bluuebunny/crossref_metadata_2025 huggingface dataset:
From Atomic-Level Lattice Structure to Estimate the Silicon Mechanical Bulk Behaviour Using the Atomistic-Continuum Mechanics
Authors: Lin Chun Te , Chiang Kuo Ning
Published: March 2009

This paper proposes a novel atomistic-continuum mechanics (ACM) based on the finite
element method (FEM) to investigate the mechanical bulk behavior of atomic-level single crystal
silicon under uniaxial tensile loading. The ACM could be reduced efficiently the computational time
and maintained the simulation accuracy. A general form of Stillinger-Weber potential function was
used for interaction between the silicon atoms in the ACM simulations. Simulation results shows that
the Young’s modulus of single crystal silicon were 121.8, 153 and 174.6 GPa along the (100), (110)
and (111) crystallographic plane, respectively. These results are in reasonable agreement with the
experiment and simulation results reported in the literature.
On the Study of the Mechanical Behaviours of the Flange Repaired Composite Panels under Tension
Authors: Jiang Yun Peng
Published: March 2009

Firstly the tension experiment was undertaken to investigate the mechanic behaviors of
the flange repaired composite panels in this paper. Emphases were played on the damage initiation
and the failure strength for the repaired composite structure. Then numerical studies were conducted
by using finite element method. The effect of geometric non-linearity on the stress-strain response
was taken into account through quadrilateral, thick shell elements (S8R). A better agreement with
experiment could be obtained when geometric non-linearity was considered. In addition, a user
material subroutine (UMAT) was implemented into ABAQUS for studying damage initiation and
its progression in the composite structure. Finally, all the predicted strain distributions, damage
development and strength of the repaired laminate were compared with experiments. The
predictions and experiments were found to be in good agreement.
Synthesis and Forming of Titanium Matrix Composites by Casting Route
Authors: Sung Si Young , Choi Bong Jae , Kim Young Jig
Published: March 2009

The aim of this study is to evaluated the possibility of the in-situ synthesized (TiC+TiB)
reinforced titanium matrix composites (TMCs) for the application of structural materials. In-situ
synthesis and casting of TMCs were carried out in a vacuum induction melting furnace with Ti and
B4C. The synthesized TMCs were characterized using scanning electron microscopy, an electron
probe micro-analyzer and transmission electron microscopy, and evaluated through thermodynamic
calculations. The spherical TiC plus needle-like and large, many-angled facet TiB reinforced TMCs
can be synthesized with Ti and B4C by a melting route.
Physical and Mechanical Properties of Mullite-Whisker Reinforced Alumina Composites
Authors: Pang Wei Kong , Tezuka Nobuo , Low It Meng , Mehrtens E.G. , Latella Bruno A.
Published: March 2009

Reaction sintering and hot-isostatic-pressing (HIP) have been used for the compaction and
densification of mullite-whisker-reinforced alumina composites. The effect of alumina matrix
constraints on the in-situ transformation sequence in alumina-halloysite-AlF3 system was studied
using differential thermal analysis. The physical and mechanical properties of the HIPed samples
have been characterized in terms of bulk density, apparent solid density, porosity, Young’s moduli,
flexural strength, hardness and the fracture toughness.
Optimization of Composite Housing in a Multi-Special Camera Using Kriging Algorithm
Authors: Park Jung Sun , Im Jong Bin , Ro Youg Hee
Published: March 2009

This paper is concerned with the optimization of composite housing in a multi-spectral
camera using Kriging algorithm. The effective use of Kriging on physical problems has been
expanded to provide global approximations for optimization problems. There are two major strategies
to improve efficiency and accuracy of approximate optimization using Kriging. These methods are
performed by the stochastic process, stochastic-localization method (SLM), as the criterion to move
the local domains and the design of experiment (DOE), the classical design and space-filling design.
The proposed methodology is applied to the design of a Multi-Spectral Camera (MSC), as a practical
example, which will provide high resolution panchromatic and multi-spectral images and is carried by
a satellite designed to fulfill the need for further Earth observation and allowing scientists and
communication experts to conduct potentially valuable experiments. When this composite structure is
optimized, design constraints are taken for natural frequency and shear stress which should be
considered in a launching environment.
Improvement of the Crack Resistance of a Carbon/Epoxy Composite at Cryogenic Temperature
Authors: Kim Myung Gon , Hong Joong Sik , Kang Sang Guk , Kim Chun Gon , Kong Cheol Won
Published: March 2009

The improvement of crack resistance is essential to the application of composites for
cryogenic use such as structures storing liquid oxygen or liquid hydrogen. In this study, an effort to
improve the crack resistance of a carbon/epoxy composite was made by adding MWNTs
(Multi-Walled Carbon Nanotubes) to the resin formulation. Ahead of the investigation of MWNT
effect, an epoxy matrix system was developed by mixing two kinds of epoxy resins and adding
additives for high toughness at cryogenic temperature. The MWNT-added carbon/epoxy
unidirectional prepregs were fabricated by way of a filament winding method with different
concentrations of MWNTs (0.2wt% and 0.7wt%). The mechanical tests were performed inside an
environmental chamber at room temperature and -150°C. The developed material system has little
influence on interlaminar shear strength but resulted in higher fracture toughness at -150°C than those
of baseline material. Microcrack densities after thermo-mechanical cycles were measured through an
optical microscope.
Characterization of “Green” Composites Reinforced by Cellulose Nanofibers
Authors: Takagi Hitoshi , Asano Akira
Published: March 2009

Environment-friendly “green” composites were fabricated from a starch-based,
dispersion-type biodegradable resin and cellulose nanofibers. The mixture of the dispersion-type
biodegradable resin and cellulose nanofibers were blended well by using a home-use mixer and a
stirrer, and then dried in air or in a vacuum. Composites were prepared by conventional hot pressing at
a constant temperature of 140°C and at pressures from 10 to 50 MPa. Their flexural strength as well as
flexural modulus increased with increasing the molding pressure, and were also affected by
preparation methods and conditions. Their mechanical properties such as strength and modulus had a
good correlation with their density. Especially it can be seen that there is significant effectiveness in a
stirrer mixing process, which results in the improved uniform dispersion of nanofibers.
Environmental-Friendly Sandwich Panel Using Bamboo Skin Wastes as Core Material
Authors: Kamarulzaman Norlida , Bahari Shahril Anuar , Zakaria Mohd Nazarudin , Jamaludin Mohd Ariff
Published: March 2009

This paper discusses the results from a study that has been undertaken to develop a product from
bamboo culm’s outer skin that was considered as wastes. Initially, by means of a simple process of
gluing and pressing, bamboo panel composites were produced with Gigantochloa scortechinii
bamboo skin wastes. Using existing sandwich technology, layered or sandwich panel were then
produced using the bamboo skin wastes panel as the core material while plywood were used as the
outer layer. The aim was to access the bending strength of the bamboo skin wastes panel, the
sandwich panel and subsequently to compare them with common bamboo composites that utilized
either strips or splits in their production process. Though the product has limited strength and is
restricted to interior and non-structural components, it is still very well suitable for wall, doors,
tabletops and shelves.
Fungal and Alkali Interfacial Modification of Hemp Fibre Reinforced Composites
Authors: Pickering K.L. , Li Y. , Farrell R.L.
Published: March 2009

The aim of the current work was to investigate using fungi to treat hemp fibre to create
better bonding characteristics in natural fibre reinforced polypropylene composites. X-ray diffraction
(XRD), lignin testing and scanning electron microscopy (SEM), were used to characterise the effect
of treatment on hemp fibres. A combined alkali and fungal treated fibre composite produced the
highest tensile strength of 48.3 MPa, an increase of 32% compared to composites with untreated fibre.
A Method for Identifying Asymmetric Dissimilar Constant Fatigue Life Diagrams for CFRP Laminates
Authors: Kawai Masamichi
Published: March 2009

The full shape of constant fatigue life (CFL) diagram has been identified for three kinds
of carbon fiber-reinforced plastic (CFRP) laminates of [45/90/-45/0]2s, [0/60/-60]2s and [0/90]3s
lay-ups, respectively. First, the effects of mean stress on fatigue behavior are observed for the
quasi-isotropic [45/90/-45/0]2s CFRP laminate. It is clearly observed that the CFL diagram turns out
asymmetric and the peak of the CFL diagram is slightly offset to the right of the alternating stress
axis. The CFL plots indicate that the alternating stress component of fatigue load becomes maximal
at a critical stress ratio closely equal to the compressive strength to tensile one (i.e. a C/T strength
ratio). It is also demonstrated that CFL curves for different constant values of life are linear in the
range of a short life, but they turn quadratic in the range of a longer life. Similar features are
observed for the other kinds of CFRP laminates. Then, to construct the asymmetric dissimilar shape
of CFL diagrams, a new methodology is developed on the basis of the static strengths in tension and
compression and the reference S-N relationship for the critical stress ratio. An efficient procedure
for determining the reference S-N relationship for the critical stress ratio by using fatigue data for
another stress ratio is also developed.
Off-Axis Nonlinear Behavior of Hybrid GFRP/Al Laminates and Simulations by FEM
Authors: Takashima H. , Kawai Masamichi , Matsuda Tetsuya
Published: March 2009

Off-axis tensile behavior of two grades of hybrid laminates, GLARE-2 and GLARE-3,
made of unidirectional glass/epoxy laminae (GFRP) and aluminum (Al) alloy sheets is examined
for various fiber orientations, and the differences in mechanical properties between the
unidirectional and cross-ply hybrid laminates are quantified. The problem of accurately describing
the nonlinear deformation of GLARE laminates under off-axis loading conditions is revisited, and
the effect of local nonlinear deformation in the constituent GFRP layers on the overall inelastic
behavior of GLARE laminates subjected to inclined tensile loading is elucidated by means of
elastic-plastic finite element (FE) analyses.
Nano-Structured CrN/CNx Multilayer Films
Authors: Vyas A. , Shen Yao Gen , Zhou Zhi Feng , Li K.Y.
Published: March 2009

CrN/CNx nano-scale multilayered films were deposited on Si (100) substrate by closed-field
unbalanced magnetron sputtering. Designed experimental parameters enabled an evaluation of the
effects of negative substrate bias voltage (Vb), and bi-layer thickness λ (by changing substrate
rotation rate) during deposition on the structural and mechanical properties of multilayer films.
These multilayers were characterized and analyzed by transmission electron microscope (TEM),
X-ray diffraction (XRD), atomic force microscopy (AFM), and nanoindentation measurements. In
all cases, the CNx layers were amorphous and independent of Vb, while the microstructures of the
CrN layers were dependent primarily on Vb. The CrN layers showed a mixed structure phase
consisting of CrN, Cr2N, and Cr at Vb = -(40-120) V. At higher Vb values (-140 V or above), the
Cr2N phase was dominant along with low CrN phase content. AFM measurements revealed that the
root-mean-square (rms) surface roughness of the CrN/CNx film was 2 nm at Vb= -200 V whereas
the rms values were about 9.5-3.3 nm for lower Vb values of -(40-180 V). By nanoindentation
measurements, a maximum hardness of about 36 GPa was observed at Vb= -140 V. The improved
mechanical properties of the films are correlated to the phase formation during deposition.
Investigation of Material Removal Mechanism in EDM of Sintered NdFeB Permanent Magnet
Authors: Li Li , Niu Zong Wei , Zhang Jian Hua
Published: March 2009

Sintered NdFeB permanent magnet is widely used in many applications because of its
excellent magnet property. However the report of EDM research on NdFeB magnet is not available.
This paper presents a detailed investigation of the material removal mechanisms of sintered NdFeB
magnet through analysis of the machining debris and the surface SEM quality. It is included three
types of machining mechanisms: melting and evaporating, thermal cracking, spalling or whole grain
removal.
High Proton-Conducting Sulfonated Poly (Ether Ether Ketone)/ Functionalized Mesoporous Silica Composite Membranes
Authors: Lin Yu Feng , Ma Chen Chi M. , Lin Yao Yu , Yen Chuan Yu , Hung Chih Hung
Published: March 2009

A novel organic–inorganic mesoporous silica functionalized with perfluoroalkylsulfonic
acid groups analogous to that of Nafion® has been prepared. A condensation reaction between surface
silanol groups of the mesoporous silicas and 1,2,2-trifluoro-2-hydroxy-1-trifluoromethylethane
sulfonic acid Beta-sultone was conducted. High proton conducting sulfonated poly(ether ether
ketone) (sPEEK)/ functionalized mesoporous silica composite membranes were prepared through
homogeneous dispersive mixing and solvent casting method. In the study, proton conductivity (σ) of
composite membrane is increased from 0.01 to 0.038 (S/cm) as the modified mesoporous silica
content is increased from 0 to 5 wt. %. It is found that the ion exchange capacity (IEC) is increased
from 1.54 to 1.70 (meq/g) as the modified mesoporous silica content is increased from 0 to 5 wt. %.
From morphology investigation, it is found that incorporation of modified mesoporous silica by rotary
vacuum evaporation enables the preparation of homogeneous membranes. The membranes present a
good adhesion between inorganic domains which could be used for fuel cell applications.
Self-Detection of Temperature in TiNi Fiber Reinforced Smart Composite Materials
Authors: Yamashita Keitaro , Shimamoto Akira
Published: March 2009

The method of generating the most practicable shape recovery force in smart composite
materials which embedded shape-memory alloy (SMA) fiber under the resin matrix is electric
heating. However, because the calorie for the heating of the resin matrix increases in the low
temperature environment, it is necessary to control the electric heating corresponding to an ambient
temperature to obtaining a steady shape recovery force. Then, the method of self-detecting the
temperature without using a special temperature sensor by measuring the electrical resistance of the
SMA fiber in the composite material was examined.
Vibration and Sound Radiation of Truss Core Panels
Authors: Ren Jian , Deng C.H. , Hou Q.Z.
Published: March 2009

The dynamic response and the sound radiation of truss core panels are investigated in this
paper. The spectral element model for the truss core panel is developed. The element model is
established by employing shape functions derived directly from the solution of distributed parameter
models for each beam element. Forced vibrations of a fluid-loaded beam in a rigid baffle are
considered. The spectral formulation can be easily and efficiently coupled with the Fourier transform
(FT) based analysis of the structure’s sound radiation in a surrounding acoustic medium. Hence the
proposed formulation is an efficient numerical tool for the analysis of the dynamic and acoustic
performance of the considered truss core sandwich panels. The comparison of the sound
characteristics selected as sound transmission reduction index to the psychical parameters of the truss
core beam is carried out.
Performance of a Dielectric Elastomer Generator Diaphragm as a Smart Composite at Different Pre-Strain Levels
Authors: Khosroshahi M.R. , Ghaffarian S.R. , Khodaparast P.
Published: March 2009

Dielectric elastomers (DEs) could be considered as a new type of transducers. They can
convert electrical and mechanical energies in a bi-directional manner. In this work, the
electromechanical behavior of a DE diaphragmatic generator was investigated. Circular diaphragms
were fabricated using a prestretched DE film sandwiched between laminates of compliant electrodes.
A special chamber was used to apply pressure. Pressure-Volume characteristics of diaphragms were
measured to calculate elastic energy density. DC voltages were applied to the electrodes and the
generated voltages were measured. It was concluded that efficiency of generators was strongly
dependent on the amount of biased voltage, pre-straining level and applied pressures.
A New Dewaxing Method and its Effect on the Properties of Low-Pressure Injection Molded Ceramics
Authors: Wu Yin , Si Wen Jie , Miao He Zhuo
Published: March 2009

A new dewaxing method for low-pressure injection molded ceramics is presented.
Supercritical extraction with carbon dioxide was used to remove paraffin wax from the ceramic green
parts. The composition of organic additives for low-pressure injection molding feedstock and the
extraction condition for the green parts were investigated. Moreover, the properties of sintered ceramic
samples dewaxed by supercritical carbon dioxide were compared with those by thermal dewaxing. The
results show that the new binder system containing 50wt% paraffin wax, 35% bee wax and 15% stearic
acid fulfills the requirements of both low-pressure injection molding feedstocks and supercritical
dewaxing, where the feedstock has high fluidity, low viscosity and quick solidification. The efficient
extraction condition for supercritical dewaxing from the green parts is at 30MPa pressure and 45°C.
Under this condition, defect free ceramic green parts can be obtained. Dewaxing methods have significant
influence on the properties of sintered parts. The mechanical properties of the sintered sample can be
improved by supercritical dewaxing. With this method, the bending strength of sintered samples (σ =
331.6 MPa) is higher than that obtained by thermal treatment (σ = 312.3MPa). The sintered samples
dewaxed by supercritical CO2 have shown the property of higher density and less distortion compared to
the thermal dewaxing method. Moreover, with supercritical extraction the dewaxing time can be reduced
to about one tenth of the time required by thermal dewaxing.
Preparation of Porous Alumina Ceramics by Spark Plasma Sintering
Authors: Cho Won Seung , Yoo Yeon Chul , Whang Chin Myung , Cho Nam Hee , Hwang Woon Suk , Kim Jun Gyu , Kwon Young Jae
Published: March 2009

Porous alumina bodies were successfully prepared by spark plasma sintering of alumina
powders with different amounts of graphite, and by subsequently burning out the graphite. Highly
porous bodies were fabricated by spark plasma sintering at 1000°C for 3 min under a pressure of 30
MPa. The heating rate was 80°C/min, and the pulse pattern (on-off) was 12:2. For example, alumina
bodies prepared by the addition of 10 ~ 30 vol% graphite showed high porosity of 50 ~ 57%. Porous
alumina bodies prepared by the addition of 10 ~ 30 vol% graphite had a high compressive strength of
200 ± 55 MPa, about 35 times higher than those obtained on samples prepared by pressureless
sintering, and about 2.5 times higher than those in samples prepared by hot-pressing. The significant
improvement in strength relative to values obtained with conventional sintering was attributed to
better sintering resulting from the rapid heating between particles.
Fabrication of Reticulated Porous Ceramics with Controlled Structure by Centrifuging Process
Authors: Pu Xi Peng , Zhang Da Feng , Liu Xue Jian
Published: March 2009

Reticulated porous ceramics (RPCs) with uniform structure were fabricated by a two-step centrifuging process. The two-step centrifuging process includes two centrifuging steps. In the first stage, the polyurethane sponges are coated with thin slurry through high speed centrifuging process. In the second stage, the as-prepared dried green body was recoated with thixotropic slurry through centrifuging process with an appropriate centrifuging speed. According to the results, the RPCs with controlled structure can be fabricated by modulating the rotation speed in the second centrifuging process.
Effect of the Formation of SiC Whisker on the Properties of Al2O3-ZrO2-C Materials
Authors: Gu Hua Zhi , Shao Rong Dan , Zhang Wen Jie , Wang Hou Zhi , Yang Kai Bao , Yu Shu Zhong
Published: March 2009

SiC whisker was produced through the reaction between carbon and silicon powders during the
sintering of Al2O3-ZrO2-C materials. The thermodynamic conditions and growth mechanism were
discussed. The results showed that rod-shaped and dumbbell-shaped SiC whiskers are formed,
respectively. The main composition of the beads in dumbbell-shaped whisker is SiOX with a small
amount of Na and Ca, but the rods are SiC. In addition, the dumbbell-shaped SiC whisker contributed less
than straight rod-shaped SiC whisker to improving the physical properties of Al2O3-ZrO2-C materials.
CNTs/Si3N4 Composites Fabricated by Reaction Bonded Processing
Authors: Huang Zhi Yong , Liu Xue Jian , Sun Xing Wei , Huang Li Ping
Published: March 2009

The CNTs/Si3N4 ceramic matrix composites were prepared by the reaction bonded processing.
The phase compositions, chemical compatibility, mechanical properties, and microwave attenuation
properties of the composites were investigated. XRD analysis shows the composites consist mainly of the
α- and β-Si3N4, with a trace of unreacted silicon. The SEM micrograph displays the fractured surface of
the composites studs with intact CNTs, indicating that CNTs and Si3N4 are chemically compatible. The
composites with 1.0wt.% CNTs have a strength of 280 MPa, hardness of 8.2 GPa and toughness of 2.3
MPa·m0.5. The average value of the transmission attenuation reaches 6 dB at X band, indicating the
composites have a potential for application in electromagnetic adsorbing or shielding.
Synthesis of Aluminum Titanate Solid Solution by Solid State Reaction of Fine Commercial Al2O3, TiO2 and MgO Powders
Authors: Xu Gang , Tu Con Jiang , Weng Wen Jian , Du Pi Yi , Shen Ge , Han Gao Rong
Published: March 2009

The synthesis of aluminum titanate solid solution (Al2(1-x)MgxTi1+xO5, x=0, 0.1, 0.2) powders
was realized by solid state reaction method using fine commercial α-Al2O3, TiO2 and MgO powders as
raw materials. The effect of the introduced amount of MgO on the phase formation of aluminum titanate
solid solution was investigated by XRD following the phase evolution. It was revealed that the
introduction of MgO strongly affects the formation of Al2(1-x)MgxTi(1+x)O5 solid solution. The easily
formed MgTi2O5 acts as the nucleus prompting the formation and lowering the synthesis temperature. The
microstructure and properties of the solid solution ceramics were also studied by SEM and measuring the
fracture strength and the thermal expansion coefficient.
Fabrication of Fe-Al Intermetallic/TiC-Al2O3 Ceramic Composites from Ilmenite by Reaction Sintering
Authors: Zou Zheng Guang , Yin Chuan Qiang , Wu Yi , Li Xiao Min
Published: March 2009

Fe-Al intermetallic/TiC-Al2O3 ceramic composites were fabricated by in-situ carbothermic
and aluminothermic reduction from natural ilmenite. Synthesis and sintering of the composites were
accomplished unanimously in the vacuum hot pressure furnace. The thermodynamic process, the
composition, the microstructure as well as the properties of the FeTiO3-Al-C system were studied in
detail through theoretical analysis and experimental research. It was shown that the synthesis process
started from the melting aluminium, followed by the deoxidation of ilmenite step by step via a series of
different valent titanium oxides to form TiC, Al2O3 and Fe-Al as the ultimate productions. The particle
sizes are mostly 3-5μm, and their distributions are uniform. Meanwhile, the addition of additives can
improve the wettability of alloy to ceramic phases and the combination of the interfaces, giving rise to the
properties of the composites as a whole.
Preparation of Nanoporous Super Thermal Insulation Material Compounded with Xonotlite-SiO2-Aerogel and Characterization of the Pore Structure
Authors: Cao Jian Xin , Zhang Yu , Zeng Ling Ke
Published: March 2009

Ultra-light calcium silicate material constructed with fibrous xonotlite crystals has an
advantage of low-thermal conduction coefficient. But the microporous structure can hardly make a better
performance in terms of super thermal insulation. Although nanoporous structure of SiO2-aerogel
satisfies the requirement, its tenacity is not strong enough to produce by itself blocky super thermal
insulation material. This research, thus proposes to apply SiO2-aerogel as nanoporous carrier in the
process of preparation, with Ultra-light calcium silicate material constructed with fibrous xonotlite
crystals as the matrix so as to prepare nanoporous super thermal insulation material compounded with
Xonotlite-SiO2-aerogel via so-gel method and ethanol supercritical drying. SEM and pore size
distribution techniques were here applied to characterize the morphology and pore structure of the
composite material. The results show that the SiO2-aerogels were better distributed in pore of calcium
silicate matrix, with the pore size distribution of composite ranging from 10 nanometers to 50 nanometers,
and average pore size less then 20 nm.
Inhibitory Effect of Synthetic Nano-Hydroxyapatite on Dental Caries
Authors: Lu Kui Long , Meng Xiang Cai , Zhang Jiu Xing , Li Xing Yi , Zhou Mei Ling
Published: March 2009

The objective of this study was to investigate the inhibitory effect of the synthetic nanohydroxyapatite (HA) on dental caries. The nano-HA was synthesized by using the depositing reaction of Ca (H2PO4)2. The artificial dental caries was made by using sour solution and inoculating Streptococcus mutans (S.mutans) to the Sprague-Dawley (SD) rat’s mouth respectively. After mineralization of solution of nano-HA for 10 days, the hardness of enamel was measured. The inhibitory effect of the synthetic nano-HA on dental caries was detected by gargling way to rinse the rat tooth with the solution of nano-HA in the animal test. Transmission electron microscopy (TEM) revealed that the dried HA particles were needle-like with ф5-20nm×60nm and the sintered HA particles were spherical with less than 100nm. The remineralized test indicated that the solution of nano-HA with different shapes enhanced the hardness of artificial caries and improved the remineralization of artificial caries. The animal test showed that the dried nano-HA had the inhibitory effect on dental caries. The good absorptive effect of the nano-HA on both the saliva protein and the glucans leads to the development of interventions that could reduce or modify bacterial colonization of tooth surfaces.
Preparation of Antibacterial Ceramics with Silver-Carrying Nano-Hydroxyapatite
Authors: Su B.H. , Xiong Zhao Xian
Published: March 2009

In this paper, antibacterial agent of silver-carrying nano-hydroxyapatite is synthesized by an
ion exchange reaction, which is mixed thoroughly with a commercial glaze for antibacterial ceramics.
The valence states of Ag in antibacterial agent are confirmed to be +1 and 0 by XPS. Antibacterial effect
against bacterium of E. coli is also tested. Experimental results indicate that the antibacterial ceramics
exhibit excellent antibacterial performances, with bactericidal rate of 99.92%.
A Study on Biomineralization Behavior of Silk Fibroin Film
Authors: Zhao Yong , Chen Jing , Nie Rong Rong , Deng Xia , He Gang , Niu Lin , Wang Chang Xiang , Chen Zhi Qing
Published: March 2009

The aim of the present study is to evaluate the biomineralization behavior of silk fibroin. The
biomimetic mineralization was carried out in an alternative calcium/phosphate soaking solution (ACPS).
The formation of calcium phosphate deposits was identified by scanning electron microscopy (SEM),
energy-dispersive X-ray (EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy
(FTIR). A quick formation of well-crystallized apatite on the surface of the silk fibroin film indicates that
biomineralization may be an effective approach to obtaining fibroin/HAP composites.
Structure and In Vitro Bioactivity of Si Enriched Hydroxyapatite/TiO2 Coatings on Pure Titanium by Micro-Arc Oxidation
Authors: Nie Rong Rong , Zhu Feng , Shen Li Ru , Chen Zhi Qing , Li Xiao Yu , Deng Xia , He Gang , Zhao Yong , Liang Zhi Hong
Published: March 2009

The effect of Si doping on the bioactivity and characteristics of hydroxyapatite/TiO2 composite
films was investigated. Pure titanium plates were treated to form Ca, P and Si enriched titania-based films
by using micro-arc oxidation (MAO). Then, some specimens were undergone a further hydrothermal
treatment to produce a thin outermost layer of hydroxyapatite (HA). Experiments revealed that that the
film, which was about 10μm thick, was composed of amorphous silicon dioxide, amorphous calcium
phosphate, rutile and anatase. The film was porous and uneven, with the pore size of 1-4μm. No obvious
cracks exist on the surface. In order to investigate the cytocompatibility of the films, periodontal ligament
(PDL) cells were seeded onto the surface of the films. It was concluded that the Si ion did not influence
the characters of MAO film but Si enriched hydroxyapatite/ TiO2 composite coatings exhibited an effect
on cell attachment.
Degradation Behavior of β-Ca3 (PO4)2/β-Ca2P2O7 Bioceramics
Authors: Li Yuan Yuan , Yang De An , Zhao Hong
Published: March 2009

β-tricalcium phosphate (β-TCP) added with certain amounts of β-calcium pyrophosphate
(β-CPP) was prepared. Degradation behavior of β-TCP/β-CPP ceramic was tested by soaking in Tris
solution for 20d. The morphologies of composites before and after degradation were observed by SEM.
The weight loss was tested after soaking in immersion solution. The results showed that the β-TCP/β-CPP
ceramic had great potential as a biodegradable bone substitute.
Design and Properties of Fire-Proof Coating for Tunnels
Authors: Yao Ya Dong , Yin Guang Fu , Cheng Xiao Wei , Gou Xiang Li
Published: March 2009

Silicate fireproof coatings for tunnels (FCT) have many eminent properties. But low adhesion
strength and poor water/fire-resistance of this kind of materials largely limit its applications. Here we
reported a new kind of FCT based on high alumina cement as principle adhesive, redispersible powder as
assisting adhesive, ammonium polyphosphate as fire-retardant material, vermiculite as adiabatic padding,
and magnesium hydroxide as assisting reagents. The influence of various experimental conditions on fire
resistance, adhesion strength and water resistance were carefully studied. Results showed that dispersible
emulsoid powder was a key component affecting adhesion strength and water resistance of FCT, whereas
fire-retardant material posed significant effects on the fire resistance.
Microstructure Characteristics in the BaTiO3-La2O3-Nb2O5 Ternary System
Authors: Wang Yue Hui , Wang Ting , Shi Shi Kao , Shen Jian Hong , Zhou Ji
Published: March 2009

A series of powders of (Ba1-xLa2x/3)(Ti1-xNb4x/5)O3 (0.05≤x≤0.3) have been synthesized by solid-state reaction route, and the effects of the dopants on the microstructure of BaTiO3 were investigated by XRD, SEM, HTEM and EDS in the BaTiO3-La2O3-Nb2O5 ternary system. It was found that the secondary titanium-rich phase occurred for x ≤ 0.1, while Ba3La3Ti5Nb5O30 yields as secondary phase for x ≥ 0.2. In the whole range of 0.05 ≤ x ≤ 0.3, the crystal structure of BaTiO3 solid solutions is cubic system. There are two substitution modes in the system: the substitution mode of La ions dissolved into Ba sites is significant for x ≤ 0.2, but the substitution mode of Nb ions dissolved into Ti sites is significant for x>0.2. TEM observation and EDS analysis revealed that the concentration gradient of Nb existed and La almost distributed homogeneously in a grain. Thus, the dielectric materials composed of La-Nb-codoped BT are not fitted to form the core-shell structure for the higher dopants.
Development of Glass Ceramic by Sintering and Crystallization of Glass from Phosphorus Slag
Authors: Lin Qian , Cao Jian Xin , Fu Cheng Bing , Zhang Yuan
Published: March 2009

The phosphorus slag produced as the waste of yellow phosphorus manufacturing was studied for the production of calcium-aluminum-silicone system glass ceramic materials. The thermal behavior and crystallization processes of fine powders of parent glass with chemical composition (wt. %) 52-60 SiO2, 22-28 CaO, 2-10 Al2O3, 3-8Na2O+K2O, 1.7-2.1P2O5 and 1.6-2.0 F were carefully studied by DTA, XRD and SEM techniques. The desired sequence of events, i.e. nucleation, sintering and devitrification occurred by heat treating the glass powder. The results showed that the phosphorus slag can be as a main raw material directly in production of the glass ceramic.
Effects of Acidic Amino Acids on Hydroxyapatite Morphology
Authors: Gao Wei Min , Ruan Cheng Xiang , Chen Yun Fa
Published: March 2009

Hydroxyapatite nanoparticles were synthesized in the presence of two kinds of acidic amino acids in order to investigate the effects of acidic amino acids on the morphology of hydroxyapatite obtained by homogeneous precipitation and hydrothermal treating. The results of X-ray diffraction analysis and microphotographs of transmission electron microscope showed that the morphology of hydroxyapatite nanoparticles changed significantly only with aspartic acid. Hydroxyapatite synthesized with aspartic acid showed smooth flake-like morphology at pH= 11 and flake-like morphology with stripes at pH= 8. However, hydroxyapatite synthesized in the present of glutamic acid showed rod-like morphology at both pH values. Variation in the morphology of nanoparticles could be consistent with the difference in the affinity of amino acids binding at the hydroxyapatite crystal surface. The adsorption process was revealed by computer simulation of molecular mechanics using energy minimizing method.
Hydrothermal Conversion Deposition of ZnFe2O4 Doped TiO2 Thin Films and their Photovoltaic Response
Authors: Guo Zhi Hong , Ling Yun Han , Jiang Wu Feng , Li Hong Yi , Bai Xin De
Published: March 2009

To improve its visible light response capability, a new narrow bandgap zinc ferrite
semiconductor was in-situ introduced into the matrix of titanium dioxide nano film. ZnFe2O4 doped TiO2
composite films have been successfully formed on glass and stainless steel substrates from aqueous
solution through equilibrium reaction between iron (III)-titanium (IV)-fluoric complex and boric acid,
followed by in-situ hydrothermal conversion and crystallization in the Zn2+-contained basic environment.
The obtained films were densely packed and had no visible cracks; clear photovoltaic responses were
observed in the anodic direction, and they were much larger in the presence of ferrite dopant. It is
suggested that the shift of the corrosion potential was ascribed to photo-induced charge separation
between the conduction band of ZnFe2O4 and its counterpart TiO2 nano-particles.
Effects of Nanosized Iron Oxide with Different Morphology on Nanomechanical Properties of Nanocomposite Coating
Authors: Wang Qi , Jang Min , Chen Yun Fa
Published: March 2009

The nanocomposite coatings were prepared on the surface of PVC substrate using spinning
technique with attempts of introducing nanosized iron oxide particles with different morphology into the
organic-inorganic hybrid matrices. The hybrid matrices were derived from 3-glycidoxypropyltrimethoxysilane
(GLYMO) and tetraethoxysilane (TEOS) with a process of hydrolyzing and condensation.
Nanosized iron oxide particles were synthesized by hydrolysis of FeCl3 solution at different pH value and
different temperature. The effects of different additions on nanomechanical properties of the
nanocomposite coatings were investigated using X-ray powder diffraction (XRD), transmission electron
microscopy (TEM) and MTS Nano Indenter XP system. It was found that the acicular α-FeOOH and
spherical α-Fe2O3 particles were synthesized, both of them dispersed homogeneously. Nanoindentation
and nanoscratch behaviors of the nanoindenter system showed that both of the nanocomposite coatings
reinforced the nanomechanical properties of the PVC obviously. Especially, the contribution of acicular
α-FeOOH was more remarkable than the spherical α-Fe2O3.
Suspension Characteristics and Rheological Properties of Aqueous Alumina/Zirconia Freeze Casting Slurries
Authors: Lyu Seung Woo , Park Young Min , Yang Tae Young , Ryu S.C. , Stevens Ron , Park Hong Chae
Published: March 2009

The dispersion and rheological behavior of aqueous alumina, zirconia, and mixed alumina/
zirconia slurries have been studied in terms of solid loading and the incorporated multiple processing
additives. Darvan-C, Dynol 604, Glycerol, and PVA were used as the dispersant, surfactant,
cryoprotectant, and binder, respectively. Sedimentation density increased significantly on adding the
dispersant; its effectiveness was similar for both the alumina and zirconia suspensions. With further
addition of binder, the sedimentation density decreased. The suspension viscosity generally behaved in an
opposite manner to the sedimentation density, i.e., low sedimentation density gave high low-shear
viscosity, indicative of high order structure formation in the suspended particles. Shear rate rheology of
suspensions with high dispersant content showed a shear thinning but with low dispersant content (≤2
wt.%), however, it showed a shear thickening at high shear rate (>600 s-1).
Spherical Indentation on Glass-Coated Al2TiO5-Mullite Composites
Authors: Lee Kee Sung , Park Sang Hyun , Kim Ik Jin
Published: March 2009

A glass layer with high hardness and fatigue resistance is coated on the aluminum titanate (Al2TiO5) – mullite (3Al2O3⋅2SiO2) composites to improve wear and fatigue resistances. Mullite is added to aluminum titanate to constraint the decomposition of aluminum titanate and exhibit high mechanical strength as well as high elastic modulus. The aluminum titanate composites with various quasi-ductilities through controlling the contents of mullite in the substrate layers are prepared in this study. The results of the load-displacement curves and the resulting contact damages on the surface of glass coating layer by spherical indentation indicate that mullite addition and the glass coating is effective.
Microwave Dielectric Property of Porous Silicon Nitride Ceramics
Authors: Li Jun Qi , Luo Fa , Zhu Dong Mei , Zhou Wan Cheng
Published: March 2009

This paper presents the microwave dielectric property of porous silicon nitride ceramics at a
frequency of 9360 MHz, which were fabricated by the nitridation of silicon powder. The porous ceramics
with different volume fraction of porosity from 18.6% to 56.2% were produced by adding different
amount of the pore-forming agent into the initial silicon powder. Microstructural analysis revealed a
dense matrix containing large pores and cavities with needle-shaped and flaky β-Si3N4 grains distributing
in it. The results showed that the dielectric constant of the ceramics reduces with the porosity increases.
With the addition of α-Si3N4 powder in the raw silicon powder, the nitridation rate is raised, and the
dielectric constant and the dielectric loss of the ceramics decrease notablely.
Ultra Stable Sealing Glass for Intermediate Temperature Solid Oxide Fuel Cells
Authors: Zhu Q. , Peng L. , Huang W. , Xie Z.
Published: March 2009

A concept for quantitative design of sealing glasses was proposed for planar solid oxide fuel cells (SOFC) applications, by which chemical and physical compatibility of a glass with other materials can be predicted through simulation based on a thermodynamic model and a combined model. Using this method, a sealing glass was successfully developed. The thermal expansion coefficient (TEC) of the glass was determined to be 9.9×10-6 K-1 (room temperature to 631°C), which is very close to the value of 10.0 × 10-6 K-1 measured for 8YSZ. Investigations revealed that the sealing glass had very good thermal stability, where the change of the TEC value was within the range of equipment error. The glass was also proved to be chemically compatible with 8YSZ, by the fact that no obvious interfacial reaction was detected after being heat-treated with 8YSZ at 700°C for 500 h.
Piezoelectric and Dielectric Properties of (Bi0.5Na0.5)TiO3- (Bi0.5K0.5)TiO3-BaTiO3 Lead-Free Piezoelectric Ceramics
Authors: Chen Zhi Wu , Lu Zhen Ya
Published: March 2009

A lead-free piezoelectric ceramic ternary system based on (Bi0.5Na0.5)TiO3 (BNT)-(Bi0.5
K0.5)TiO3(BKT)-BaTiO3(BT) near the morphotropic phase boundary (MPB) between the tetragonal
and rhombohedral phases has been investigated. The samples were prepared by a conventional
sintering technique. Piezoelectric properties, dielectric properties and microstructures of
BNT-BKT-BT lead-free piezoelectric ceramic were studied. The X-ray diffraction (XRD) patterns
show that the ceramics possess a single-phase perovskite structure. The measurements of
piezoelectric properties reveal that this system has a relatively high piezoelectric performance: the
piezoelectric constant d33 reached to 178pC/N and planar electromechanical coupling factor kp
enhanced to 0.325. The BNT-BKT-BT ternary system ceramics could be well sintered at 11500C with
a high-density ratio of more than 95% of the theoretical density.
Investigation of Field-Induced Piezoelectric Properties in Pb(Mg1/3Nb2/3)O3-PbTiO3 Ceramics for Transducer Applications
Authors: Lente M.H. , Zanin A.L. , Garcia D. , Eiras José Antônio , Leija L. , Vera A. , Calas H. , Moreno E.
Published: March 2009

Pb(Mg1/3Nb2/3)O3-PbTiO3 based ceramics were produced by conventional sintering method and their electric-field induced electromechanical properties were determined. Large fieldinduced electromechanical coupling factors, with high piezoelectric anisotropy, were obtained in this relaxor material at relatively low DC electric bias field. A circular ultrasonic transducer with non uniform radial induced polarization was constructed using this material for field diffraction control.
A Novel 3D Patterning Technique for Forming Advanced Ceramics
Authors: Wang D.Z. , Edirisinghe Mohan J. , Jayasinghe S.N.
Published: March 2009

In this paper a novel and versatile 3D print-patterning technique coupling electrohydrodyanmics
and a specially designed and constructed plotting device is elucidated. This unit is capable of
free-forming advanced ceramics and we demonstrate this by using it to print-pattern a 5mm × 5mm ×
1mm walled zirconia structure layer by layer. The wall thickness achieved is ~150$m, almost half that of
similar structures prepared using ink-jet printing. The as-printed structure was studied by scanning
electron microscopy and some of its typical features are discussed and related to the forming process.
Structural Design and Optimization of a 3-Axis Miniaturized Machine Tool with High Precision Positioning Stages
Authors: Lee J.H. , Wang Wei , Kweon Sung Hwan , Kim Young Shin , Lee Young Moon , Yang Seung Han
Published: March 2009

The procedure of structural design on miniaturized machine tool (mMT) is proposed and structural optimization by applying robustness evaluation method is presented in this paper. The design procedure of a kind of mMT which is a 3-axis miniaturized milling machine tool (mMMT) is discussed and three different structures of mMMT are proposed based on previous design procedure. The most suitable structure is selected using robustness evaluation method, which is Taguchi method, due to volumetric error function. The design parameters of selected structure are optimized.
Design and Numerical Simulation of a Three-Dimensional Nozzle Microstructured Mixer
Authors: Pan Min Qiang , Tang Yong , Lu Long Sheng , Wan Zhen Ping , Liu X.K. , Liu Xiao Qing
Published: March 2009

A passive microstructured mixer based on micro-ploughing technology with a multi-tooth tool is proposed. The mixer uses multiple three-dimensional nozzles to split one of the liquids into several micro-plumes. The fins on the surface of the nozzles induce a second liquid to generate turbulence around the local surface of the fins. The machining mechanism for fabricating 3D nozzles on a stainless steel sheet by micro-ploughing technology with a multi-tooth tool was studied. The machining process mainly involves four stages: tool-feeding, fin-forming, micro-hole-forming and tool-retracting. Simulation and flow visualization were used to evaluate its performance. The simulation results show the fin structure can induce local surface turbulence. The flow visualization indicates that when the flux is between 0.5ml/s and 3ml/s, the two liquids are fully mixed in 1second.
A Study of Measurement Technology for Ultra-Precision Freeform Surfaces
Authors: Li H.F. , Cheung Chi Fai , Kong Ling Bao , Lee Wing Bun , To Sandy
Published: March 2009

Ultra-precision freeform surfaces have become widely used in advanced optics manufacture. Although these surfaces can be fabricated by ultra-precision freeform machining technology with sub-micrometer form accuracy and surface finish in nanometer range, our current understanding on the evaluation of surface quality of these surfaces is still far from perfect. In this paper, a study of measurement technology for ultra-precision freeform surfaces is presented.
Geometric Machining Mechanism of the Ultrasonic Drilling
Authors: Lee Sun Kyu , Jang S.H. , Lee Seok Woo , Choi Hon Jong
Published: March 2009

The application of an ultrasonic vibration is one of promising means in machining micro-holes. In this study, the differences of in the geometric machining mechanism between the ultrasonic and the conventional drilling were investigated. Specifically, the uncut chip thickness before machining and the tool trajectories of the cutting edges were formulated and compared with machining results. Through the machining experiments, it was found that those these parameters well matched with the appearance of both the disposed chips and the machined surface. Furthermore, the results indicated that the change of uncut chip thickness resulted in decreased machining resistance as well as improvement of the machined surface
Macroscopic Properties of Inhomogeneous Material with Randomly Distributed Pores
Authors: Imatani Shōji , Fujiwara Daisuke
Published: March 2009

Porous materials such as engineering ceramics and metal foams have a specific feature such that internal structure has a significant influence on the mechanical properties from the viewpoint of porosity and morphology. This paper discusses the relationship between microscopic morphology and macroscopic properties of the porous materials based on the homogenization technique, in which pores are randomly distributed over the domain. Various types of pores are examined and the conjunction between different elemental types is discussed. A wide range of porosity is covered from a low porosity of 5% such as engineering ceramics to 80% of foam-like materials within the same numerical strategy. It is found that the macroscopic property with low porosity shows good agreement with both experimental curve and micromechanics prediction, in which the elasticity coefficient is affected by morphology of internal structure. In contrast with the low porosity, the morphology effect diminishes and is hardly observed in high porosity region where the macroscopic stiffness is almost linear on the porosity.