bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancement of the Optical Performances for the LED Backlight Systems with a Novel Dual Lens-Cap
Authors: Chao Paul C.P. , Liao Lun De , Chiu Chi Wei , Shen Chien Yu
Published: March 2009

A novel dual-cone-shaped side-emitting lens cap for High Brightness Light Emitting
Diodes (HB-LEDs) is proposed for improving brightness and high uniformity of the direct LED
backlight Units (BLUs) for large-sized LCD-TVs. Combining the designed lens cap with red, green
and blue (RGB) chips on a Metal Core Printed Circuit Board (MCPCB), the LED module with the
proposed cap is able to provide a compact white light source with unique features such as instant
color variability and lower power usage, etc. The dual-cone-shaped of the proposed lens cap is
designed to emit most of the light rays to the sides, only a small portion of light upward along the
optical axis of the lens, providing a uniform luminance distribution and the high brightness on the
backlight. In addition, a small reflective surface in semi-circular shape is designed and placed upon
the proposed LED module about 10mm, the surfaces of which are attached with reflective films to
increase the level of light mixing in the larger, global reflector optical box. With the structure of the
LED module well designed, the LED backlight Module would be designed for the large-sized LCDTV
using the fewer number of LEDs to lead to lower power consumption. The results indeed
identify the attributes of the BLU, which make it possible to achieve excellent backlight
performance using a direct illumination approach from the light source of “Dual-Cone-Shaped Side-
Emitting Lens Cap of LEDs.”
The Driver Circuit and Focusing Lens Designed for the Laser Range-Finder
Authors: Chen Ming Fei , Li I. Feng , Hu Chun Wei
Published: March 2009

This paper has partitioned the laser range-finder into two parts: one is the laser diode
(LD) driver circuit and the other is the focusing lens. The LD’s surface temperature rise will affect
the LD’s light-power simultaneously when an LD works in a steady current. For this reason, we
designed a driver circuit to control the LD’s light power to be effective and so as to freely adjust the
LD’s brightness. There are three parts in driver circuit: the regulated power circuits, the regulated
current circuit, and the limited current circuit. This investigation used a power meter to measure the
LD’s power which was relative to the surface temperature. Then the experimental results were
compared with the PSpice simulation, and the differences between the result and the simulation
were eventually analyzed.
The limited current circuit is an important part in our systems because the LD is easily damaged
when active current is unstable. Similarly, the surface temperature would be raised after the LD is
working for a while which results in the circuit failure. If the LD has worked for a very long time,
the heat generated in the circuit should be taken care of. Therefore, we added an automatic power
control circuit (APC) into the LD driver circuit in order to reduce the impact of heat.
The emitted distance of laser beam could be up to 10 meters with adjusted focusing lens. The
laser spot was extended into an ellipse before focusing laser beams. Therefore, we had to put a
focal lens to shape the the laser spot into a circular spot. During this experiment, the LD did not
work directly without installing the heat sink. Otherwise, the high temperature would damage LD
immediately.
Nanoindentation Size Effect of KDP Crystal by Instrumented Indentation Testing
Authors: Wang H.X. , Wang Jing He , Dong Shen
Published: March 2009

Indentation tests and single-point scratch tests are probably the simplest methods of
measuring the elastic, plastic and fracture behavior of brittle materials. In this paper, the nearsurface
mechanical properties of KDP single crystal have been investigated including the elasticity
like Young’s modulus E, and the plasticity like the hardness H. These material properties can be
used to predict the material responses in optical manufacturing operations. Hardness and elastic
modulus on different crystal plane of KDP single crystal have been examined under different loads
by nanoindentation test, and the influence of the indentation load on hardness and elastic modulus
have been also analyzed systematically. The results show the nanoindentation size effect, that is, the
hardness and elastic modulus increase as the indentation load decreases. The hardness and elastic
modulus have strong anisotropy in the different crystallographic orientation of the same crystal
plane.
Development of a Millimeter Scale Turning Centre for Gear Hobbing
Authors: Chan Sunny , Wong Sammy , Kong Tom C. , Du Ru
Published: March 2009

Conventional machining is generally preferred in manufacturing metal components with
2½D features and/or 3D silhouettes. With the ever increasing demand for reduced sizes and
increased accuracy, however, traditional machine tools have become ineffective for cutting
miniature components. A typical example is gear manufacturing. It is known that gears are
machined using the gear hobbing process in which the cutter axis and the workpiece axis are
required to be synchronized to an accurate constant ratio. According to a market survey, only a few
machine tools can make gears with the size of φ1.0 mm. This paper presents our effort in
developing a PC-based millimeter scale CNC turning centre with gear hobbing capability to
machine miniature gears. In this machine, the synchronization required by the gear hobbing process
was achieved directly by controlling the AC servomotors. Experiment results show that the machine
is able to machine high quality components with diameter as small as 0.075 mm and hob gears with
module as small as 0.09.
Calibration of a Photogrammetric System for Semiautomatic Measurement: CaM-DisT®
Authors: Arias Pedro , Lorenzo Henrique , Ordóñez Celestino , Armesto Julia
Published: March 2009

Nowadays some measurement tasks are usually made by the joint use of different
systems, techniques, even sciences, trying to find the best results together with less work time. This
is the case of close range photogrammetry and laser distancemeter. It is possible to find some works
where they are applied together in so different sceneries as architectonic conservation, civil
engineering, building, etc. One of the scopes where these techniques can be applied is in the
measurement of facades of buildings in construction [1,2]. During the constructive process it is
necessary to make periodic measurements, and also during the whole life of the building, as a
control tool [3]. At the present day some of these measurements are hand-made, with the risk of
having an industrial accidents in some situations. In this work we present a methodology based on a
photogrammetric - distancemeter joining measure system, in order to semi-automate some
measurement procedures in building construction. The system consists of a semi-rigid calibrated
support putting up a laser distancemeter and a digital camera, called CaM-DisT®. The support was
specifically designed for this kind of application. The development of the system was made in four
steps: establishment of the mathematical background; design of the support; construction of the
support; and calibration of the complete system. The calibration process was made by two different
alternatives which are xpounded this contribution in detail.
Effects of the Tool Angles on the Machined Surface Quality of KDP Crystal in Diamond Turning
Authors: Wang Jing He , Chen Ming Jun , Dong Shen , Wang Shi Qian
Published: March 2009

In the ultra-precision machining of KDP crystal, there are many factors affecting the
surface quality[1-3]. The experiments show that the rake angle and back angle of the tool have
significant effects on machined surface roughness. Therefore, an efficient way to improve the
surface roughness is to select a proper negative rake angle. In this study, the ANSYS static analysis
method was employed to analyze the stress field distribution within the whole cutting region. A
finite element simulation model was set up to calculate the residual stresses variation with tool’s
angles, which can be considered to select optimal rake and back angles in the ultra-precision
machining of KDP crystal. Results show that the optimal tool rake angle and back angle are -49°
and 7°, respectively. Finally, by using different tool angles to process KDP crystal and utilizing
AFM to analyze the surface roughness, it can be found that the measurement results agree well with
what are deduced from theoretical calculation.
The Wear Behavior of Pulse Current Electroforming Ni-P-SiC Composite Coatings
Authors: Hou Kung Hsu , Jeng Ming Chang , Shen Yung Kang , Ger Ming Der
Published: March 2009

In this study, the SiC particles with a mean diameter of 300nm were used to be codeposited
with Ni-P base to produce Ni-P-SiC composite coatings by means of the pulse current
electroforming technology. The relationship between the SiC particles and phosphorous contents in
the composite coatings has been constructed. The wear behavior of the Ni-P-SiC composite
coatings was examined by that measurements data including the wear weight loss, the coefficient of
friction, and the temperature increments under the wear tests, in which were correlated to the
observation and analysis of the worn surface of the composite coatings. Experimental results show
that the wear resistance of Ni-P-SiC composite coatings is superior to Ni-P composite coatings, if
they are under the same level of hardness. In addition, the wear weight loss of Ni-P-SiC composite
coatings is even about 62% less than that of Ni-P composite coatings, if they are based on the same
production conditions. Further more, both the hardness and wear resistance of Ni-P-SiC composite
coatings are superior to pure Ni coating, wherein its wear resistance is even up to 10 times better
than that of pure Ni coating.
A Rapid Prototyping Apparatus for Forming Ceramic Parts
Authors: Liu Fwu Hsing , Liao Yunn Shiuan
Published: March 2009

This article proposes a rapid prototyping apparatus of selective laser sintering for
forming silica ceramic green parts. The main differences between the proposed and other RP
processes for forming ceramic part are the slurry material used to obtain fine layer thickness and
the capability of constructing support structure to increase the dimensional accuracy of the
workpiece having an overhang. The RP apparatus developed by us comprises a laser scanning
system, a material paving system, and a computer control system. A CO2 laser is adopted to scan
over a mixture made of a silica sol and silica powder. The silica sol acts as a binder to gel the silica
powder together, which forms a 3D object using laser gelation method. A series of experiments
were carried out to obtain the optimal process parameters. An SEM is employed to analyze the
microstructure of the ceramic part. It has been found that the smallest layer is of 100 μm thick. The
results show that both the accuracy of the material paving mechanism and the optimal process
parameters can fulfill the requirements of the RP processes.
Microfluidic Parallel Form Mixer Utilizing Chaotic Electric Field
Authors: Yau Her Terng , Chen Chieh Li , Cho Ching Chang
Published: March 2009

The past few years, have witnessed a rapid increase in the application of microfluidic
devices to chemical and biological analyses. These devices offer significant advantages over their
traditional counterparts, including reduced reagent consumption, a more rapid analysis and a
significant improvement in performance. Species mixing is a fundamentally important aspect of
these devices since it is this mixing which generates the biochemical reactions necessary for their
successful operation. Many microfluidic applications require the mixing of reagents, but efficient
mixing in these laminar (i.e., low Reynolds number) systems are typically difficult. Instead of using
complex geometries and/or relatively long channels, an electric field is applied to drive flow mixing
in microchannels. Generally, the fluid is driven by the application of an external periodic AC
electric field. However, the chaotic AC electric filed is never used to drive flow mixing in
microchannels. Chaotic behavior is a very interesting nonlinear effect. In some physical systems,
chaos is a beneficial feature as it enhances mixing in chemical reactions. This paper presents a
numerical investigation of electrokinetically-driven flow mixing in microchannels with chaotic
electric field. The simulation results show that the application of a chaotic external field enables a
reduction in the mixing channel length and a high degree of mixing efficiency. It is shown that a
mixing performance as high as 90% can be achieved by chaotic external electric field.
Solution for Best Fitting Spherical Curvature Radius and Asphericity of Off-Axis Aspherics of Optical Aspheric Surface Component
Authors: Dong Guo Jun , Han Cheng Shun , Dong Shen
Published: March 2009

This study aimed to establish the coordinate transformation between the off-axis
aspherics coordinate system σ and the axial symmetry aspherics coordinate system σ by
transforming coordinates and present the computation models of asphericity in rectangular
coordinate system and cylindrical coordinate system respectively. The asphericity expressions in
both coordinate systems were applicable to the comparative sphere calculation of Off-axis aspherics
with different figures. We selected an Initiation sphere in view of technology, along with equations
in a right coordinate system for certain caliber and structure. Then, by numerical computation, we
selected the best fitting sphere and simplifed the complex models by choosing a right coordinate
system. At last, the solution for asphericity and the best fitting sphere curvature radius of off-axis
aspherics were introduced by examples.
Optical System Design with High Resolution and Large Field of View for the Remote Sensor
Authors: Chang Jun , Weng Zhi Cheng , Wang Yong Tian , Cheng De Wen , Jiang Hui Lin
Published: March 2009

In this paper, we are presenting a design method and its results for a space optical system with high resolution and wide field of view. This optical system can be used both in infrared and visible configurations. The designing of this system is based on an on-axis three-mirror anastigmatic (TMA) system. Here the on-axis concept allows wide field of view (FOV) enabling a diversity of designs available for the Multi-Object Spectrometer instruments optimized for low scattered and low emissive light. The available FOVs are upto 1º in both spectrum ranges, whereas the available aperture range is F/15 - F/10. The final optical system is a three-mirror telescope with two on-axis and one off-axis segment and its resolution is 0.3m or even lower. The distinguished feature of this design is that it maintains diffraction-limited image at wide wavelengths. The technological developments in the field of computer generated shaping of large-sized optical surface details with diffraction-limited imagery have opened new avenues towards the designing techniques. Such techniques permit us to expand these technological opportunities to fabricate the aspherical off-axis mirrors for a complex configuration.
A Kinematic Study on a Novel Press System
Authors: Hsieh Wen Hsiang
Published: March 2009

The work aims to present a novel press system, and to investigate its feasibility by
performing a kinematic study. Firstly, the new design is proposed, which is composed by a motor,
a constant speed coupling, a gear reducer, a generalized Oldham coupling, and a slider-crank
mechanism. Secondly, its structural sketch is drawn, and its kinematic dimensions are obtained by
studying its motion geometry. Then, a design example is given for illustration. Moreover, the solid
model of the design is established, and then the validity of the design is verified by kinematic
simulation using ADAMS software. Finally, the effects of different link ratios on the output motion
are examined by conducting a number of simulations. The results of simulations show that the new
design can produce more flexible output motion than a mechanical press. In addition, it has the
advantages of lower cost, high reliability, and lower energy consumption, compared to a servo
press.
Effects of Surface Cleanness, Bonding Pressure and Contact Area of ACF on Interfacial Impedance of Chip on Glass Bonding in Flat Panel Display Assembly
Authors: Tsai Jhy Cherng , Wang Wen Tsung
Published: March 2009

Chip on glass (COG) bonding using Anisotropic Conductive Film (ACF) is the best
process for assembling ICs on thin substrate glass with fine pitch in current practice. This paper
investigates the effects of surface cleanness of the substrate, bonding pressure and contact area of
COG bonding with ACF on interfacial impedance (II) via experiments. Indium tin oxide (ITO),
350±15nm in thickness, coated on 0.4mm glass is used as the substrate with φ4μm ACF particle in
the experiment. Surface cleanness is measured by wetting tension, an alternative measurement of
surface energy. Experiments with three levels for each parameter are designed and conducted.
Reliability tests, including temperature test, humidity test, cycling test and boiling test, are also
conducted to allocate best parameters in the COG bonding process. Experimental results showed
that the contact area of ACF must be more than 1,500μm2 in order to provide stable II. Surface
cleanness of ITO glass is suggested to be higher than 46 dyne/cm as measured by wetting tension
test. Bonding pressure, ranging from 40 to 80 Mpa, does not have strong effect on II. Temperature
test under -40°C /30min to 85°C/30min at 120cycle and humility test at 85°C under 85%RH for 500
hours showed that higher surface cleanness results in better bonding result as the variation of II is
lower. Boiling test at 121°C under 2atm for 8 hours showed that surface cleanness should be over
46 dyne/cm, as measured by wetting tension test, to ensure stable bonding result.
A Study of Glass Milling Using Rotary Ultrasonic Machining
Authors: Kuo Kei Lin
Published: March 2009

Employment of rotary ultrasonic machining (RUM) technique to mill glass material was
attempted in this research. The feasibility and efficacy of the novel milling process were evaluated.
The challenge of the attempt in the present study had to do with the fact that the direction of RUM
tool oscillation was inherently perpendicular to the direction of milling. The RUM apparatus
employed for the study comprised a computerized feeding system, a drive control system and an
ultrasonic oscillation system. The RUM system was also characterized by having a feeding system
fit for a PC-controlled stepping motor. It was found that the oscillation associated with the RUM
milling was effective in reducing the machining resistance encountered during milling process,
making it possible to increase the feed rate and thus the material rate, as well. However, the
increased milling depth and feed rate would have an adverse effect on the tool life in terms of more
breakage of grinding grits on the tool, thus resulting in faster wear rate of the milling tool.
A Method to Improve Uniformity of Material Removal of Chemical Mechanical Polishing in LCOS Process
Authors: Sun Yu Hui , Kang Ren Ke , Guo Dong Ming
Published: March 2009

LCOS panel as a kind of new LCD is a sort of liquid crystal display device that operates
in a reflective mode. In this paper, a method on realising planarization in large scale liquid crystal
on silicon with chemical mechanical polishing (CMP) technology is discussed in detail. The nonuniform
distributions of polishing pressure and the relative speed between the wafer and the
polishing pad are main factors affecting the within-wafer non-uniformity. This research integrated
a physical mixed model of chemical-mechanical polishing that combineed the effects of polishing pad
roughness and slurry hydrodynamic pressure. Based on the contact mechanics and modified Reynolds
equation, the asperity contact and fluid flow pressures were calculated. Taking into account the
effects of kinematic parameters, the material removal rate(MRR) on silicon panel front surface was
obtained. In the last section the design of a schematic carrier with multi-zone, in which the
compensation back pressure can be applied, is presented. The model and the design can be used for
providing theoretical guide to the development of CMP equipments and selection of the kinematic
variables in CMP process.
Study on Effects of Grinding Speed on Finish and Precision Machining in Quick-Point Grinding
Authors: Xiu Shi Chao , Yuan Suo Xian , Li Chang He , Cai Guang Qi
Published: March 2009

According to the analysis in theory, the model of quick-point grinding is different from
conventional cylindrical grinding because it is point contact between the grinding wheel and the
workpiece due to the point-grinding angles in two directions and the lower grain depth of cut in the
process. Especially, the grinding speed has the great effects on the micro-geometry properties and
the machining precision of the workpiece surface in the process. Based on the theoretical studies on
the surface roughness, the grinding experiments and the measurements of the surface roughness at
high grinding speeds were performed in quick-point grinding process. Furthermore, the influencing
mechanism of the grinding speed on the ground surface roughness was analyzed. Some conclusions
of the grinding parameters influencing precision machining and surface integrity were deduced.
Development of a New Optical Coordinate Measurement Machine in Cylinder Coordinates
Authors: Zheng Zi Wen , Jia Li De , Li Sheng Yi , Dai Yi Fan
Published: March 2009

A new special-purpose optical coordinate measurement machine has been developed with the cylinder coordinates to solve the problem of testing aspherics with full aperture in the stage of grinding and pre-polishing .A full aperture measurement was made by testing several meridians in the point by point manner. In the aspect of hardware, the system is composed mainly by an ultraprecise air guide-way, realizing the linear motion, and a graduator, realizing the rotary motion. In the aspect of software, the mathematical model of the system was analyzed and a new algorithm for the full-aperture testing of rotationally symmetric aspherics was built. The testing software and data-processing software are written on the VC++6.0 and Matlab6.5 platform respectively. The maximum measurement range of the system is 600mm, the maximum sag: 25mm, the minimum sampling step, 1 mm and the accuracy is better than 1um in full scale, after the compensation of the systematic errors. The requirement in the grinding and pre-polishing process for the test of aspheres has been satisfied. The real experiments indicate: the system runs well and has a good repeatability and accuracy.
Application of Porous Silicon on the Gas Diffusion Layer of Micro Fuel Cells
Authors: Lee Chi Yuan , Lee Shuo Jen , Dai Ching Liang , Chuang Chih Wei
Published: March 2009

This investigation utilizes porous silicon as the gas diffusion layer (GDL) in a micro fuel cell. Pt catalyst is deposited on the surface of, and inside the porous silicon, to improve the performance of a fuel cell, and the Pt metal that remains on the rib is used to form a micro thermal sensor in a single lithographic process. Porous silicon with Pt catalyst replaces traditional GDL, and the relationships between porosity and pore diameter, and the performance of the fuel cell are discussed. In this work, electrochemical etching technology is employed to form porous silicon to replace the gas diffusion layer of a fuel cell. This work focuses on porous silicon with dimensions of tens of micrometers. Porous silicon was applied to the gas diffusion layer of a micro fuel cell. Boron-doped 20 '-cm n-type (100)-oriented doubly polished silicon wafer was used on both sides. The process is performed to etch a fuel channel on one side of a silicon wafer, and then electrochemical etching was adopted to form porous silicon on the other side to fabricate one silicon wafer that combines porous silicon with a fuel channel on a silicon wafer to minimize a fuel cell. The principles on which the method is based, the details of fabrication flows, the set-up and the experimental results are all presented.
Characteristics of Micro-Precision Machining of Glasses by Powder Blasting
Authors: Yoo Woo Sik , Jin Quan Qia , Park Dong Sam , Seong Eun Je , Han Jin Yong
Published: March 2009

Powder blasting is similar to sand blasting and effectively removes hard and brittle materials. With
an increase in the need for machining of ceramics, semiconductors, electronic devices and LCDs, micro
abrasive jet machining has become a useful technique for micro-machining. In this study, we first
investigated the effects of the blasted glass surface’s characteristics and shape under different blasting
parameters; second, we examined the predictive models for material removal and surface roughness that
have been developed in terms of blasting pressure, scanning speed and abrasive flow, using response surface
methodology by experimental data. The established equation shows that the blasting pressure was the main
factor influencing the material removal and surface roughness. In addition, analysis of variance for the firstorder
model of material removal and surface roughness shows that the coefficient of determination (R2) is
99% and 98%, respectively. The associated p-value for the two models was lower than 0.01, indicating that
the models are statistically significant.
Nano Molding Technology for Optical Storage Media with Large-Area Nano-Pattern
Authors: Shin Hong Gue , Kim Heon Young , Kim Byeong Hee
Published: March 2009

Nano hot or thermal embossing has many advantages of comparatively few process steps,
simple operation, relatively low tooling cost and high replication accuracy for small features.
However, because of its long processing time, it has been known as being less competitive than
nano injection molding. In order to overcome the weakness of long processing time, the high speed
nano hot embossing system has been developed and its characteristics were investigated. Nanopatterned
stampers made of Ni and Si were fabricated by the laser mastering and electroforming
process and the DRIE and LPCVD or thermal oxidation process respectively. In order to make the
processing time shorter and get relatively higher aspect ratio nano/micro features, especially, the
temperatures of the molds were controlled actively and precisely during the embossing process.
Through various experiments, nano embossing parameters, such as temperature, pressure and
processing time, are optimized and the high aspect ratio nano features could be obtained.
Stress Analysis of Optical Fiber Sensor Embedded Composite Subjected to Tri-Axial Normal Loadings
Authors: Her Shiuh Chuan , Yao Bo Ren
Published: March 2009

Optical fiber sensors have been developed during the past decade to measure a wide
range of physical quantities such as strain and temperature. The perturbation of the surrounding
field in the host due to the presence of the optical sensor will not only alter the values of the field
variables being measured, but may also affect the integrity of the host. Resulting degradations can
compromise the accuracy and long term reliability of the smart structure. The present paper focuses
the attention on constitutent interaction between the optical fiber, coating, matrix and host material.
An analytical model to predict the stress fields in the vicinity of the embedded optical fiber was
derived. The theoretical development was based on the four concentric cylinders models which
represented the optical fiber, protective coating, matrix and host material, respectively. The
interfaces between each constitutent were assumed to be perfect bonds, so that the tractions and
displacements were continuous across each interface. In this investigation, the host structure was
subjected to three normal loadings along the axial directions. Numerical examples were presented to
investigate the effects of the coating and host material on the stress distribution in the vicinity of the
embedded optical fiber.
Innovative Methodologies for the Simulation of Static Recrystallisation during the Solution Soaking Process of Shape Extrusion
Authors: Sheppard Terry , Velay Xavier
Published: March 2009

Materials which form the surface and subcutaneous layers of an extrudate experience
large deformations when they traverse the die land. This, when added to the inhomogeneity caused
by the dead metal zone, leads to considerable modifications to the deformation parameters when
compared to the remainder of the extrusion. The distribution of structure is therefore greatly
inhomogeneous. Reference to both empirical and physical models of the recrystallisation process
indicates that nucleation and growth will differ at these locations in those aluminium alloys that are
usually solution treated and aged subsequent to the deformation process. Since static
recrystallisation has a significant influence on many of the properties of the extrudate, it is therefore
essential to provide the methodology to predict these variations. In the work presented, a physical
model, for AA2024, based on dislocation density, subgrain size and misorientation is modified and
integrated into the commercial finite element method (FEM) code, FORGE, to study the
microstructure changes. Axi-symmetrical and shape extrusion are presented as examples. The
evolution of the substructure influencing static recrystallisation is studied. The predicted results
show an agreement with the experimental measurement. The distribution of equivalent strain,
temperature compensated strain rate and temperatures are also presented to aid interpretation.
Importantly the properties of hard alloys improve as the temperature of the extrusion is raised. This
phenomenon is discussed and theoretically justified. This paper also presents some innovative work
where the physically based models, and the Cellular Automata (CA) method, are combined to
simulate the static recrystallisation process. The FEM is adopted to provide the initial morphology
and state variables for the structure models, such as the equivalent strain, the temperature and the
equivalent strain rate. The subgrain size, and dislocation densities are calculated from physically
based models and are transferred to CA models to construct the data required to define the initial
state for recrystallisation. Simulation results are compared with experimental measurements. It is
demonstrated that CA integrated with the physically based models is effective in predicting the
structural changes by selecting a suitable neighbourhood and reasonable transition rules.
Effects of CVD C or SiC on the Mechanical and Chemical Properties of Carbon Fibers
Authors: Xu Xian Feng , Xiao Peng , Xiong Xiang
Published: March 2009

After removal of the resin from PAN-carbon fibers, the fibers were coated with C or SiC by
chemical vapor deposition (CVD) and the effects of these CVD coatings on the mechanical and chemical
properties of carbon fibers were investigated. DTG analysis was conducted at different temperatures
(993K, 1053K and 1113K) to establish the oxidation reaction models of the C/C or C/SiC coated fibers.
The results showed that the CVD coatings enhance the oxidation resistance of the carbon fibers. The
surface morphology of the CVD C or SiC fibers was investigated by SEM. The tensile strength of the
fibers was found to decrease rapidly after CVD, while the Young’s modulus remained almost constant.
These changes can be explained by the interface performance of the carbon fibers and the mechanism of
CVD C or SiC deposition. The difference in dilatability between the CVD C or SiC layers and the carbon
fibers was the main reason for the tensile failure.
Effects of Molding Pressure on the Microstructure and Mechanical Properties of 2D-Cf/SiC Composites by PIP Routes
Authors: Jian Ke , Liu Jing Yu , Chen Zhao Hui , Ma Qing Song
Published: March 2009

Carbon fiber cloth reinforced silicon carbide (2D-Cf/SiC) composites were prepared through
polycarbosilane(PCS) /divinylbenzene(DVB) pyrolysis with SiC as inactive filler. Effects of the molding
pressure on the microstructure and mechanical properties of 2D-Cf/SiC composites were investigated.
With increasing molding pressure from 0MPa to 3MPa, the fiber volume fraction of the composites was
increased. As a result, the strengths of the composites were enhanced. But when the molding pressure
exceeded 3MPa, SiC particles would damage the carbon fibers seriously. Therefore, although the fiber
fraction of the composites was increased further, the flexural strengths of the composites were decreased.
It was found that the composites fabricated with the molding pressure of 3 MPa exhibited highest flexural
strength, reached 319.4 MPa.
Synthesis of Nanocrystalline 0.94Bi0.5Na0.5TiO3-0.06BaTiO3 Powder by a Citrate Method
Authors: Tian Zhi Bin , Wang Xiao Hui , Li Ji , Zhao Wei , Li Long Tu
Published: March 2009

A citrate method to synthesize 0.94Bi0.5Na0.5TiO3-0.06BaTiO3 nano-powder was studied. The
stable gel was obtained by the control of the pH value and temperature of the precursor solution. The
BNBT nano-powder was produced after calcining the xerogel at 600°C~800°C. The average grain size of
the powder calcined at 700°C for 3 h is 50 nm, and the grain size of the ceramic sintered at 1080°C is 0.7
μm. The sintering temperature used is 100°C lower than the BNBT ceramic prepared by traditional
method, but the electrical properties were comparable. In addition, it was found that the ball-milling
process has important effect on the morphology of the ceramics and the orientation crystals were
eliminated due to the disintegration of agglomerates during milling.
Development of Ceramic Composites for Industrial Wood-Cutting Tools
Authors: Kübler Jakob , Eblagon Fernando , Graule Thomas , Ehrle Bruno
Published: March 2009

Industrial wood cutting is a highly demanding application for cutting tool materials as a wedge angle of ~50°, a tip radius in the 1 m range, and high wear, temperature and corrosion resistance are needed. For this application Si3N4 based ceramic matrix composites (CMC) were developed. Cutting tests showed that reinforcing Si3N4 with 30 wt.% SiC gives a good balance between fracture toughness and wear resistance. The use of an yttria / lanthana sintering aid system resulted in a fine-grained microstructure without degrading the fracture toughness. Post heat treatment was essential for the integrity of the cutting edge. Finally, cutting tests proved that the CMC cutting tips had a 3-fold lifetime compared to tungsten carbide.
Synthesis and Properties of Polyethylene Glycol Diacrylate /2-Hydroxyethyl Mathacrylate Hydrogels
Authors: Tan Guo Xin , Wang Ying Jun , Guang Yan Xia
Published: March 2009

The bioactive synthetic hydrogel materials were prepared with polyethylene glycol diacrylate (PEGDA) and 2-hydroxyethyl mathacrylate (HEMA) by UV photo-polymerization. The aim of this study was to prepare a scaffold material by combining HEMA into a composite polymeric PEGDA-based hydrogel, which were used as bioactive artificial cartilage. The structure and properties of the synthetic hydrogels were investigated in details using FTIR techniques. The swelling data indicated that the equilibrium water content depended on the precursor feed ratio. It was found that adding the HEMA into the PEGDA-based hydrogels was very helpful to improve the swelling properties.
Preparation of ZrO2(f)/PMMA-PMA Composites by a Suspension Polymerization Process
Authors: Zheng Bin , Cao Li Yun , Huang Jian Feng , Wu Jian Peng
Published: March 2009

Yttria stabled zirconia fiber reinforced polymethyl methacrylate-polymethyl acrylate (PMMAPMA)
composites (ZrO2(f)/PMMA-PMA) were prepared by a suspension polymerization method. The
effects of MMA/MA volume ratio, initiator and fiber mass ratio on the mechanical properties of the
composites were investigated. Results showed that the flexural strength of the composites reaches the
optimum value when the volume ratio of methyl methacrylate /methyl acrylate (MMA/MA) = 9/1. With
the increase of benzoyl peroxide (BPO) mass ratio, the flexural strength of ZrO2(f)/PMMA-PMA
composites increases to maximum and then decreases. With the increase of ZrO2 fiber mass ratio, the
microstructure of the fractured surfaces changes from smooth to crapy, implying that the toughness of the
composites is improved.
Improved Principal Component Analysis on the Comprehensive Hemocompatibility Evaluation of Biomaterials
Authors: Lin Jiang Li , Cai Ke , Zou Yuan Wen , Gou Li , Ran Jun Guo , Yin Guang Fu
Published: March 2009

Hemocompatibility of a biomaterial is determined by the interactions between its surface and
blood. Due to the complicated action mechanism, various effective ways and the multiple affective
factors of the hemocompatibility, a comprehensive evaluation needs to be built instead of single index.
Therefore, the platelet consumption ratio of 10 kinds of biomaterials including Ti6Al4V-TiC-DLC
gradient coat material was studied based on image analysis method. Combined with the kinetic clotting
time and the hemolysis ratio, the comprehensive hemocompatibility evaluation of the material is carried
out based on the improved principal component analysis. First, linear transformation of negative index is
carried out. Second, index is under a dimensionless using the logarithmic treatment, then to acquire all
variants’ principal component and their characteristic vectors. Finally, comprehensive evaluation index
of hemocompatibility is constructed. The improved principal component analysis avoids the effect of
correlativity among indexes during anaphase evaluation, and can more correctly maintain the original
information of indexes. Thus, the research provides a new idea to the comprehensive evaluation of
Hemocompatibility.
Strength and Fracture Mode for Dental Colored ZrO2 Ceramics Coated with Dental Porcelain
Authors: Yi Yuan Fu , Liu Hong Chen , Lin Yong Zhao , Deng Bin , Wen Ning , Tian Jie Mo
Published: March 2009

The purpose of this study was to investigate the flexural strength and the mode of failure of
dental colored ZrO2 ceramics with or without porcelain coating. Colorants (Fe2O3,CeO2, etc.) were mixed
with 3Y-TZP powder to prepare colored dental zirconia. Specimens were made in monolithic or bilayered
forms which were coated with veneering porcelain. Experimental results showed that there were not
significantly differences of bending strengths between white and colored materials or between bilayered
specimen, while the strength of monolithic specimen were significantly higher than their bilayered
counterpart. In all bilayered specimens, the bulk fracture initiated at the tensile surface of the core
material and was consistently accompanied with porcelain crush and delamination at the interface.
Colorants for 3Y-TZP had minor effects on its mechanical properties.
Preparation of TiO2-Ni Wear-Resistant Film on Metal Surface
Authors: Li Chang Hong
Published: March 2009

TiO2-Ni wear-resistant film on metal surface is manufactured by electroless composite plating.
TiO2 content in the film depends on the concentration of TiO2 particle in the plating liquid. The optimal
TiO2 content in the plating liquid is 15-20g/l. TiO2 content in the film is 5-8%. When TiO2-Ni composite
film is treated at 200°C, its hardness increases with the prolonging of heat-treatment time. After 10 hours
heat-treatment at 200°C, the hardness increases from HV 750 kg/mm2 to HV 1300 kg/mm2.
Fabrication of TiC Coating on Carbon Steel Surface by SHS/PHIP
Authors: Zhao Hong , Zhang Xing Hong
Published: March 2009

A TiC coating was fabricated on a carbon steel surface by SHS/PHIP (combustion synthesis/pseudo heat isostatic pressing) process. Phases in the coating were determined by XRD. We employ SEM-EDS to analyze the microstructure of the coating and bonding interface between the substrate and the coating, and the distribution of elements adjacent to the interface. The microhardness of the coating was also measured. Our results showed that the coating was composed of TiC and Fe phases, with dense and pure microstructure. Metallurgical bonding was formed between the substrate and coating. The result of thermal shock resistance test showed that the coating has good bonding strength and hardness of the coating was four times higher than that of the substrate.
Friction and Wear Behavior of TiN/TiAlN Coated Ti(C,N)-Based Cermets
Authors: Zheng Li Yun , Zhao Li Xin , Zhang Jing Jun
Published: March 2009

Ti(C,N)-based cermets were coated with a TiN/TiAlN coating using ion plating technology.
The sliding wear test was performed for the coated cermets and the microstructure, composition and
surface roughness of the coated cermets under different velocities and loads were characterized. The
results showed that the friction coefficients of the coated cermets were lower than that of the neat cermets.
Under the same load, the adhesion phenomenon of the counterpart materials on the specimens was
improved and the mean friction coefficient increased with increasing sliding speed. Under the same
sliding velocity, the average friction coefficient of the coated cermets was lower under higher load. The
wear mechanisms were mainly adhesive wear and abrasive wear.
Preparation of Ceramic Composite Coatings on Ti-6Al-4V Alloy by Surface Nanocrystallization/Micro-Arc Oxidation
Authors: Hao Guo Dong , Guo Yong Liang , Zhang Xin Mei , Liu Gang , Jiang Zhao Hua
Published: March 2009

Nanostructured surface layer was produced on the Ti-6Al-4V alloy by surface mechanical
attrition treatment (SMAT) technique, and then the ceramic composite coatings of surface nanocrystallization/
micro-arc oxidation (SNC/MAO) were prepared on the nanocrystallized surface of
Ti-6Al-4V alloy by pulsed single-polar micro-arc oxidation in NaAlO2 solution. The phase composition,
morphology of surface and section and element content of the nanostructured surface layer and the
ceramic coatings were investigated by XRD, TEM, SEM and EDS, respectively. The results showed that
after the SMAT technique treatment for a short period of time, the surface layer was refined into ultrafine
grains. The thickness of the coatings on the substrate treated by SMAT technique is about 10μm by
micro-arc oxidation, which is thicker than the ones on the substrate untreated by SMAT technique, and
the ceramic coatings are mainly composed of Al2TiO5. Besides, a bright interface layer comes out
between the substrate and the coating when the substrate treated by SMAT technique. The influences of
the SMAT technique on the surface morphology of the ceramic coatings also changed. The coatings using
the SMAT technique were more compact and less porous than the ones on the substrate untreated by
SMAT technique. The content of elements in the nanostructured surface layer on Ti-6Al-4V alloy had
changed after the SMAT technique: the content of Ti increased, the content of V decreased, and the
content of Al changed a little. The contents of Al and P in the coating increased while the content of Ti
decreased.
Modeling and Simulation of Ceramic/Metal Gradient Thermal Barrier Coating
Authors: Hu Chun Zhi , Zeng Fan Ming , Xiao Jin Sheng
Published: March 2009

Using the development tool C++ Builder and adopting object oriented programming method,
the ceramic/metal gradient thermal barrier coating design software (CCDS) is developed according to
software engineering criterion. The CCDS, which has user-friendly interface, is composed of three
functional modules: preprocess module, analysis module and post process module. In addition, this
software is attached with an optimal design module and an expert module. The calculation and design of
the ceramic/metal gradient thermal barrier coating can be carried out by the CCDS, and the numerical
results show good agreement with the analytical results.
Coupled Thermomechanical Analyses for Thermal Shock of Ceramic/Metal Gradient Thermal Barrier Coatings
Authors: Xiao Jin Sheng , Cai Yong Hua , Zhao Zai Li
Published: March 2009

A coupled and uncoupled non-linear thermomechanical finite element analysis using ANSYS
have been carried out to analyze the heat transfer and associated thermal stresses during different
simulated thermal shock processes, and the results of two analyses are discussed. It indicates that
piezocaloric effect can be neglect when thermal shock intensity is mild and piezocaloric effect should be
taken into account when thermal shock intensity is severe.
A XPS Study of Atmospheric Plasma Sprayed TiB2 Coatings
Authors: Liu Jun Hu , Blanpain Bart , Wollants Patrick
Published: March 2009

TiB2 coatings were plasma sprayed in air and were studied by XPS. There are five elements in
the top surface of the studied coatings, namely, B, C, N, O and Ti. Oxygen pick-up in the coatings results
in formation of oxides of boron and titanium. Nitrogen was shown to exist in N-Ti and O-N-Ti in the
coating. Depending on the spraying parameters, mono-boride as well as di-boride was also detected in the
studied coatings. With careful peak fitting it was shown that oxygen may exist in the coating as dissolved
atomic O in addition to as lattice oxygen in the oxide of boron and titanium.
Effects of SrAl2O4 Homo-Buffer Layer on SrAl2O4:Eu Phosphors Film Grown on Glass by RF Sputtering
Authors: Fu Xiao Yan , Yamada Hiroshi , Xu Chao Nan
Published: March 2009

The influence of pre-deposition of homo-buffer layers on film quality is studied for
SrAl2O4:Eu2+ (SAO) crystalline film prepared by RF magnetron method. This preparation technique is
necessary to prepare high quality films suitable for the development of SAO devices. Crystallinity and
surface morphology were characterized by X-ray diffraction and scanning electron microscopy. After
introducing a homo-buffer layer, not only the crystalline but also the surface morphology and adhesion of
the film were obviously improved. These results imply that the buffer layer relaxes the strain due to the
lattice mismatch between SAO and quartz glass, which improved the crystalline and adhesion of the film.
Analysis of Electric Conductive Activation Energy from the Electric Conductivity of Silicate and Borate Glasses
Authors: Jung Young Joon , Kim Young Seok , Lee Kyu Ho , Kim Tae Ho , Ryu Bong Ki
Published: March 2009

This work is to compare the electric conductive activation energies with increasing Na2O in
SiO2 and B2O3 glasses. The electrical conductivity is measured by TER2000 analyzer and it is compared
with value calculated by Arrhenius equation. The conductivity of SiO2 system glasses is higher than B2O3
system glasses, and the highest value is 1.36 × 10-4 cm-1 in 60SiO2-40Na2O glass. The activation energy
from conductivity is proportion to temperature and inverse proportion to Na2O contents. The activation
energy is analyzed from density and CTE (thermal expansion coefficient).
Hydrothermal Synthesis of Fe/N Co-Doped Titanium Dioxide and its Sterilization Activity via E. Coli under Visible Light Irradiation
Authors: Wei Yi , He Rong Liang , Cao Wen Bin
Published: March 2009

Using TiOSO4 as precursor, Fe(NO3)3⋅9H2O as the source of Fe, CN3H5⋅HCl as the source of N,
Fe/N co-doped TiO2 powder has been prepared by hydrothermal method. The as-prepared powders were
characterized by XRD, BET, TEM and UV-Vis spectrophotometer. The nanocrystalline Fe/N Co-doped
TiO2 powders are composed of anatase and show light-yellow in color. The grain size is about 11.1nm and
the specific surface area is 145m2/g. XPS results show that N atoms and Fe atoms were incorporated into
the lattice of TiO2 and the concentration of N and Fe doped in TiO2 was 0.8at% and 2.2at%, respectively.
The UV-Vis diffuse reflection spectra indicate that the absorption edges of the co-doped TiO2 powders
has well red-shifted into visible light region up to 606nm. The Fe/N co-doped TiO2 exhibits excellent
photocatalytic activity by sterilizing E. coli completely within 1 hour under visible light irradiation.