bluuebunny/crossref_metadata_2025 huggingface dataset:
Transient Liquid Phase Bonding of 2D Fiber Reinforced Carbon-Carbon Composites
Authors: Xiong Jiang Tao , Li Jing Long , Zhang Fu Sheng , Wang Zhong Ping
Published: March 2009

2D Fiber Reinforced carbon-carbon composites (C/C) was successfully bonded to itself with Ti-Ni-Ti sandwich interlayer by transient liquid phase bonding at 1050°C for 20~100 min under axial pressure of 0.1 MPa. The microstructures of joints were investigated and bonding strengths were examined, fracture surfaces were characterized by SEM and XRD. The results show that Ti-Ni eutectic liquid infiltrates into the interconnected capillaries of C/C through the open pores of the C/C boding surface. The presents of the breakpoints in joint alloy and the reaction between Ti and C are beneficial to the improvement of bonding strength. The shear strength of joint is as high as 37.4 MPa.
The Preparation and Properties of Si3N4-Filled Epoxy Resin Composites for Electronic Packaging
Authors: Fu Ren Li , Chen Ke Xin , Tang Jin , Shen Yuan , He Hong
Published: March 2009

Si3N4-filled epoxy resin composite was fabricated employing liquid press molding method.
Properties, such as thermal conductivity, dielectric constant of Si3N4-filled epoxy resin composite were
evaluated, the effect of the content of Si3N4 and surface treatment of the filler was also considered. A
silane coupling agent, namely NH2−(CH2)3Si−(OC2H5)3, was applied to functionalize the surface of Si3N4
filler. Experimental results showed that the thermal conductivity of the composites is strongly dependent
on the filler and is dominated by the interface of epoxy resin and Si3N4 particles. As the Si3N4 volume
fraction increasing, thermal conductance of Si3N4-filled composite was improved obviously, especially
for that of silane-treated Si3N4 powder filled composite. Dielectric constant of the composite increases
linearly, however, it still remains at a relatively low level (<5, at 1MHz).
Preparation and Characterization of Copper-Coated Alumina Powders
Authors: Zhao G. , Shi Z.M.
Published: March 2009

Copper-coated alumina powders were prepared by a chemical plating method. The processing parameters such as compositions of plating solution, dispersants and passivants were optimized to obtain high-quality Cu-coated alumina powders. The phase composition, surface morphology and granularity of the coated powders were analyzed. Experimental results showed that the alumina powders coated with copper can be successfully prepared by the chemical plating method at room temperature, and the additions of dispersant and passivant can sufficiently improve the dispersity of powders and can depress the oxidation of copper layers precipitated from the plating solution. The granularity of alumina powders is increased by about 60 nm after being coated with the copper layer.
A Novel Approach to Prepare Ni-Coated TiB2 Cermet
Authors: Fang Zhou , Fu Zheng Yi , Wang Hao , Wang Wei Min , Zhang Qing Jie
Published: March 2009

A novel approach was developed to prepare Ni-coated TiB2 cermet. Fine Ni particles with
mean particle size of about 80 nm were impacted onto coarse TiB2 particles having a mean size of about 5
μm to form Ni-coated TiB2 powder by Hybridization. The conventional blended TiB2-Ni powder, as well
as Ni-coated TiB2 powder, was sintered by hot pressing (HP) method and Spark Plasma Sintering (SPS)
method. Compared with the conventional blended TiB2-Ni cermet, particle features and mechanical
properties of the Ni-coated TiB2 cermet were investigated. The microstructure analysis reveals that the
thickness of Ni film is around 4 nm. It is concluded that the mechanical properties of Ni-coated TiB2
cermet are superior to the blended TiB2-Ni cermet.
Electrical Characteristics and Microstructures of Nd2O3-Doped Bi4Ti3O12 Thin Films
Authors: Su K.L. , Sun Y.H. , Chen Min , Wan Z.M. , Hou Z.H.
Published: March 2009

Nd-doped bismuth titanate and random oriented Bi4-xNdxTi3O12 (BNT) thin films were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique. These samples had polycrystalline Bi-layered perovskite structure without preferred orientation, and consisted of well developed rod-like grains with random orientation. The remanent polarization (Pr) and coercive field (Ec) of the BNT film with x = 0.5 were above 19 μC/cm2 and 50 KV/cm, respectively. Nd doping into BIT caused a shift of the Curie temperature (TC) of the BIT from 675°C to 660, 520, 410 and 256oC for the films with x = 0.25, 0.5, 0.75 and 1.0, respectively. The experimental results indicated that Nd doping into BIT result in a remarkable improvement in ferroelectric and dielectric properties.
Residual Stress Field of Ellipsoidal Ceramic Particles Ni-Base Alloy Composite Coating
Authors: Liu Xie Quan , Zheng Jian , Yao Zhan Jun , Li Bao Feng
Published: March 2009

Ni base alloy ceramic composite coating fabricated through vacuum fusion sintering process
can acquire high strength and good thermal fatigue resistance. Composite coating was mainly composed
of Ni base alloy and ellipsoidal ceramic particles with random orientation. The three-phases model is used
to study the thermal expansion strains in composite coating. First, Eshebly-Mori-Tanaka method was
used to determine effective eigen strain of two-phases model formed by the ellipsoidal matrix shell being
around a ellipsoidal ceramic particle, then disturbance strain in two-phases model aroused thermal
inconsistency is obtained. Finally thinking average stress in effective matrix vanish, the residual stress
field in Ni base alloy and particles can be gotten by considering random orientation of two-phases models.
It will exert influence on strength and fatigue life of the composite coating.
Application of Multilayer Collagen/HA Scaffold in Cartilage Tissue Engineering
Authors: Wu Gang , Wang Ying Jun , Lu Hua Ding , Chen Xiao Feng , Ye Jian Dong , Ning Cheng Yun , Zhao Na Ru
Published: March 2009

In this article, a multilayer tissue engineering scaffold has been fabricated. The uppermost layer
is consisted by the collagen and the downmost layer is consisted by the collagen/hydroxyapatide.
Between the two layers, there have several continues changed collagen/HA layers at different ratio. These
gradient scaffolds have been made by the freeze dried method. The morphology of the multiphase
scaffold has been observed by the SEM. The chondrocytes from New Zealand rabbit knee joint were
separated, harvested and cultured on the top layer of the scaffold. The histological and the immunohistochemical
testing show that the chondrocytes keep its normal type in the 2 culture weeks.
Degradation Behavior of Calcium Sulfate/β-Tricalcium Phosphate Composites in Tris
Authors: Yang Zi , Yang De An , Zhao Hong
Published: March 2009

CaSO4/β-TCP composite powders were prepared by mixing CaSO4 and β-TCP. The CaSO4
/β-TCP (VS: VP) values were varied from 3:2 to 0:1. The composites were sintered at different temperatures.
Tris was used to evaluate degradation behavior of the composites. The morphologies of composites
before and after degradation were studied by SEM. The results show that degradation was
increased with the increasing of VS: VP and decreased with the increasing of sintered temperatures.
Physicochemical and Mechanical Properties of Composite of Chitosan Microspheres/Calcium Phosphate Cement
Authors: Liu Rui , Dong Li Min , Zan Qing Feng , Wang Chen , Tian Jie Mo
Published: March 2009

The aim of this work is to improve the mechanical properties of calcium phosphate bone
cement (CPC) by appending chitosan microspheres to CPC base. That chitosan degrades rapidly than
bone cement has been proved by previous investigations. Porous CPC has low compressive strength
because of the pores in it weakening the structure. Additive chitosan microspheres can improve the
mechanical properties by bearing the compress with the CPC base and produce pores after degradation.
This study investigates the effect of chitosan microspheres on the setting time, mechanical properties,
phase evolution and morphology of CPC. The additive proportion of chitosan microspheres ranges from 0
wt% to 30 wt%. Compared with original CPC, the modified CPC has higher compressive strength,
without significantly affecting the chemical properties. The phase composition of the CPC is tested by
XRD. The microstructures of CPC are observed using SEM. The final setting times range from 5~15
minutes and can be modulated by using different liquid and powder (L/P) ratio.
Apatite Forming on the Surface of Apatite-Wollastonite/β-Tricalcium Phosphate Bioactive Ceramic
Authors: Xiao Bin , Yang Wei Zhong , Zhou Da Li , Yin Guang Fu , Chen Huai Qing
Published: March 2009

Bioactive composite of apatite-wollastonite(AW)/β-tricalcium phosphate (β-TCP) was prepared. The nucleation and growth of bio-apatite on the surface of AW/β-TCP ceramic in simulated body fluid (SBF) were investigated. The surface morphological structure, phase compositions and microstructure of the materials were characterized by scan electron microscopy (SEM), X-ray diffraction (XRD) and infrared spectroscopy (IR); Results show that the surfaces of the AW/β-TCP composite ceramic are covered with a layer of carbonate hydroxyapatite (HCA) when soaked in SBF, which indicates their bioactivity; Such HCA layer is composed of fine ball-like HA granules. With excellent bioactivity and bio-absorption, AW/β-TCP bioactive composite ceramic is expected to be a good candidate for bone substitutes and bone tissue engineering scaffolds.
Development of Ultrafine Fibrous Hydroxyapatite/Polymer Scaffold by Electrospinning
Authors: Deng Xia , He Gang , Liao Yun Mao , Yao Yong Yi , Chen Zhi Qing , Li Gang , Zhao Yong , Nie Rong Rong , Liang Zhi Hong , Qu Yi Li , Tian Kun
Published: March 2009

A three-dimensional biomimetic electrospun scaffold was prepared from a nanohydroxyapatite/ polymer blend in the present study. Viscosity of n-HA/PEA compound solution determined by PEA concentration and additives of n-HA was investigated while other parameters were fixed in the electrospinning process. The fiber diameter increased with the increasing viscosity of solution. 20wt% n-HA in the composite ultrafine fibrous scaffold was proved to be a preferable ratio. The n-HA/PEA scaffold was characterized by XRD, SEM and EDX. The fibrous electrospun scaffold, which is made up of ultrafine fibers with average diameter 400±50 nm and well-interconnected pores, was characterized with high surface–to-volume ratio, which is conducive to cell and tissue growth. A comparatively uniform distribution of n-HA crystals in a single fiber even in the whole scaffold was confirmed by EDX. The biocompatibility of the composite was investigated by culturing osteobalsts on the scaffold. Good cell adhesion and proliferation manner was observed on the fibrous scaffold by SEM and MTT assay. It could be expected that the electrospun HA/PEA composite scaffold would be a potential biomimetic extracellular matrix biomaterial for bone tissue engineering.
Experimental Study of Biomimetic Mineralization on the Surface of Piezoelectric Pulp-Cap Film
Authors: Man Yi , Qu Yi Li , Wang Peng , Chen Zhi Qing , Gong Ping , Zhang Min , Zhu Jian Guo , Chen Qiang , Tian Kun , Ye Yong Mei , Niu Lin , Deng Xia , Nie Rong Rong
Published: March 2009

To study the biomimetic mineralization behaviour of piezoelectric pulp-cap films, bioelectret
chitosan films were prepared by polarization in an electric field and soaked in PBS with lysozyme for
piezoelectricity attenuation testing. The results showed that comparing these with samples stored in an
exsiccator, the films soaked in PBS had accelerated d33 loss. Calcium phosphate crystals nucleated and
grew on the surfaces of samples soaked in supersaturated calcification solution at 37 for 1, 6, 12 and 24
h. OCP and HA were found to co-precipitate on the surfaces within 24 h of immersion. This novel
piezoelectric inorganic-organic pulp-cap has the potential to be applied in dental pulp capping.
Fabrication and Isothermal Oxidation Behavior of the Co-Deposited EB-PVD (NiAl + YSZ) Coating
Authors: Gong Sheng Kai , Li He Fei , A Hesnawi , Jiang Kuo , Sun Li Dong
Published: March 2009

The influence of YSZ addition on isothermal oxidation behavior of EB-PVD NiAl bond
coatings on Ni based superalloy was investigated. The oxidation rate of the YSZ doped bond coat is
almost the same as the bond coat without the doping of YSZ. Four different areas exist on the surface of
the coating after 100 h oxidation, including the spalled area, the high Al-contained area, the high
Cr&Ni-contained area and the high Ti-contained area.
Thermal Shock Experiment and Simulation of Ceramic/Metal Gradient Thermal Barrier Coating
Authors: Xiao Jin Sheng , Liu Kun , Zhao Wen Hua , Fu Wei Biao
Published: March 2009

A thermal shock experiment is designed to explore the thermal shock properties of
ceramic/metal gradient thermal barrier coating. The specimens are heated up by oxygen-acetylene flame
and cooled by water spray. The experiment procedure includes two stages, heating the specimen from the
initial temperature 30°C for 40s, and then cooling for 20s. The heat transfer and the associated thermal
stresses produced during the thermal shock procedure are simulated by finite element method.
Experimental results indicated that the specimen of gradient coating behaves better in thermal shock
experiments, which agree with the results of simulation.
Crystallization of a SiO2-MgO-Al2O3-K2O-Fe2O3-F Glass
Authors: Tian Qing Bo , Wang Yue , Yue Xue Tao , Yin Yan Sheng , Fan Su Hua
Published: March 2009

The phase-separation and the crystallization of SiO2-MgO-Al2O3-K2O-Fe2O3-F glass were
investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe of
microanalyzers (EPMA). The results reveal that the varieties and the morphology of crystalline phases
formed depend sensitively on the thermal treatment schedules. During the isothermal treatments, the
crystalline phases of mica, mica and iron oxide (FeFeO4), and FeFeO4 as major crystals are precipitated in
the glass samples heat-treated at 900, 1000 and 1050°C respectively. However, the two-step heat
treatment beginning at 900°C for 1h and subsequently followed at 1050°C for 1h leads to the precipitation
of mica crystal and no any signs of FeFeO4 crystalline phase is observed. Also the morphology of sample
is different from that of the isothermally treated glass at 1050°C, but is similar from that of sample at
900°C. A “worm”-shaped phase-separation is observed in the sample heated at 800°C for 0.5h, which
exhibits different morphology from that of droplet- or globule-shape conventionally discerned. EPMA
results show that the incorporation of Fe2O3 accelerates accumulation of fluorine element, promoting the
phase-separation and the crystallization of the present glass.
Manufacture Process of Light Calcium Carbonate from Limestone
Authors: Wang Qi , Han Min Fang , Wang Jun Wei
Published: March 2009

This process and parameters of fabricating light calcium carbonate from limestone were
discussed in the paper. Raw limestone in experiment comes from Luquan city, Hebei province. The
results of chemistry and XRD analysis indicate that ingredient of this limestone is mainly calcium
carbonate, dolomite, silicon dioxide, which takes 83.81%, 11.03% and 1.67% separately, and a few of
other impurities. The process includes calcinations, assimilation, carbonation, drying and others. It was
ascertainable that the time of calcinations exceeded 5 hours at 850~ 950 and loss of calcinations was
42%. The time of assimilation was around 25 minutes at 70~90The time of carbonation was about 30
minutes at 50~90, and the airflow was about 160L/min and PH of latex after carbonation was 7.2~7.4.
The light calcium carbonate product was obtained in experiment, whose fine sphere size was about 10
nanometer, with the agglomeration particle size 2~3μm. The degree of white improved from 42 to 76. As
a result, the comprehensive properties of the produce were improved consumedly.
Effect of Phenolic Resin on the Basic Properties of Woodceramics and Biomorphic SiC Ceramics
Authors: Hou Guang Ya , Qian Jun Min , Wang Hong Jie , Jin Zhi Hao
Published: March 2009

Biomorphic SiC ceramics were fabricated by infiltrating liquid silicon into woodceramics
which were prepared from beech and pine impregnated with phenolic resin (PR) of different viscosity in
order to reinforce the cell wall of wood. The viscosity of phenolic resin was adjusted by ethanol according
to the weight ratio of PR to ethanol. The samples not impregnated with resin were compared. Effect of
viscosity of phenolic resin on the dimension shrinkage, weight loss, porosity and the axial and radial
flexural strength were investigated. Microstructural observation and phase identification of woodceramics
and biomorphic SiC were performed by SEM and XRD, respectively. The results show that, the
lower the viscosity of phenolic resin was, the higher the dimension shrinkage, weight loss and porosity of
woodceramics were. Biomorphic SiC was a diphase composite consisting of major phase β-SiC and
secondary phase Si. Woodceramics made from pine swelled or broke and strength of woodceramics
fabricated from beech declined when higher viscosity resins were impregnated. The flexural strength of
biomorphic SiC increased with increasing in viscosity of PR. The axial flexural strength was significantly
higher than the radial flexural strength because of anisotropic pore microstructures.
A New Method for Effective Utilization of Melted Solid Waste
Authors: Wang Nan , Zhu Guo Cai , Zhao Yong Hong , Sun Heng Hu
Published: March 2009

With the rapid development of the national economy, an effective way is urgently anticipated
to unburden the pressure of low resources utilization, high energy consumption and serious environment
pollution resulting from industry solid waste. In the present paper, a new process by applying atomization
technique into disposing of melting slag is proposed for highly effective utilization of solid waste. It is
characterized as simultaneous completion of super cooling and fine pulverized, and improvement on
utilization efficiency of melted slag for increase of activity and saving of milling energy. This method is
believed to be a new available approach to greatly promote the development of our recycling economy
Photo-Catalytic Properties of Ceramic Coating of TiO2
Authors: Li Hai Yang , Luo Zhong Kuang , Cai Hong Hua , Liu Jian Hong , Zhang Pei Xin , Liang Xun , Ren Xiang Zhong
Published: March 2009

TiO2 coatings on ceramic substrate were prepared using TiOSO4 and silica sol. Coatings were
then heat-treated respectively at 300°C, 400°C or 500°C for 30mins. Degradation of the solution of
chlorinated methane by UV light and TiO2 coating were investigated. It can be concluded from the results
that the coating with composition of 80wt%TiO2-20wt%SiO2 heated at 500°C display better degradation
effect than the other coatings. As the initial concentration of chloromethane goes up, the degradation rate
increases; while as the degree of substitution by chlorine goes up, the catalytic effects decreases.
Preparation of Sialon from Solid Wastes by Colloidal Process
Authors: Yao Yun , Xu Li Hua , Qiu Jin
Published: March 2009

Based on the slip casting and the preparation of sialon synthesized from clay, fly ash and
gangue by the carbothermal reduction nitridation, the influences of compositions, dispersant additive and
sintering process on the properties of materials have been investigated in present work. The experimental
results indicate that disposal of fly ash via a pickling process can greatly reduce the content of iron, and
the effect is obvious with increasing the concentrations of hydrochloric acid and pickling temperature.
Therefore the component of the final product can be purified. It is also noted that the final density of the
sintered body using colloidal process is superior to that of using conventional dry pressing, although the
slightly higher green density is observed in dry pressing body because of high compaction pressure.
Preparation and Photocatalytic Property of Platinum-Modified TiO2 Ceramic Film Using Different Compound Techniques
Authors: Jiang Yan Li , Liu Hui Ling , Jiang Zhao Hua , Yao Zhong Ping , Cui Rui Hai , Hao Guo Dong
Published: March 2009

The anodized TiO2 ceramic film was post-treated by photoreduction and ion sputtering, respectively, to deposit platinum on the surface of the films. Surface morphology, the main elements of the films and platinum distribution on the film surface were investigated by scanning electron microscopy and energy dispersive spectroscopy. The phase composition of the films was examined by X-ray diffraction. The photocatalytic activity was compared through the effect of the films on photocatalytic (PC) degradation rate of the humic acid. The results showed that both films were composed of Pt5Ti3, rutile (R) TiO2 and anatase (A) TiO2, and the content of TiO2 (R) of the film prepared by photoreduction was a little more than that of the film by ion sputtering. Compared with Pt on the Pt-TiO2 ceramic film by photoreduction, Pt on the Pt-TiO2 film by ion sputtering dispersed more evenly and the grains were much smaller. Pt particulates in the film post-treated by ion sputtering were more strongly combined with the film than those by photoreduction. Besides, the PC degradation rate of humic acid by both Pt-TiO2 films were higher than that by TiO2 film, and Pt-TiO2 film by ion sputtering had higher catalytic activity and longer using life than that by photoreduction.
Photocatalytic Degradation of Methyl Orange on ZnO in Aqueous
Authors: Li Xiu Yan , Zeng Ling Ke , Liu Ping An , Wang Hui , Shui An Ze
Published: March 2009

The photocatalyst of nanometer ZnO powder was prepared by precipitation method with
ZnSO4⋅7H2O and Na2CO3 as raw materials. Laboratory experiments with methyl orange (MO) as the
model pollutant have been carried out to evaluate the photocatalytic activity of nanometer ZnO
photocatalyst. A high-pressure mercury lamp was used as the energy source for the photocatalytic
experiments. The effects of process parameters such as catalyst loading, initial methyl orange concentration,
pH and electrolyte on the photodegradation have been investigated.
Coloring Mechanism of Pr-CeO2 Nano-Crystalline Red Lanthanide Pigments Prepared by Low-Temperature Combustion Synthesis
Authors: Zhu Z.F. , Zhou Y. , Wang R.L.
Published: March 2009

Pr-CeO2 nano-crystalline red lanthanide pigments were prepared from cerium (III) nitrate hexahydrate
and praseodymium oxide by low-temperature combustion synthesis. Its ignited temperature was
approximately 250°C. The prepared pigments were characterized by DSC, XRD, SEM and XPS. The
results showed that the crystallite size decreases with increasing Pr mol concentration. The valence of
praseodymium in the pigments and its coloring mechanism were also investigated. The trivalent Pr
entered into CeO2 crystal lattice and formed Pr-CeO2 solid solution, which was based on the fluorite
structure. It substituted trivalent Pr for tetravalent Ce in CeO2 crystal and was compensated by oxygen
vacancies, which caused the distortion and the defection of the crystal lattice. Therefore the pigments can
absorb the light with the wavelength of approximate 600nm and present the red tonality.
Synthesizing Nano-Scale Titanium Nitride Powders by Solvothermal and Carbothermal Methods
Authors: Tan Guo Qiang , Ren Hui Jun , Miao Hong Yan , Dong Min , Xia Ao
Published: March 2009

Xerogel was prepared by the sol-gel method using butyl titanate, alcohol, carbamide and
glucose as raw materials. The precursor powders were obtained after xerogel was solvothermally treated
at 220oC for 2 h. The IR analysis suggests that the precursor with 10% excess glucose gave an absorption
peak at 1084.37cm-1, which was assigned to Ti-OH bond, while no such a peak can be observed for that
with 30% excess glucose. The prepared precursor powders were then sintered at 1400oC in nitrogen
atmosphere. XRD and SEM results indicated that the sintering time and the contents of glucose had great
effects on synthesizing titanium nitride powders. The titanium nitride powders with a high purity and a
mean grain size of about 35 nm could be prepared by heating the precursor with 10% excess glucose at
1400oC for 6.5 h.
Preparation and Characterization of Nano-Sized Ni Powders inside a Nonionic Polymer Network
Authors: Kim Tea Wan , Kim Dong Hyun , Park Seong Soo , Kim Kwang Ho , Park Hong Chae , Yoon Seog Young
Published: March 2009

Monodispersed and nano-sized Ni powders were synthesized from aqueous Ni sulfate hexahydrate (NiSO4· 6H2O) inside sucrose as a nonionic polymer network by using wet chemical reduction process. The influence of a nonionic polymer network on the particle size of the Ni powders were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). The Ni powders obtained by adding of sucrose were nearly spherical in shape and seemed to be nano-sized, typically in the range of 100 nm with not being agglomerated. As the sucrose content increased, the particle size of Ni powders steeply decreased and reached the minimum value, however, the particle size increased again with a further increase of sucrose content. This is believed to be due to the pore size of the swollen polymer network. As a result, the particle size of the Ni powders prepared by the reduction inside polymer network was strongly dependent of the sucrose content.
One-Dimensional Oxide Nanomaterials through Rheological Self-Assembling
Authors: Chen Wen , Mai Li Qiang , Qi Yan Yuan , Jin Wei , Hu T. , Guo W.L. , Dai Y. , Gu E.D.
Published: March 2009

This article introduces a process for the growth of one-dimensional oxide nanomaterials that combines rheological phase reaction and hydrothermal self-assembling process. Fundamentals and practical approaches of hydrothermal self-assembling process and rheological phase reaction are briefly described. Particular attention is devoted to the rheological self-assembling for the growth of low dimensional oxide nanomaterials. Many examples are shown that the rheological self-assembling is an effective method to prepare one-dimensional nanomaterials, organic-inorganic hybrids and 1-D nanomaterial array for optical-electronic and electrochemical devices and catalysis. Morphologies, microstructures, properties, and application of one-dimensional oxide nanomaterials are reviewed.
Synthesis and Characterization of Boron Carbide Nanobelts
Authors: An Xiao Qiang , Zhai Hua Zhang , Cao Chuan Bao , Zhu He Sun
Published: March 2009

Boron carbide nanobelts have been synthesized successfully by carbothermal growth method. Boron oxide, activated carbon, gallium oxide and sodium chloride in the molar ratios of 1: 5: 0.03: 0.2 were used as raw materials. The width and thickness of the nanobelts range from 1 to 10 μm, and 80 to 150 nm respectively. The length is up to 50–200 μm. Diffraction peaks in the XRD pattern can be indexed to rhombohedral boron carbide with lattice parameters of a=5.616Å, c=12.067 Å. SAED pattern recorded along [ 010 ] zone axis shows (104 ) growth direction. A vapor–liquid–solid (VLS) growth process on the active catalyst surface is supposed to interpret the growth mechanism of as–synthesized nanobelts.
Bridgman Growth of a Novel Piezoelectric Single-Crystal Material: Ca3NbGa3Si2O14
Authors: Wu An Hua , Xu Jia Yue , Zhou Juan , Lu Bao Liang , Wu Xian Jun , Li Xin Hua , Qian Guo Xing
Published: March 2009

Langasite (La3Ga5SiO14, LGS) and its isomorphs, were regarded as potential substrate materials for surface acoustic wave (SAW) and bulk acoustic wave (BAW) applications. Among these homologous compounds, the ordered structure crystals have attracted much attention for their low Ga2O3 content, high acoustic velocity and low acoustic loss. In this work, the ordered langasite structure crystals Ca3NbGa3Si2O14 (CNGS) were grown with vertical Bridgman method for the first time. The CNGS crystals with 25mm in diameter and 40mm in length were grown successfully from its stoichiometric melt through LGS crystal of Ø10mm×40mm being chosen as seed. X-ray powder diffraction experiments showed that the CNGS single crystals had a single phase and had the same structure as the LGS crystal. The transmittance spectra with the wavelength from 200 to 800nm were recorded by means of Spectrophotometer at room temperature.
Preparation and Characterization of Cerium Hydrate Fiber
Authors: Sung Jia Ming , Lin Sung En , Wei Wen Cheng J.
Published: March 2009

Cerium hydrate fiber (CHF), which showed an aspect ratio greater than 100, was
synthesized by a novel method, which used the mixing of cerium nitrate (Ce(NO3)3), sodium hydrate
(NaOH) and citric acid (C6H8O7) synthesized at a relative low temperature and ambient pressure. The
precipitates were characterized by XRD, SEM and TEM. The results showed that in addition to fibers,
two morphologies could be obtained depending on the synthesizing conditions. Aging time and
formulation were two key factors for the control of the aspect ratio of the precipitates. By a heating
treatment at 600oC for 2 h, the homogenous and well-crystallized cerium dioxide (CeO2) fiber can be
fabricated. The effects of synthesis parameters, such as the concentration of the starting solution,
aging period, and pH value were reported and discussed.
Microstructure and Resistivity of Iridium Oxide Thin Films by Pulsed Laser Deposition Technique
Authors: Zhang Lian Meng , Gong Yan Sheng , Wang Chuan Bin , Shen Qiang
Published: March 2009

Highly conductive IrO2 thin films were prepared on Si (100) substrates by pulsed laser deposition technique from an iridium metal target in an oxygen ambient atmosphere. The effect of substrate temperature on the structure and electrical properties of IrO2 films was investigated. The deposited films at substrate temperatures ranging from 250 to 500°C under an oxygen pressure of 20Pa were pure polycrystalline tetragonal IrO2 and the preferential growth orientation changed with the substrate temperature. IrO2 films were well solidified with the fairly homogeneous thickness and exhibited a good adhesion with the substrate. The room-temperature resistivity of IrO2 films decreased with the increase of substrate temperature and the minimum resistivity of (42±6) μ-·cm was deposited at 500°C.
Structure and Optical Properties of Si Films Deposited by Inductively Coupled Plasma CVD at Room Temperature
Authors: Wang Xiao Qiang , He De Yan , Li Jun Shuai
Published: March 2009

Si films were deposited by inductively coupled plasma chemical vapor deposition at room temperature with a mixture of SiH4/H2. The microstructure of the film was characterized with Fourier transform of infrared, Raman spectroscopy, atomic force microscopy. We found that SiH4 concentration strongly affects the structure of Si films and nano-crystalline film can be synthesized at room temperature by optimizing the silane concentration. The analysis for optical properties of the films suggested that the optical band gap EOPT of films are distinctively lower than those of amorphous Si films. It has been observed that the EOPT of sample decreases with the increasing of H content in film.
Preparation and Properties of Al2O3 Particle Dispersed 3Y-TZP Nanoceramics Doped with TiO2
Authors: Chen Bo Jun , Zeng Zhao Qiang
Published: March 2009

Al2O3 particle dispersed 3Y-TZP nanoceramics doped with TiO2 was fabricated by the vacuum
reduction of Ti(OH)4, Al(NO3)3 and 3Y-TZ powders at 873K for 2h and sintered in air at 1573K~1823K
for 2-6h. The relation between Al2O3 and TiO2 content, sintering parameters, relative density and grain
sizes were studied. Microstructural investigations revealed that, in comparison with direct powder mixing,
the reduction method is more efficient in achieving a homogeneous dispersed fine alumina second phase,
which results in the reduction of matrix grain size and the increase of the relative density of the 3Y-TZP
ceramic. TiO2 addition facilitates the sintering process but may cause significant abnormal grain growth
which can be offset by the homogeneity of the powder dispersion. A final 3Y-TZP-TiO2 ceramic matrix
with grain size below 500nm dispersed with ultrafine second phase Al2O3 was obtained.
Phase-Transformation Kinetics of TiO2 in TiO2/(O′+β′)-Sialon Multi-Phase Ceramics
Authors: Yang Jian , Xue Xiang Xin , Pan Li Mei , Wang Mei , Qiu Tai
Published: March 2009

TiO2/(O′+β′)-Sialon multiphase ceramics with different phase composition of TiO2 were
prepared by pressureless sintering under high-purity N2 atmosphere with (O′+β′)-Sialon powder and nano
TiO2 (anatase) powder as raw materials, Yb2O3 or Tb2O3 as additive. For each sample, the weight
percentage of anatase in TiO2 was calculated from XRD data and the kinetics of anatase-rutile
transformation was investigated, wherein the emphasis was placed on the influence of Yb2O3 and Tb2O3.
The results indicate that the added Tb2O3 and Yb2O3 serve the significant function of inhibition and
promotion on the phase transformation, and the effects are enhanced and attenuated with increasing
additive content, respectively. For the sample without additive, the transformation process follows
apparent first-order kinetic model. The addition of Yb2O3 or Tb2O3 results in completely different
transformation kinetic law. For the samples with Yb2O3 added, the transformation is an apparent
second-order reaction, whereas a unique kinetic model, CA=kt1/2+C, is valid for the samples containing
Tb2O3. In the two cases, the effect of the additive content on the transformation can be perfectly reflected
by the apparent rate constant.
Joining of SiC Ceramic by Hot Pressing Reaction Joining Process Using Ni-51Cr Powders as Filler
Authors: Mao Yang Wu , Li Shu Jie , Zhang Yan
Published: March 2009

Joining of ceramics is of importance from both technical and economical points of view.
Joining of recrystallized SiC ceramic to itself has been realized by hot pressing reaction joining process
using Ni-51Cr powders (consisting of Ni+51wt%Cr powders) as filler. The optimized technological
parameters have been obtained by orthogonal experiment, which are joining temperature of 1150°C,
holding time of 20min, joining pressure of 10MPa and cooling rate of 0.25°C/s. The most effective factor
to influence the weld strength is joining pressure within the range of testing. Under the optimized
conditions, the maximum relative bending strength of joint, 70.7%, is achieved. The microstructure and
phase composition of the weld zone were examined by SEM, EDX and XRD. The results show that
interdiffusions and chemical reactions take place in the joining process. A reaction layer, which is mainly
composed of Ni2Si and Ni3C with a little Cr, exists between the welding base material SiC ceramic and
the filler reaction product layer called as interlayer, which is mainly composed of Ni2Si and Cr.
Investigation of High-Quality ZnO Film on Polycrystalline Diamond Wafer for Fabrication of High Frequency SAW Filter
Authors: Wang X.B. , Chen J.J. , Li D.M. , Zeng Fei , Pan F.
Published: March 2009

ZnO films with piezoelectric properties were deposited on polycrystalline diamond wafers for
high frequency surface acoustic wave filter applications by dc reactive magnetron sputtering. The
influences of different sputtering pressures and substrate temperatures on the properties of ZnO films
were discussed. Highly c-axis oriented, fine-grain ZnO films with excellent surface flatness (average
surface roughness of 5.3 nm) and high resistivities (6.3×107 *·cm) have been obtained. Then Al films for
interdigital-transducer were deposited on ZnO/diamond by electron evaporation, a 2.48 GHz longitudinally-
coupled double-mode surface acoustic wave filter has been fabricated using the Al/ZnO film on
diamond wafer.
Cracking Stress of Nano-Fibers Composite Ceramics
Authors: Ni Xin Hua , Yao Zhan Jun , Liu Xie Quan , Wang Jun Ying
Published: March 2009

Recent experiment showed that nano-fibers composite ceramics, fabricated through SHS
process, could acquire high toughening and strengthening. Composite ceramics are mainly composed of
fiber eutectic with random orientation, in which nanometer sized zirconia fibers are dispersed within the
alumina matrix. First, it can be visualized that tensile force is transmitted from the matrix to the
nano-fiber by means of shear stress that develop along the fiber- matrix interface. Then the shear stress on
the surface of the fiber eutectic is obtained. It related to the volume fraction and slenderness ratio of the
nano-fibers, and external strain of the fiber eutectic. The maximum shear stress is at the ends of the fiber
eutectic perpendicular to applied tensile stress. As maximum shear stress on the surface of the fiber
eutectic is equal to the critical shear stress, the composite ceramics would crack. So the applied tensile
stress on composite ceramics arousing the surface crack of the fiber eutectic is gotten.
Influences of Duty Ratio on Structure and Corrosion Resistance of Ceramic Coatings on Ti-6Al-4V by Micro-Plasma Oxidation
Authors: Ben Hong Qi , Yao Zhong Ping , Jiang Zhao Hua
Published: March 2009

Duty ratio is a key factor during micro-plasma oxidation process. Its influences on structure
and corrosion resistance of ceramic coatings on Ti–6Al–4V by pulsed bi-polar MPO in NaAlO2 solution
were investigated. The ceramic coatings were composed of Al2TiO5, α-Al2O3 and rutile TiO2, of which
Al2TiO5 was the main crystalline. The coating can be divided into a porous outer layer and a dense inner
layer. Compared with the condition of the same duty ratio for both pulses, the rise of anode duty ratio (D1)
led to an increase in the amount of Al2TiO5 and α-Al2O3 and increased the thickness of the coating;
whereas the rise of cathode duty ratio (D2) led to a decrease in the amount of α-Al2O3 and decreased the
thickness of the coating. Besides, the corrosion resistance of the coated samples was better than that of
Ti-6Al-4V substrate. When D1 / D2 = 60 / 30, the produced coating’s corrosion resistance was best.
Preparation of BaTi4O9 - BaPr2Ti4O12 Composite Powders via Ethylenediaminetetraacetic Acid Precursor
Authors: Song Ying , Liu Fu , Sun Qiu , Huang Xian Li , Wang Fu Ping
Published: March 2009

BaTi4O9 - BaPr2Ti4O12 microwave dielectric ceramic composite powders were prepared by
a polyacrylamide gel route using ethylenediaminetetraacetic acids (EDTA) as a chelating agent. This
method provides a fast, cheap, reproducible and easy to scale-up way to prepare homogeneous mixed
phases compounds. A light green, molecular-level, homogeneously mixed gel was prepared by the
gelification of acrylamide. The precursors and derived oxide powders were characterized by thermal
analysis (TG-DSC) and X-ray powder diffraction (XRD). Two phases and well-crystallized BaTi4O9 -
BaPr2Ti4O12 composite powders were obtained at 1200 °C for 4 h.
First-Principles Study of Nonmetal-Doped Titanium Oxides
Authors: Gao Xue , Shang Jia Xiang , Zhang Yue
Published: March 2009

The electronic structures of anatase titanium oxides (TiO2) substitutional doping with N, F, C, P and S for O have been studied by first-principles method based on the density functional theory. The lattice distortion and densities of states of nonmetal-doped anatase TiO2 as well as photocatalytic activity were discussed. Comparing the effects of these five nonmetal ions (N, F, C, P and S) in the anatase TiO2, the substitutional doping of N is the most effective to get better visible-light activity because of its least lattice distortion and a large band-gap narrowing effect and the suitable relative position of the impurity states in band gap.
First Principle Study on Electronic Structure of Nanocrystalline BaTiO3 Ceramics
Authors: Deng Xiang Yun , Li Long Tu , Wang Xiao Hui , Gui Zhi Lun
Published: March 2009

The full potential linearized augmented plane wave method within the generalized gradient
approximation was used to calculate electronic structure of nanocrystalline BaTiO3 ceramics. We
calculated the total and partial density of states of 50 nm BaTiO3 ceramics. The results show that the
atoms distribution of nanograin BaTiO3 ceramics is different from those of coarse BaTiO3 ceramics. It is
also revealed that the hybridization between Ti 3d and O 2p is very strong, which is very important to the
ferroelectric stability of nanocrystalline BaTiO3 ceramics.
Microstructure and Optical Characterization of Au/SiO2 Nano-Composite Multilayer Films
Authors: Zhang Yun , Zhang Bo Ping , Jiao Li Shi , Li Xiang Yang , Masumoto Hiroshi , Goto Takashi
Published: March 2009

Au/SiO2 nano-composite multilayer thin films with different thickness were prepared on a
quartz substrate by magnetron plasma sputtering. The microstructure, morphology and optical properties
of the films were investigated by using TEM and optical absorption spectra. [Au/SiO2]×5 and [Au/SiO2] ×
11 multilayer thin films have well-defined interface. The thickness of the multilayer was 60nm and 130
nm for the thin films with 5 and 11 layers, respectively. The optical absorption peaks due to the surface
plasma resonance appeared at a wavelength of 560 nm for the both [Au/SiO2]×5 and [Au/SiO2]×11 thin
films. The intensity of the absorption peak increased with increasing numbers of deposition layers. The
optical absorption spectra of Au/SiO2 multilayer thin films are well agreement with the theoretical optical
absorption spectra calculated from rewritten Maxwell–Garnett effective medium theory.
Mechanical and Electrical Properties of Boron-Oxygen-Nitrogen Film as Buffer Layer
Authors: Chen Guang Chao , Li B. , Tong Yu Mei , Lu Fan Xiu , Boo Jin Hyo
Published: March 2009

BON film was fabricated as buffer layer by radio frequency plasma enhanced metal-organic chemical vapor deposition with 100 kHz frequency and trimethyl borate precursor. The typical binding energy of each element is 191.5 eV of B1s, 399.4 eV of N1s, and 531.2 eV of O1s in the films detected by XPS. HRTEM showed the film contained amorphous composition and nano-sized crystalline particles. Electrical properties of films were characterized by I–V curve. The order-magnitude of electric conductivity was measured as several tens (·cm)-1. The hardness of BON film was ~ 10 GPa.
Functionally Graded Piezoelectric Ceramics for Ultrasonic Transducers
Authors: Jin Deng Ren , Meng Zhong Yan , Wu Wen Biao , Qin Bing
Published: March 2009

Functionally graded piezoelectric ceramics (FGM) plates are attractive due to their ability to
broaden the frequency bandwidth of the ultrasonic transducers. A resistivity gradient La-doped Lead
Zirconate Titanate/Al-doped Zinc Oxide (La-PZT/Al-ZnO) piezoelectric ceramics plate was developed
using a powder metallurgical process. Grading of the piezoelectric modulus across the plate was
experimentally confirmed by the electrical impedance analysis and its gradient distribution was
characterized using the profile-technique. The distribution of Zn2+ ions in the PZT region was examined
using EPMA, XRD and SEM/EDX, respectively. Analysis results show that the gradient distributions of
structural and electrical properties inside the FGM plate are mainly caused by the diffusion and
aggregation of Zn2+ ions in the PZT layer. The functionally graded piezoelectric ceramics plate presented
here will be useful for broadening the frequency bandwidth of piezoelectric transducers.
Interfacial Cracks Control of Y-TZP/Stainless Steel FGM Fabricated by Slip Casting
Authors: He Xin , Liu Jia Chen , Men Rong Lei , Zhang Xin Xin
Published: March 2009

Three mole percent Y2O3 doped tetragonal polycrystals (TZP) and stainless steel functionally
graded materials (FGMs) were fabricated by slip casting. The optimal conditions for control of interfacial
cracks by adjusting shrinkage of each component and temperature gradient were investigated.
Experimental results showed that sintering shrinkage mismatch of adjacent intermediate interlayer could
cause interface cracks, as well as speedy temperature dropping rate in the cooling process. Based on
suitable adjusting of sintering shrinkage and controlling of cooling rate, a satisfying interfacial
microstructure without apparent cracks for FGM of 3Y-TZP/SUS with three intermediate layers was
obtained.
Preparation and Microwave Permittivity of SiC-AlN Solid Solution Powders
Authors: Liu Xiao Kui , Zhou Wan Cheng , Luo Fa , Zhu Dong Mei
Published: March 2009

SiC-AlN solid solution powders were prepared from the mixtures of aluminum, silicon and carbon black in a nitrogen atmosphere with preheating self-propagating high temperature synthesis (SHS) method. The powders synthesized with different ratios of Al/Si were mixed with paraffin wax and the microwave permittivity of the mixtures was measured at the frequency of 8.2~12.4GHz. The results were contrasted with that of SiC powders synthesized by preheating SHS in argon and nitrogen atmosphere respectively. The ε′, ε″, and the tgδ (ε″/ε′) of the mixture of SiC prepared in a nitrogen atmosphere are highest, followed with those of the SiC-AlN solid solution powders and the SiC powders prepared in an argon atmosphere. Along with the increase of atomic ratio of Al/Si, the ε′, ε″, and tgδ of SiC-AlN solid solution decrease. We believe that, with the increase of AlN dissolved, the concentration of carriers and the effect of dielectric relaxation will decrease because of the two contrary dopants.
Electro-Mechanical Coupling Performances of a Piezoelectric Bimorph
Authors: Yan Shao Ze , Zhang Fu Xing , Wen Shi Zhu
Published: March 2009

The influence of electro-mechanical operation conditions on the actuation capabilities of the
piezoelectric bimorph is investigated in this paper. The objective is to compare the performance of the
piezoelectric bimorph in different operation conditions and to determine the optimum operating
conditions. An experimental set-up is built, and a series of experiments are presented to investigate the
static and dynamic characteristics of the bimorph, including tip displacements of the bimorph under
different preloads, dynamic response at different drive frequencies, step response and creep. Some
properties such as displacement output, force output and hysteresis of the piezoelectric bimorph under
different operating conditions are evaluated. Experimental results indicate strong dependence of both
elastic and piezoelectric properties of the bimorph on the operating conditions.
Mechanical Properties of Piezoelectric Stack Actuators under Electro-Mechanical Loading
Authors: Yan Shao Ze , Zheng Kai , Xun Jian
Published: March 2009

The responses of the piezoelectric stack actuator under electro-mechanical loading are
investigated. Two types of tests are performed: influences of the preload on characteristics of the stack
and dynamic test. Experimental results indicate strong dependence of the stack properties on the
electro-mechanical loading conditions. The displacement output is initially enhanced with an increase of
the mechanical preload, and the maximum value is obtained at the preload of about 0.4 kN. But much
higher preload will cause the decrease of the displacement output. The effective piezoelectric coefficient
and the hysteresis degree are employed to describe the variations of the stack’s performances caused by
the mechanical preload. The effective piezoelectric coefficient under different preloads can be calculated
by using experimental results of the displacement output and input voltage. Within low frequency band of
about 400 Hz, the displacement magnitude of the stack is nearly constant, and the phase lag increases with
the increase of the driving frequency at the applied sine sweep voltage with the amplitude of 150V.
Dynamic Properties of Fine-Scale 1-3 PZT/Epoxy Piezoelectric Composites
Authors: Zhen Yu Hua , Li Jing Feng
Published: March 2009

Fine-scale 1-3 PZT/epoxy piezoelectric composites were prepared by a dice-fill process, and
their resonance characteristics and dynamic piezoelectric properties were investigated. The resonance
characteristic was deeply influenced by PZT volume fraction and the thickness of 1-3 PZT/epoxy
composite. The experiments proved that reducing the distance between PZT rods and/or increasing the
height/width ratio could weaken the additional coupling effect of lateral resonance mode on thickness
mode. The PZT/epoxy composites displayed only thickness-mode resonance when the distance between
PZT rods was reduced to 220μm and its aspect ratio was increased up to 10.