bluuebunny/crossref_metadata_2025 huggingface dataset:
Properties of Coating Films Synthesized from Colloidal Silica and Methyltrimethoxysilane
Authors: Park Hoy Yul , Na Moon Kyong , Yoon Seog Young , Park Seong Soo
Published: March 2009

Colloidal silica/methyltrimethoxysilane (MTMS) sol solutions were prepared in variation
with the ratio of MTMS to colloidal silica. Sol solutions were prepared by sol-gel reaction. To
understand their physical and chemical properties, dip coating of sol solutions was performed on the
glass substrates. The state of coating films was investigated in variation with the amount of MTMS
and reaction time. The contact angle and thickness of coating films increased with an increasing
amount of MTMS. The surface roughness of coating films decreased with an increasing amount of
MTMS. Coating films were stable until 550°C. Thermal degradation temperature of coating films
decreased with an increasing amount of MTMS.
Strengthening of Water Glass Based Aerogel by TEOS
Authors: Hwang Hae Jin , Kim Chul Eui , Cha Young Chul
Published: March 2009

In order to prevent the irreversible collapse of the silica aerogel backbone upon the drying
of the liquid phase of silica wet gel derived from water glass based silicic acid, we tried to strengthen
the aerogel back bone by aging silica wet gels in water and TEOS/ethanol solutions. Although aging
of silica wet gels in water has been shown to grow the neck between silica particles of the aerogel
backbone, it is hard to obtain a crack-free aerogel monolith. On the other hand, the mechanical
stability of silica aerogels was improved significantly by aging the wet gel in TEOS/ethanol solutions
with different TEOS content.
Photocatalytic and Photoelectrochemical Properties of Nitrogen-Substituted TiO2 Thin Films Prepared by an RF Magnetron Sputtering Deposition Method
Authors: Kitano Masaaki , Kudo Takeshi , Matsuoka Masaya , Ueshima Michio , Anpo Masakazu
Published: March 2009

Highly nitrogen-substituted TiO2 (N-TiO2) thin film photocatalysts were prepared by a
radio-frequency magnetron sputtering (RF-MS) deposition method. N-TiO2 thin films with low
nitrogen concentration (0.5%) exhibited a small absorption band as a shoulder in the 400-500 nm
wavelength region, indicating that isolated N 2p orbitals are formed above the O 2p orbitals.
However, N-TiO2 with higher nitrogen concentration (6%) exhibited a sharp absorption edge at 500
nm, indicating that visible light absorption is due to a band gap transition. These N-TiO2 thin films
could operate as photocatalysts to decompose 2-propanol diluted in water under visible light. The
band structure of N-TiO2 was also determined by photoelectrochemical measurements and H2 and O2
evolution was carried out from an aqueous solution involving sacrificial reagents.
Photocatalytic Degradation of Organics Diluted in Water Using TiO2 Loaded on Fluoride-Modified Mesoporous Silica
Authors: Kawasaki Shinichi , Okada Yusuke , Yuan Shuai , Mori Kohsuke , Yamashita Hiromi
Published: March 2009

The synthesis of the hydrophobic mesoporous silica MS(F) was performed using tetraethyl
orthosilicate, triethoxyfluorosilane as the source of the fluoride and dodecylamine as templates. The
TiO2 loaded on the hydrophobic MS(F) (TiO2/MS(F)) exhibited the efficient photocatalytic
performance for the degradation of alcohols (iso-butanol) diluted in water. The photocatalytic
reactivity for the degradation increased with increasing the content of fluoride ions on these
photocatalysts. The hydrophobic mesoporous surface is suitable as the photocatalytic reaction field
for the degradation of organic compounds diluted water.
Ag-Doped TiO2 Immobilized on Al2O3 Bead as Oxidation Catalyst
Authors: Panyathanmaporn Thammarat , Jaroenworaluck Angkhana , Supothina Sitthisuntorn , Chumnanklang Rung-Arun , Juengsuwattananon Kannikar , Jinawath Supatra , Sooknoi Tawan , Jiamsakul Siriya , Tawkaew Sittinun
Published: March 2009

Ag-doped TiO2 catalyst employed as the oxidation catalyst candidate was prepared by
two methods, co-precipitation and dip coating method. Co-precipitation method was conducted by
adding AgNO3 into the titanium precursor before gelation and then the obtained solution was coated
on the alumna beads. Dip coating method was conducted by coating the first layer on alumina beads
with titanium precursor followed by coating the second layer with AgNO3. The fired Ag-doped
TiO2 coated on alumina beads was used as catalyst for catalytic oxidation of methanol and carbon
monoxide by using oxygen as oxidizing agent in a gas-phase reactor. The methods of catalyst
preparation were found to affect the catalytic efficiency. Dip coating method showed better
oxidation reaction as Ag-doped TiO2 catalysts were well dispersed on the alumina beads.
Suspension Stability of BaTiO3 Nanoparticles under Electrical Applied Field
Authors: Kim Y. , Jun B.S.
Published: March 2009

The suspension stability was investigated as the function of particle number concentration,
applied force, and the distance between cathode and anode. The suspension was prepared by
using BaTiO3 nanoparticles in a mixed solution with ethanol and acetylacetone. The highest zeta
potential value was 30 mV, when the mixing ratio of EtOH and Acac was 75 : 25. EPD conditions
of BaTiO3 nanoparticles suspension with 0.05 wt% were settled at the conditions of an applied dc
field of 20 V/ and an electrode distance of 1.5 at 300 seconds of deposition time.
Synthesis, Preparation and Catalytic Activities of V-Doped TiO2 Gel Coating on Porous α-Al2O3 Beads
Authors: Jaroenworaluck Angkhana , Panyathanmaporn Thammarat , Soontornworajit B. , Supothina Sitthisuntorn , Tawkaew Sittinun , Jiamsakul Siriya , Sooknoi Tawan
Published: March 2009

TiO2 and V-doped TiO2 gel were synthesized and coated onto porous α-Al2O3 beads to
study the thermal catalytic activities of oxidation reactions. Titanium isopropoxide (Ti(OPr)4) and
1,2-butadiol(Bu(OH)2) were used as starting chemicals for preparation of TiO2 gel without Vdoping.
After aging at ambient temperature for one week, a TiO2 gel was obtained. The
concentration of Ti(OPr)4 was varied, 0.2, 0.3, 0.7 and 2.4 M was used. For V-doping of the TiO2
gel, 0.05, 0.20 and 0.75 mole% of V was prepared by ultrasonically dissolving vanadium
acetylacetone (V(acac)2) in 1,2-butadiol. The solutions were then added to Ti(OPr)4. Finally, the
mixed solutions were kept under ambient temperature for one week to form the V-doped TiO2 gel.
TiO2 and V-doped TiO2 were calcined at 300, 400, 500, 600, 700, and 800 °C. XRD analysis, SEM
and TEM in conjunction with EDS analysis were used to identify the phases present, grain size and
morphology. The TiO2 grains have a particle size in the nano-scale range. Doping TiO2 with V
could retard growth of the TiO2 particles and affect phase transformation at higher calcination
temperatures. Both the TiO2 and V-doped TiO2 gels were prepared and coated onto α-Al2O3 beads
to test oxidation reactions in a purpose-designed reactor. The results of the catalytic reactions
indicated that V-doped TiO2 had a higher oxidation activity than the undoped TiO2 gel. The content
of vanadium was related to the reaction efficiency.
The Effect of Isothermal Heat Treatment on the Rolling Contact Fatigue of Carburized Low Carbon Microalloyed Steel
Authors: Lee Jae Seong , Song Bok Han , Sung H. G. , Kim S. Y. , Hur Bo Young
Published: March 2009

In case of the low carbon chromium steel that have widely been used for the carburized
gears or rolling bearings, the austenite grain coarsening may be occasionally occurred during
carburizing. To restrain this phenomenon, most of hot forged parts have been given to an isothermal
heat treatment or normalizing immediately after hot forging and/or prior to carburizing. Therefore,
their production cost includes unexpected additional expenses caused by such a non-value added
process. To confirm the possibility of an energy saving, as well as attaining a superior fatigue life,
in the production of automotive parts to be carburized, the austenite grain coarsening with the
manufacturing process of the microalloyed steel, containing Nb and B as a grain refining elements,
was investigated. The heat treatment characteristics and rolling contact fatigue behavior of the
carburized specimens with the isothermal heat treatment were also investigated. In spite of omitting
the isothermal heat treatment after hot forging, the abnormally coarse austenite grains were not
found out in the carburized specimens. However, the rolling contact fatigue life of the carburized
specimens, in which the isothermal heat treatment was omitted, was shorter than that of
isothermally heat-treated specimens.
Titania Coating of Wasted Silica Particles and their Photocatalytic Property
Authors: Karino Shinji , Abe Hisao , Hojo Junichi
Published: March 2009

TiO2-coated SiO2 particles were prepared using industrially-wasted amorphous SiO2
powder by an alkoxide method, in which the mean particle size of SiO2 was approximately 100 nm.
The SiO2 powder and titanium tetraisopropoxide were mixed in ethanol and an appropriate amount
of distilled water was added to the suspension for hydrolysis of the alkoxide. The product was
calcined in the temperature range from 600 to 1300°C to crystallize the deposited TiO2. The
homogeneous deposition of TiO2 on the SiO2 surface was observed by SEM. It was found that the
SiO2-support tended to retard the transformation from anatese to rutile. The maximum
photocatalytic activity for decomposition of methyleneblue was obtained on the TiO2-coated SiO2
powder calcined at 1000°C, and was higher than that of a commercial TiO2 powder.
Visible Light Response of ZrO2 by Nitriding and its Photocatalytic Activity
Authors: Mishima Takahiro , Matsuda Motohide , Miyake Michihiro
Published: March 2009

A novel Zr2ON2 catalyst was successfully prepared by nitriding ZrO2, which has a potential
enough for H2 formation by the reduction of water under UV irradiation. It was found that the Zr2ON2
had a stable photocatalytic activity for water oxidation and reduction in the presence of sacrificial
reagents (methanol or Ag+) under visible light irradiation (λ < 500 nm).
XPS Investigation of Passive Layer on Copper-Bearing Antibacterial Ferrite Stainless Steel
Authors: Zou De Ning , Wan Xiao Jing , Zhang Wei
Published: March 2009

After solid-solution and aging treatment, the copper-bearing ferritic stainless steel has
been investigated by TEM fitted with X-ray EDS and XPS methods. The TEM and EDS shown that
the rod-like precipitation phase was є-Cu, and distributed dispersively throughout in the matrix. The
most important result from XPS analysis confirmed that except the topmost of passive film, copper
appeared as element state and its concentration kept constant in the inner surface of the material. It
was found that the material shown an excellent antibacterial property to staphylococcus and
coliform bacteria, after passive film elimination,
Effect of Sn-Addition on the Bonding Strength between Casting Au-Pt-Cu Alloy and SiO2-Based Porcelain
Authors: Lee S.H. , Byeon J.W. , Doh Jung Mann , Lim H.N. , Yoon Jin Kook , Jung H.Y.
Published: March 2009

Effects of 0.5 wt% Sn-addition to the dental casting Au-12Pt-0.6Cu alloy on the
interfacial microstructures and bonding strength between porcelain and the alloy were investigated.
Porcelain powders (SiO2-based oxides) are bonded through a thermal schedule consisting of preoxidation,
1st firing, and 2nd firing. Interfacial microstructures were examined after pre-oxidation
and 2nd firing, respectively, by scanning and transmission electron microscopy. The bonding
strength of the Au-12Pt-0.6Cu and Au-12Pt-0.6Cu-0.5Sn alloys with porcelain was about 24.6 MPa
and 46.2 MPa, respectively. The higher bonding strength of the Sn-added alloy compared with that
of the alloy without Sn is attributed to the SnO2 formed at the interface between porcelain and the
alloy during pre-oxidation. SnO2 layer is thought to enhance chemical bonding with various oxides
in the porcelain and, accordingly, improve bonding strength.
A Study on Boiling Heat Transfer Augmentation of Heating Process Using Ultrasonic Vibrations
Authors: Yang Ho Dong , Oh Yool Kwon
Published: March 2009

The present study was experimentally investigated the effect of ultrasonic vibrations on
boiling heat transfer augmentation during the heating process. The experiments were carried out
under the constant wall temperature condition and were divided into two cases applying with and
without ultrasonic vibrations, respectively. Also, the temperature distributions in a vessel filled with
water were measured using thermocouples during the heating process, heat transfer coefficient and
augmentation ratio of heat transfer on states of convection, subcooled boiling and saturated boiling
were calculated from obtained temperature profiles. In addition, the profiles of pressure variations
measured using a hydrophone were compared with the augmentation ratio of heat transfer in acoustic
fields. The results of experimental study were revealed that general profiles of heat transfer
coefficient and augmentation ratio of heat transfer is more increased the convection state than the
others states. Moreover, the profiles of acoustic pressure is relatively higher near ultrasonic transducer
than other points where is no installed it and affects the augmentation ratio of heat transfer. In the end,
as well as known “acoustic streaming” induced by ultrasonic vibrations is one of the prime effects
acoustically augmented boiling heat transfer or phase change heat transfer.
Affinity of Cd and Ni on IDA Immobilized Magnetic Beads with Different Lengths of Spacer Arms
Authors: So Hyung Suk , Yoo Yeong Seok , Schaeffer Andreas
Published: March 2009

To develop the extraction media for Cd and Ni from aqueous solutions, magnetic beads
containing IDA group with strong attraction to heavy metals were produced using the activating
agents Epichlorhydrin (Ep) and 1,4-Butanedioldiglycidylether (Bu), respectively. Then the beads
were agitated at a pH of 6 after being added to Cd and Ni aqueous solutions of various concentrations.
It was confirmed that the heavy metals combined with the magnetic beads within a short time through
the process. After the process, the magnetic beads were collected with a magnet, and then dissolved in
acid for the analysis of heavy metal concentration. The analysis of heavy metals in the acid solution
could be analyzed with an AAS (atomic absorption spectrometer). The results showed that the heavy
metal extraction efficiency of Bu was relatively higher than that of the Ep. It supported the hypothesis
that the relatively longer length of Bu’s spacer made more free positioning possible when the IDA
group combined with the heavy metal.
Comparison of Intensity Method and Counting Method in Measurement of Fiber Orientation Angle Distribution Using Image Processing
Authors: Kim Jin Woo , Lee Dong Gi
Published: March 2009

The fiber reinforced composites has high specific strength and stiffness than metallic
material and are an anisotropic material whose mechanical properties, such as strength and elasticity,
change with their fiber orientation state, the fiber length, the fiber aspect ratio, fiber mat structure, etc.
Above all, the fiber orientation angle distribution state of fiber reinforced composite is fundamental
element of mechanical properties. So, many researches on this element have been conducted by
means of nondestructive method currently. The fiber distribution state is measured by intensity
difference of pixel using image processing and these methods are intensity method by calculating of
intensity value of pixel and counting method by calculating of fiber quantity. In this research, the fiber
orientation simulation picture was constructed by plotter according to change of fiber’s diameter,
length and orientation. The fiber orientation distribution state was measured by this intensity
information. The fiber orientation angle distribution state measured by intensity method and counting
method was compared with fiber orientation function calculation value.
Deformation Behavior of Functionally Graded Ti-Ni Shape Memory Alloys
Authors: Nam Tae Hyun , Kim Hyun Gon , Choi Ju Young , Lee Jung Moo , Kang Suk Bong , Lim Cha Yong
Published: March 2009

Deformation behavior of temperature gradient anneal(TGA) treated Ti-50.0Ni(at%)
alloys were investigated by means of thermal cycling tests under constant load and tensile tests.
TGA treated Ti-Ni alloy wires showed a sequential deformation behavior along the length of the
specimen since the stress required for the B2-B19’ transformation increased with decreasing
annealing temperature. Considerably large residual elongation(about 0.4 %) occurred in the TGA
treated Ti-Ni alloy under the applied stress of 80 MPa, which is ascribed to the fact that yield stress
of the sample annealed at 823 K is lower than the stress required for the B2-B19’ transformation of
the sample annealed at 658 K.
Development of Eco-Flux Laminated Strip for Air Atmosphere Brazing
Authors: Shin Y.S. , Lee Young Sup , Lee C.H.
Published: March 2009

The purpose of this study is to introduce and discuss flux laminated strip. Flux laminated
strip can be used for air atmosphere brazing. The new product is fabricated by four processes:
embossing of strip; multi bending of embossed strip; flux injection; and resizing of the material. This
flux laminated strip exhibits similar melting characteristics to flux cored and flux coated alloys. The
flux laminated strip eliminates the need for a separate fluxing operation that is typically needed when
using bulk alloy. The product ensures the correct amount of flux during the brazing process and
reduces the post-braze clean time. The ability to produce a quality joint while reducing the amount of
pre-braze and post-braze operations make flux laminated strip an innovative Eco-braze-materials.
Development of Miniaturized Micro Metal Forming Manufacturing System
Authors: Lee Hye Jin , Lee Nak Kyu , Choi Seo Gou
Published: March 2009

The existing forming press uses a hydraulic actuator and high powered mechanical
actuator, therefore occupying a large space because of its size. This type of system is inefficient for
manufacturing micro size and precision products. As forming components are small in size, forming
equipment must also be small in size because the forming die and load must be small. The micro
forming manufacturing system is an ultra precision forming equipment the size of several micros to
millimeters and precision of sub-micro to micrometer. This micro forming manufacturing system
has the advantage of minimization in manipulating distance and working space. As equipment and
tools become smaller in size, minute inertia force and high natural frequency can be obtained.
Therefore, high precision forming performance can be obtained. This allows the factory to quickly
provide the customer with goods because the manufacturing system and process are reduced. To
construct a micro manufacturing system, many technologies are necessary such as high stiffness
frame, high precision actuating part, structural analysis, high precision tools and system control. In
this paper Research development about a micro metal forming manufacturing system has been
developed. To coincide with the purpose to be more practical, we set the development of the
equipment including micro deep drawing, micro punching and micro restriking process to the goal.
To achieve this goal, the miniaturized micro metal forming manufacturing system is designed and
made with miniaturized size system. A micro deep drawing process and system dynamic
characteristic experiments are researched using this miniaturized micro forming system. A micro
deep drawing experiment is performed using micro thin foil materials (Al-1100, SUS-304). If this
miniaturized micro forming technology is used, efficient material practical use in the micro forming
field which uses the micro metal thin foil is possible.
Distribution and Shape of the Pores in Water Permeable Concrete
Authors: Yang Z. X. , Yoon Jeong Bae , Kim J.O. , Hwang Kyu Hong , Jun B.S. , Lee J.B. , Kim M.C.
Published: March 2009

Porous concretes with continuous voids have been gaining more interest as an ecological
material because of their useful functions such as water permeability and adsorption ability. So pore
size distribution and the shape of especially open pores are the key point to permeability. In this study,
the size and shape of pores of water permeable concrete were primary controlled by the size and shape
of aggregates and secondly by the expanding agents to the cement pastes. 2 types of raw coase
aggregate, type I and type C which mean fabricated by impact crusher and concrusher, were taken into
uses and 3 sizes of aggregate were used, namely 3 to 5mm, 5 to 13 mm, and 13 to 20 mm. The
compressive strength was found to be higher when using impact crushed aggregate. And the smaller
size of aggregate was used, the higher compressive strength was achieved.
Effect of Annealing on the Mechanical Property and Machinability of Free-Cutting Phosphor Bronze Alloy
Authors: Cho Hoon , Lee Byoung Soo , Yang Jin Seok , Jo Hyung Ho
Published: March 2009

Free-cutting phosphor bronze alloy (ASTM C54400) was used as a material for automotive
parts and industrial valve parts for its high strength, machinability and excellent corrosion resistance.
To obtain desired mechanical strength of the alloy, the process parameters including continuous
casting speed, reduction in area and annealing temperature have to be controlled. In this study, we
investigated the effect of annealing on the mechanical property and machinability of free-cutting
phosphor bronze alloy fabricated by continuous casting with different casting speeds of 80, 100, and
120 m/min, respectively. After annealing, the tensile strength of the alloy decreased with increasing
annealing time owing to the occurrence of recrystallization and grain growth. In the cast and swaged
alloy produced at casting speed of 120 m/min, the grain growth occurred rapidly. In contrast, in the
alloy produced at the casting speed of 80 m/min, the grains growth rate was low. Furthermore, the
effect of Pb particle in the alloy on machinability was also investigated by using a tool dynamometer
installed force sensor.
Effect of Cr on the High Temperature Corrosion of Al3Ti-Cr Alloys in SO2 Atmosphere
Authors: Choi Jee Hoon , Lee Dong Bok
Published: March 2009

Three types of L12-type Al3Ti-Cr alloys, of compositions 67Al-25Ti-8Cr, 66Al-24Ti-
10Cr, and 59Al-26Ti-15Cr in atomic percent, were corrosion tested at 900, 1000, and 1100oC in an
Ar-1% SO2 gas atmosphere for up to 150 h. The alloys were resistant to corrosion because a thin
Al2O3 barrier layer was formed on the alloy surface due to the high Al content in the alloys. Due to
the very strong Al affinity for oxygen, virtually no sulfur was detected inside the oxide scale.
Effects of Processing Factors on the Mechanical Properties of PBO Filament/ Epoxy Composite Materials
Authors: Wang Bin , Jin Zhi Hao , Qiu Zhe Ming , Liu An Hua
Published: March 2009

The role of the basic factors in the wet fiber winding process was investigated from the
point of view of the actual wet-wound parameters and the property of composite material. In the
present work, a PBO fiber-reinforced epoxy-matrix composite material was prepared by a wet
fiber-winding process. The effects of processing factors such as the volume fraction of PBO fiber,
the preheating temperature of mandrel, the infiltration temperature and time of epoxy resin, and
winding tension, on the tensile strength and interlaminar shear strength (ILSS) of the unidirectional
composite materials were investigated. To evaluate correctly how the above-mentioned parameters
affect the mechanical performances of the composite materials, a pair of standardized pressure
vessels with a diameter of 150 mm were fabricated via the winding method. The optimum
conditions are obtained as follows: the preheating temperature of mandrel is 60-70 °C, winding
tension is 30-40 N, and the penetration temperature and time of epoxy resin into PBO fiber are 45
°C and 1-2 s, respectively. Under the conditions, the ILSS and tensile strength of the composite
materials are 30 MPa and 2980 MPa, respectively. The burst pressure and performance factor of the
manufactured pressure vessels is as high as 34 MPa and 60.4 km, respectively. It is demonstrated
that high quality rings and vessels can be efficiently manufactured by methods described in the
paper.
Extrudability Improvement of 7000 Series Al Wrought Alloys by Thixoextrusion
Authors: Yoon Young Ok , Jang Dong In , Jo Hyung Ho , Kim Shae K.
Published: March 2009

The present study discussed extrudability improvement for 7000 series Al wrought alloys
by thixoextrusion, with emphasis on controlling thixoextrusion parameters, such as initial ram
speed, die bearing length and extrusion temperature of billet in semisolid state. The results of
thixoextrusion experiments about microstructures and extrusion pressures were compared with
conventional hot extrusion results. The maximum extrusion pressure for thixoextrusion was greatly
decreased than that of conventional hot extrusion. This will contribute to extrudability in terms of
extrusion pressure, which in turn means that shorter process time is required and smaller extrusion
machine can be applied for the same operation. It is also possible to make complex shape
components of 7000 series Al wrought alloys, which is not possible by conventional hot extrusion
processes. The elongated grains to extrusion direction were generally observed during conventional
hot extrusion, while the thixoextruded microstructures were isotropic.
Identification of Phases in the Wide-Gap Region Brazed with BNi-3 Filler Metal Powder Using Electron Backscatter Diffraction
Authors: Kim Yong Hwan , Kim Il Ho , Kim K.T. , Shin Seung Y. , Kwun S.I.
Published: March 2009

The phases formed in the wide-gap region brazed with BNi-3 filler metal powder in IN738
superalloy were investigated by electron backscatter diffraction (EBSD). The morphology and
chemical composition of the phase were investigated by field emission scanning electron microscopy
(FESEM) and Auger electron spectroscopy (AES). The wide-gap region brazed with BNi-3 filler
metal had a microstructure consisting of primary Ni3B, binary eutectic of Ni3B-Ni solid solution and
ternary eutectic of Ni3B-Ni-Ni3Si structure. EBSD pattern analysis revealed that the Ni3B had
orthorhombic structure with lattice parameter of a=0.439, b=0.522 and c=0.662 nm, and the Ni3Si
phase had cubic structure with lattice parameter of a=0.350 nm.
Influence of the Ball Diameter, Material and Taper Design on Transferred Stresses of Ceramic THR
Authors: Lee Soo Wohn , Carrillo Daniel G. , Kang D.K. , Lira-Olivares Joaquín
Published: March 2009

The brittleness of ceramics has been their weak spot when considering them for total hip
replacements. There are several situations from which concentrated stresses can develop and induce failure
of the components. It is not a problem of the material’s properties in particular but also its design. This
means that even proof tested-third generation-ISO obeying ceramics may fail if the incidence of the design
parameters on them is not carefully evaluated. In this paper, the finite element analysis technique is used to
show how the change of ball diameter can affect the Vonmises stress on the ball head component when it is
subjected to a high (trauma-like) load. The analysis is nonlinear and was carefully tested for convergence.
3D models of four different ball head diameters where constructed, two designs of the bore/cone interface
with two sets of material properties (Alumina and Zirconia) were considered. The results from these
analyses are given in the form of stress maps on the ball heads; such data may be useful for surgeons,
patients, and designers because it shows a direct relationship between two important parameters on ball head
design (diameter and bore) and material properties, on the stresses that can cause failure of the component
when they are concentrated in small elements of volume.
In-Situ Joining of Combustion Synthesized Ni3Al Intermetallic Compounds with AZ91D Mg Alloy
Authors: Cho Gue Serb , Lee Kang Rae , Choe Kyeong Hwan , Lee Kyong Whoan , Kim Ki Young
Published: March 2009

We focused on the surface reinforcement of ligth weight casting alloys with Ni3Al
intermetallic compounds by in-situ combustion reaction to improve the surface properties of nonferrous
casting components. In the present work, by setting the mixture of elemental Ni and Al
powders in a casting mold, the powder mixture reacted to form Ni3Al intermetallic compound by
SHS reaction ignited by the heat of molten AZ91D Mg alloy and simultaneously bonded with the
Mg casting alloy. The AZ91D Mg alloy bonded with the Ni3Al intermetallic compound was
sectioned and observed by optical microscopy and scanning electron microscopy(SEM). The
chemical composition of intermetallic compounds and diffusion layer formed around bonding
interface were identified by energy dispersive spectroscopy(EDS), X-ray diffraction analysis(XRD)
and electron probe micro analyzer(EPMA).
The main intermetallic compound was Ni3Al phase and a little Ni2Al3 intermetallic compound
was formed from the Ni and Al powder mixtures. Residual pores were observed in the synthesized
intermetallic compound. The AZ91D Mg alloy and Ni3Al intermetallic compound were bonded
very soundly by the interdiffusion of Mg, Ni and Al elements, but some cracks were observed
around the bonded interface on the interdiffusion layer. The diffusion length formed between
AZ91D Mg alloy and Ni3Al was different depending on the diffusivity of Ni and Al elements into
the molten Mg alloy. Ni was more deeply diffused into the Mg alloy than Al. The diffusion layer
was about 200m thickness and various phases were formed by the interdiffusion of Mg, Ni and Al.
From this challenge we have successfully produced a coating layer based on nickel aluminide on
ligth weight Mg alloy using molten metal heat without any additional process. On the basis of the
results obtained, it is concluded that near-net shaped nickel aluminide coating layer can be formed
using this unique process.
In–Situ Synthesis of Cop/Cu Coating by Laser Cladding
Authors: Lu Y. , Lee J.H. , He Y. Zh.
Published: March 2009

Homogeneous Cop/Cu coating alloys were fabricated by laser cladding rapid solidification
technique and their microstructures were investigated, with the emphasis on the influence of
processing on microstructure. The experimental results showed that a Cop/Cu composite coating can
be successfully in situ synthesized when the processing conditions were controlled. The as-solidified
microstructures were characterized by a homogeneous distribution of small spherical Co-rich
particles dispersed in the Cu-rich matrix. The Cop/Cu coating was consisted of γ-Co, Cu-rich solution
and et al. With the increasing of line energy, the spherical particles diameter in coating was
increasing. The structural evolution and refining mechanism of the Cop/Cu coating were also
discussed.
Crystalline Phases and Particle Characteristics of the Combustion-Synthesized TiO2 Nanoparticles
Authors: Lee Gyo Woo , Choi Shang Min
Published: March 2009

TiO2 nanoparticles were synthesized with using N2-diluted and O2-enriched coflow
hydrogen diffusion flames. We investigated the effects of the flame temperature on the crystalline
phases and particle characteristics of the TiO2 nanoparticles that were formed. For the higher
temperature conditions, the maximum centerline temperatures that were measured were greater than
approximately 1,600K, and TiO2 nanoparticles, which had spherical shapes with diameters of
approximately 60nm, were synthesized. For the lower temperature conditions, the maximum
centerline temperatures that were measured were less than approximately 1,600K, and the diameters
of the nanoparticles that were formed had unclear boundaries that ranged from 35 to 50nm. From the
XRD analyses, it was believed that the crystalline structures of the nanoparticles that were formed
were divided into two types. For the higher temperature cases, the fractions of the TiO2 nanoparticles
that were synthesized, which had anatase-phase crystalline structures, increased with the increase of
the flame temperatures. On the contrary, for the lower temperature cases, the fraction of anatase-phase
nanoparticles increased with the decrease of the flame temperatures.
Mechanical Properties and Formability of AZ31 Magnesium Alloy Processed by Differential Speed Rolling
Authors: Huang Xin Sheng , Suzuki Kazutaka , Watazu Akira , Shigematsu Ichinori , Saito Naobumi
Published: March 2009

An AZ31 (Mg-3Al-1Zn-0.35Mn in mass%) alloy sheet exhibiting the inclination of the
basal plane from the rolling plane at about 15º, was fabricated by a DSR processing with a roll speed
ratio of 1.167. Compared with the normal rolled sheets, the DSR processed sheets showed a lower
0.2% proof stress, a larger elongation, a smaller r-value and a larger n-value. The Erichsen value at
room temperature significantly increased from 2.2 to 3.1, and the deep drawability also improved.
Microstructural Evolution and Crystal Orientation of Electromagnetically Stirred Al Alloy in the Semi-Solid State
Authors: Lee Dock Young , Kang Suk Won , Kim Ha Young , Kim Ki Bae
Published: March 2009

Through more than three decades of development, a semi-solid metal processing has been
successfully established as a unique casting technique to produce a structural component for an
automobile industry with high integrity and improved mechanical properties. A slurry-on-demand
process to make the semi-solid slurry having a fine and globular microstructure has been very
important in the semi-solid metal process. In the present study, the orientation distribution functions
(ODFs) calculated from the pole figure data were examined and tried to characterize the bulky
morphology of primary solid phase of the semi-solid slurry of Al-Cu alloy produced with various
magnetic flux density of 100 to 300Gauss in the specially designed electromagnetic (EM) stirrer.
Columnar dendritic structure of primary α phase was turned into a rosette and globular structure by
EM stirring during solidification. The primary α phase was refined and globularized with increasing a
magnetic flux density of EM stirring. Also, due to the EM stirring the tendency to random orientation
was appeared. In the case of unstirred Al-Cu alloy the <110>//ND texture was developed strongly and
<100>//ND and <111>//ND texture was weakly developed. But with the increase of the EM stirring
strength, <100>//ND and <111>//ND texture were more strongly advanced. Due to EM stirring the
texture was almost completely randomized.
Microstructure and Formability of Different-Speeds Rolled AZ31 Mg Sheet
Authors: Lee Jae Seol , Son Hyeon Taek , Kim Young Kyun , Oh Ik Hyun , Kang Chang Seog , Bae Jung Chan
Published: March 2009

The aims of this study ares to investigate the microstructure evolution of AZ31 Mg alloys
with normal rolling and different speeds rolling during hot rolling affects microstructure, texture
and mechanical properties of AZ31 Mg alloy. In the microstructures of as-rolled both samples,
twins are clearly apparent, small and recrystallized grains are visible along some grain boundary
and twinned regions. The tensile strength and yield strength of DSR sample were slightly higher
than that of NR sample. Also, in the case of the NR sample, tensile strength indicated different
values to the rolling directions. From this result, NR sample compared to DSR sample strongly
indicated to the plastic anisotropy tendency. Therefore, it is noted that DSR sample could be
presented to the good formability, comparing to the NR sample. DSR samples deformed at 473K
and 523K could be perfectly formed, indicating the potential application of the DSR process to
improve formability of the Mg alloys at warm temperatures.
Prediction of Temperature Distribution during Curing Thick Thermoset Composite Laminates
Authors: Oh Je Hoon
Published: March 2009

A 3-D transient heat transfer finite element (FE) analysis was performed to simulate the
curing process of thick thermoset composites. The simulated temperature was compared with the
available experimental data to check the validity of the analysis. The influence of thickness of
composite laminates on the temperature distribution was investigated, and how the size of laminates
affects the inside temperature was also discussed. The results indicate that the laminate thickness
rather than the laminate size has a significant influence on temperature distribution, and the 3-D
analysis offers more accurate predictions than the 1-D analysis.
Product Geometry for Process Parameter during Rotary Swaging Process as Chipless Forming Process
Authors: Lim Seong Joo , Choi Ho Joon , Yoon Duk Jae , Jeong Ha Guk , Lee C.H.
Published: March 2009

This study deals with the dimensional accuracy of outer diameter and geometrical
workability in rotary swaged product for various process parameters such as percent reduction in
outer diameter and the ratio of thickness to outer diameter of a tube. It is generally known that greater
cold strengthening is achieved by rotary swaging process rather than by conventional process such as
rolling with respect to the same reduction of cross-sectional area. Percent reduction in the diameter
and the ratio are considered and selected as important process parameters because of playing a key
role during rotary swaging process. In case of tube under rotary swaging process the ratios have
influence on geometrically proper workability without defect for different percent reductions in the
diameter. In addition the change of metal flow of workpiece under the swaging process is
microscopically and globally observed to analyze the reason why dimensional accuracy of the outer
diameter of final product is improved after the rotary swaging process. This work might provide
available information for the optimum rotary swaging process.
Effect of Deformation Temperature and Strain on Recrystallization Behavior of a Nb Micro-Alloyed Steel
Authors: Zhang Zhao Hui , Liang Xiao Kai , Liu Yong Ning
Published: March 2009

The post-dynamic softening of Nb micro-alloyed steel and plain carbon steel was
investigated through stress relaxation method. Meanwhile, By comparison with C-Mn steel, the
effect of deformation temperature and strain on post dynamic recrystallization of Nb steel was
studied . The result shows that element Nb in solution state can dramatically improve the apparent
activation energy of static recrystallization. At lower temperature, the recrystallization can be
retarded and precipitation of Nb(C, N) occured. If strain is more than the critical strain of dynamic
recrystallization, the metadynamic recrystallization takes place. If fully metadynamic
recrystallization takes place, the kinetics is no longer dependent on strain of the kind of steels.
Study on the Oxidation and Electrical Resistivity of Reaction-Bonded Silicon Carbide at High Temperature
Authors: Lu Zhen Lin , Xie Hui , Gao Ji Qiang , Jin Zhi Hao
Published: March 2009

The oxidation behavior and electrical resistivity of reaction-bonded silicon carbide
(RB-SiC) at high temperature (900 °C) had been studied in this paper. The results showed that the
weight of RB-SiC would be increased when it was oxidized at 900. The relationship between the
weight-gain of RB-SiC and oxidation times followed the parabolic curve. The oxidation resistance of
RB-SiC at 900 could increased by the increase of SiC particles sizes. But the electrical resistivity of
RB-SiC had not affected by the oxidation at 900. The oxidation mechanism of RB-SiC and the
affecting factor on oxidation of RB-SiC were analyzed and discussed.
The Behavior of Phase Transformation Characteristics and Ageing on Alloying Method of CuZnAl Shape Memory Alloy
Authors: Yang Gon Seung , Lee Jung Il , Jang Woo Yang
Published: March 2009

The effect of transformation temperature and phase transformation characteristics by
alloying method of CuZnAl shape memory alloy with a small of misch metal and Zr contents were
investigated. The addition of misch metal and Zr was very effective for reducing the grain size. After
solution treatment, the specimens were post-quench aged or step quenched at 373K to 623K for
variation of hardness value. It was found that the hardness value was very increased at 473K and
523K. The fracture mode has been changed from trans granular brittle fracture to ductile fracture with
void formation and coalescence by the addition of misch metal and Zr. Ageing of the β-phase
decreased the Ms temperature, but that of the martensite phase increases the As temperature. The
change in As temperature with post-quench aging can be attributed to recovery of order in the
β-phase.
Ti-Ca-P Films Formed by RF Magnetron Sputtering Method Using Dual Targets
Authors: Watazu Akira , Kimoto Katsuhiko , Tsutomu Sonoda , Tanaka Kinya , Sawada Tomoji , Toyoda Minoru , Saito Naobumi
Published: March 2009

Ti-Ca-P films on commercial pure (cp) titanium plates were uniformly deposited using
dual target RF magnetron sputtering apparatus with DC magnetron sputtering system under the
conditions of 50 W DC power to a cp titanium target and 200 W RF power to a β-tricalcium phosphate
(β-TCP) target for 60 min in 2.2×10-1 Pa Ar. Resulting samples had smooth surface like mirror.
Crystal structure of the film was amorphous. The film had the chemical composition of about 3: 1.7:
1: 11 in Ti: Ca: P: O ratio under controlling the β-TCP target RF sputtering power and the titanium
target DC sputtering power. The film and the method are expected to be useful for remodeling
surfaces of various titanium implants.
Fabrication and Characterization of Slag Fiber by Melt Extraction
Authors: Song Yeong Hwan , Seong Hwan Goo , Park Soo Han , Ahn Duck Kyu , Seo Chang Hwan , Hur Bo Young
Published: March 2009

The influence of wheel speed and melt temperature on the surface characteristics of slag
fibers were examined in mineral fibers synthesized from the steel-making slag, using a modified melt
extraction method, i.e. melt spinning. The synthesized fibers were characterized by optical
microscope and scanning electron microscopy. It was found that the wheel speed of 700 rpm
generated better quality of mineral fibers in terms of diameter and length. This was attributed to the
relative extent of contact width between the flowing melt and the rotating wheel. The thickness of the
slag fibers were also decreased with increasing the slag melt temperature due mainly to significant
decrease in the viscosity of the slag melt. In addition, the lower melt temperature caused an increase in
number of shots plus the mineral fibers.
Design of Glass-Ceramic Matrix by Modification of Microstructure for High Strength LTCC Application
Authors: Kim Jin Ho , Hwang Seong Jin , Kim Hyung Sun
Published: March 2009

For low temperature co-fired ceramics (LTCC) materials, BaO-B2O3-MgO-Al2O3 glass
system was tested. The starting temperature for densification of a sintered body was at 700°C and the
onset temperature for crystallization of a sintered body was 820°C. With the sintering temperature,
the sintered body was investigated with shrinkage, crystal phases, thermal properties, and mechanical
properties. The glass transition temperature was constant with increasing frit size. However, the onset
point of crystallization increased with increasing frit size. The formation of crystal phase was celsian
(BaAl2Si2O8). From our results, it is possible to achieve the glass-ceramic having the high strength
and the ability of sintering at low temperature using controlling the sintering temperature of
BaO-B2O3-MgO-Al2O3 system glass frit.
Development of Artificial Soil Using Sewage Sludge
Authors: Yoo Yeong Seok , Shin Hyun Chul , So Hyung Suk , Kim Beom Suk , Kim Jong Bo
Published: March 2009

We made artificial soil using sewage sludge, the organic wastes. The optimum
composition is 50% of sewage sludge cake, 45% of illite low-quality clay, 3% of glassfrit, and 2% of
other components. The surface was coated with γ-alumina. For an optimum manufacturing condition,
we sintered and bubbled the plastic material with dry surface by flowing N2 gas at 800°C for 20
minutes. The developed artificial soil shows excellent characteristics; more than 60% of porosity, of
0.8 of density g/cm3, 80ton/m2 of compression, pH 7.4, cation exchange capacity (CEC) 10 meq/100g
and about 2000 of hydraulic conductivity. The developed product performs 1.5 ~ 10 times better than
the existing perlite in open porosity, nutrient holding capacity, proof compression and CEC. However,
the bulk density is 1.5 times higher and heavier than perlite, it is not so problematic to green roof. The
developed artificial soil shows positive effect on the development of ecotype leaf or the growth speed
by period comparative to the common fertile soil. The number of pollens and lipid shows excellent
growth on the artificial soil. The product can be applied to various kinds of plants such as flowering
plants, foliage plants, trees and ground cover plant. It can also be applicable to other large amounts of
plants grown on the other artificial grounds (slope, road, etc.)
Dielectric Properties of Sol Infiltrated Lead Zirconate Titanate Ferroelectric Thick Films
Authors: Lee Sung Gap , Park Sang Man , Lee Young Hie , Nam Sung Pill
Published: March 2009

Ferroelectric PZT(70/30) thick films were fabricated by the hybrid technique adding the sol
coating process to the screen-printing process to obtain a good densification. Structural and electrical
properties of the thick films with the sol concentration were investigated. The relative dielectric
constant increased and dielectric loss decreased with increasing the sol concentration, the values of
the thick film coated with sol concentration of 1.5 M were 698 and 2.5 % at 1 kHz, respectively. And
the remanent polarization and dielectric breakdown strength of the thick film coated with sol
concentration of 1.5 M were about 38 μC/cm2 and 200 kV/cm, respectively. The leakage current
densities were less than 10-8 A/cm2 at the applied electric field range of 0-100 kV/cm in all thick films.
Emergence Change of Carbon Dioxide from Artificial Skin by Titania Photocatalyst
Authors: Watanabe Eiji , Fukaya Mitsuharu , Taoda Hiroshi
Published: March 2009

The influence of the titania photocatalyst particle of the nanometer region on the human
being and biology’s to be doubted. Removing the uneasiness will expand further uses for the
photocatalyst nanoparticle. Then, we attempted to examine the effect of several titania photocatalyst
nanoparticles to the artificial skin like the human body under the UV and visible light irradiation
conditions. The decomposition degree of the artificial skin was evaluated from the monitoring of
the amount of carbon dioxide generated from them by the titania photocatalyst nanoparticle activity.
Under the UV irradiation condition, it was almost found the carbon dioxide emergence from the
artificial skin by the activity of the titania photocatalyst nanoparticle. On the other hand, under
visible light condition it was mostly detected.