders. The same starting materials were chosen for both SG and HY method, a
Ti-organometallic precursor and, as solvent, an hydroalcoholic solution. The work is focused on the
different methodology and on the outcome related to the two methods (we describe step by step
both of them). HY TiO2 powder shows smaller grains than SG TiO2 maintaining spherical shape. A
comparison among different handled HY powders shows the role of dwelling time (at fixed
temperature) on the nanostructure of grains. Experimental observations are mainly based on XRD
and SEM analyses.
Adsorption and Incorporation of Cadmium into a Calcium Hydroxyapatite
Authors: Marchat David , Bernache-Assollant Didier , Champion Eric , Bêche Eric , Flamant Gilles
Published: March 2009

The removal of cadmium from water by fixation into a calcium phosphate apatite
Ca10(PO4)6(OH)2 (CaHA) was investigated in batch experiments. These ones were carried
out using a wide range of initial Cd2+ concentration, three different temperatures, and
several CaHA surface areas. The amount of immobilized cadmium was proportional to the
surface area of CaHA, whatever the experimental parameters might be. It could reach 7.1
mol of Cd per mol of starting CaHA. Thermal and XPS analyses on the exchanged
powders proved that a part of cadmium was quickly adsorbed at the grains surface in the
form of hydrated complexes [Cd(OH2)n]2+. The latter were formed by an ionic exchange
between adsorbed calcium and cadmium of the solution. Adsorption reaction was mainly
limited by the number of specific sites available on the grains surface.
Structural analyses showed that another part of Cd was slowly incorporated into a solid
solution Ca10-xCdx(PO4)6(OH)2 (CaCdHA) onto the CaHA crystals surface. Results
demonstrated unambiguously that the incorporation process was a surface precipitation and
not an intracrystalline diffusion.
Catalysts for Wet Air Oxidation Based on Ce-Zr-Pr-O Mixed Oxides Prepared by Soft Chemistry
Authors: Mikulová Jana , Rossignol Sylvie , Barbier Jr. Jacques , Kappenstein Charles , Duprez Daniel
Published: March 2009

Sol-gel Zr0.1Ce0.9O2 and Zr0.1(Ce0.75Pr0.25)O2 mixed oxides and coprecipitated pure ceria
CeO2 displaying the fluorine type structure have been used as platinum or ruthenium catalysts’
supports for catalytic wet air oxidation (CWAO) of aqueous solution of acetic acid (78 mmol.L-1).
These catalysts were prepared by conventional impregnation (5 wt-%) from platinum and ruthenium
precursor salts or by exchange (~2 wt-%) in the case of ruthenium. A screening of catalysts in
CWAO at 200°C under 2 MPa was performed and reveals that the best platinum catalyst is
supported on pure ceria displaying large surface. For ruthenium catalysts, the highest conversion
after 3 hours of reaction has been reached by the Ru/Zr-Ce-O system.
Novel Synthetic Clays for Cation Exchange
Authors: Kodama Tatsuya , Gokon Nobuyuki , Komarneni Sridhar
Published: March 2009

This paper reviews synthesis, characterization and cation exchange properties of a novel
swelleing mica "Na-4-mica" and their synthetic analogues with a high layer charge denisty.
Na-4-mica (Na4Mg6Al4Si4O20F4) of a synthetic brittle mica has a very high Al(III) content and but
exhibits unusual swelling behavior and selective cation exchange properties potentially useful in
hazardous cation separations from solutions. Although normal brittle micas do not swell in water at
all, this synthetic mica can readily become hydrated upon contact with water or even in moist air. This
mica has a theoretical cation-exchange capacity of 468 milli-equivalents per 100 g on an anhydrous
basis. The present authors found a simple and cost-effective preparation process of micro- or
nano-crystallites of this mica from naturally occurring clay kaolinite. The fine mica is a selective
exchanger for Sr, Ba, Ra, Pb, Cu, or Zn. The modified micas, such as "Na-3-mica" and "Na-2-mica"
were also synthesized by the similar syntehtic processes. Na-3-mica improved the cation exchange
kinetics and capacity for Sr. These micas also exhibited extremely low cation leachability once
dehydrated at room temperature or moderate temperatures, and, hence, are expected to be useful for
radioactive strontium or radium removal followed by its immobilization for safe disposal.
Harvesting and Manipulating Zeolite Nanocrystals
Authors: Sarangapani Prasad S. , Neal Natahn T.H. , Knott Matthew R. , Thompson Robert W. , Chiang Antony S.T.
Published: March 2009

Recently, we have developed techniques to synthesize, isolate, harvest, and
assemble silicalite nano-crystals into tightly bound aggregates having zeolitic domains
interspersed by mesoporous areas. Crystals with well-defined zeolite structure, as small
as 45 nm, have been synthesized then assembled into aggregate particles or planar films.
This talk will touch briefly on two of these synthesis techniques, some characterizations
of these aggregated nanocrystals, and some projections for future work in the area.
Oriented films of zeolite crystals also can be prepared, using a concentrated
precursor solution; an example of this process will be shown from prior work.
Silicalite-1 microspheres, using a Dowex® ion-exchange resin as a macrotemplate,
were prepared in the size range of ~.5-.65 mm, using hydrothermal synthesis times of 25
h, 35 h, and 45 h at 80 oC. Steaming time and temperature studies were also performed to
determine the effect on the quality of the calcined product.
Structure and Catalytic Testing of Hybrid Al2O3 Systems Deposited on Heat Resisting Steel Substrate by High-Temperature Oxidation and PVD Methods
Authors: Reszka Kazimierz
Published: March 2009

Catalytic combustors for automotive presents a basic problems with obtaining the well developed
oxide surface marked by the occurrence of acidic and basic sites and performing the function of the
catalytic element carrier. The paper includes the comparison of structure and catalytic properties of:
- Al2O3 films obtained by oxidizing the foil made of 0H18J5 alloy in the presence of SO2, at the
1093K , - Al2O3 films obtained by oxidizing the foil, coated firstly with an Al film, in the presence
of Ar+50%O2 at the 1133K, - Al2O3 film systems obtained by oxidizing the foil in the presence of
Ar+50%O2 at the 1133K, then coated an Al nano-film and again oxidized under the same
conditions, - Al2O3 film systems obtained, as previously, by oxidizing the foil, which was firstly
coated with an Al2O3 nano-film by reactive magnetron sputtering. The catalytic activity of
deposited films was determined from the basic sites identified by 2-methylol-3-butyn-2-ol
conversion into acetone and acetylene, and from the acidic sites identified by its dehydration into 2-
methylol-1-buten-3-yn.The structure analysis of the oxide films obtained by oxidizing under SO2
revealed the occurrence of θ-, γ- and α-Al2O3 phases, however the oxide films obtained by
oxidizing the foil with an Al precursor in the presence of Ar+50%O2 contained a small amount of
hematite. The catalytic test revealed that the films containing θ- and γ -Al2O3 have acidic and basic
sites and their catalytic activity is high, whereas α-Al2O3 and amorphous films do not show such the
activity.
Photocatalytic Fiber for Environmental Application
Authors: Ishikawa Toshihiro
Published: March 2009

In order to avoid large problems regarding peering of the titania layer coated on the
substrate, we developed an epoch-making “strong titania fiber” consisting of photoactive surface
layer with a nanometer-scale compositional gradient, which can effectively oxidize any kind of
organic materials. An effective water-purification system using this fiber has been also developed.
The basis of this technology is to incorporate a selected low-molecular-mass additive (Ti(OC4H9)4)
into a precursor polymer from which the ceramic forms. After melt-spinning the resulting precursor
polymer, thermal treatment of the spun fiber leads to controlled phase separation (“bleed-out”) of the
additive; subsequent calcination stabilizes the compositionally changed surface region, generating a
functional surface layer. This fiber consists of the silica-based core-structure and the gradient-like
surface titania layer, which are strongly sintered. We also developed a water-purifier using this fiber
(felt material). Any bacteria (common bacterium, legionera pneumophila, colon bacillus,
heterotrophic bacteria, and so forth) and organic chemicals (dioxin, PCB, and so forth) were
effectively decomposed into CO2 and H2O passing through the above purifier.
Decomposition of Orange II with Si/SiC-TiO2 Fine Open-Cell Photocatalytic Filter
Authors: Tani Eiji
Published: March 2009

Lightweight fine open-cell porous Si/SiC ceramic filter was fabricated using
polyurethane sponge. The thickness of the strut and the cell size of porous Si/SiC ceramics were
almost the same size of the original sponge. This porous ceramic was an ideal structure for
photocatalyst supports. The contact probability between photocatalyst and pollutant could be
easily increased by using this ceramic filter coated with photocatalyst. The TOC value of Orange
II solution, coloring matter, could decrease remarkably using this photocatalytic ceramic filter and
germicidal lamp.
Environmental Applications of the Reactive Titania Coatings Elaborated by Suspension Plasma Spraying
Authors: Toma Filofteia Laura , Bertrand Ghislaine , Meunier Cathy , Begin Sylvie , Klein Didier , Coddet Christian
Published: March 2009

This paper deals with the elaboration of titanium dioxide coatings, designed for
photocatalytic applications, obtained by a non-conventional method of deposition: suspension
plasma spraying (SPS). SPS is an alternative of the atmospheric plasma spraying (APS) in which
the feedstock material is a suspension of the powder to be sprayed. The method consists in injection
and atomization of a slurry (suspension of fine particles in a solvent) in an enthalpic source
(plasma). TiO2 P25 powder (Degussa AG) was mechanically dispersed in distilled water and
ethanol and injected in Ar-H2 or Ar-H2-He plasma under atmospheric conditions. SEM and XRD
were performed to study the microstructure and the crystalline phases of the titania coatings.
Photocatalytic efficiency of the elaborated samples was evaluated from the conversion rate of
nitrogen oxides. The present results showed that the suspension plasma spraying allows to produce
reactive surfaces for the removal of air pollutants, that in the same working conditions, present a
higher photocatalytic activity compared to that of the initial raw powders.
Sol-Gel-Derived Hydroxyapatite and its Application to Sorption of Heavy Metals
Authors: Deptuła A. , Chwastowska J. , Łada Wiesława , Olczak T. , Wawszczak D. , Sterlinska E. , Sartowska B. , Goretta K.C.
Published: March 2009

Hydroxyapatite (HA) microspheres of diameter <70 μm have been synthesized by solgel
processing. The starting sols were prepared by ultrasonic mixing of concentrated solutions of
calcium acetate (1.7M) with 85% H3PO4, followed by emulsification in dehydrated 2-ethyl-1-
hexanol. Drops of emulsion were solidified by extraction of water with this solvent. The final
thermal treatment was a 2 h soaking in air at 900°C. Properties such as hydraulic resistance and
sedimentation rate, which are important for application in ion-exchangers, were superior for our
prepared microspheres in comparison with irregularly shaped commercial HA. Adsorption of the
following metals was investigated: U, Zn, Fe, Cu, Ni, Co, Cd, Pb, Mn, Al, Cr, As, Sb, Bi and
Mo. Retention was ≈100% for of all the metals studied when pH > 3–4. On average, ≈1/20 moles
of metal reacted with 1 mole of HA. Adsorbed metals could be desorbed with efficiencies of
60–90%. In addition, nuclear-waste-saturated beds of HA could be transformed to insoluble
ceramics by thermal treatment. The cost of producing HA microspheres was estimated to be
comparable to current prices of irregularly shaped commercial hydroxyapatite powders. For
radioactive contaminants such as U, for which resorption need not be considered, porous
monoliths were produced by use of industrial reagents. The retention capacity was determined to
be 30 mg of U per 1 mg of monolith.