bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrothermal Preparation of Hydroxyapatite/Chitosan Nanocomposites via In Situ Precipitation
Authors: Lu Xiao Ying , Liu Zh. , Weng Jie
Published: March 2009

The cylindrical chitosan (CS)/hydroxyapatite (HA) nanocomposites were
hydrothermally prepared via in situ precipitation and characterized by x-ray diffractometer
(XRD), Fourier transform infrared spectrometer (FT-IR), thermogravimetry (TG) and scanning
electronic microscope (SEM). The results show that the as-prepared products are composed of CS
and low-crystalline HA phases, and some extent of interaction between CS and HA phases exists
in the composites, which is greatly influenced by the temperature and pH value in the
hydrothermal process. The crystal size of HA uniform-distributed in CS matrix is calculated to be
no larger than 100nm while the crystallinity of CA is greatly increased in the hydrothermal
process, which is beneficial to the mechanical properties of the composites. It is proposed that the
nano-structure of HA/CS composite will have the better biomedical properties in the biomaterials
applications.
Selective Bone Formation on Hydroxyapatite-Granule-Implanted Titanium
Authors: Watazu Akira , Li Ying Zhe , Tsutsumi Sadami , Matsumura Kazuaki , Saito Naobumi
Published: March 2009

Hydroxyapatite (HA)-granule-implanted cylindrical titanium composites, which uniformly have HA granules on the curved surface, were formed by a hot pressing using HA-granuleimplantation system under the conditions of 1023 K, 1 h, 1960 N in vacuo. Cracks were not observed in the HA granules. The HA-granule-implanted titanium samples were implanted in a mandible of a dog. After 1 year, new thin bones like pillars were selectively structured on the HA granules with bone induction ability. The HA-granule-implantation technique is expected to be useful for designing shape of bone around titanium implant in order to match living bones.
The Surface Valence Band Structure and Hemocompatibility of Rutile Titanium Oxide Films
Authors: Xu Lan Xin , Leng Yong Xiang , Zhang Qi , Yang Ping , Huang Nan
Published: March 2009

Rutile titanium oxide films were fabricated by reactive unbalanced magnetron sputtering.
The blood compatibility is evaluated in vitro by clotting time and platelet adhesion measurement.
The surface valence band electronic structure is gained by the XPS valence band spectra. The rutile
titanium oxide films exhibit attractive hemocompatibility. The result of the valence band electronic
structure of the films on the surface indicated that the rutile titanium oxide film represent an n-type
semiconductor characteristics and the characters result in the prevention of the charge transfering
between the blood and materials and overall excellent antithrombogenic properties.
Bonelike Apatite Formation on Synthetic Organic Polymers and Fiber Coated with Titania
Authors: Liu Jin Fang , Hayakawa Satoshi , Tsuru Kanji , Jiang Jian Zhong , Osaka Akiyoshi
Published: March 2009

Rutile films were deposited on polyethylene terephatalate (PET), polytetrafluoroethylene
(PTFE), Silicone, poly6-caprolactam (Nylon6), polyhexamethylene adipamide (Nylon6,6) and
Nylon fiber substrates using 0.03 M TiOSO4 and 0.03 M H2O2 aqueous solution at 80°C for 24 h.
The rutile films exhibited excellent in vitro bioactivity as they induced apatite deposition in a
simulated body fluid (SBF).
Chemical Treatment for Inducing Bioactivity of TiO2 Coating
Authors: Zhao Xiao Bing , Liu Xuan Yong , Li Baoe , Ding Chuan Xian
Published: March 2009

In this work, nano-TiO2 powders were deposited onto Ti-6Al-4V substrates to produce
coating using plasma spraying. The TiO2 coatings were respectively by acid, alkali and heat
treatment to produce the bioactive surface. The bioactivity of TiO2 coating was examined by
simulated body fluids test. The results obtained indicated apatite was formed on the surfaces of
nano-TiO2 coatings treated by H2SO4, HCl and HF solutions, while it could not be formed on the
surface of the nano-TiO2 coating treated by NaOH solution at low concentration. After alkali attack
and heat treatment at 600°C, the bioactivity of nano-TiO2 coating disappeared.
The Effects of Anodic Oxide Films Produced by β-Glycerophosphate and Calcium Acetate Anodizing on Attachment and Spreding of Osteoblaste-Like Cell
Authors: Jung Y.T. , Park J.W. , Yeo S.I. , Choi Byung Ju , Kim Kyo Han , Suh Jo Young
Published: March 2009

The effect of anodic oxide films produced by β-glycerophosphate (β-GP) and calcium
acetate (CA) anodizing on osteoblast-like cell attachment and spreading were evaluated in this
study. Anodic oxide films were produced in different conditions: Group 1, 0.02 M β-GP and 0.2 M
CA; Group 2, 0.03 M β-GP and 0.2 M CA; Group 3, 0.03 M β-GP and 0.2 M CA. Anodic oxide
surface was significantly rougher in comparison to the control untreated titanium surfaces, and the
surface roughness and composition of phosphate and oxide increased as the concentration of β-GP
was increased. There was no significant difference in the cell viability when cells were cultured on
the control or anodized surface using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide
(MTT) assay. Scanning electron micrographs revealed more spread cells on the anodized surface
than on the smooth control surface. In conclusion, we suggested that the positive effects of anodized
surfaces produced by β-GP and CA on spreading of osteoblast-like cells may be the result of the
difference of surface roughness and amount of Ca and P in the oxide layer.
Effects of the Composition of the Bioactive Composite Calcium Phosphate Cement on Its Behavior in the Solution
Authors: Liu Chang Sheng , Chen Chien Wen , Ducheyne Paul
Published: March 2009

In this paper, the hydration product of calcium phosphate cement with bioactive glass
containing Si was used to investigate the effect of chemical composition on its bioactivity. The
variation of concentrations of Ca2+, P and Si in TE solution complemented with electrolytes typical
for plasma (TEE) and the formation of amorphous calcium phosphate layer on the surface of the
materials were investigated by immersing the designed materials in TEE solution in vitro. The results
showed that the composition of the bioactive composite CPC greatly affected its behavior in the
solution and the formation of bioactive apatite. After immersed in TEE solution, the Ca ions were
uptaken for all the samples, showing the decreases of Ca concentration during the entire duration, but
the concentration of P ions increased sharply at the initial stage, and then decreased due to the
formation of amorphous calcium phosphate layer on the surface of the materials. FTIR revealed that
the layer was poorly crystallized Ca-deficient carbonate apatite. The thickness of the layer was more
than 12 um, which layer was composed of rod-like apatite with directional arrangement. All the data
obtained would be useful for the design and optimization of the orthopedic degradable implant
inorganic materials.
Bone-Bonding Strength of a New Composite Bone Cement
Authors: Goto Koji , Kawanabe Keiichi , Fujibayashi Shunsuke , Kowalski R. , Nakamura Takashi
Published: March 2009

A composite bone cement designated G2B1 that contains β tricalcium phosphate particles
was developed as a bone substitute for percutaneous transpedicular vertebroplasty. In this study, both
G2B1 and commercial PMMA bone cement (CMW1) were implanted into proximal tibiae of rabbits
with a metal frame fixed on it, and their bone-bonding strengths were evaluated at 4, 8, 12 and 16
weeks after implantation using a detaching test. Some of the specimens were evaluated histologically
using Giemsa surface staining and scanning electron microscopy (SEM). It was found that the
bone-bonding strength of G2B1 was significantly higher than that of CMW1 at each time point, and
significantly increased from 4 weeks to 8 and 12 weeks, while it decreased significantly from 12
weeks to 16 weeks. Giemsa surface staining and SEM showed that G2B1 contacted bone directly
without intervening soft tissue in the specimens at each time point, while there was always a soft
tissue layer between CMW1 and bone. The results indicate that G2B1 has excellent bioactivity.
Antibacterial Effect of Silver-Zeolites in Glass-Ionomer Cements
Authors: Lee Ju Hye , Lee Sang Bae , Kim Kyoung Nam , Kim Kwang Mahn , Lee Yong Keun
Published: March 2009

In this study, the antibacterial effects of glass ionomer cement containing silver-zeolite were evaluated. New antibacterial glass ionomer cements with silver-zeolite were prepared as follows. Silver-zeolite (1, 3, and 5 wt%) was incorporated into the glass ionomer cement powder and then mixed with the polyacidic liquid at the ratio recommended by the manufacturer. Agar diffusion test was used to evaluation of antibacterial effect. Setting time, film thickness and compressive strength were also determined. Paired samples t-tests and ANOVA were used, and P<0.05 was considered significant. Film thickness and setting time were increased dependent on the amount of silver-zeolite. Glass ionomer cement with 1 wt% of silver-zeolite seemed to increase the compressive strength. However, increasing ratio of compressive strength was diminished beyond 3 wt%. Glass ionomer cements containing silver-zeolite have been successfully demonstrated to have antimicrobial effects on S. mutants in vitro. These results indicate that glass ionomer cement containing silver-zeolite have the potential to enhance antibacterial of dental cement in oral cavity.
Rheological Properties of an Injectable Bioactive Calcium Phosphate Material
Authors: Bosco Julia , Fatimi Ahmed , Quillard Sophie , Bouler Jean Michel , Weiss Pierre
Published: March 2009

An injectable bone substitute (IBS) made of a suspension of calcium phosphate ceramic
was used to filled dental root canal after removing of canal pulp. Compared with current filling
materials, which are toxic to periapical tissues, calcium phosphate materials, due to their
biocompatibility and bioactive properties, may be viewed as possible alternatives.
The aim of this study was first to determine if an injectable bone substitute could be used to obtain
further healing of apical tissue by the neoformation of a mineralized barrier. In the next step, the
paper will focus on rheological measurements as a tool for physical characterisation and on the
improvement of the injection technique. Rheology concerns the flow and deformation of the
suspension and, in particular, its behaviour in the transient area between solids and fluids. The
results showed that injection is possible with a good level of BCP granules at the end of the root
dental canal with extracted tooth. Other experiments with other animal models closer to a Human
model have to be performed before human trials.
Osteoconductivity of Porous Titanium Having Young’s Modulus Similar to Bone and Surface Modification by OCP
Authors: Suzuki Yuko , Nomura Naoyuki , Hanada Shuji , Kamakura Shinji , Anada Takahisa , Fuji Takeshi , Honda Yoshitomo , Masuda Taisuke , Sasaki Keiichi , Kokubun Shoichi , Suzuki Osamu
Published: March 2009

The present study was designed to investigate whether porous titanium (Ti) having Young’s modulus similar to bone has osteoconductive characteristics in rat critical-sized calvarial bone defect. The effect of coating by octacalcium phosphate (OCP) was also examined. OCP is known as a precursor of initial mineral crystals of biological apatite in bones and teeth. Ti powder was prepared by plasma rotating electrode process in an Ar atmosphere. Then, porous Ti disks, 8 mm in diameter with 1 mm thick, were obtained using the particles ranging from 300 to 500 +m, by sintering at 1573 K without applied pressure. The disks had about 35 vol% in porosity and about 10 GPa in Young’s modulus which corresponds to that of human cortical bone. Newly formed bone was observed so as to fill the pore up at 12 weeks, confirming the ability to conduct the ingrowths of the bone tissue. Although in vitro study showed that proliferation of mouse bone marrow stromal ST-2 cells was inhibited on the dishes coated by OCP rather than the control dish, OCP coating on porous Ti seemed to stimulate the bone formation in vivo. Taken together, it seems likely that porous Ti having Young’s modulus similar to bone shows osteoconductive characteristics to conduct bone ingrowths. OCP could be a potential coating agent to assist bone regeneration on porous Ti.
Apatite Formation on Porous HA/TCP in Animals’ Serums In Vitro
Authors: Deng Chun Lin , Wang Ying Jun , Wu Yao , Wang Xin Long , Chen Xiao Feng , Zheng Hua De , Chen Ji Yong , Zhang Xing Dong
Published: March 2009

Porous HA/TCP bioceramics were immersed in pure dog serum to observe apatite
formation. Deposited crystals were examined using SEM. Results showed that beamed sheet-like
crystals formed on the surface of ceramics granules, and after postponement immersion time, crystals
extended and became bigger. EDS and IR results suggested formed crystals were defect-calcium type
carbonated hydroxyapatite. HRTEM photograph suggested formation process of new-formed
crystals from non-crystal to crystal in serum. Directional organisms acted maybe as a template in
process of crystals formation, so new crystals developed along certain direction.
Functional Gradient Alumina Ceramics with Controlled Porosity
Authors: Andertová Jana , Havrda Jiří , Tláskal Radek
Published: March 2009

The work deals with preparation of functional gradient alumina ceramics with controlled
porosity by slip casting method of aqueous alumina suspension containing pore-generating agent.
The sol-gel transition of AlO(OH) was employed to stabilize pore-generating agent in the
suspension. The composite bodies with layers of variable porosity were prepared. Based on
dilatometer measurement the admission difference of irreversible dilatation changes #αirr between
compounded layers was determined in order to prepare defect free bi-layer bodies. The dependence
of physical and mechanical properties of as fired composite bodies on the porosity value was
expressed.
Impression Creep in TBC and Advanced Ceramics Materials
Authors: Dorčáková Františka , Jan Vít , Hegedűsová Lucia , Dusza Ján
Published: March 2009

The indentation creep of free-standing Y-ZrO2 layer and 20Sc-60Si-20Mg-80O-20N
oxynitride glass has been investigated. Creep experiment has been performed with flat cylindrical
indenter (hot pressed SiC) in the temperature range from 860 °C to 1300 °C at the loads from 20 to
100 MPa. The strain-time relationship was registered and the creep exponent and activation energy
of creep have been calculated. The microstructure changes have been observed and documented.
Viscosity as a function of temperature and the glass transition temperature (Tg) were determined in
oxynitride glass and compared with values from compressive creep.
Advanced Environmental Barrier Coatings (EBC’s)
Authors: Kulkarni T. , Basu S.N. , Sarin V.K.
Published: March 2009

Dense, uniform and crack-free mullite (3Al2O3·2SiO2) coatings were deposited on Sibased
substrates by chemical vapor deposition using the AlCl3–SiCl4–H2–CO2 system. The coatings
were compositionally graded, with the Al/Si ratio increasing towards the outer surface of the
coatings for improved corrosion resistance. Mullite grains nucleated when the surface composition
of the growing coating was in a narrow range close to that of stoichiometric mullite. The growth
rate and crystal structure of mullite were dependent upon temperature, pressure, reactant
concentration, and reactant ratios. The phase transformations occurring in these coatings during
high-temperature anneals in the range 1100–1400 °C were studied.
Fracture of Ceramics with Near Surface Gradient Residual Stresses
Authors: Anglada Marc
Published: March 2009

The fracture toughness and strength of ceramics can be improved with respect to
monolithic ceramics by developing graded materials as laminates composed of periodic alternating
layers of one material separated by layers of a second material. The second layer must contain
residual compressive stresses which are induced during densification because of differential thermal
contraction of the layers. The overall residual stresses increase the apparent fracture toughness of
the laminate. However, most deleterious natural flaws and most of the damage induced in service
by the environment, contact loading, wear, etc, are small cracks on the surface of the outer layer, so
that the effect of the laminate residual stresses on these cracks should be rationalised to understand
their behaviour. This work presents an analysis of the influence of the gradient residual stresses on
the behaviour of surface cracks under bending and indentation in materials with outer layers either
with tensile or compressive residual stresses.
Microstructure and Mechanical Properties of Al-Cu-Cr Quasicrystals/Al Matrix Composites Synthesized by Hot-Pressing Technique
Authors: Qi Yu Hong , Zhang Z.P. , Liu D.L. , Hei Z.K.
Published: March 2009

Microstructure and mechanical properties of 20% Al-Cu-Cr/Al composites synthesized
by hot-pressing technique after annealing, quenching and aging was studied by means of X-ray
diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscopy
(TEM) and uniaxial compressive test. Microstructure of Al-Cu-Cr particles in the composites after
hot-pressing is mainly consist of icosahedral quasicrystals and which transformed into decagonal
quasicrystals after annealing. Microstructure of matrix in the composites after hot-pressing,
annealing, quenching and aging is pure Al, Al + Al2Cu, supersaturated solid solution Al and Al +
Al-Cu transition phases respectively. Hardness, fracture strength and the Young’s modulus of the
composites are improved by age-hardening.
Controllability of a Magnetorheological Fluid Squeeze Film Damper under Sinusoidal Magnetic Field
Authors: Zhu Chang Sheng
Published: March 2009

The controllability of a magnetorheological(MR) fluid squeeze film damper under a
sinusoidal magnetic field was experimentally studied on a flexible rotor. It is shown that the
frequency of the excitation magnetic field has a great effect on the controllability of the MR fluid
damper. As the magnetic field frequency increases, the controllability of the MR fluid damper
significantly reduces. There is a maximum frequency of the magnetic field for a given magnetic field
strength or a minimum strength of the magnetic field for a given magnetic field frequency to make the
dynamic behavior of the MR damper be controllable. When the magnetic field frequency is over the
maximum one or the magnetic field strength is less than the minimum one, the controllability of the
MR fluid damper almost completely disappears and the dynamic behavior of the MR fluid damper
with the sinusoidal magnetic field is the same as that without the magnetic field.
The Elastic-Viscoplastic Field at the Tip of Mode II Quasi-Static Propagating Crack in Rate-Sensitive Material
Authors: Liang Wen Yan , Wang Zhen Qing , Lu Hong Quing , Wang Yong Jun
Published: March 2009

Under the assumption that the artificial viscosity coefficient at the propagating crack tip is
in inverse proportion to power law of the plastic strain rate, a rate-sensitive constitutive relationship is
derived for perfect elastic-plastic material. With the adoption of the rate-sensitive constitutive
relationship, it is asymptotically investigated the propagating tip fields of plane strain mode II. And
the quasi-static equations are obtained separately governing the stress and strain fields at the crack-tip
by means of Airy stress function. Numerical calculations of governing equations are carried out by
double parameters shooting, with selections of appropriate values of each characteristic parameter by
combinations of boundary, and the fully continuous stress-strain fields are obtained at the crack-tip.
The analytical and computational results indicate that viscosity effect is an important factor in
crack-tip fields.
Effect of Fatigue Crack Propagation in the Shape Memory Alloy Fiber Reinforced Smart Composite
Authors: Shimamoto Akira , Furuya Yasubumi , Abe Hiroyuki
Published: March 2009

In this paper, the TiNi fiber reinforced / Polycarbonate(PC) composite material is
developed, and its properties is studied. Conducting fatigue experiments, shape memory effect of the
material for preventing fatigue crack growth are investigated. The fatigue behavior and crack
propagation are observed under increasing temperature with a SEM servo-pulser, which is a fatigue
testing instrument with scanning electron microscope. As the results, the effectiveness of fatigue
resistance is confirmed. The shape memory effect and expansion behavior of the matrix caused by
increasing temperature create the effect of the fatigue crack propagation control. It is verified that the
controlling of fatigue crack growth is attributed to the compressive stress field in the matrix which is
caused by shrinkage of the TiNi fibers above austenitic finishing temperature (Af).
Surface Characteristics of Zirconia-Coated TiO2 and its Phase Transformation
Authors: Jaroenworaluck Angkhana , Sunsaneeyametha Weeraw , Stevens Ron
Published: March 2009

Recently, zirconia has been considered as a suitable material for surface coating nanosized
TiO2 for use as an electrode in a solar cell application. In this study, the TiO2 (P-25) coated ZrO2 was
synthesized from P-25 TiO2 and coated with zirconium n-propoxide in the range of 2.5-50 wt.%.
The surface of the TiO2 coated with ZrO2 were examined by X-ray diffraction (XRD) analysis, high
resolution transmission electron microscope (HRTEM), which showed zirconia could coat onto the
P-25 TiO2 surface. Any excess of zirconia has been deposited as separated particles. Peaks for
tetragonal zirconia were observed from the XRD patterns in zirconia-coated P-25 containing more
than 20 wt. % of zirconia after calcinations at 500 °C, 800 °C and 1300 °C. In addition, peaks of
anatase could be observed from XRD patterns of the samples after calcination at 1300°C. The results
show that coating zirconia onto the TiO2 grain surfaces may act to retard the phase transformation
from anatase to rutile.
Fabrication Process and Magnetostriction of Infiltrated Terfenol-D/Epoxy Composite
Authors: Kwon Oh Yeoul , Kim Kyung Hoon , Yu Min Kyu , Hong Soon Hyung
Published: March 2009

Giant magnetostrictive composites have attracted a great deal of attention by
supplementing shortcomings of monolithic Terfenol-D such as brittleness, eddy current loss and
formability. Recently, infiltrated Terfenol-D/Epoxy composite has been developed as an alternative
composite. This composite was fabricated by an unidirectional solidification of Terfenol-D followed
by an infiltration of epoxy. The iron content in composite has been changed in order to control volume
fraction of RFe2 phase producing magnetostriction on Terfenol-D/Epoxy composite. The
magnetostriction of both as-grown and infiltrated Terfenol-D/Epoxy composite was measured to
confirm the effects of eutectic phase and heat treatment on magnetostriction. The enhancement of
magnetostriction of Terfenol-D/Epoxy composite was mostly contributed by the eutectic phase
through the hindering of movement and rotation of domain walls. The magnetostriction modelling of
Terfenol-D/Epoxy composite was suggested, based on the change of texture and elastic modulus. The
suggested model was in good agreements with the experimental results on the measurement of
magnetostriction of Terfenol-D/Epoxy composite.
Fabrication and Characterization of Composite Microspheres Containing Carbonated Hydroxyapatite Nanoparticles
Authors: Zhou Wen You , Wang Min , Cheung W.L.
Published: March 2009

Nano-sized carbonated hydroxyapatite (CHAp) particles were firstly synthesized using a
nanoemulsion method. TEM analyses revealed that as-synthesized nanoparticles were
calcium-deficient and spherical in shape (diameter: 16.8±2.6nm). Biocomposite microspheres
comprising CHAp nanoparticles and poly(L-lactide) (PLLA) were fabricated using the single
emulsion solvent evaporation technique. SEM images showed that composite microspheres were
mainly 5-30 μm in size despite the change of CHAp nanoparticle content. When the CHAp
nanoparticle content in composite microspheres was below 10 wt%, all nanoparticles were
encapsulated within the microspheres which possessed a nanocomposite structure. DSC results
showed that the crystallinity of the PLLA matrix of microspheres increased from 38 to 42% when the
CHAp nanoparticle content was increased from 0 to 20 wt%. The biocomposite microspheres should
be a suitable material for constructing bone tissue engineering scaffolds.
Preparation of Mesophase Pitch from Coal Tar Pitch for C/C Composites
Authors: Ji Yong Bing , Li Tie Hu , Lin Qi Lang , Fang Chan Ging , Wang Xiao Xian
Published: March 2009

Mesophase pitch (MPP) has a high carbon yield and excellent graphitizability, compared with
commercial coal tar pitch (CTP), which make it suitable for the preparation of C/C composites. In this paper,
two MPP were prepared by heat-treatment of two coal tar pitches (CTP and modified coal tar pitch (MCTP)) in
the presence of nitrogen. Elemental analysis and FTIR were used to monitor the change of chemical structures
of MPP transition from CTP and MCTP. The pyrolysis behaviors of CTP and MCTP were studied by means
of thermal analysis (TG and DSC). The morphologies of MPP were inspected by optical microscope. The
structures of the MPP were characterized by XRD. The results show that there are more alkyl functional groups
existing in CTP and MCTP than in MPP, and MPP has a higher C/H ratio than CTP and MCTP, which
indicate MPP formation predominantly polycondense aromatic and release the alkyl functional groups. An
endothermic band due to volatilize light compounds around 290 °C, two exothermic peaks at 430°C and 490
°C were characteristic of polymerization reactions, exothermic peaks of MCTP are higher than that of CTP
because the former has a higher reaction active for its more alkyl side chain. The optical texture of MPP from
CTP is mosaics texture, while from the MCTP is flow domains texture. (002), (101) peaks of graphite occur on
XRD patterns, the peaks of MPP from MCTP are higher and narrower than MPP from CTP, which indicates
the former is more graphitizability than the latter.
Effect of Al(Cr) Content on the Distribution of Al2O3(Cr2O3) Particles Formed by Internal Oxidation
Authors: Liang Shu Hua , Xiao Peng , Wang Xian Hui , Fan Zhi Kang
Published: March 2009

This investigation was conducted to study the effect of Al(Cr) content in Cu-Al(Cr)
pre-alloyed powders on the distribution of Al2O3(Cr2O3) particles formed by internal oxidation. The
results show that the distribution of Al2O3 particles is different with the change of Al content in Cu-Al
system. When the Al content is above 1.2wt.%, the Al2O3 particles tend to distribute along the grain
boundaries of copper matrix , whereas when the Al content is above 2.0 wt.%, the Al2O3 particles
have distributed along the grain boundaries. However, it is interesting to note in Cu-Cr system that
most of the formed Cr2O3 particles prefer to distribute in the grain of copper matrix when the Cr
content is less than 5wt.%, which is quite different from that of Cu-Al system.
Biodegradation of Bagasse Fiber Reinforced Biodegradable Composites
Authors: Cao Yong , Shibata Shinichi , Goda Koichi
Published: March 2009

Biodegradable composites made from bagasse fiber and biodegradable resin were prepared
and the biodegradation were investigated by the soil burial test in terms of the effects of fiber content,
alkali treatment to bagasse fiber and different soil. The biodegradable resin showed some extent
biodegradation. The addition of bagasse fiber caused the acceleration of weight loss of the fiber
reinforced composites in comparison with the neat biodegradable resin. The weight loss of the
composites increased with the increase in the fiber content, which could attribute to the preferential
degradation of bagasse fiber and the resin around the fiber. However there was no significant
difference in weight loss between untreated and alkali treated fiber composites. Furthermore, it is
noted that the weight loss drastically increased in the case of the composites buried in the
microorganism enriched soil. This results from the increase of bacteria and fungi in soil. The
photographs and SEM micrographs showed the degradation of the resin and the composites.
Chemical-Thermal and Mechanical Coupling Model for the Cure of a Thermosetting Matrix: Application to FEM Simulation
Authors: Jugla Guilhem , Jochum Ch. , Grandidier J.C.
Published: March 2009

The general aim of this work is to provide a numerical tool devoted to the description of
thermosetting matrix properties evolutions all over the cure. The study is related to quality of cure
and residual stress state topics, especially for thick matrix. A formulation as simple as possible of
some important basic couplings that occur during the cure of a class of structural thermosetting
matrix is proposed. A methodology of linking thermal, diffusion and mechanical phenomena
together is presented. First FEM results of cure simulation are presented and compared with
experimental data of the cure.
A Proposal of Calculation Method for Equivalent Property of Composite Materials
Authors: Nakai Hiroaki , Tomioka Hiromasa , Kurashiki Tetsusei , Zako Masaru
Published: March 2009

To predict the mechanical properties of composite materials by using computer is
complicated, because it is difficult to model directly by ordinary FEM. A calculation method by using
the mesh superposition method and periodic boundary condition has been proposed in order to obtain
the equivalent mechanical properties of composite materials easily. The numerical results by
proposed method have shown good agreement with ones by the traditional procedure. The proposed
method is efficient for the materials with complicated structure like woven fabric composites etc.
Sintering Shrinkage Anisotropy of Spherical Alumina Powder Compacts with Particle Orientation
Authors: Liu Yan Chun , Shui An Ze , Ren Xue Tan , Zeng Ling Ke
Published: March 2009

Spherical alumina powder and dispersant were mixed with distilled and deionized water, and ball
milled to make alumina slurry. The slurry was dried in a high magnetic field to make a compact.
Subsequently, the compact was cold-isostatic-pressed (CIP) to enhance the homogeneity in particle packing
density. Anisotropy of shrinkage during sintering was examined for the alumina compacts in detail. Particle
orientation existed in the spherical alumina powder compacts prepared in 10T, and made them shrink
anisotropically during sintering. Sintering shrinkage was larger in the direction parallel to magnetic field
direction (i.e., the c-axis direction of alumina crystal) than that in its perpendicular direction. The particle
orientation structure in the compacts was confirmed with the immersion liquid method of polarized light
microscope, and the grain alignment structure in the sintered bodies was also observed with X-ray diffraction,
the c-plane was perpendicular to the magnetic field direction. On the other hand, isotropic sintering shrinkage
occurred in the spherical alumina powder compacts prepared in 0T, which did not hold the particle orientation.
The experimental results indicate that sintering shrinkage of spherical alumina powder compact depends on
alumina crystal axis direction. Origin of the sintering shrinkage anisotropy for the spherical alumina powder
compacts can be attributed to the particle orientation caused by high magnetic field.
Compressive Experiment and Damage Simulation of a Composite Structure with Ply Drop-Off
Authors: Shao Xiao Jun , Yue Zhu Feng
Published: March 2009

Compressive experiments and finite element method (FEM) have been used to study the
mechanical behavior of composite laminate with plies drop-off. A user subroutine has been
implemented to ABAQUS to simulate the damage development of the laminate plate. This user
subroutine has taken consideration of the mechanical properties degradation according to
development of three types of damage. The load-strain curves can agree with each other between
experiments and FEM. The detail of damage development of the plies drop-off composite laminate
under compressive loading can be described as followed. Matrix cracking damage and fiber-matrix
shearing damage occur simultaneously at first, and then fiber buckling damage initiates. Matrix
cracking and fiber-matrix shearing are very dangerous to the carrying capacity of laminate and fiber
buckling intensifies further this effect. The initiation and development of fiber buckling indicates
that laminate loses carrying capacity at all.
Morphology of Rotationally Moulded Microfibril Reinforced Composites and its Effect on Product Performance
Authors: Lin Richard , Bhattacharyya Debes , Fakirov S.
Published: March 2009

Rotational moulding (rotomoulding) is one of the fastest growing plastics manufacturing
processes using linear polyethylenes dominantly as raw materials. However, due to their modest
mechanical properties, rotational moulders worldwide are keen to develop stronger and stiffer
materials. In the present study, an attempt was undertaken to apply the concept of microfibril
reinforced composites (MFCs) for improving the material performance. Melt blended and
subsequently cold drawn and undrawn linear medium density polyethylene (LMDPE) with either
poly(ethylene terephthalate) or poly(ethylene naphthalate) possessing MFC structure were mixed
with neat LMDPE and thereafter processed via rotational moulding. The rotomoulded samples were
characterised morphologically and tested mechanically. The obtained unsatisfactory mechanical
characteristics led to the subsequent morphological study which revealed some interesting
phenomena for the rotomoulded products containing MFC blends.
Molecular Dynamics Simulation of Single Chain in the Vicinity of Nanoparticle
Authors: Hynstova K. , Jancar Josef , Zidek J.
Published: March 2009

Molecular simulation of single chain in the vicinity of nanoparticle in comparison with
pure system is presented. According to the Rouse theory, chains were considered as a sequence of
beads connected together by harmonic springs. The motion of atoms was supported by thermal energy
and retarded by the resistance of surrounding. New atom position, in given time, was determined by
the Smoluchowski equation, that consists of two terms: first one includes the influence of the
inter-atomic collisions, the sterical obstacles and the strong intermolecular interactions in friction
coefficient, second one express the energy field aggregated from potentials of all atoms. Sinusoidal
shear stress was applied to the chain. The output of the model was energy as a function of time. The
energy course was also sinusoidal but shifted according to the deformation. The amplitudes and phase
shifts were analyzed for the chains under different conditions .The chains were subjected to the model
first as the standalone objects. Then, barrier was defined and chains placed in the vicinity of it. The
barrier acted as a volume excluded hindrance. This type of chain molecular dynamics could be used as
a stand-alone model or it could be suitable component for complex models, for example network
model of polymer nanocomposite.
Microstructure and Mechanical Properties of TiCp/ZA-12 Composites
Authors: Xiang Wang , Gai Peng Tao
Published: March 2009

TiCp/ZA-12 composites have been fabricated by XDTM method and stirring-casting
techniques. The behavior of TiC particle in the solidification interface has been studied through
conventional and directional solidification techniques. The results demonstrate that under
conventional solidification conditions, the particles with lower content mainly distribute in eutectic
phases; while when at a larger content of TiC particles, they exist both in eutectic phases and in
primary phases. Under directional solidification, due to the repulsion of primary phases of alloy on
TiC particles, the particles congregate and form band structure, and extent of the congregation in
band structure relates to TiC particles content. With the increasing of TiC particles content, their
congregation in band structure decreases, and the band structure disappears when the content of TiC
particles exceeds 6%. The tests for mechanical properties reveal that the tensile strength and yield
strength increase with increasing fraction of TiC particles. When the fraction of TiC particles
increase up to 10%, the tensile strength and yield strength are 390MPa and 340MPa, respectively
and they increase by 11% and 17% than that of matrix respectively.
Permeability Modeling Considering Microstructure of Preform
Authors: Lee Do Hoon , Lee Joon Ho , Lee Woo I.
Published: March 2009

Liquid molding processes are becoming more popular among the composite
manufacturing industries due to their versatility and economy among other merits. In analyzing the
flow during the process, permeability is the most important parameter. Permeability has been
regarded as a property of the porous medium. However, in many practical cases, the value may vary
depending on the flow conditions such as the flow rate. It is speculated that this deviation is caused by
inhomogeneous microstructure of the medium. In this study, numerical simulations as well as
experimental measurements have been done to investigate the cause of deviation. Microstructure of
porous medium was modeled as an array of porous cylinders. Resin flow through the array was
simulated numerically. Simulations were performed for two different flow conditions, namely
saturated flow and unsaturated flow. Based upon the results, permeabilities were estimated and
compared for the two flow conditions. In addition, a model was proposed to predict the permeability
for different flow conditions. Results showed that experimental data were in agreement with the
prediction by the model.
Elastic-Viscoplastic Behaviour of Plain-Woven GFRP Laminates: Analysis Using Homogenization Theory
Authors: Matsuda Tetsuya , Nimiya Y. , Ohno Nobutada , Kawai Masamichi
Published: March 2009

In the present study, a method for reducing the domain of analysis is developed for the
homogenization analysis of plain-woven laminates. Moreover, the method is applied to the
quantitative prediction of elastic-viscoplastic deformation of plain-woven GFRP laminates. It is first
shown that the internal structures of plain-woven laminates satisfy point-symmetry on the assumption
that the laminates have the in-phase or out-of-phase laminate configuration of plain fabrics. The
point-symmetry is then utilized for the boundary condition of unit cell problems, reducing the domain
of analysis to 1/4 and 1/8 for the in-phase and out-of-phase laminate configurations, respectively.
Using the present method combined with the nonlinear time-dependent homogenization theory, the
elastic-viscoplastic behavior of plain-woven GFRP laminates under in-plane on- and off-axis loading
is analyzed. In addition, the tensile tests of a plain-woven GFRP laminate at a constant strain rate are
performed at a room temperature. Comparing the results of the present analysis with the experimental
ones, it is shown that the analysis successfully predicts the in-plane elastic-viscoplastic behavior of
the plain-woven GFRP laminate.
Mechanical Performance of Carbon/Epoxy Composites with Embedded Polymeric Films
Authors: Qi Ben , Bannister Michael
Published: March 2009

This paper presents experimental results on the mechanical performance of advanced
carbon/epoxy composites with embedded polymeric films. The composite laminates with polymeric
films, which are potentially used as a sensor/actuator carrier for structural health monitoring
applications, were investigated under various mechanical loadings including low velocity impact,
single lap shear and short beam shear. The preliminary work showed that embedment of those
polymeric films does not degrade, but could significantly improve, the mechanical properties of the
composite laminates.
Effective Hyperelastic Behaviour of Fiber Reinforced Polymer Composite Materials
Authors: Yang Qing Sheng , Xu Fang
Published: March 2009

The macroscopic hyperelastic behavior of fiber reinforced polymer composites is studied
using the micromechanical model and finite deformation theory. It is assumed that the fiber and
matrix are hyperelastic media and undergoing finite deformation. The local fields of a
representative volume element are calculated by the hyperelastic finite element method. Then an
averaging procedure is used to find the homogenized stress and strain and the macroscopic curves
of stress-strain are obtained. The several microstructural parametric effects on the macroscopic
hyperelastic behavior are considered. The numerical examples show the hyperelastic behavior and
deformation of the composites.
Measurement of Thermal Expansion Coefficients of a Thin Film of Different Ceramic Coatings by Shearography
Authors: Habib Khaled
Published: March 2009

In the present work, thermal expansion coefficients of a number of ceramic coatings were
studied by a non-destructive technique (NDT) known as shearography. Ceramic coatings, i.e., a
white enamel and a yellow Acrylic Lacquer on a metallic alloy, i.e., carbon steels, were
investigated at a temperature range simulating the severe weather temperatures in Kuwait,
especially between the daylight and the night time temperatures, 20-60 0C. The investigation was
focused on determining the in-plane displacement of the coating, which corresponds to the thermal
deformation (strain), with respect to the applied temperature range. A mathematical relationship
was derived along with the experimental data. The mathematical relationship described the
thermal deformation of a coated film as a function of temperature. Furthermore, results of
shearography indicate that the technique is found very useful NDT method not only for
determining the thermal expansion coefficients of different coatings, but also the technique can be
used as a 2D- microscope for monitoring the deformation of various coatings in at a submicroscopic
scale.
Mechanical Properties of Vinyl Ester Composites Cured by Microwave Irradiation: Pilot Study
Authors: Ku H. , Trada Mohan , Puttgunta V.C.
Published: March 2009

Composite components made from vinyl ester resins by Centre of Excellence in
Engineered Fiber Composites (CEEFC), University of Southern Queensland (USQ) suffer
considerable shrinkage during hardening. Currently, CEEFC solves the shrinkage problem by
breaking a large composite component into smaller composite parts because smaller parts tend to
have less shrinkage. These smaller parts are then joined together to form the overall structure. The
shrinkage of vinyl ester particulate composites has been reduced by curing the resins under
microwave conditions. The reduction in the shrinkage of the resins by microwaves will enable the
manufacture of large vinyl ester composite items possible. This project investigates the difference
in impact strength, tensile strength and Young’s modulus of 33 percent by weight of fly-ash
particulate reinforced vinyl ester composite, VE/FLY-ASH (33%) cured under microwave and
ambient conditions. Drop weight impact tests were used to find out the impact strength of the
composite, while tensile tests were used to find out the tensile strength and Young’s modulus of
the composite. The power levels of microwaves used were 180 and 360 W; the duration of
exposure of the composite samples to microwave irradiation varied from 20 to 50 seconds. The
difference in impact strength and Young’s modulus between microwave cured vinyl ester
particulate composites and those cured under ambient conditions had been found to be minimal.
However, the tensile strength of the composite samples cured under microwave conditions can be
higher than those cured under ambient conditions.
Preparation and Characterization of Properties of Microcapsules for Polymeric Composites Self-Repairing
Authors: Wang Rong Guo , Liu Wen Bo , Li H.Y. , He Xiao Dong , Zhang Fei Hu
Published: March 2009

Microcapsules self-repairing polymeric composites belong to a new kind of smart
materials. In this work, microcapsules used for polymeric composites self-repairing were prepared
by in-situ polymerization. Optical microscopy, scanning electronic microscopy (SEM), fourier
transfer infrared spectroscopy (FT-IR), and thermal gravity analysis (TGA) were used to determine
the properties of prepared microcapsules such as grain size and their distribution, wall thickness,
content of core materials and thermal performances of microcapsules. Results showed that the
average grain size was 210 μm and the wall thickness was in the range of 1.8-5 μm depending on
agitation rate. Thermal analysis indicated that the repairing agent’s core materials were
encapsulated in microcapsules.
The Effect of Various Reinforcements on the Ablation, Thermal and Microstructural Properties of Phenolic Matrix Composites
Authors: Pasbakhsh Pooria , Zamani J. , Shokuhfar Ali
Published: March 2009

The ablation properties, thermal resistance and micro structural behavior of the phenolic resin
(Resole) composites have been investigated in this research. Different materials, such as carbon fabrics,
glass fabrics, also silica and zirconia powders have been used as reinforcements for synthesis of the
composites. The specimens were prepared with three sets of compositions. The first set was produced
with 37.5 wt% of Resole and 62.5 wt% of reinforcements. Another set of specimens were produced with
40wt% Resole, 40 wt% of silica and 20 wt% of zirconia. Also to achieve high insulation index in
Resole/carbon fabrics composites a thin film of zirconia coated at the back side of the specimens. To
explore the ablation characteristics of the composites in terms of insulation index, erosion rate and
microscopic pattern of ablation, an oxyacetylene torch flame with heat flux of 10 Mw/m2 at
approximately 2800°C was used. The ablation behavior and microstructure of the burnt-through
specimens were also observed, using scanning electron microscopy. It was found from ablation test that
the erosion rates of the Resole/carbon fabric specimens are 20% lower than the other specimens.
Additionally the high insulation index of the Resole/carbon fabrics coated with zirconia indicates that
these composites are the best ablative materials in the present study. It has been also reported that those
specimens filled with zirconia have the highest insulation index. Although the erosion rate of the
Resole/silica composites were 20% higher than the Resole/glass fabrics, but a 5mm depth hole (from 10
mm thickness of the whole specimen) was seen at the center of the Resole/glass Fabric specimens. SEM
observations show that proper adhesion between reinforcements and matrix is important to achieve
improved ablative properties, it was also reported many changes in diameter, shape and the surface of the
carbon fibers through the ablated area. These changes can be reduced from surface to back side of the
specimens.