bluuebunny/crossref_metadata_2025 huggingface dataset:
Absolute Measurement of Aspheric Surfaces Using White-Light Interferometry
Authors: Chang Su Ping , Xie Tie Bang , Wang Xuang Ze , Guo Jun
Published: March 2009

White-light interferometric technique has been widely applied in the measurement of
three-dimensional profiles and roughness with high-precision. Based on the characteristic of
interferometric technique, a new method combined with image location and a three-dimensional
stage is proposed to achieve the non-contact absolute shape measurement for aspheric and spherical
surface in a slarge range. The interference fringes vary with the horizontal displacement of the
measured surface, the surface information was obtained by locating the transformation of the
maximal intensity in the interferograms. Two main influence factors are discussed; they are
performance of the inerferimetric microscope and the stage. Since the performance of the stage
directly determines the measurement precision, a three-dimensional displacement stage with a large
range and a high precision was developed. Some experiments were carried out to verify the
performance of the three-dimensional displacement stage and the validity of the new measurement
method with satisfactory results.
Study on Accuracy Test Methods for Sun Sensors
Authors: Chen Fei Fan , Feng Jing , Wang Ming Hao
Published: March 2009

Sun sensor is one of the key attitude sensors widely used in spacecraft attitude
determination. Its accuracy is one of the major technical specifications. In this paper, we propose
two methods for accuracy test and evaluation, which have been proved to be efficient and
convenient. With these two methods, it is possible to isolate and then, eliminate the rotational error
from the rotation table that holds the sun sensor so that the performance of the sun sensor can be
evaluated. The proposed two methods can be also applied to test the performance for other angle
measuring devices.
Integration of Micro Temperature Sensor and Heater in a Stainless Steel-Based Micro Reformer
Authors: Lee Chi Yuan , Lee Shuo Jen , Dai Ching Liang , Wu Chin Hua , Ger Ming Der
Published: March 2009

With advances in micro fuel cell development, the production of hydrogen for micro reformer has become increasingly important. However, some problems regarding the micro reformer are yet to be resolved. These include reducing the size, reducing the quantity of CO and combining the fuel cell, among others. Accordingly, in this investigation, a micro temperature sensor and a heater are combined inside a stainless steel-based micro reformer to measure and control the temperature and thus improve performance and minimize the concentration of CO. In this work, micro-electro-mechanical-systems (MEMS) of the micro channel type are fabricated on a stainless steel substrate to enhance the methanol conversion ratio. The micro temperature sensor and heater are made of gold and placed inside the micro reformer. Although the micro temperature sensor and heater have already been used to measure and control temperature in numerous fields, they have not been employed in micro reformer and commercial products. Therefore, this study presents a new approach for integrating a micro temperature sensor and heater in a stainless steel-based micro reformer to minimize the size and improve performance.
Research on Material Removal of a New Micro Machining Technology Based on the Magnetorheological Effect of Abrasive Slurry
Authors: Yu Juan , Yan Qiu Sheng , Lu Jia Bin , Gao Wei Qiang
Published: March 2009

Based on the magnetorheological (MR) effect of abrasive slurry, the particle-dispersed
MR fluid is used as a special instantaneous bond to cohere abrasive particles and magnetic particles
so as to form a dynamic, flexible tiny-grinding wheel to polish optical glass, ceramic and other
brittle materials of millimeter or sub-millimeter scale with a high efficiency. Experiments were
conducted to reveal the effects of different process parameters, such as grain sizes of abrasive
particles, machining time, machining gap between the workpiece and the rotation tool, and rotation
speed of the tool, on material removal rate of glass surface. The results indicate the following
conclusions: material removal rate increases when the grain size of abrasives is similar to that of
magnetic particles; machining time is directly proportional to material removal, but inversely
proportional to material removal rate; machining gap is inversely proportional to material removal;
polishing speed has both positive and negative influence on material removal rate, and greater
material removal rate can be obtained at a certain rotation speed. In addition, the difference of the
machining characteristics between this new method and the traditional fixed-abrasive machining
method is analyzed.
Method of Examining Surface Cracks on Monocrystalline Silicon
Authors: Fang Feng Zhou , Liu Yu Chan , Pei Qing Xiang , Hu Xiao Tang
Published: March 2009

A new method on examining the micro cracks of monocrystalline silicon during nano
indentation is proposed. It is established based on a study of the increasing rate of absorbed energy
in nano indentation. This method provides a simple approach in understanding whether cracks on
the silicon surfaces occur, while it is tedious in conventional method.
Investigation on Elliptic-Shaped Flaring Process of Metal Tube with Finite Element Method
Authors: Kwan Chin Tarn
Published: March 2009

In this study, the finite element method was used to investigate the cold elliptic-shaped
flaring process of metal tubes with a conical punch from a tube billet. A series of simulations on
tube flaring was carried out using the FEM program DEFORM 3D. The influence of process
parameters such as tube wall thickness, punch conical length, aspect ratio of elliptic shape, friction
factor, punch fillet radius and strength coefficient of the billet material on the critical flaring ratio of
the tube were analyzed.
Analytical Calculation of the Light Extraction Efficiency of Micro Cavities Light-Emitting Diodes
Authors: Chao Paul C.P. , Liao Lun De , Fan Yi Hua , Shen Chien Yu , Kao Yung Yuan , Huang Jeng Shen
Published: March 2009

Using TracePro® Monte-Carlo ray-tracing simulations, this paper investigates the improved light extraction efficiency (LEE) obtained by patterning the surface and/or substrate of GaN LEDs with unique three-dimensional micro-cavity patterns. The simulations commence by considering the case of a sapphire-based GaN LED. The effects on the LEE of the micro-cavity dimensions, the absorption coefficient of the active layer, the point source location, and the chip dimensions are systematically examined. Subsequently, the LEE performance of the sapphire-based GaN LED is compared with that of a thin-GaN LED for various surface texturing strategies. In general, the results show that patterning either the surface or the substrate of the LED structure provides an effective improvement in the LEE of both the sapphire-based GaN LED and the thin- GaN LED. For both LED structures, the maximum LEE enhancement is obtained by patterning both the upper surface of the LED and the substrate surface. However, the simulation results indicate that the improvement obtained in the LEE is the result primarily of pattering the upper surface of the LED.
Investigation on Steady-State Wire Drawing for Strain-Rate Sensitivity Materials
Authors: Shih Hung Rung , Kwan Chin Tarn
Published: March 2009

In this reaearch, the finite element method is used to investigate the steady-state wire drawing process for strain-rate sensitivity materials. A series of simulations on the wire drawing using the program DEFORM-2D were carried out. The influences of the process parameters such as drawing speed and strain-rate sensitivity index of the wire material on the drawing die stress, the separation force, the effective strain-rate distribution, and the effective stress distribution of the drawing die were examined.
Study on Thixo-Extrusion of Semi-Solid Wrought Magnesium Alloy
Authors: Yan Hong , Fu Ming Fu , Tao Xu Chun , Hu Hong We
Published: March 2009

The traditional extrusion and thixo-extrusion processes of wrought magnesium alloy were
studied with both computer numerical simulation and experimental methods. The thixo-extrusion
set-up was made. The constitutive model of semi-solid AZ61 alloy was established in our prior
literature. The comparison of two forming processes had been done. Results indicated that smaller
load and uniform strain & stress were acquired in thixo-extrusion process. Simulation results were in
good agreement with experimental ones.
Analysis of Metal Flow through a Porthole Die to Produce a Rectangular Hollow Profile with Longitudinal Weld Seams
Authors: Liu Gang , Zhou Jie , Huang K. , Duczczyk Jurek
Published: March 2009

A detailed analysis of metal flow through a porthole die to produce a rectangular hollow
aluminium profile was performed by means of three-dimensional FE simulation using DEFORM
3D. It was aimed at revealing the flow patterns of a medium-strength aluminium alloy 7020 through
a porthole die and gaining an insight into the formation of longitudinal weld seams inside the
welding chamber during extrusion. In the case of extruding a rectangular hollow profile through a
porthole die with four ports, two neighbouring ports were different from each other. Using an FE
model including these two ports, different flow patterns of two individual metal streams were
revealed. The 3D FE simulation also showed how two unequal metal streams contacted each other
and became bonded in the welding chamber under a certain hydrostatic pressure and at a certain
temperature, before the metal flew through the die bearing. The difference in velocity between the
metal streams led to uneven flow at the die bearing and thus a wavy extrusion nose.
Simulation of Direct Extrusion Process and Optimal Design of Technological Parameters Using FEM and Artificial Neural Network
Authors: Karayel Durmus
Published: March 2009

This study aims the modeling and simulation of the direct extrusion process and
determination of optimal process parameters using Finite Element Method (FEM) and Artificial
Neural Network (ANN) cooperatively. First, the die set has been designed for direct extrusion of an
aluminum rod and its numerical simulation has been prepared by mean of ABAQUS/EXPLITIC
finite element code. So, both the values of the process parameters according to extrusion load and
the critical stress values have been determined. After, the ANN model of the process has been
developed under MATLAB and has been trained with the results of finite element simulations.
Also, the optimization software which can run together the ANN model has been developed and has
been used to determine the optimum process parameters.
Constitutive Models for AZ31 Magnesium Alloys
Authors: Bruni Carlo , Donati Lorenzo , El Mehtedi Mohamad , Simoncini M.
Published: March 2009

The present investigation aims at studying and modelling the flow behaviour of the AZ31 magnesium alloy by means of torsion tests performed in extended ranges of temperature and strain rates. Two types of rheological models were considered. The former is based on the power law equation, whilst the latter is based on the Sellars and Tegart approach. The effectiveness of the two constitutive models in describing the flow behaviour of the AZ31 magnesium alloy under investigation was evaluated. It was observed that both the equations are able to predict the flow behaviour of the material at different temperatures and strain rates. In particular, the former is very effective in predicting the hardening stage of the flow curve, whilst the latter allows to fit the softening stage. The models were used for the finite element analysis of a complex extrusion process and the results, in terms of the load-stroke curves, compared to each other.
Damage of T300 Carbon Fiber during Precursor Pyrolysis
Authors: Wang Song , Chen Zhao Hui
Published: March 2009

C/SiC, C/Si-O-C and C/C composites reinforced with T300 carbon fiber were fabricated via polycarbosilane (PCS), polysiloxane (PSO), and phenolic resin precursor polymers infiltration/pyrolysis, respectively. Flexural strength and fracture toughness of the composites were evaluated. The results showed that all the composites had poor mechanical properties, less than 160 MPa in flexural strength and 5 MPa•m1/2 in fracture toughness. Deep investigation illuminated that the fiber was damaged severely during the preparation of the composites, especially in the first cycle of precursor pyrolysis. Great degradation of the fiber has relationship with coarsening of the microstructure. Bad in-situ strength of the fiber resulted in poor performance of the composites.
Influence of Carbon Cloth Filaments Upon the Properties of 2D C/SiC via Precursor Infiltration and Pyrolysis Process
Authors: Zhang Feng , Hu Hai Feng , Wang Qi Kun , Zhang Yu Di , Zhang Chang Rui
Published: March 2009

In this paper, 2D C/SiC composites with different carbon cloth filaments (1K, 3K) were
prepared via precursor infiltration and pyrolysis (PIP) process. The flexural strength of 2D-1K C/SiC
composites was 380MPa, and fracture toughness was 16.8MPa-m1/2, while those of 2D-3K C/SiC were
305MPa and 14.4MPa-m1/2, respectively. The differences of these two composites were analyzed from
fiber volume ratio in the composites, density, and fracture surface (SEM) of the samples.
Preparation and Properties of Hot Pressed 2D C/SiC Composites
Authors: Hu Hai Feng , Zhang Feng , Wang Qi Kun , Zhang Yu Di , Chen Zhao Hui
Published: March 2009

In this paper a pseudo-HP process, which uses solid powder to transfer pressure to prepare
complex shape articles, was adopted to prepare 2D C/SiC composites. Nano-SiC powder was used to
lower the sintering temperature, thus decreasing the damage to carbon fibers. The optimum processing
parameters are as follows: sintering temperature 1850°C, holding time 60min, sintering pressure 10MPa.
The maximum strength is over 300MPa, and toughness is around 8MPa·m1/2. BN powder is more
lubricous than carbon powder, and thus is more convenient for demoulding and pressure transferring.
Precursor Infiltration and Pyrolysis (PIP) was used to further densify the composites after HP process, and
strength and toughness of the samples were slightly enhanced.
Oxidation Resistance of 2D C/SiC Composites Fabricated by FCVI
Authors: Wang Chun Peng , Tang Jie , Chen Yu Feng
Published: March 2009

Two-dimensional waved carbon fiber preforms were chemical vapor infiltrated under forced
flow, thermal gradient mode for preparation of 2D C/SiC composites. In order to improve the oxidation
resistance of the C/SiC composites, B4C powders were added into the preforms and aqueous silica
sol-B4C compound coating was claded on the surfaces of composites. It was found that the oxidation
resistance of 2D C/SiC composites at temperatures lower than 1273K was improved because of the
formation of B2O3 and borosilicate glass by preventing the diffusion of oxygen.
Preparation and Characterization of Kaolinite-Glucose Intercalation Compound
Authors: Gao Li , Wang Lin Jiang , Du Yi Ting , Zhang Guo Wei
Published: March 2009

Kaolinite-glucose intercalation compound was synthesized by the intercalation of polar
organic big molecule dodecylamine and then displaced by glucose in the layer of kaolinite. XRD, FT-IR,
TG and DSC were used to study the reaction process and the characters of the products. The results
indicated that the basal spacing of kaolinite increased to 2.280 nm from 0.717 nm, and the hydrogen
bonds were formed between dodecylamine NH and kaolinite Si-O after dodecylamine intercalation.
Kaolinite-dodecylamine intercalation compound was stable below 295 °C. After displacement reaction
by glucose, the basal spacing of kaolinite increased to 3.364 nm, and the intercalation rate reached 87%,
the hydrogen bonds were formed between glucose C=O and kaolinite inner surface hydroxyl.
Kaolinite-glucose intercalation compound was stable below 302 °C.
Bi4-xLaxTi3O12 Ferroelectric Thin Films Prepared by RF Magnetron Sputtering
Authors: Li Xing Ao , Liu Zu Li , Zuo An You , Yuan Zuo Bin , Yang Jian Ping , Yao Kai Lun
Published: March 2009

Bi4-xLaxTi3O12 (BLT) ferroelectric thin films were deposited on Pt/Si substrates by RF magnetron sputtering with Bi4-xLaxTi3O12 (x=0.5, 0.75, 1) targets with 50-mm diameter and 5-mm thickness. The effects of La contents on microstructure and ferroelectric properties of Bi4-xLaxTi3O12 thin films were investigated. The grain growth behavior and ferroelectric properties such as remanent polarization were found to be dependent on the La contents in the BLT thin films.
Wear-Resistant Property of SiCp/Al Composites
Authors: Li Duo Sheng , Zuo Dun Wen , Zhou Xian Liang , Zhang Jian Yun , Hua Xiao Zhen
Published: March 2009

Al alloy reinforced with SiCp (size: 70-220μm) was fabricated by pressureless-infiltration. Its wear resistant property was investigated under different heat-treatment conditions, and morphology of worn surface was examined. The results showed that the composite was integrated, uniform and compact, and its wear resistant property was better than that of the unreinforced matrix alloy. It was indicated that some rigid SiCp in the abraded surface of the composite could support part of loads and replace matrix to wear-tear, which improved the wear resistant property. Compared to annealing, solution aging strengthens Al alloy matrix and cohesion with SiCp, and the wear resistant property of composites was better. Combining interface is also an important factor which influences on wear resistant property. During the wear test, the smaller SiCp size, the more interfaces, there are more SiCp falling off because of loosening combining interface, which results in more wear-tearing value. The wear rate of composite increases with decreasing SiCp size, thus, the composite with larger SiCp has better wear-resistant property than that with smaller SiCp. At last, the wear mechanism of the composite was also studied, and it showed that abrasive wear dominated in the abrasion process.
Properties of Carbide-Metal Cermets Prepared from Composite Powders by Direct Reduction and Carburization Process
Authors: Yan Li , Shao Gang Qin , Xiong Z. , Shi Xiao Liang , Duan Xing Long , Wang T.G.
Published: March 2009

The transition-metal carbide cemented by metal has excellent combined properties. In this
study, cermets were prepared by vacuum sintering from carbide-metal composite powders. The
transition- metal oxides (Cr2O3, MoO3, V2O5, Nb2O5 and TiO2), cementing-metal oxides (Co3O4 and
NiO), and carbon black were used as raw materials to pre-synthesize composite powders such as
Cr3C2-Co, Mo2C-Co, VC-Co, NbC-Co and TiC-Ni, by a direct reduction and carburization process in
vacuum. Results show that the participation of Co3O4 and NiO as well as the vacuum circumstance were
greatly propitious to the carburization of transition-metal oxides into carbides. The carbothermal
condition was greatly improved by the direct reduction and carburization process.
A Comparative Research on the Compositions and Microstructure of the Ti(CN) Based Cermets in Different Sintering Atmospheres
Authors: Wang She Chuang , Zhou Shu Zhu , Peng Wei Zhen , Miao He Zhuo , Pan Wei
Published: March 2009

The composition, microstructures and properties of the Ti(CN) based cermets have been
characterized by using SEM/BSE and energy spectrometer. Results shows that the carbon content of the
cermets through N2 and Ar sintering was lower by 0.5% than vacuum sintering and the nitrogen content of
the cermets through N2 sintering was higher by 20~25% than the Ar and vacuum atmosphere sintering.
When sintered in Ar or N2, the balance between the carbon and nitrogen in the cermets was broken to form
a surface defects, which would result in poor properties. The structure of vacuum sintering is more
uniform and the properties are better.
Preparation and Characterization of Ti0.6Cr0.4OxNy Nano-Sized Powder
Authors: Wang Hong Zhi , Zhang Qi , Gu Yun Xin , Li Yao Gang , Zhu Mei Fang
Published: March 2009

Ti0.6Cr0.4OxNy bimetallic metal oxynitride nano powder was synthesized by ammonolysis of the nanosized Cr2O3/TiO2 composite powder with n(Ti):n(Cr)=6:4 at 800oC for 8 h. The precursor and the resulting oxynitride were characterized by Auger electron spectroscope (AES), X-ray diffraction analysis (XRD), electron probe microanalysis (EPMA), transmission electron microscopy (TEM), and BET surface area techniques. The result indicated that the precursor was homogenous mixture of Cr2O3 and TiO2 with high BET surface area. The as-synthesized oxynitride powder contains only Ti0.6Cr0.4OxNy with cubic structure. The BET surface area of the oxynitride powder is 37.42 m2/g and the particle size is in the range of 20~30 nm.
WC-Co Tool Failure Mechanism in Titanium Alloys Machining
Authors: Zhao Xiu Xu , Zhou Zu De , Shao Gang Qin
Published: March 2009

The 5-axis milling processes were conducted with several uncoated WC-Co tools, which are with taper ball end mills with four flutes. There is a severe problem of high rate of tool failure, which has led to the high cost and low productivity of the milling process. In order to find out the real reason, some former work, which included the tool geometry analysis, tool path and tool posture analysis, as well as the cutting force calculating, had been done. It has been found that most of the tool failures are resulted from cutting edge chipping or the workpiece material of titanium alloys attached to the tool. Meanwhile, a suddenly applied load or an abrupt unloading of the tool at the end of a cut is another important factor. Moreover, the tool materials had been analyzed, which included the element composition analysis with XRD, the microstructure analysis with SEM. XRD results indicate the cobalt at the tip of tool is less than at the shank of tool. SEM results indicate there are micro-cracks concentrated in the cutting edge area. The tool material failure mechanism will be set up based on the tool material analysis in this study.
Growth of Apatite in Bovine Serums on Porous HA/TCP Ceramics
Authors: Deng Chun Lin , Wang Ying Jun , Chen Ji Yong , Zheng Hua De , Chen Hu , Zhang De Gui , Zhang Xing Dong
Published: March 2009

Porous HA/TCP bioceramics were immersed in pure bovine serum to observe the growth and
formation of apatite. HRTEM, FTIR, and SEM coupled with EDS were used for the characterization of
immersed samples. SEM results showed that some beamed crystals formed on the surface of ceramics
granules, and with postponement of immersion time, crystals extended and became bigger, strap-like
crystals became sheet-like crystals. HRTEM observations indicated that new-formed crystals developed
along axes direction according to parallel layers. IR spectrum showed CO3
2- characteristic peaks existed
besides O-P-O and OH- characteristic peaks. EDS results showed that calcium and phosphor ratio was
1.95 (mol ratio). The results indicated that bovine serums were advantaged to bone-like apatite formation.
Effect of Carbonate on the Properties of Bone Cement Containing PCCP and DCPA
Authors: Ye Jian Dong , Wang Xiu Peng , Chen Ling
Published: March 2009

A novel calcium phosphate cement (CPC) was prepared by mixing partially crystallized calcium phosphate (PCCP) containing carbonate and dicalcium phosphate anhydrous (DCPA) in this work. The effects of the carbonate content on the phase composition, strength, prosity, and degradation of the set bodies were studied. The results showed that the cement formed into hydroxyapatite (HAp) after setting, in which carbonate doped into the HAp crystal lattice. With the increase of the carbonate to phosphate ratio in PCCP, the compressive strength of the cement declined and the setting of the cement accelerated. Furthermore, the calcium phosphate cement formed a more porous structure with the increase of the carbonate to phosphate ratio in PCCP. The results also indicated that the degradation of CPC may be speeded up by introducing carbonate to the cement.
In Vitro Biocompatibility Evaluations of Four Dental Ceramics
Authors: He Hua Wei , Li Bo , Li Guang Da , He Zhi Xiu , Chen Zhi Qing
Published: March 2009

This study sought to compare the biocompatibility of four dental ceramics so as to provide
indications useful for the further development of dental materials. Osteoblasts were obtained by culturing
the cranial explant of SD rat and cultured in vitro when they were seeded onto four different materials:
hydroxyapatite, bioactive glass ceramics, tricalciumphosphate-hydroxyapatite and nano-hydroxyapatite
(nHA). The phase contrast microscope and scanning electron microscope were used to evaluate the cell
morphology and attachment. The content of alkaline phosphatase was calculated by molecular biological
methods. MTT method was performed to find the alteration of proliferation. Then by use of wash way
method, the adhesion ability was tested. The results showed that all of the four bioceramics had good
cytocompatibility. There were significant differences among them on the levels of cell growth, differation
and adhesion in vitro. The biocompatibility of nHA is the best and of conventional HA is the worst.
Fabrication and Evaluation of the Nano-Ceramics Modified Epoxy Coatings
Authors: Cong Wei Wei , Zhou Zhang Jian , Song Shu Xiang , Ge Chang Chun
Published: March 2009

Several kinds of ceramic powders including SiC, TiO2 and Al2O3 were selected as fillers blending with epoxy resin, curing agent and other additives to prepare a heavy-duty and anti-wear coating. The effects of filler sort, powder size, dispersion homogeneity on the coating properties were investigated. The results showed that the wear resistance and corrosion resistance of the coating could be improved significantly after meliorating the dispersion of the ceramic particles in epoxy resin. Other mechanical properties were also studied in order to support the view on the positive effect of the nano-particles in the epoxy coating.
Perturbation Molecular Dynamics Simulation of Thermal Conductivity of Zirconia
Authors: Zhang Feng , Fan Qun Bo , Wang Fu Chi , Zhang Hui Ling
Published: March 2009

Thermal conductivity of zirconia and yttrium stabilized zirconia (YSZ) is calculated with perturbation molecular dynamics method (PMD). The results showed that thermal conductivity of YSZ is lower than that of pure zirconia and PMD is a very effective way in thermal conductivity calculation for ceramics. In higher temperature region, the calculated values show a different tendency with the experiment ones, which is because that photon conduction is not considered in PMD method. By taking photon effects into account, the calculated thermal conductivity curve is found fairly well coherent with measurements. In addition, the thermal expansion of zirconia is also presented by calculating the volumes at different temperatures. The results and methods in this paper have been proved to be very helpful in further design of new ceramic materials in the field of thermal barrier coatings (TBCs).
Structure and Dielectric Properties of AlN Multilayered Film on Al Substrate
Authors: Song Xiu Feng , Fu Ren Li , He Hong , Wang De Liu
Published: March 2009

AlN multilayered films were deposited on Al substrates using RF reactive magnetron
sputtering with Al targets under Ar and N2 atmosphere. Circles of deposition and annealing were
repeatedly performed. Macrostructure observations, crystallographic analyses and dielectric property
measurements were carried out. The grains of AlN film had a worm-like shape. When the number of
layers (and cycles) increased, the (100) and (110) oriented grains weakened and the structure of film
changed into (002) and (101) oriented. The capacity–frequency (C-f) curves of Cu-AlN-Al-Cu capacitors,
measured at 100 Hz - 1 MHz, showed that the dielectric constant and the dielectric loss of AlN decrease
with increasing number of cycles, attributed to annealing processes that influences film microstructure
and the orientation of worm-like shape grains.
Properties and Structure of BaO-ZnO-B2O3 Glasses
Authors: Kim Young Seok , Jung Young Joon , Lee Kyu Ho , Kim Tae Ho , Ryu Bong Ki
Published: March 2009

The effect of coordination number on glass properties was investigated by measuring the glass
forming region, glass transition temperature, dilatometric softening temperature, density and chemical
durability of the glasses. The coordination number of B and Zn in the system 20BaO-xZnO-(80-x) B2O3
glasses (x=0~40mol%) was measured by IR, respectively. No change in the coordination number (CN) of
B was revealed, and the coordination of Zn was 4 at ZnO 10mol%, which increased the properties of
glasses. On the other hand, the coordination number (CN) of B and Zn changed from CN4 to CN3, CN4 to
CN6 over ZnO 20 and 10mol% respectively, which decreased the properties of glasses.
Difference in Ordering Ability Between Ca(Al1/2Nb1/2)O3 and Ca(Fe1/2Nb1/2)O3
Authors: Shen Jie , Zhou Jing , Zhu Jie , Chen Wen
Published: March 2009

Ca(Al1/2Nb1/2)O3 (CAN) and Ca(Fe1/2Nb1/2)O3 (CFN) were prepared by solid reaction route.
With the sintering temperature increased, the Q×f value of CAN changes from 7 200 to 17 500 GHz due to
the changing of the ordering degree, whereas, the dielectric constant and Q×f value of CFN decrease
remarkably without structural changing. The reason of this phenomenon is that the difference in size of
two B-site ions in CAN is larger than that in CFN. As a result, the ordering degree of CAN is more
sensitive to the conditions of sample preparation, compared with CFN.
Structure Property of Titanium Dioxide Thin Films in Sintered Temperature by the Sol-Gel Method
Authors: Huang Chien Jung , Liao Kuo Chien , Su Yan Kuin
Published: March 2009

Titanium dioxide (TiO2) thin film on glass substrate is fabricated by sol-gel method. The TiO2
film is sintered at various temperatures for investigation on the refraction index and crystallization
characteristic. The lower refractive index of the TiO2 thin film is 1.89 when the sintering is performed at
the low temperature of 200°C and the thickness is 448 nm. However, the higher refractive index of 2.55
and chemical stability of the TiO2 film in rutile phase are obtained via sintering temperature at 700°C.
Preparation and Characterization of Raspberry-Like TiO2/Cu Composite Particles
Authors: Yan Jun , Cui Hai Ping , Du Shi Guo , Wang Bin
Published: March 2009

Raspberry-like TiO2/Cu composite particles were prepared under mild conditions (75°C and
ambient pressure) by hydrolysis of Ti(OBu)4 in acidic aqueous solution and subsequent reflux in the
presence of micron size Cu powders. A 3-level and 4-factor design was employed to evaluate the effect of
the main parameters on the coating quality. TiO2 particles of approximate 100nm in size were found
coating on the surfaces of Cu powders to form raspberry-like structure. Ti and Cu element mainly existed
on the composite particle surface as the chemical state of Ti4+ and Cu2+. TG-DTA analysis showed the
TiO2 coating increased the thermal stability of Cu particles. The composite particles began oxidizing at
400°C while pure copper particles oxidized at 200°C.
Nanoporous TiO2/SiO2 Composite Prepared by a Combined Sol-Gel and Hybrid Method
Authors: Xu Wen Yuan , Wei Lu Bin , Luo Ming Biao
Published: March 2009

Titania-silica nanocomposites with different TiO2/SiO2 compositions have been prepared by a
sol-gel and hybrid method from tetraethylorthosilicate (TEOS) and tetrabutyl titanate(TBT) and
β-Cyclodextrin as a pore-forming template. Drying and calcining of the hybrid xerogel can lead to the
formation of nanoporous particles with surface areas in the range of 298-418 m2/g. The effect of the
β-cyclodextrin concentration, the molar ratio of TiO2/SiO2 and the calcining temperature on the phase
composition and structural properties of TiO2/SiO2 composites were also investigated. The results show
that an increase in β-cyclodextrin concentration can lead to a decrease of the surface area and an increase
of average pore size, which can be controlled by the amount of β- cyclodextrin in the hybrid sol.
A Series of Bi-Based Oxychlorides as Efficient Photocatalysts
Authors: Lin Xin Ping , Huang Fu Qiang , Wang Wen Deng , Shan Zhi Chao , Shi Jian Lin
Published: March 2009

A series of layered-structure Bi-based oxychlorides such as BiOCl, Bi3O4Cl, Na0.5Bi1.5O2Cl,
Bi4NbO8Cl and MBiO2Cl (M = Ca, Sr, Ba, Cd, Pb) used as efficient photocatalysts. Among them, Bi3O4Cl
(Eg = 2.79 eV), Na0.5Bi1.5O2Cl (Eg = 3.03 eV), Bi4NbO8Cl (Eg = 2.38 eV) and PbBiO2Cl (Eg = 2.45 eV) are
visible-light-responsive. The powders synthesized by solid state reactions were characterized by X-ray
diffraction (XRD) and UV-Vis diffuse reflection spectrum. Their photocatalytic activities were evaluated
by the degradation of methyl orange. The results generally show that the UV-induced photocatalytic
performances of the novel oxychloride catalysts are better than or comparable to that of anatase TiO2. The
high photocatalytic performance of Bi-based oxychlorides is mainly ascribed to the presence of strong
internal static electric fields between layers.
Self-Organized Zirconia Nanotube Arrays Prepared by Anodization
Authors: Xu Rong Qing , Zhao Jian Ling , Tao Jin Liang , Lu Zun Ming , Li Yang Xian
Published: March 2009

The zirconia nanotube arrays on zirconium substrates were formed in (NH4)2SO4 electrolytes
containing different concentrations of NH4F (0.5-2.0 wt%). Highly self-organized zirconia nanotubes can
be formed with a diameter ranging from 15 nm to 144 nm and a length of 32 μm. The morphology of the
nanotubes was strongly influenced by the applied voltages and electrolyte concentrations. Electrochemical
testing and scanning electron microscope observation indicated the nanotubes were formed due
to the competition of zirconia formation and dissolution under the assistance of electric field.
Preparation and Characterization of CPC Interclating α-ZrP as VOCs Adsorbent
Authors: Zhang Dong Hai , Li Zi Qiang , Chen Yun Fa
Published: March 2009

In this study, α-ZrP-CPC layered compound was gained by inserting cetyl pyridinium chloride
(CPC) into α-ZrP with amines as pillaring agent. The amount of CPC intercalated reached the highest
with the molar ratio of the amine/α-ZrP being 2. The lower concentration of CPC resulted in more CPC
molecules intercalated into the interlayer of α-ZrP. The intercalation products were characterized by
XRD, IR, TG-DSC and SEM. The result of TG-DSC showed that the amount of xylene adsorbed reached
the peak value of 5.56%, when the content of CPC in α-ZrP-CPC was 41%.
High Temperature Properties of Geopolymeric Ceramic
Authors: Jia Yi Hai , Han Min Fang , Xu Ze Sheng , Gao Yan , Meng Xian Xian
Published: March 2009

With fly ash, metakaolin, slag and alkaline activator as raw materials, the geopolymeric
ceramic was synthesized and the properties, such as the weight loss, compressive strength and the
structures, at high temperatures of 400~1200°C were measured. The weight loss is in the range of 8~13%
from 400°C to 800°C. Comparing with the strength at room temperature, the compressive strength of
samples is mostly increased at 400°C and all of them increased at 800°C. 9.65~28.32% strength declines
at 1200°C. The variation of the compressive strength with temperature is explained based on the analyses
of the phases constitutes and the thermal properties of samples.
Synthesis of Low Agglomerating Spherical α-Fe2O3 Nanopowders
Authors: Wang Qi , Chen Yun Fa , Yang Min , Wu Xiao Feng , Tian Ya Jun
Published: March 2009

Low agglomerating spherical α-Fe2O3 nanopowders were synthesized by catalytic phase
transformation in hydrothermal reaction and then dried through freeze-drying. It was found that the
as-synthesized particles were spherical and the particle size results obtained from the different
measurement methods, including BET, XRD, TEM, SEM and laser particle size analyzer, were almost
the same, implying that the α-Fe2O3 nanopowders were low agglomerating.
Tailoring of the Dielectric Properties of Some Low Sintering Temperature Ceramics
Authors: Marinel Sylvain , d' Astorg Sophie , Chaouchi Ahcène
Published: March 2009

Bearing in mind the attractive dielectrics properties of Ba5Nb4O15, Zn3Nb2O8 and ZnTiO3, we
have investigated the lowering of the sintering temperature of these dielectrics using ZnO-B2O3 glass frit
addition. The control of the temperature coefficient of the permittivity has been also examined using two
different methods. The first method consists in mixing the two oxides ZnTiO3 + TiO2 which exhibit a
temperature coefficient with opposite sign. The second method is based on the stacking of two ceramic
layers having opposite sign of temperature coefficients. This has been successfully tested in the
Ba5Nb4O15 / Zn3Nb2O8 system.
Structure and Thermal Expansion Behavior of Dy2-xGdxMo4O15 Solid Solution
Authors: Wu M.M. , Xiao X.L. , Cheng Y.Z. , Peng J. , Chen D.F. , Hu Zhong Bo
Published: March 2009

A new series of solid solutions Dy2-xGdxMo4O15 (x = 0.0-0.9) were prepared. These compounds
all crystallize in monoclinic structure with space group P21/c. The lattice parameters a, b, c and unit cell
volumes V increase almost linearly with increasing gadolinium content. The intrinsic thermal expansion
coefficients of Dy2-xGdxMo4O15 (x = 0.0 and 0.25) were obtained in the temperature range of 25 to 500°C
with high-temperature X-ray diffraction. The correlation between thermal expansion and crystal structure
was discussed.
Simulation of the Grain Boundary Effects in PTCR Ceramics
Authors: Fang Chao , Zhou Dong Xiang , Liu Hu An , Gong Shu Ping
Published: March 2009

The positive temperature coefficient of resistivity (PTCR) behavior of semiconductive BaTiO3
ceramics is often explained by the Heywang model. However, Heywang model couldn’t explain some
experimental phenomena of jump range more than 106. This paper considered that the migration of
donors, electrons and holes has important influence on grain boundary effect. A differential equation
about Fermi level was established on the base of Heywang model. By solving the equation the jump range
can be calculated quantitatively. It was found that a potential well exists on the edge of grain due to the
donor ionization, and the experimental phenomena of PTC jump range more than 106 could be explained.
Lambdoidal Reinforced Microstructure of Mactridae Shell
Authors: Chen Bin , Peng X. , Fan J. , Sun S.
Published: March 2009

A scanning electron microscope (SEM) was used for observing the microstructures of a
Mactridae shell. It showed that the shell is a kind of natural bioceramic composite, which consists of
aragonite sheets and organic matrix with laminated structure. It also showed that there are various
reinforced microstructures in the shell, which include a kind of lambdoidal one. The maximum
pullout force of the lambdoidal reinforced microstructure, which is related to the fracture toughness of
the shell, was analyzed and compared with that of a conventional 0°-structure based on their
representative models. The result indicated that the maximum pullout force of the lambdoidal
reinforced microstructure is markedly larger than that of the 0°-structure, which was experimentally
verified.
Analysis of Profitability in Chinese Listed Ceramic Companies
Authors: Hua Rong Hui
Published: March 2009

There are seven ceramic companies listed in Shanghai and Shenzhen Stock Exchanges.
Because they belong to traditional industry sector, the profitability of most companies is weak. Listed
companies experienced reform from 2005, and all of their shares can be liquid 12 or 24 months later. In
the paper, we analyze the impact of the reform on those companies.
Oxidation of Short Carbon Fiber Reinforced ZrB2-SiC Ceramics under Atmospheric and Oxyacetylene Torch Conditions
Authors: Yang Fei Yu , Zhang Xing Hong , Du Shan Yi
Published: March 2009

The oxidation behavior of ZrB2-20 vol.% SiC (ZS) and ZrB2-20 vol.% SiC containing 20 vol.%
short carbon fiber (ZSC) was studied using thermal gravimetric analysis and oxyacetylene torch test. It
was shown that weight gains changed from 3.71 wt.% for ZS to 4.57 wt.% for ZSC after heating 10°C
/min to 1450°C in air. A thin layer of Si-rich glass and then a depletion layer of SiC was found on the cross
section of both materials and carbon fiber of ZSC exposed in air was oxidized. Under oxyacetylene, an
average mass loss of 0.8 wt.% for ZS and 0.9 wt.% for ZSC was measured after 180 seconds. After
exposure, an oxidized layer with the formation of ZrO2 and SiO2 was found on the surface of both
materials. Meanwhile, fiber in the surface of ZSC appeared oxidized and removed.
Combustion Synthesis of Si3N4 from Si/NH4Cl at Low Nitrogen Pressure
Authors: Chen Yi Xiang , Li Jiang Tao , Lin Zhi Ming , Liu Guang Hua , Yang S.L. , Du Ji Sheng
Published: March 2009

Combustion synthesis (CS) of Si3N4 was accomplished by using as-milled Si/NH4Cl as
reactants at low nitrogen pressure. The additive of NH4Cl decreased the combustion temperature and
promoted the Si nitridation. Full nitridation of Si was achieved by burning Si in pressurized nitrogen with
10 ~ 25 wt. % NH4Cl as additives while no Si3N4 diluent added. The maximum combustion temperature
(Tc), the combustion velocity (u) together with the α-Si3N4 content and mean particle size (d50) of the
powder products were found to be great dependent on the NH4Cl content added in the reactants. Fine
Si3N4 powder products with α-phase content up to 85 wt. % were obtained via steady combustion mode. A
mathematical approach named combustion wave velocity methods for the analysis of temperature profiles
in CS was proposed and the reaction kinetics was discussed. The apparent activation energy calculated
according to the temperature profile analysis method is 29.7 kJ/mol, which agrees well with the
corresponding low temperature nitriding combustion of Si.
Processing and Characterization of Ultra-High Temperature Oxide Fiber-Reinforced Oxide Ceramic Matrix Composites with Improved Thermomechanical Properties
Authors: Kaya Cengiz , Kaya Figen
Published: March 2009

A combined technique comprising electrophoretic deposition (EPD) and low-pressure
infiltration was used for the fabrication of multi-layer woven mullite ceramic fabric reinforced alumina
ceramic matrix composites (CMCs) for high temperature applications. Two different interface materials,
NdPO4 and ZrO2 were synthesised and used for coating the woven ceramic fibres by EPD. The
manufactured CMC components with suitable interface material are targeted for use at 1300-1400 oC in
an oxidising atmosphere and have shown very good mechanical properties in multi-layer plate forms.
Damage mechanisms, such as debonding, fibre fracture, delamination and matrix cracking within the
composite plates subjected to flexural loading are analysed. It is shown that the composites with NdPO4
interface and 40 vol.% fibre loading have better mechanical properties in terms of strength and
damage-tolerant behaviour. The final components produced are considered to be suitable for use as
shroud seals and insulating layers for combustor chambers in aircraft engines.
Toughness and Superplastic Deformation of Laminated Ceramic
Authors: Wang Guo Feng , Liu Lin , Wang Hai Yang , Zhang Kai Feng
Published: March 2009

Tape casting and hot-press sintering were used to fabricate an Al2O3/3Y-TZP laminated
composite. In order to investigate the deformation properties, the as-prepared material was deep drawn at
high temperatures. It was found that the microstructure of the material sintered at 1550°C was fine and no
significant pores were detected from SEM observations at the interfaces between the two types of layers.
The superplastic forming experiment shown that, when the strain rate was constant, temperature had a
great influence on the superplasticity of the Al2O3/3Y-TZP laminated composite. A hat-like part with the
largest deformation height was obtained at 1500°C.
Pulsed Power Supply of Ferroelectric Ceramics by Shock-Induced Depoling
Authors: Du Jin Mei , Liu Gao Min , Zhang Fu Ping , He Hong Liang
Published: March 2009

In the frame of shock-induced depoling, PZT 95/5 ferroelectric ceramics with niobium doped has been assembled for the pulsed power supply, and the electrical current output has been investigated under the action of shock wave in a "normal mode". The electrical response of LRC load especially for the small resistance (R) and small inductance (L) load was studied. Plane-shock-wave tests were conducted, and the PZT 95/5 ceramics stacked in parallel were devised to generate high-power electrical pulse. An output current of 7 kA has been obtained, and the corresponding rise time of the front edge is under 500 ns. Theoretical calculations were conducted and a good agreement with the experiment presented.
Transient Thermal Stress Analysis of a Plate with Double-Sided FGM Coatings
Authors: Zhao Jun , Li Yan Zheng , Ai Xing
Published: March 2009

In this paper, the transient heat conduction and transient thermal stresses in an infinite plate
with double-sided functionally graded coatings (FGM coatings) under the convective boundary condition
are investigated. The thermo-physical properties of the two symmetrical FGM coatings are assumed to
have distributions of power forms along the thickness direction of the plate, the effects of which on the
thermal shock resistance of the FGM coated plate are analyzed via numerical calculations. And
consequently some design rules for the double-sided FGM coatings are put forward, which provide a
guidance for the development of FGM coated cutting tools.
Splat Formation of Plasma Sprayed Functionally Graded YSZ/NiCrCoAlY Thermal Barrier Coatings
Authors: Ma Zhuang , Zhou Fang Ji , Cao Su Hong , Wang Fu Chi , Fan Qun Bo
Published: March 2009

Splat morphologies of YSZ/NiCrCoAlY TBCs by plasma spray were characterized using SEM.
Based on some assumptions, plasma jet temperature field was established by numerical simulation and
the effects of spray parameters are individually studied to optimize the spray process parameters.
Furthermore, the interaction wetting ability was taken into account in order to investigate the interaction
effect between ZrO2 and NiCrCoAlY droplets. It shows that T enhances markedly with increasing in I and
decreasing in FAr; while in despite of the insignificant effect of FHe on T, the temperature of powder in
plasma jet enhances with increasing in FHe. As a result of higher thermal conductivity of powder in He
plasma gas. NiCrCoAlY droplet impacting solidified NiCrCoAlY splat wets well and spreads fluently
while that impacts solidified YSZ splat spreads restrictedly for the poor wetting on the YSZ splat surface.
Microwave Characteristics of ZnO-Doped CeO2 Dielectric Resonators
Authors: Hsu Cheng Hsing , Tung Hsin Han , Lai Chun Hung , Chung Man Hsiang
Published: March 2009

CeO2 ceramics with ZnO additions (1 and 2 wt%) were prepared with conventional solid-state route have been investigated. Doping with ZnO (up to 1 wt%) can effectively promote the densification of CeO2 ceramics at low sintering temperature. At 1550 oC, CeO2 ceramics with 1 wt% ZnO addition possesses a dielectric constant ( ε r) of 23.2, a Q×f value of 53000 GHz and a temperature coefficient of resonant frequency (τf) of –47 ppm/oC.
Pulsed Laser Deposition and Characterization of InZnO Alloyed Thin Film
Authors: Shan F.K. , Liu G.X. , Shin Byoung Chul , Lee Won Jae , Oh W.T.
Published: March 2009

High-quality In2O3 powder and ZnO powder had been used to make the ceramic target and the
atomic ratio of 1 to 1 of indium and zinc had been prepared in this study. The alloyed thin films had been
deposited on sapphire (001) substrates at different temperatures (100–600°C) by using pulsed laser
deposition (PLD) technique. An x-ray diffractometer and an atomic force microscope were used to
investigate the structural and morphological properties of the alloyed thin films. It was observed that the
alloyed thin films deposited at the temperatures lower than 300°C were amorphous, and the alloyed thin
films deposited at high temperatures were crystallized. A spectrophotometer was used to investigate the
transmittances of the alloyed thin films. It was found that the alloyed thin films were of high quality. The
band gap energies of the alloys were calculated by linear fitting the sharp absorption edges of the
transmittance spectra. The Hall measurements were also carried out to identify the electrical properties of
the thin films.