bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of PbO Concentration on the Templated Grain Growth of PMN-32.5PT Ceramics
Authors: Liu Dan , Yan Yong Ke , Zhou He Ping
Published: March 2009

<001> textured 0.675Pb(Mg1/3Nb2/3)O3-0.325PbTiO3 (PMN-32.5PT) ceramics were prepared
by templated grain growth with micron scale BaTiO3 platelet templates. 0%~7% excess PbO was added
to form liquid phase. The influence of liquid phase concentration on the growth of matrix and templated
grains was investigated. The growth process was controlled by a dissolution-precipitation mechanism.
The templated grain growth was accelerated by the formed liquid phase and resulted in highly textured
PMN-32.5PT ceramics.
Preparation and Characterization of Desulfurization Sorbent from Hydrated Lime and Blast Furnace Slag
Authors: Gong Guo Zhuo , Ye Shu Feng , Li Feng , Cui Yan Bin , Tian Ya Jun , Chen Yun Fa
Published: March 2009

A series of sorbents for SO2 in flue gas were prepared from hydrated lime and blast furnace slag
using a factorial experiment design. It is found that the reaction between hydrated lime and blast furnace
slag is fast. The reactivities of the as-prepared sorbents are higher than those of hydrated lime alone due to
the formation of calcium silicate hydrates, and hence the utilization of hydrated lime as well as the Ca in
the blast furnace slag is improved. Furthermore, the effects of preparation variables on the reactivity of
the sorbents are also discussed.
Effect of Calcination Temperature on the Microstructure and Morphology of Bi3.25La0.75Ti3O12 Powders Synthesized from Polymerized Precursors
Authors: Fang Pin Yang , Fan Hui Qing , Qiu Shao Jun , Liu Lai Jun , Chen Jin
Published: March 2009

Lanthanum-modified bismuth titanate, Bi3.25La0.75Ti3O12 (BLT), powders were prepared from
polymerized precursors using citric acid as a chelating agent and ethylene glycol as an esterification
agent. The effect of calcination temperature on the microstructure and morphology of powders were
studied. It was shown that the pure and normally stoichiometric phase of BLT powders could be obtained
at relative low temperature from 550o to 700oC even if the bismuth content is not excess in the starting
precursors while the secondary phase could be detected at both lower and higher calcination
temperatures. The shape of the BLT grains is also strongly influenced by the calcination temperature.
Growth and Characterization of Silicon Carbide by Sublimation
Authors: Wang Yang , Wan Long , Liu Xiao Pan , Ma Wen Min
Published: March 2009

Bulk silicon carbide (SiC) single crystal was fabricated by attaching abrasive SiC powder
directly to graphite electrode. The substrate temperature was important to SiC crystal growth. When the
temperature of substrate varied from 2300K to 2600K, with substrate temperature increase, the size of
finally obtained SiC single crystal increased. At 2600K, the maximum size of SiC crystal, 2cm in
diameter, was obtained. The effect of temperature to SiC single crystal growth rate and the growth
kinetics were discussed. The phase composition and surface morphology was studied by XRD and SEM
respectively.
Thermal Decomposition Kinetics of Ammonium Aluminum Carbonate Hydroxide
Authors: Zhang Hai Jun , Xiu En Xia , Wang Xiu Juan , Jia Quan Li , Sun Hong Wei , Jia Xiao Lin
Published: March 2009

The thermal decomposition of ammonium aluminum carbonate hydroxide was studied under
non-isothermal conditions in air. The decomposition kinetics were evaluated from data of TG-DTA by
means of the Kissinger equation and the Coats-Redfern equation. The values of the activation energy E,
the preexponential factor A and the algebraic expression of integral G(α) functions of the thermal
decomposition were calculated. The ammonium aluminum carbonate hydroxide (AACH) was
characterized by X-ray diffraction, differential thermal analysis and thermogravimetric and field emission
scanning electron microscopy.
Structure Design for the Joining of Ceramics and Metal
Authors: Song Yin Suo , Lin Bin , Yang Fei
Published: March 2009

According to an actual design for the joining of ceramics and metal, four joining design
principles, heat expansion matching principle, homogeneous transition principle, cushion principle and
thermal protection principle, are proposed in this paper. The weakness and stress concentration point of
the joining are analyzed through finite element analysis. Following the joining design principles, the
design scheme and finite element analysis are improved on. Finally the satisfactory residual intensity
coefficient is given.
Expansion Coefficient of Sealing Material for Ceramic Metal Halide Lamps
Authors: Geng Zhi Ting , Liu Yu Zhu , Liu Xing Tao
Published: March 2009

In order to make a good ceramic metal halide lamps, to form the solid hermetic sealing
supplied by the ceramic discharge and metal electrode is very important. It is different with the quartz
tube, after heating softly, ceramics tube can’t stick with metal electrode lead together through squeezing.
For the sealing, it is necessary to adopt the appropriate sealing materials. In our research work, studied the
thermal expansion coefficient of the Al2O3-Dy2O3-SiO2 sealing material was a key for ceramic metal
halide lamp.
Wettability of Graphite/Ni plus Cr System
Authors: Li Shu Jie , Song Min Jian , Xia Yun Ling , He Yue Hui , Mao Yang Wu
Published: March 2009

Carbon fiber reinforced CMCs (ceramic matrix composites) are promising high temperature
structural materials for aeronautical and astronautical industries. But the engineering application of the
materials strongly depends on the joining technique. As a fundamental research, high strength graphite
can be used to simulate carbon fiber. The study of wettability of graphite by liquid metals contributes to
the development of joining technique of carbon fiber reinforced CMCs. The wettability of graphite/Ni
plus Cr system was investigated using the sessile drop method. The contact angle was determined by high
temperature photography. The microstructure and composition of the interfacial zone were analyzed by
SEM, EDX and XRD. The contact angle of graphite/Ni plus Cr system decreases with increasing the Cr
content. It becomes zero, when the Cr content reaches 50wt%. The wetting of graphite/Ni plus Cr system
is chemical wetting. The contact angle of the system decreases with increasing the wetting temperature or
prolonging the holding time. The higher the Cr content, the more remarkable the effects of the
temperature and the holding time on the contact angle are. Microstructure and phase analysis reveals that
inter-diffusions and interfacial reactions take place in the wetting process. The reaction products include
Cr3C2. The formation of Cr3C2 contributes to the interfacial bonding and results in the accumulation of Cr
in the interfacial zone.
Stiffness of Cermets Containing Interfacial Arc-Microcracks
Authors: Lu Xiao Bo , Liu Xie Quan , Li Bao Feng , Zhao Yun Xu
Published: March 2009

The interfacial arc-microcracks have large influence on the behaviors of cermets. The
emerging cause of arc-microcracks is interpreted and the interaction between ceramic particles and
arc-microcracks is accounted for determining the equivalent eigen strains by using the random two
phase element method. Then the effective volumetric modulus and shear modulus of the cermets is
estimated. The results show the effective volumetric modulus and shear modulus of the cermets is
associated with the stiffness of the matrix and ceramic particles, the volume fractions of ceramic
particles and arc-microcracks, the subtending angle and thickness of arc-microcrack..
Microstructure and Thermal Shock Resistance of LaPO4-ZrO2
Authors: Li Zhong Qiu , Liu Jia Chen , Li Shun , Zhou Bing , Jing Wei
Published: March 2009

LaPO4-ZrO2 composites were prepared by slip casting and pressureless-sintered in air. The
effects of LaPO4 addition on microstructure and thermal shock resistance were addressed. The thermal
shock resistance of the composites was evaluated by air quenching and a subsequent three-point bending
test to determine the strength degradation. Comparisons were made with results from parallel experiments
conducted using a ZrO2 ceramic without LaPO4 additions. The reference ZrO2 ceramic showed the
expected substantial strength losses when thermally quenched from 470oC above room temperature. By
contrast, the LaPO4-ZrO2 ceramics, while displaying reduced strength relative to the reference ZrO2
ceramics, exhibited minimal strength degradation under severe thermal shock conditions.
Optimal Design for Mechanical Properties of Composite with Combination of Genetic Algorithm and Artificial Neural Network
Authors: Zhang Fan Wei , Zhou Song Bang , Zhang Yue , Zhang Da Hai , Li Zhong Ping
Published: March 2009

Improved genetic algorithm, combined with artificial neural network, is present for the optimal
design of 2.5D braided composite. Dispersal simulation data, including maximal stresses and elastics
properties, are adopted by artificial neural network for the calculation of strength property. Based on
calculation method of strength mentioned above and other calculation models for other mechanical
properties, genetic algorithm is employed for the design of structure parameters of 2.5D braided
composite, such as wrap fiber density, fill fiber density and interface strength. These structure optimal
parameters are finally optimized for practical application.
Ab-Initio Study on Adsorption and Diffusion of Au Atoms on Clean Si(001) and H-Si(001) Surface
Authors: Ju Wei Wei , Li Tong Wei , You Jing Han , Tang Zheng Xin , Gong Xiao Yang , Wang Hui , Zhen Zhi Qiang , Zhang Qing Guo
Published: March 2009

Performing ab-initio total-energy calculations to investigate the adsorption and diffusion
processes of the Au atoms with both the clean Si(001)-(1×1) and H-terminated Si(001)-(2×1) surfaces. It
was found that, on the clean Si(001)-(1×1) surface, the most stable adsorption sites for Au atoms are
middle part of four Si atoms, while on H-terminated Si(001)-(2×1) surface, the most stable sites are the
middle part of a Si-Si dimer. The result showed that surface hydrogenation make most stable site transfer
and affect the adsorption of Au on Si(001) surface.
Effect of Glass Phase on the Thermal Shock Resistance of ZrB2-SiC Ultra High Temperature Ceramic
Authors: Zhu Shi Zhen , Xu Qiang , Feng Chao , Zhao Jun Feng , Cao Jian Ling , Wang Fu Chi
Published: March 2009

Two kinds of ultra high temperature ceramics (UHTC), ZrB2-20Vol.%SiC and ZrB2-15Vol.%
SiC-5Vol.% SiCn (nano-size) were prepared by spark plasma sintering (SPS). The residual strength was
used to characterize thermal shock resistance of ZrB2-SiC ceramics by quenching tests in the water. The
mechanism of thermal shock damage of the ceramics was examined by SEM analysis. The results showed
that the formed glassy phase has significant effect on thermal shock resistance of ZrB2-SiC ceramics.
When the thermal shock temperature rises, the residual strength of ZrB2-SiC ceramics after thermal shock
will decrease gradually. The formed glassy phase when quenched from the temperature of 1400°C can
repair or heal the cracks and induce the higher residual strength. However, when the temperature
increases to 1600°C, the residual strength of ZrB2-SiC ceramics decreases significantly due to the
volatilization of the glassy phase. The residual strength of ZrB2-15Vol.% SiC-5Vol.% SiCn ceramic is
higher than that of ZrB2-20Vol.%SiC ceramic, because nano SiC is easy to be oxidized and to induce the
formation of more glassy phases and to improve the thermal shock resistance of the sample.
Microstructure and Mechanical Properties of ZrB2-Based UHTC via Reactive Hot Pressing
Authors: Qu Qiang , Han Wen Bo , Meng Song He , Zhang Xing Hong , Han Jie Cai
Published: March 2009

ZrB2-based ultra-high temperature ceramics (UHTCs) were prepared from a mixture powder of
Zr/B4C/Si with different ratio via reactive hot pressing. The experimental results showed that the sintering
temperature above 1800°C was necessary for enhancing the activity of the powders and thus improving
the densification of the product. The sinterability and densification properties of ZrB2-based UHTCs
meliorated with the amount of Si increasing. However, many large ZrB2 agglomerates formed when the
amount of synthesized SiC in the product reached 25vol%, which led to decrease the mechanical
property. The composite had highest mechanical properties when the volume ratio of ZrB2: SiC: ZrC was
73.86:20:6.14, and its flexual strength and the fracture toughness were 645.8MPa and 5.66MPa·m1/2
respectively. The microstructure investigation showed the in-situ formed SiC and ZrC were located in the
triple point of ZrB2 grains with a size less than 3μm.
Oxidation Kinetics of ZrB2-SiC Composites
Authors: Tian Ting Yan , Zhou Chang Ling , Sun Feng , Cheng Zhi Qiang , Wang Chong Hai , Zhang Yu Jun
Published: March 2009

An oxidation kinetics model of hot-pressed ZrB2-SiC composites was established and then
proved by experiments. The relationship between oxidation rate and temperature was attained by reaction
activation energy and frequency factor at the different oxidation stages. Results showed that the relations
between the oxidation gain of unit area and the oxidation time are linear, conic and parabolic, respectively,
during the stage of the oxidation prophase, midterm and anaphase.
Fracture Strength of Ultra-High Temperature Ceramics
Authors: Zeng Tao , Fang Dai Ning , Lu Xia Mei , Zhou Fei Fei
Published: March 2009

This paper presents a theoretical model to predict the fracture strength of ultra-high
temperature ceramics (UHTCs). According to different mechanisms, the environmental temperature is
divided into four ranges. Effects of temperature and oxidation on the fracture strength of UHTCs are
investigated in each temperature range. The results show that oxidation plays an important role in
enhancing the fracture strength of UHTCs at high temperatures.
Preparation of Nano-Laminated Composite by Electrophoretic Deposition
Authors: Lin Wei , Wang Chang An , Huang Yong
Published: March 2009

Electrophoretic deposition (EPD) has been widely studied in preparing clay-modified
electrodes (CMEs) and in assembly of nano-laminated composite that mimics nacre. In this paper, the
hydrothermal intercalation and EPD were combined to prepare CMEs with a uniform and continuous
polymer/clay composite film of brick-and-mortar nano-laminated structure. X-ray diffraction, scanning
electronic microscopy and thermal gravimetric analysis were employed to characterize the structure and
composition of the films. Stability of aqueous suspension, temperature for hydrothermal intercalation and
deposition time, etc. were systematically studied and discussed.
Preparation of Mg-W Graded Materials by Spark Plasma Sintering
Authors: Shen Qiang , Liu Ying Hu , Zhou Jing , Luo Guo Qiang , Zhang Lian Meng
Published: March 2009

A new kind of functionally graded materials (FGM) with density gradient has come to show
great potentials as flier-plates for creating quasi-isotropic compression waves. In order to meet the
demand of lower density in the front face and wider density range for such flier-plate, Mg with a density
of 1.74g/cm3 and W of 19.3g/cm3 are selected to make Mg-W system density graded materials. Mg-W
alloys with various mass fractions of Mg and W were sintered by spark plasma sintering (SPS) technique
at low temperatures, and the processing of densification is mainly investigated. It is found that, up to
92wt%W, the Mg-W alloys can be fully densified at 873K due to the conglutination of Mg particles. The
Mg-W alloys still exist as a mechanical mixture of Mg and W. Finally, the Mg-W density graded materials
with a density change from 1.74g/cm3 to 10.55g/cm3 have been successfully prepared.
Phase Development during Mixed–Oxide Processing of a [Na0.5K0.5NbO3]1-x -[LiTaO3]x Powder
Authors: Skidmore T.A. , Stevenson T. , Comyn T.P. , Milne S.J.
Published: March 2009

Powders of the solid solution series [Na0.5K0.5NbO3]1-x - [LiTaO3]x, with x = 0.06, are shown to
transform from an orthorhombic to a tetragonal crystal system as calcination temperature is increased in
the range 850 °C to 1100 °C. Addition of 3 wt% of each alkali carbonate prior to calcination allows
retention of the orthorhombic phase to 1100 oC. The latter changes in phase content are attributed to a
partial compensation of alkali oxide volatilisation losses. The approach of adding extra alkali carbonates
lead to an increase in d33 coefficient in sintered ceramics.
Influence of Sintering Temperature and Sintering Aid on Electrical Properties of (K, Na)NbO3-LT Ceramics
Authors: Dai Ye Jing , Zhang Xiao Wen
Published: March 2009

In this paper, 0.95K0.5Na0.5NbO3-0.05LiTaO3 ceramics were synthesized by conventional
mixed-oxide technique. To clarify the optimal sintering condition, three kinds of different temperature
conditions were used. It was found that the samples sintered near 1130 °C had the best piezoelectric
properties (d33~155 pC/N). In addition, sintering aid such as K5.4C1.3Ta10O29 was investigated to confirm
whether it really benefited to the sintering process and increased the piezoelectric property of ceramics.
Automatic Multimode Measurement for Microwave Ceramics
Authors: Xiao F. , Xiong Zhao Xian , Dong X.Y. , Yang G.S.
Published: March 2009

Automatic measurement system with multimode for microwave ceramic materials is
developed. Based on traditional parallel-plate resonance method, the whole system is composed of a
parallel-plate cavity, a vector network analyzer (VNA), an interface card for GPIB to USB, and a PC with
measurement programs. Besides the fundamental mode, higher order resonant modes are also measured
at the same time. Based on a platform of VEE, a set of analysis software is programmed with the functions
of not only automatically calibrating and searching resonant frequencies but also automatically
computing and displaying the dielectric parameters of microwave materials with high reliability and
efficiency in a wide frequency range.
Synthesis of Nanocrystalline Ce0.8Sm0.2O1.9 by Citrate Gel Method
Authors: Guan Xiang Feng , Wang Yan An , Zhou He Ping , Zhou Li Hua
Published: March 2009

A citrate gel method was applied to synthesize Ce0.8Sm0.2O1.9 powders by using cerium and
samarium nitrates as raw materials and citric acid as complexing agent. It was shown that Ce0.8Sm0.2O1.9
phase was formed when the decomposition of the dried gel completed at 500 °C. The crystallite size of the
synthesized powders calcined at 500 °C for 2 h is 5-10 nm. The powders can be easily sintered in air to
yield over 97 % relative density at 1250 °C, which is significantly lower than sintering temperature of
over 1500°C required by the doped ceria powders prepared via conventional ceramic techniques.
Preparation of SrFe0.6Cu0.3Ti0.1O3-δ Mixed Oxygen-Ionic and Electronic Conductor
Authors: Zhang Heng , Dong Xin Fa , Lin Wei Ming
Published: March 2009

SrFe0.6Cu0.3Ti0.1O3-δ (SFCTO) composite-oxide powder was synthesized by citric acid complex
method and studied as mixed oxygen-ionic and electronic conducting membrane material. The formation
process of the perovskite-type compound was detected by XRD, infra-red spectrum and thermo gravimetric
analysis; the effects of ethylene glycol added in the sol formation process on the size distribution of
the powder and the oxygen permeation flux of the membrane were examined. A stable sol was formed
when the molar ratio of total metal ions to citric acid and ethylene glycol was 1:2:3 and the pH value was
5.5; the characteristic absorption peaks of citric acid in the dried gel, O-H and -COO-, moved toward low
frequency direction for 200 cm-1 and 135 cm-1 respectively due to the complexing action of the metal ions
and citric acid. As the dried gel was heated in air up to 400°C, SrCO3 phase appeared by the combustion
of citric acid and ethylene glycol. The perovskite phase started to form at 700 °C, SrCO3 phase reduced
gradually and the single phase of SFCTO was obtained at 900 °C. The SFCTO dense membrane prepared
under the optimum conditions exhibited an oxygen permeation flux of 0.7 ml·min-1·cm-2 at 900°C.
Preparation and Structural Characterization of a Needlelike Carbon from the Refined Coal Tar Pitch
Authors: Zhao Xue Fei , Lai Shi Quan , Zhang Ya Ru , Liu Shu Lin , Gao Li Juan , Yu Hong Wu
Published: March 2009

A refined coal tar pitch with softening point of 33oC was obtained by a mixed solvent extraction method. The pitch was carbonized at 500oC to get micrometer carbon material with needlelike structure. The carbonized produce was further calcined at 1500oC for 30h. The resultant product was characterized by SEM, OM, EDS and XRD. Experimental results indicated that a mixed solvent extraction method could effectively get rid of primary quinoline insoluble (QI). SEM and OM examinations showed that there were more than 70% fibrous structures and a small amount mosaic structures. The size of the fibrous structure was greater than 150μm in length and less than 30μm in width. The result of EDS exhibited that the material mainly consisted of carbon. XRD analysis revealed that there was a sharp diffraction peaks at 26.5oC, which was corresponded to the (002) plane of graphite structure.
Influence of Mechanical Milling and Annealing Atmosphere on the Photoluminescence Properties of ZnS:Cu,Cl Phosphors
Authors: Wang Wen Deng , Huang Fu Qiang , Xia Yu Juan , Lin Xin Ping , Liu Min Ling , Shi Jian Lin
Published: March 2009

ZnS:Cu,Cl phosphors were synthesized by high temperature (1200 °C) solid state reaction,
mechanical milling (rotation speed = 0, 75, 150, 250 and 350 r / min) and the final annealing at 750 °C for
1 h in different atmospheres (hydrogen sulfide, sealed evacuated silica tubes and Ar). The as-prepared
phosphors were characterized by X-ray powder diffraction and photoluminescence spectra. It was found
that mechanical milling led to width increases of diffraction peaks. Both the mechanical milling and
atmosphere play important roles in the photoluminescence performance of the phosphors. Some
phosphors prepared by the three-step method possess higher photoluminescence performances than the
normal one-step method. Particularly, the luminescence intensity of the phosphor milled at the rotation
speed of 75 r / min and then treated in Ar atmosphere is about one time higher than that prepared by the
normal one-step process.
Gallium and Nitrogen Co-Doped ZnO Thin Films by Pulsed Laser Deposition
Authors: Liu G.X. , Shan F.K. , Shin Byoung Chul , Lee Won Jae
Published: March 2009

Pulsed laser deposition (PLD) technique is a very powerful method for fabricating various
oxide thin films due to its native merits. In this study, gallium and nitrogen co-doped ZnO thin films
(0.1 at.%) were deposited at different temperatures (100-600°C) on sapphire (001) substrates by using
PLD. X-ray diffractometer, atomic force microscope, spectrophotometer, and spectrometer were used
to characterize the structural, the morphological and the optical properties of the thin films. Hall
measurements were also carried out to identify the electrical properties of the thin films.
Luminescence Property of Eu2+ Doped Strontium Silicate Yellow Phosphor for White Light Emitting Diode
Authors: He Hong , Fu Ren Li , Song Xiu Feng , Wang De Liu
Published: March 2009

Eu2+ activated strontium silicate (Sr3SiO5:Eu2+) yellow phosphor was prepared by the conventional solid-state reaction technique in reduction atmosphere with starting materials SrCO3, SiO2 and Eu2O3. The phase, morphology and luminescence property of the samples were analyzed. The X-ray diffraction analysis showed the main phase in all samples is tetragonal Sr3SiO5. With Eu2+ ions doped into the host lattice, the Sr3SiO5:Eu2+ phosphors absorb light energy in the UV-visible spectrum region and show an intense broad emission band in the yellow colour range (around 570 nm) and a weak band in the blue region (around 470 nm). The excitation and the emission bands are originated from the 4f−5d transition of Eu2+ ions. When the concentration of Eu2+ ions increases, the emission peaks of phosphors shift to longer wavelengths. The effective emission in the yellow colour indicates that phosphor as potential candidates for white light-emitting-diodes.
Preparation and Luminescent Properties of Zn2SiO4:Mn2+
Authors: Cao Li Mei , Bu Wen Bo , Ren Chuan Ai , Xu Xiao , Li Qiang
Published: March 2009

Zn2SiO4:Mn2+ was synthesized via a dipping method. Stoichiometric high pure SiO2 was put
into the solution of zinc nitrate and manganese nitrate. The mixture was milled while being heated until
the water was vaporized completely. The as-received mixture was added into the ethanol, and dispersed
well, then the mixture was milled and heated to remove the ethanol thoroughly by evaporation. The
precursor were dried for several hours at 60°C, and annealed in a reducing atmosphere of active carbon at
1000°C for 4 h. As-prepared powders of Zn2SiO4:Mn2+ was tested by XRD and SEM. Its luminescent
properties were characterized by excitation and emission spectra. The results are compared with those of
Zn2SiO4:Mn2+ prepared by a general solid state reaction.
Preparation and Characterization of SrAl2O4: Eu,Dy Powders
Authors: Hu Jin , Wang Kai Jun , Zhu Xiao Quin , Liu Jian Liang
Published: March 2009

A new method for preparing long afterglow phosphor and properties had been studied in the paper. In the new process the activated Al-Sr alloy powder hydrolyzes in pure water. The hydrolysates contain the mixture of Sr(OH)2.8H2O and Al(OH)3 in main, included a little Al(OH)3, AlOOH, SrCO3, and 3SrO.Al2O3. 6H2O. After heat treatment at 700°C for 1 hour, the mixture of SrO and α-Al2O3, γ-Al2O3 were formed. As a precursor, the hydrolysates after heat treatment had been used to prepare long after phosphor Eu, Dy co-doped SrAl2O4. The crystal structure of hydrolysates and Eu, Dy co-doped SrAl2O4 was analyzed by XRD. The luminescent properties of long afterglow material were studied. The Results showed the emission spectra of Eu and Dy co-doped SrAl2O4 lied near 520nm, resulted from the character transition of 4f5d-4f of Eu2+ ion. The method can improve afterglow properties dramatically. The initial luminescent intensity of long afterglow material reached 18cd/m2, and the duration time lasted 46 h.
Preparation of Transparent Nd:Gd2O3-HfO2 Ceramic
Authors: Feng Tao , Shi Jian Lin , Xu Hai Fang , Jiang Dan Yu
Published: March 2009

Nd:Gd2O3-HfO2 powder has been prepared with a co-precipitation method. The size of
Nd:Gd2O3-HfO2 powder is near 50nm. Transparent Nd:Gd2O3-HfO2 ceramics were successfully fabricated
by sintering the powder compact at 1800°C under H2 atmosphere. The synthesis process and optical
properties were investigated in detail. By measuring the optical properties of transparent Nd:Gd2O3-HfO2
ceramics, we found that the absorption bond of Nd ions near 808nm is enlarged, and the FWHM of the
emission bond near 1060nm is near 25nm. It was believed that Nd:Gd2O3-HfO2 transparent ceramic is
potential laser material for the usage in solid-state heat-capacity laser(SSHCL) application.
Preparation of Transparent AlON Ceramics Using Single-Phase Powder Obtained from Carbothermal Reduction
Authors: Pang Wei , Wu Deng Xue , Wang Hai Ping , Qi Jian Qi , Zhou Ji Cheng , Wen Jin Song , He Jun Feng , Wen Ya , Liao Zhi Jun , Lu Tie Cheng
Published: March 2009

Single-phase AlON powder was prepared by carbothermal reduction in flowing nitrogen
atmosphere, using nano-sized alumina and carbon powder as raw materials. Transparent AlON ceramic
samples using the single-phase powder were prepared by sintering at the temperature of 1880°C for 10h,
20h and 40h in flowing nitrogen atmosphere, respectively. It showed that the transparency and the density
of the ceramic samples increased with increasing temperature holding-time. And the microstructures of
the obtained samples were observed.
Preparation of Transparent AlON Ceramics Using Powder Synthesized from Nano-Sized Al2O3 and AlN
Authors: Qi Jian Qi , Lu Tie Cheng , Zhou Ji Cheng , Pang Wei , Wen Jin Song , Wang Hai Ping , He Jun Feng , Wen Ya , Cheng Zi Meng , Liao Zhi Jun , Wu Deng Xue
Published: March 2009

The single-phase AlON powder used to prepare transparent ceramics was synthesized from
solid-state-reaction using nano-sized Al2O3 and AlN powders with high purity. An appropriate amount of
the powder was molded into pellets and isostatically pressed using polyvinyl alcohol as the binder. The
AlON ceramic samples were obtained by sintering the pellets at 1880°C for 10 h, 20 h and 40 h,
respectively. The transparency of the samples increased as the temperature holding time was prolonged.
The density, phase compositions and microstructures of the sintered samples were discussed in detail.
Effect of Ho2O3 Doping on Performance of ZnO Varistor
Authors: Lu Zhen Ya , Liu Yu Xiang , Chen Zhi Wu , Wu Jian Qing
Published: March 2009

The effect of Ho2O3 doping on the electrical properties and microstructure of ZnO base varistor
was investigated. It was found that Ho2O3 is an effective dopant for increasing the breakdown electric
filed. The Ho2O3 doping can also improve the nonlinear performance both in low and high current area.
But excessive doping of Ho2O3 will decrease the withstanding surge current. With 0.8mol% Ho2O3
doping, the varistor samples exhibit a breakdown voltage of about 400V/mm, a nonlinear coefficient of 80
and the withstanding surge current of 8/20μs, waveshape is higher than 5kA. Ho2O3 dopant can hinder
ZnO grain growth and make the crystal grains more uniform.
Synthesis and Thermoelectric Properties of Ba8Ga16+xSbxGe30-2x (x=0,1) Clathrate Single Crystals
Authors: Wang H.F. , Cai Ke Feng , Li H. , Wang L. , Li X.L.
Published: March 2009

Ba8Ga16Ge30 clathrate material has being intensely investigated as a candidate of promising
thermoelectric materials. In this work, Ba8Ga16+xSbxGe30-2x (x=0,1) single crystals have been synthesized
by the Ga flux method, using high purity elemental Ba, Sb, Ga, and Ge as starting materials. Powder
X-ray diffraction, Scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy
and Raman spectroscopy were used to characterize the single crystals. Seebeck coefficient of the crystals
was measured from 300 to 800 K. The result indicates that the crystals are p-type semiconductor, which is
different from the crystals synthesized by the Czochralski method. The Seebeck coefficient almost does
not change after doping Sb in the whole temperature measured and it is in the range of 200 to 300μV/K.
Dipole Cluster State and Dielectric Relaxation in Relaxor Ferroelectrics
Authors: Li Q.C. , Liu J.M.
Published: March 2009

The Ginzburg-Landau theory on ferroelectrics with random field induced by dipole defects is studied using Monte Carlo simulation in order to investigate the possible dipole clustering and freezing behaviors as well as the dielectric relaxation of relaxor ferroelectrics. The dipole clustering above the transition temperature and the cluster-freezing far below this temperature are identified. The intrinsic correspondence between dipole-clustering/freezing and the multi-peaked time-domain distribution of dielectric relaxation is established.
Hydrothermal Synthesis of Sodium-Potassium Niobate Nanopowders
Authors: Wang Shi Ping , Miao Hong Yan , Tan Guo Qiang
Published: March 2009

Sodium-potassium Niobate (K0.4Na0.6NbO3, KNN) nanopowders were prepared by hydrothermal synthesis at the temperature range of 140-180°C for 12-48h using Nb2O5, NaOH and KOH as source materials. By means of XRD and SEM techniques, the effects of composition and hydrothermal treatment process, such as the rate of [R]/[Nb], the concentration of the alkali, the hydrothermal treatment temperature and the hydrothermal treatment time, on the microstructures and the crystallinity of alkali metals niobate were investigated in details. Results show that K0.4Na0.6NbO3 powders could be achieved by hydrothermal synthesis at the temperature range of 140-180°C with the alkalinity concentration of 2-8M. With the increase of hydrothermal reaction temperature and time, the crystallinity of KNN particles was improved. The obtained K0.4Na0.6NbO3 polycrystalline particles have rhombic structure.
Dielectric Behavior of (1-X)BaTiO3-XCaCu2.94Mn0.06Ti4O12 Composite Ceramics
Authors: Yang Gang , Yue Zhen Xing , Li Xiang , Wang Tian , Li Long Tu
Published: March 2009

(1-X)BaTiO3-XCaCu2.94Mn0.06Ti4O12 (BTO-CCMTO) composite ceramics with X =0.1 and
0.2 were prepared through solid state reaction route. X-ray diffraction (XRD) analyses showed that a
co-existence structure of BTO and CCMTO phase can be realized when the sample was sintered at 950°C.
Furthermore, influences of CCMTO on the dielectric behaviors of the BTO-CCMTO composite ceramics
were investigated. The results showed that the dielectric permittivity of the BTO-CCMTO composite
ceramics increases with increasing amounts of CCMTO and the Curie peak of the pure BTO ceramics is
greatly suppressed due to the addition of CCMTO. The dielectric loss of the BTO-CCMTO composite
ceramics can be kept in the same magnitude order as that of the BTO ceramics.
Preparation and Performance of AlN-ZrO2 Multiphase Material
Authors: Wang Rong Lin , Wang Zhi Fa , Bu Jing Long , Zhang Li Fang
Published: March 2009

AlN-ZrO2 composites were prepared by solid state reaction in N2 atmosphere at 1500°C for 4h
with PSZ and Al powders as raw materials. Effects of Al content on performance of the composites and
the process of nitriding reaction were investigated. The results showed that surface layer reaction of
samples happened between 450°C and 765°C, and diffusion reaction happened between 765°C and
1500°C. With increasing of Al content, thermal expansion coefficient decreased, bending strength
increased, thermal shock resistance and oxidization resistance were improved. Finally, bending strength
of 73.61 MPa and thermal expansion coefficient of 6.06×10-6 /°C were realized for AlN-ZrO2 composites.
Preparation of Silicon Dioxide Fiber via Sol-Gel Process
Authors: Wang Xiao Hui , Liang Xiao Ping , Xin Shao Bo
Published: March 2009

Silicon dioxide gel fibers were prepared by hydrolysis reaction of tetraethyl orthosilicate
(TEOS). TEOS was used as basic materials, anhydrous ethanol (EtOH) as solvent and hydrochloric acid
(HCl) as the catalyst. The best proportion of the chosen materials (TEOS, EtOH, H2O and HCl) was
1:1:1.5:0.03(molar ratio).Gel fibers were investigated by thermogravimetry (TG). Silicon dioxide fibers
were obtained by treating the gel fibers at different temperatures. The calcined fibers were characterized
by scanning electron microscopy (SEM). The optimal sintering schedule was obtained. Silicon dioxide
fiber dried at 200°C for 1 hour then calcined at 800°C for 3 hours was the best.
Properties of Mechanical Activation Combustion Synthesied High α-Content Silicon Nitride Powders and Sintered Bulk Ceramics after Iteration Reactions
Authors: Ren Ke Gang , Chen Ke Xin , Zhou He Ping , Jin Hai Bo , Zhong Ji Dong , Ning Xiao Shan
Published: March 2009

Effect of iteration times on mechanically-activated combustion synthesis of high α-content
Si3N4 powders was investigated. Properties of the as-synthesized powders such as α-content (Cα) as well
as specific surface area (As) were examined. Results showed that both of Cα and As became higher after
iteration reactions. The mechanical properties of the sintered bulk ceramics from as-synthesized powders
were also tested to reveal the sinterability of the powders. Results showed that relative density of all the
sintered bulk ceramics were higher than 97%. Furthermore, fracture toughness had a trend of becoming
higher, which reached a value of 10.2 MPam0.5. Correspondingly, bending strenth became a bit lower.
Layer Structure Growth of Orthorhombic Boron Nitride Thin Films by RF-PEPLD
Authors: Li Wei Qing , Zhou Li Jun , Zhao Yong Nian
Published: March 2009

Orthorhombic boron nitride film is prepared on Si(100) substrate by radio frequency plasma
enhanced pulse (Nd:YAG) laser deposition (RF-PEPLD) in Ar-N2 gas system, assisted with substrate
pulse negative bias -150v, substrate temperature of 500°C and deposition time of 30 minutes. The phase
compositions of the film are characterized by Fourier transform infrared (FTIR) spectroscopy,
glancing-angle X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM).
The results show that high quality orthorhombic boron nitride film has been prepared. A layer structure
growth mechanism of orthorhombic boron nitride phase upon RF-PEPLD is discussed in this paper. A
thin layer h-BN [101] is deposited before depositing o-BN and h-BN mixed phase, then o-BN percentage
composition of the BN film becomes creasing.
Synthesis of SiCW/(Mo,W)Si2 Composite by the "Chemical Oven" Self-Propagating Combustion Method
Authors: Xu Jian Guang , Zhang Hou An , Jiang Guo Jian , Li Wen Lan
Published: March 2009

SiC whisker reinforced (Mo,W)Si2 composite powder has been successfully synthesized by a novel process, named as chemical oven self-propagating high temperature synthesis (COSHS). The mixtures of Si and Ti powders were ignited as chemical oven. XRD result shows that the combustion product is mainly composed of (Mo,W)Si2 solid solution and SiC phases. SEM photo and EDS result show that SiC whisker is formed during this process. The as-prepared SiCW/(Mo,W)Si2 composite powder has been pressureless sintered. The microstructure and mechanical properties of the composite were investigated. Relative densities of the monolithic material and composite are 91.2% and 92.2%, respectively. The composite containing SiC whisker and (Mo,W)Si2 solid solution has higher Vickers hardness than monolithic MoSi2. Especially the room-temperature flexural strength of the composite is higher than that of monolithic MoSi2, from 135.5MPa for MoSi2 to 235.6MPa for composites with 10 vol.% WSi2 and 15 vol.% SiC, increased by 73.9%. The morphology of fractured surface of composite reveals the mechanism to improve flexural strength of MoSi2. The results of this work show that in situ SiCW/(Mo,W)Si2 composite powder prepared by COSHS technique could be successfully sintered via pressureless sintering process and significant improvement of room temperature flexural strength could be achieved. It could be a cost-effective process for industry in future applications.
Preparation and Dielectric Properties of the Layered Perovskite Sr4Bi4Ti7O24 Ferroelectric Ceramics
Authors: Chu Rui Qing , Xu Zhi Jun , Li Guo Rong , Yin Qing Rui
Published: March 2009

Sr4Bi4Ti7O24 (SBT7) ceramics were prepared. X-ray powder diffraction indicated that single
layered perovskite ferroelectrics were obtained. The ferroelectric and dielectric properties of SBT7
ceramics were investigated. The results showed that Sr4Bi4Ti7O24 is piezoelectric material. The dielectric
properties were measured as a function of temperature and two peaks were observed in the curve.
The Remanufacturing Engineering and Automatic Surface Engineering Technology
Authors: Xu Bin Shi
Published: March 2009

Entering into the 21st century, remanufacturing engineering has been developed
rapidly in China, Especially from 2005, lots of remanufacturing laws and regulations have been
released. Remanufacturing engineering is the industrialization of high technology maintenance
to the waste productions, and the advanced period of the maintenance engineering and surface
engineering. The basic character of surface engineering is synthesis, intercross, compounding,
and optimization. Surface engineering takes the “surface” as core. Nano surface engineering is
the integration and creation between the nano materials and traditional surface engineering. To
adapt the demand of remanufacturing industrialization, five kinds of automatic and
intelligentized technologies, namely automatic nano electro-brush plating technology,
automatic high velocity arc spraying technology, semi-automatic micro plasma arc welding
technology, automatic laser cladding technology, and intelligentized self-repair technology,
have been independently innovated.
Study on the Structure and Electrochromism of WO3 and Ti-Doped WO3 Films
Authors: Wang Li Ge , Li Guo Qing , Hu Yuan Rong , Gou Wei , Shi Meng
Published: March 2009

WO3 and Ti-doped WO3 electrochromic films were prepared by mid-frequency dual-target
magnetron sputtering method. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS),
transmission electron microscope (TEM) and spectrophotometer were used to characterize the
structure, morphology, composition and transmittance properties of the films, respectively. The
results show that this method is available to deposit WO3 and Ti-doped WO3 electrochromic films.
The as-deposited films prepared at room temperature are amorphous and display good transmittance.
The difference value of transmittance between the bleached and coloration states of WO3 film is
above 60% at 633nm. Ti-doped WO3 films have smoother surface and smaller grains than undoped
ones. Moreover, the crystalline temperature increases after doping titanium, because the titanium
atoms influence the lattice distortion of the WO3 films. So it is more convenient for Li+ ions to inject
into films and can enhance the response speed and stability of Ti-doped WO3 electrochromic films.
Micro-Forming Process and Microstructure of Deposit by Using Micro EDM Deposition in Air
Authors: Peng Zi Long , Wang Zhen Long , Jin Bai Dong
Published: March 2009

Based on analysis of the mechanism of Electrical Discharge Machining (EDM) and the
characteristics of deposition processing, the processing conditions of micro EDM Deposition (micro
EDD) are determined. Micro EDD is a new EDM method taking air as machining medium, using
narrow pulse width, long pulse interval, low discharge current and connecting the tool electrode with
the anode of pulse generator. Using EDM shaping machine and brass, tungsten and steel as tool
electrode respectively, micro cylinders are deposited on high-speed steel surface. And then the
microstructure of deposit is analyzed detailedly. Results show that elements of the deposited material
distribute uniformly, whose components depend on the tool electrode material. As the high cooling
rate of the solidification process, the deposit grain size refines obviously, which leads to the hardness
of tungsten or steel deposit increasing. Moreover, the Metallurgical bonding has occurred on the
interface between deposit and high-speed steel base, whose thickness is about 5μm.
Initiation and Propagation Laws of Glass Cracks in Specimens under the Action of Cylindric Indenter Subjected to Normal Load
Authors: Wan Zhen Ping , Deng Wen Jun , Tang Yong
Published: March 2009

With more and more applications of glass in advanced fields of science, the demand for glass machining precision and efficiency has increased greatly. More and more attention is being paid to glass cutting by ordinary tool because precise glass parts with various shapes can be obtained at high efficiency and low cost. But, in this method, rounded cutting edge radius of tool has important influence on precision and integrity of surface. This paper presents the laws of glass crack initiation and propagation when a cylindric indenter is used for glass indention. Research results show that two cracks that are symmetrical to the normal plane of the indentation surface occur suddenly when the load increases to a critical value. Closing occurs in the two cracks during unloading. The interior angle between the two cracks and critical load increase with rounded edge radius of cylindric indenter linearly.
The Effect of Superheated Water Vapor as Coolant and Lubricant on Chip Formation of Difficult-to-Cut Materials in Green Cutting
Authors: Han Rong Di , Zhang Yue , Wang Yang , Cao Guo Fan , Liu Jie
Published: March 2009

Green cutting is ecologically desirable and have been a tendency in the industry field. Water vapor can be introduced in metal cutting as coolant and lubricant due to its pollution-free, generating easily and unneeded disposal. Therefore, water vapor is an environment-friendly coolant and lubricant in machining. This study attempts to understand the effect of water vapor as coolant and lubricant on chip formation. In the comparison experiments to dry and wet cutting, water vapor jet flow from a developed generator is applied into cutting zone directly. When YG8 (K20 in ISO) tools are used to turn titanium alloy TC4 (Ti-6Al-4V), Ni-based super alloy GH3030 and stainless steel 1Cr18Ni9Ti in orthogonal cutting, through quick-stop tests, the photos of polished chip sections microstructure were obtained. And the results suggest that the application of water vapor produces the least BUE, tool-chip contact length but the largest deformation coefficient and shear angle. The water vapor as coolant and lubricant could be a substitution of cutting fluid to carry out green cutting in the machining of difficult-to-cut materials.
Experimental Research on Orthogonal Cutting and Oblique Cutting of Hardened Steel GCr15
Authors: Wang Yu , Wang Peng , Pen Hong Min , Li Yu Fu , Liu Xian Li
Published: March 2009

Experiment of hard cutting GCr15 with PCBN cutting tools, the influence of tool’s
inclination angle and cutting parameters (cutting speed and feed speed) on cutting forces and cutting
temperature are studied. A three-dimensional finite elements model using the commercial software
Deform 3D 5.03 is developed. The friction between the tool and the chip is assumed to follow a
modified Coulomb friction law and the adaptive remeshing technique is using for the formation of
chip. The workpiece material property is a function of temperature, strain, and strain rate in the
primary and secondary shear zones. Finite element method is used to simulate three-dimensional
precision cutting, including orthogonal cutting and oblique cutting. The cutting forces and back
forces are slightly changed by tool’s inclination angle. However, in high cutting speed, the cutting
force decrease as the tool’s inclination angle increase, while the cutting temperature increase as the
tool’s inclination angle increase. The simulation results are compared with experimentally measured
data and found to be in good agreement to some extent.
Experimental Investigation on Air Cooling of GCr15
Authors: Hu Jing Shu , Liu Dong Xia , Liu Yi Zhi , Yue Cai Xu , Liu Xian Li
Published: March 2009

Air cooling is a near dry machining method, which cools cutting area and evacuates chips
using low temperature cold wind instead of cutting liquid. It can decrease tool wear, increase tool
life, reduce machining cost and bring no chemical pollution. In this paper, air cooling test was
carried on, in which vortex tube was used for cooling and high hardness bear steel GCr15 was
machined by PCBN tool. Experiment results indicated that cold air from vortex tube has a
significant effect on cutting force, cutting temperature and chip formation process. This paper’s
conclusions will have a great reference value for the practical application of air cooling technology.
Study on Chip Breaking Behavior of 3-D Complex Groove Insert in Machining Carbon Constructional Steel at High Cutting Speeds
Authors: Zhang Hui Ping , Li Zhen Jia , Liu Er Liang , Wei Guo Liang
Published: March 2009

This paper deals with chip breaking behaviour of 3-D complex groove inserts in machining carbon constructional steel-45 steel at high cutting speeds .Cutting experiments were performed at eleven different cutting speeds. Firstly, the results showed that by increasing cutting speeds, the changes of the critical feedrate and chip breaking scopes at high cutting speeds machining with 3-D complex groove inserts were nonlinear and not monotonous function relations. Then, mathematic models were built. Secondly, the results showed that the critical depth of cut was a constant value at various cutting speeds. And, the curves of the critical depth of cut were perpendicular lines. For this purpose, the critical depth of cut mathematic model has been built. The study above lays a theory and basis for future investigation of the mechanism of chip breaking with 3-D groove insert in high speed machining.