bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Shock Behavior of Nano-Structured Functionally Graded Thermal Barrier Coatings Deposited by Supersonic Plasma Spray
Authors: Han Zhi Hai , Wang Hai Jun , Zhou Shi Kui , Xu Bin Shi
Published: March 2009

The nano-structured functionally graded 8YSZ/NiCoCrAlY thermal barrier coatings
(FG-TBCs) were prepared using a recently developed Supersonic Plasma Spraying (S-PS) system with
dual powder feed ports. The alloy powders were fed into the lower temperature regions of the plasma
plume through one of them to prevent it over molten and oxidation. The ceramic powders were fed into
high temperature regions through another for fully melted. The thermal shock behavior of the FG-TBCs
were investigated. It was found the totally 1mm thick FG-TBCs layer still maintained nano-structure form
by TEM, and also exhibited a finely lamellate microstructure mixed by alloy and ceramic with gradient
along the thickness direction by SEM. The FG-TBCs exhibit excellent thermal shock resistance due to it
was still perfect without any spallation after thermal shock test over 200 cycles under heating by oxygenacetylene
flam to 1250°C in 30s and then quenching into ambient water.
Surface Aluminizing and Internal Oxidation of Cu-Al-Y Alloy
Authors: Chen Xiao Hong , Li Yan , Tian Bao Hong , Zhang Yi , Su Juan Hua , Liu Ping
Published: March 2009

A method of the aluminizing treatment on the surface of Cu-Al-Y alloy with addition of rare
earth compound CeCl3 in 1173K was carried out. The followed internal oxidation of the aluminized
Cu-Al-Y alloy was also carried out in the commercial nitrogen gas medium to generate Al2O3 dispersed
hardening copper matrix composites. The hardness distribution in aluminized layer and microstructure
were studied. Results show that the addition of rare earth oxide CeCl3 has great accelerating effect on the
aluminizing, the aluminized layer deeper and uniform than that not add CeCl3 at the same condition. It is
possible to generate Al2O3 particles dispersed hardening layer depth reached about 200μm in the surface
of specimens with aluminizing and internal oxidation technique.
The Effect of Zn2+ Deficiency on Ordered Micro-Regions and Dielectric Properties of Pb(Zn1/3Nb2/3)O3-Based Relaxor Ceramics
Authors: Qu Shao Bo , Wang Bin Ke , Liu Zhi Yi , Pei Zhi Bin , Xu Zhuo
Published: March 2009

0.85Pb(Zn1/3Nb2/3)O3-0.10BaTiO3-0.05PbTiO3 (abbreviated as PZN-based ceramics
hereafter) ternary system ceramics with Zn2+ deficiency were synthesized by the columbite method.
The effect of deficient Zn2+ on phase structure, ordered micro-region size and dielectric properties
was investigated in detail. The analysis of Raman scattering spectra demonstrated that Zn2+ deficiency
sharply enlarged the ordered micro-region size. Zn2+ deficiency significantly increased the dielectric
constant, and decreased the diffusion degree of phase transition. There is a close correlation between
effective ordered micro-regions size and dielectric properties for the PZN-based ceramics.
Properties of Silicon Nitride Using Cordierite as Sintering Additives
Authors: Jiang Miao , Hou Feng , Xu Ting Xian
Published: March 2009

Silicon nitride materials with low dielectric properties were prepared using nano and micron
silicon nitride powders as raw materials and the green bodies were sintered with cordierite as sintering
additive in flowing nitrogen. The additives of cordierite powders prepared by sol-gel method and solidstate
reaction method could greatly decrease the sintering temperature. The dielectric constant of
materials decreased as sintering temperature fell, whereas the strength showed relatively low as the low
sintering temperature. XRD analysis showed the main phase of material was Si2N2O, which indicated that
the Si3N4 could be integrated with SiO2. Porous structures were observed by SEM, showing compact
sintering cannot be achieved at these temperatures, explaining the low strength.
Bipolar Electric Fatigue in Ferroelectric Nb-Doped PZST Ceramics
Authors: Zhou Long Jie , Rixecker Georg , Aldinger Fritz
Published: March 2009

Bipolar electric fatigue in ferroelectric niobium-doped lead zirconate titanate stannate
ceramics was investigated. Variations in the polarization and strain hysteresis loops as well as
microstructural modifications of the material due to the electric cycling were analyzed. Compared
with ferroelectric PZT ceramics cycled under similar conditions, the material exhibited a higher
resistance to electric fatigue. Properties of the specimens showed significant decays above 106.5 cycles.
Asymmetric suppression of strain hysteresis loop was monitored. At 108 cycles, the remanent
polarization, the right maximum strain and the left maximum strain decreased to 70%, 58% and 44%
of their initial values, respectively. The color of the material was changed from pale yellow to dark
grey with cycling. The properties and color of the fatigued samples were recovered almost fully to
those of the virgin state after a heat treatment at 500oC for 1 h. The pinning of domain walls, probably
by oxygen vacancies, was concluded to be the predominant fatigue mechanism for the material.
Dielectric and Magnetic Properties of BaTiO3/NiFe2O4 Composites
Authors: Shen Jian Hong , Zhou Ji , Cui Xue Min , Wang Yue Hui
Published: March 2009

A series of ferrroelectric-ferromagnetic composites were synthesized from BaTiO3 and
NiFe2O4 ferrite by conventional solid-state route. XRD studies indicated that the composites comprised of
only two phases, BaTiO3 phase with perovskite structure and NiFe2O4 phase with spinel structure. Frequency
dependence of permittivity and permeability were also measured. Experimental results showed
that the dielectric constant and initial permeability of these composites could be tunable by varying the
composition of composites. Thus, these composites can be used for multilayer chips EMI filters.
Preparation and SEM of Ni/Ce-YSZ Anode Materials
Authors: Ma Jing Tao , Lin Xu Ping , Zhang Bao Qing
Published: March 2009

Gelcasting and dry pressing are used to produce anode composites for SOFC. In this paper
a composite material Ni/Ce-YSZ containing Ni and Ce-doped Y2O3-stabilized ZrO2 (Ce-YSZ) based
on Ce-YSZ electrolyte was fabricated via sintering infiltration of NiO at the temperature of 1400°C,
followed Ni/Ce-YSZ materials are successfully produced by reduction- sintering process. Hydrogen
reduction of NiO in the NiO/Ce-YSZ anode material was accomplished successfully through pore
channels of debinded carbon volume. XRD results suggest that a solid solution of Ce-YSZ was
produced. The microstructure of NiO/Ce-YSZ, and Ni/Ce-YSZ material was observed by SEM. This
study confirms that sintering infiltration of NiO is a viable process for fabricating anode materials
based on zirconia electrolyte and there are a good interface between electrolyte and anode.
Preparation and Electrical Properties of Interconnect Material Made by Substituting Mixed Rare Earth Oxides (Sm2O3, Gd2O3, Eu2O3 and CeO2) for La2O3 in La
Authors: Zhong Hong Hai , Cheng Ji Gui , Liu Xing Qin , Meng Guang Yao
Published: March 2009

La1-xCaxCrO3 (0.1≤ x ≤ 0.4) is usually used as interconnect material for solid oxide fuel cells
(SOFCs). In this paper, composite material, the two-phase mixtures of face-centered cubic fluorite
structure CayCe1-yO2-y (0 ≤ y≤ 0.2) and orthorhombic perovskite structure [Sm(Eu,Gd)]1-zCazCrO3 (0 < z <
0.3), was prepared by an auto-ignition process in which mixed rare earth oxides (Sm2O3, Gd2O3, Eu2O3
and CeO2) are substituted for La2O3 in La1-xCaxCrO3. The direct current (DC) four-probe technique
measurement indicated that the electrical conductivities of specimens increased along with the increase of
Ca2+ content (x), especially when x=0.3 and 0.4. The material (x=0.4, about 94% relative density) showed
excellent electrical conductivities of 48 Scm-1 in air and 13 Scm-1 in H2 (purity 99.999%) at 700°C
respectively, which is about 3 times as high as that of La0.7Ca0.3CrO3.
Electrochemical Performance of Al2O3-Coated LiNi1/3Co1/3Mn1/3O2 Cathode Materials for Li-Ion Batteries
Authors: Li Jian Gang , He Xiang Ming , Zhao Ru Song , Wan Chun Rong , Zhang Shi Chao
Published: March 2009

Al2O3-coated LiNi1/3Co1/3Mn1/3O2 powders with excellent electrochemical performance have
been synthesized. The electrochemical performance of Al2O3-coated LiNi1/3Co1/3Mn1/3O2 electrodes has
been studied as function of the level of Al2O3 coating. Coated LiNi1/3Co1/3Mn1/3O2 samples shows higher
discharge capacity and better capacity retention than the base one. Among the coated samples, 1.0mol%
coated sample exhibits the best electrical performance. It presents an initial discharge capacity of 174.5
mAh g-1 over 2.5~4.4V, and 84.7% capacity retention after 30 cycles over 2.5~4.6V.
Synthesis and Electrochemical Properties of a LiNi0.7Co0.3O1.9Cl0.1 Cathode Material for Lithium-Ion Battery
Authors: Li Xin Lu , Kang Fei Yu , Zheng Yong Ping , Shi Xiu Juan , Shen Wan Ci
Published: March 2009

Partial oxygen in LiNi0.7Co0.3O2 was replaced by chlorine to form LiNi0.7Co0.3O1.9Cl0.1.
Phase structure of LiNi0.7Co0.3O1.9Cl0.1 was identified as a pure hexagonal lattice of α-NaFeO2 type by
X-ray diffraction. Discharge capacity of LiNi0.7Co0.3O1.9Cl0.1 was 202 mAh/g in initial cycle at 15
mA/g current density in 2.5- 4.3 V potential window. The constant current charge/discharge
experiments and cyclic voltammograms showed that chlorine addition was effective to improve
reversible capacity and cycle stability of LiNi0.7Co0.3O2.
Preparation and Electrochemical Characterization of Mn/Pb Composite Oxides for Supercapacitors
Authors: Zhang Zhian , Lai Yan Qing , Li Jie , Liu Ye Xiang
Published: March 2009

Mn/Pb composite oxides were prepared by solid-state reaction by KMnO4 with manganese
acetate and lead acetate at low temperature. The products were characterized by XRD and TEM. The
results show that the composite oxides are nano-size and amorphous structure. Electrochemical
characterizations were performed by cyclic voltammetry (CV) and constant current charge-discharge in a
three-electrode system. The potential windows of Mn/Pb composite oxides electrode are increased. With
increasing the ratio of Pb, the specific capacitance goes through a maximum at 20% mol Pb. The specific
capacitance of pure MnO2 is 158 F/g and is improved to 180 F/g for the Mn0.8Pb0.2Ox composite oxide by
constant current discharge.
Synthesis and Second-Order Optical Nonlinearity of Inorganic-Organic Hybrid Films Bearing Y-Type NLO Active Chromophore
Authors: Mei Xiao Nan , Lin Hai Yao , Cui Yuan Jing , Lv Ping , Qian Guo Dong
Published: March 2009

In order to achieve a large hyperpolarizability (β) value and thermal stability, a novel Y-type
silicon precursor ICTES-DBPNPI was synthesized. By the sol-gel process, the new organic-inorganic
materials having organic chromophore were prepared.
Influence of Coumarin Dyes on the Laser Performance of Pyrromethene and Perylene Dyes Co-Doped into ORMOSILs
Authors: Rong Hua , Ye Chun Fang , Yang Yu , Qian Guo Dong , Wang Zhi Yu , Wang Min Quan
Published: March 2009

Laser dyes perylene red (p-red) or pyrromethene 567 (p567) were co-doped with coumarin 440 (C440) or coumarin 500 (C500) into MTES- and VTES-derived organically modified silicates (ORMOSILs) by sol-gel process. The effects of coumarin dye concentration on the laser performances of p-red and p567 were investigated. The results from laser efficiency measurements illustrated that at optimized coumarin concentration, the slope efficiency of co-doped p-red increased by a factor of 2 while that of co-doped p567 increased marginally. It was also found that by co-doping coumarin, the laser wavelength of p-red blue shifted and the laser thresholds for p567 and p-red could be reduced. The energy transfer mechanisms involved were also discussed.
Zinc Oxide Thin Films with Reduced Native Compensative Defects Grown by Ultrasonic Spray Pyrolysis at Atmosphere
Authors: Zhao Jian Ling , Li Xiao Min , Bian Ji Ming , Yu Wei Dong , Zhang C.Y.
Published: March 2009

ZnO films were deposited on Si (100) substrate by ultrasonic spray pyrolysis at atmosphere. The film grown at optimum conditions is well crystallized with uniform, smooth and dense microstructure. Photoluminescence measurement shows a strong near band edge UV emission at 379nm and an almost undetectable deep-level emission band centered at 502nm. The resistivity of ZnO film is reduced by an order after N-In codoping, which produces p-type conduction with high hole concentration and hall mobility.
Preparation and Properties of Ti, Eu Co-Doped Y2O2S:0.06Ti,0.08Eu Phosphor with Red Long Afterglow
Authors: Huang Qui Ping , Hong Zhang Lian , Zhang Peng Yue , Fan Xian Ping
Published: March 2009

Ti,Eu co-doped Y2O2S:0.06Ti,0.08Eu phosphor with red long afterglow emission from Eu ions
was synthesized via traditional sintering method. Results showed that sintering temperature has great
influence on the crystal structure, luminescence and afterglow property of the phosphors. The best luminescence
and afterglow properties were obtained for the phosphors sintered at 1200°C for 2.5h. Furthermore,
only emissions originated from charge transition of Eu3+ was found in the luminescence spectra
whereas the afterglow spectra were composed of two sets of emissions: a broad yellow emission band
around 565nm and a group of narrow peaks in the wavelength range above 530 nm. The origin of
afterglow spectra was discussed: the former is likely related to emission from Ti related traps and the
latter is supposed to come from the Eu3+ through an energy transfer process from Ti emission to Eu3+.
Study on the Synthesis of Long Afterglow Nano-Phosphors SrAl2O4:Eu,Dy by Microemulsion Method
Authors: Wang Bing , Zhou Chuan Cang , Lu Zhong Yuan
Published: March 2009

To gain nanometer SrAl2O4:Eu,Dy phosphors, uniform fine precursors of Eu and Dy ion
doping strontium aluminate were prepared by microemulsion technology. Using as-synthesized stuff,
long afterglow phosphors SrAl2O4:Eu,Dy were obtained after sintered at 1200°C. TEM characterization
showed the morphology of their grains is sphere-shaped with size less then 100nm. XRD analysis
illuminated the crystal structure of SrAl2O4:Eu2+, Dy3+ phosphors is monoclinic. Fluorometry
examination detected the peak in emitting spectrum is at 510nm, and at 310nm in exciting spectrum,
which both have little blue shift contrasting to the same kind of phosphors synthesized by solid-state
reaction method. Finally, the major parameters influencing the grain size of prepared phosphor powders
were made a discussion.
Luminescence Properties of M2MgSi2O7: Re (M = Ba, Sr, Ca) (Re = Eu2+, Ce3+, Tb3+)
Authors: He Da Wei , Shi Yan Ning , Hou Tao , Zhou Dan
Published: March 2009

A series of phosphors of M2MgSi2O7: Eu2+ (M=Ba,Sr,Ca) have been synthesized and studied.
The excitation spectra measurement showed that the phosphors had absorption in long UV light, the
excitation spectra of the phosphors consisted of two broad bands: one in the range from 280nm to 330 nm
and the other from 360nm to 420 nm. The main excitation band centered at around 395nm was belong to
4f→5d transitions of Eu2+. Analysis of the spectra of Ce3+ and Tb3+ co-doped phosphor showed that
energy transfer from Ce3+ to Tb3+ in Ba2MgSi2O7 under UV excitation was efficient.
Luminescent Properties of Sr2B5O9Cl Phosphor Doped with Eu
Authors: Su Na , Tang Zi Long , Zhang Zhong Tai
Published: March 2009

Sr2B5O9Cl:Eu phosphor with high efficient luminescent material was synthesized by solid-state
reaction method in air. The result of X-ray diffraction showed that the pure Sr2B5O9Cl phase forms at
900°C. The emission spectrum of Sr2B5O9Cl:Eu under 254nm excitation contained two parts. One part
was constituted by a strong peak located at 417nm due to the d→f transition of Eu2+ ion, and the other part
contained five weak peaks between 580-660nm due to the 5D0→7FJ(J=1,2,3) of Eu3+ ion. The infrared
spectrum revealed that both BO3 unites and BO4 unites coexisted in the resultant product. The Eu2+ was
surrounded and protected from being oxidized by the BO4 unites. Both red and blue visible lights were
observed under ultraviolet excitation as a result of the coexistence of Eu2+ ion and Eu3+ ion.
Strong Near-Infrared Luminescence from NiSi2-Passivated Silicon Nanocrystals Embedded in SiOx Films
Authors: He Ying , Ma K. , Bi L. , Feng Jia You , Wu Q.L.
Published: March 2009

In this paper, we have investigated the near-infrared luminescence emitting from NiSi2
passivated silicon nanocrystals (NCs) embedded in SiOx films. For comparison, we also prepared the
regular specimen without NiSi2 passivation. In the both systems, the intensity of photoluminescence
emission from NC-Si increased with the increase of annealing temperature, which was explained by the
crystallization of amorphous silicon in SiOx films. The maximum intensity of near-infrared emission from
NiSi2-passivated NC-Si was stronger by factor 5 than that of regular specimen without NiSi2 passivation.
The model of NiSi2 passivation was employed to explain this phenomenon.
Morphologies and Microstructures of Antimony-Doped Tin Oxide Films Derived by Sol-Gel Dip-Coating Processing
Authors: Zhang Dao Li , Deng Zhi Bing , Chen Liang Yan , Zhang Jian Bing
Published: March 2009

A simple laboratory technique for the routine preparation of antimony-doped tin oxide (ATO)
on float glass substrates (25×76×1mm3) was described. The process employed sol-gel dip-coating
approach in the absolute ethanol solution of metal salts of tin (II) chloride dehydrate and antimony
trichloride. Microstructural and morphological analyses of as-prepared films were performed at different
conditions. With increase of annealing temperature from 400 to 550°C, the evolution of grain size and the
morphologies of ATO films were analyzed by means of atom force microscopy (AFM). The studies on the
morphological development suggested that higher annealing temperature led to a decrease in the surface
roughness of the deposited films. The XRD patterns revealed that as-prepared ATO films were in the
crystallization of a tetragonal rutile structure of SnO2 with highly (110) preferred orientation.
Fabrication of BN-AlN-TiB2 Compound Conductive Ceramics by Self-Propagating High Temperature Synthesis and Hot Isostatic Pressing
Authors: Zhou Li Juan , Zheng Yong Ting , Du Shan Yi
Published: March 2009

BN-AlN-TiB2 compound conductive ceramics from powder mixtures of BN, Al, and TiB2 was
fabricated by self-propagating high temperature synthesis (SHS) and hot isostatic pressing (HIP). The
powder mixtures were shaped by isostatic cool pressing at 5-10MPa and the combustion reaction was
carried at 100-200 MPa N2 by an ignitor. XRD experiments confirmed that the reaction was complete and
only AlN, BN and TiB2 were detected. Optical microscopy as well as SEM with an electron probe
microanalysis was used for microstructural analysis and revealed a relatively uniform distribution of
particulates. The temperature-dependence and composition-dependence of the electrical resistivity of
BN-AlN-TiB2 ceramics were studied. The results showed that the optimum composition was 5-10wt%
BN, 30-55wt% Al and 60-40wt% TiB2, and the products had the density of 90% of the theoretical,
resistivity of 80-1000 μ⋅cm and bending strength of 100-200 MPa.
Preparation and High Temperature Thermoelectric Properties of [Ca2(Co0.65Cu0.35)2O4]0.624CoO2 Compound
Authors: Li Xiao Ya , Yu Yun , Wang Dong Li , Chen Li Dong
Published: March 2009

[Ca2(Co0.65Cu0.35)2O4]0.624CoO2 polycrystalline samples were prepared using sol-gel method
followed by spark plasma sintering. Thermoelectric properties of the samples were examined from room
temperature to 1000K. The temperature dependence of electrical conductivity shows that the hole
hopping conduction mechanism is dominant for the samples. The activation energy of hopping
conduction is 0.11 eV. At the temperature of about 1000K, the electrical resistivity is 7.1m cm, the
thermopower is 160 μVK-1, the thermal conductivtity is 2.94Wm-1K-1 and dimensionless figure of merit
reaches 0.12. These results indicate [Ca2(Co0.65Cu0.35)2O4]0.624CoO2 is a potential material for high
temperature thermoelectric energy conversion.
Static and Dynamic Characteristics of Thermoelectric Ceramics
Authors: Kajitani Tsuyoshi , Miyazaki Yuzuru , Ono Yasuhuri , Begum Shahnaz , Yubuta Kunio
Published: March 2009

Structural characteristics of the high performance cobaltite thermoelectric semiconductors
have been studied intensively by means of X-ray and neutron diffraction measurements and high
resolution electron microscopy (HREM). These cobaltites consists of CoO2 triangular conducting sheets
and several different types of block layers, i.e., Na, Ca, Sr single layers, three or four layered rock-salt
layers, where Co-O2 square lattices are situated at their middle, and Bi-O or Tl-O double layers plus
alkaline oxygen layers. Cold neutron scattering technique is employed to search possible low-energy
excitation modes, being unique for nearly 1D and 2D crystals, and phonon density of states, DOS, of
several high performance cobaltites at temperatures in the range from 10K to the ambient. Low energy,
i.e., less than 2meV, excitation modes were found in the three different thermoelectric ceramics, i.e.,
γ -Na0.7CoO2, [Ca2CoO3]pCoO2, and [Ca2(Cu,Co)2O4]pCoO2. Possible origin of these low energy
excitations are discussed in terms of low-energy corrugation mode generated due to weak chemical
bondings, for which Van-der-Waals force dominates, between the CoO2 conduction sheets. These
characteristics could be the key to realize low thermal conductivity and high-ZT of these ceramics.
Synthesis and Thermal Properties of Nanoscale Skutterudite via Cross-Coprecipitation
Authors: Chu Ying , Tang Xin Feng , Wan Ling , Zhang Qing Jie
Published: March 2009

CoSb3 with nanoscale was synthesized by Cross-coprecipitation. A precursor consisting of antimony oxide and cobalt hydrate was prepared by the reaction of CoCl2, SbCl3 and both precipitators at room temperature. The precursor was reduced in thermal treatment under hydrogen atmosphere whereby the CoSb3 was thus obtained. The parameters especially reducing temperature and atmosphere (content of H2) influence the constituent phases and particle size of product significantly. The single phase CoSb3 with the average grain size of 60~70 nm was obtained after reduced at 723 K for 2 h with pure H2. Nanoscale CoSb3 powder was used as starting materials, and bulk CoSb3 compound was prepared by spark plasma sintering (SPS). The effect of grains size on thermal conductivity was investigated.
Novel High-Intensity Thermoelectric Generator and its Application on Hybrid Electric Vehicle
Authors: Zhang Zheng , Wu Jiang Hong , Si Guang Shu
Published: March 2009

The hybrid electric vehicle (HEV) equipped both engine and generator is a transitional type from the internal-combustion engine vehicle to electric vehicle, but is a self-existent type, too. Applying a thermoelectric generator to recovery the waste heat of its engine, could not only improve the energy saving, but also the discharge / charge performance of the vehicle. For this purpose, the applicable generator must be a high-power and high-density one, which exchanges energy between the waste heat flow field and the conversion electric field; moreover, the temperature field is the coupling field with them. One of the methods to increase power-density of the generator is to strengthen the conversion intensity among above fields. In this paper, firstly a novel internal-axial-netted thermoelectric generator is presented, which includes following basic ideas: (1) using the stereo-electrodes to improve the integration of thermo-elements; (2) let the thermocouples to do heat convection directly with heat gas flow in pipe, to increase the heat flow density and electric current density, reduce the thermal resistance on solid conducting; (3) using the compensating wire to connect thermoelectric circuit and elongate the distance between hot source and cold source, so a higher temperature difference and a stronger cooling effect can be made. The analyses show though this generator used existing thermoelectric materials, its out-power can be increased and volume can be compacted. After this, secondly, the application scheme and key technologies of the novel high-intensity thermoelectric generator (HTG) as a main electrical source to supply electric power in HEV are chiefly discussed also.
On the Progress of Combustion Synthesis of Si3N4 Ceramic: From Laboratory Research to Industrial Production
Authors: Li Jiang Tao , Yang Yun , Jin Hai Bo
Published: March 2009

The progress on the combustion synthesis of Si3N4 powders during the past decades was summarized with the emphasis on the recently developed mechano-chemically activated combustion synthesis (MACS) method. The effects of processing parameters such as the addition of diluent and ammonium salts into the green mixtures, the variation of nitrogen pressure as well as the mechanical activation treatment on the degree of Si to α-Si3N4 conversion was evaluated. The combination of mechanical activation and chemical stimulation was effective in enhancing the reactivity of Si powder reactants, which was responsible for the extension of the minimum nitrogen pressure normally required for the combustion synthesis of Si3N4. This breakthrough indicates that nitriding combustion of silicon in pressurized nitrogen could be promoted by activating the solid reactants instead of by increasing the pre-exerted nitrogen pressure. The MACS process was successfully applied to the industrial production of Si3N4 powders, the regularities for the large-scale synthesis were reported, and the as-synthesized Si3N4 powder products were systematically characterized.
Preparation of Submicron Silica Powders from Sodium Silicate Using Ultrasonic Energy
Authors: Lee Sang Geun , Jang Yoon Sik , Park Seong Soo , Moon Byung Young , Kang Beom Soo , Park Hee Chan
Published: March 2009

Submicron silica powders were prepared by w/o emulsion method using inexpensive sodium silicate, ammonium sulfate and Triton N-57 as SiO2 source, precipitant and emulsifier, respectively. Nano-sized silica powders with narrow size distribution were prepared at a low temperature of 25°C for 1h by ultrasonic irradiation of the reactants using a commercial ultrasonic cleaner operating at a frequency of 47kHz, whereas silica powders with larger size and broad size distribution were synthesized using the same reactants at the same temperature and for the same time by the conventional process without ultrasounds. The particle size and size distribution of the silica powders obtained by the ultrasonic process were smaller and narrower than those by the conventional process, indicating that the application of ultrasound in the synthesis of silica powders by the w/o emulsion method is an efficient way to have powders with smaller and narrower particle size distribution.
Large-Scale Fabrication of Ti3AlC2 Powder with High-Purity
Authors: Wang Chang An , Peng Chun Qing , Song Yang , Huang Yong
Published: March 2009

A synthesis method of high-pure Ti3AlC2 powder with a large scale was presented as pressureless synthesis using TiC, Ti and Al powders as starting materials at 1300~1450°C in flow Ar. The different raw material scales were tested from 2 g to 1.0 kg, and the results showed that the purities of Ti3AlC2 powders could be kept around 97 wt% at different scales of raw materials. SEM observation and particle size analysis revealed that the synthesized Ti3AlC2 powders were uniform and around 5 μm in particle size. This method can be used for mass production of Ti3AlC2 powders with high-purity.
Dielectric Properties of HGRP BaTiO3 Based X7R Materials
Authors: Guo Jian Bang , Liu Xiao Lin , Yan Tao , Chen Jian Feng
Published: March 2009

In this work, a sub-micron grained sized (<500nm) ceramic (> 92% of theoretical) has been
obtained using nano-sized BaTiO3 powders synthesized through a high-gravity reactive precipitation
(HGRP) process. Permittivity of the prepared ceramic is greater than 2500. Also, low change ratio of
temperature in the range of −55°C~ 125°C i.e.< ±15% renders the ceramic to meet the EIA X7R
characteristics. In the ceramic compositions, Dy2O3, BaCO3, CaCO3, MnCO3 and MgO were used as
dopants. After being mixed and dry-pressed, the above mentioned compositions in reducing
atmosphere (N2 and 5% H2) were sintered at 1210°C−1290°C for 2h, respectively. Experimental
results show that HGRP BaTiO3 powders have good dielectric properties. The dielectric properties as
well as the microstructure of the ceramic are both sensitive to the change of sintering temperature.
Rheological Properties of Boron Nitride-Silica Composite Suspensions
Authors: Zhou Li Zhong , Jia De Chang
Published: March 2009

In this paper, a novel colloidal forming process has been developed to prepare boron nitride-silica composites. The rheological properties of mixed boron nitride-silica powders in deionised water have been investigated by adjusting the concentration of dispersant, pH value of the solution and other process parameters. The isoelectric points for both boron nitride and silica powders are in the pH range of 2 to 3. Boron nitride doped with or without A-1 (an anionic dispersant) as a dispersant shows a similar electrophoretic behavior to silica powder, i.e. Zeta potential becomes more negative with the increase of pH value from 2 to 12. The sedimentation and rheological results of aqueous boron nitridesilica suspensions indicate that the optimized pH value is around 7.2. It depends upon the synthetic effects of dissociation of A-1 and sufficient positive adsorption sites on the particle surfaces in aqueous media. The optimum concentration of the dispersant at pH=6 is 0.6wt % (dry weight basis of composite powders). Boron nitride-silica composite suspensions with a solid content as high as 50vol% have also been achieved. A ball milling process can improve the fluidity of the suspensions.
Effect of SiC Powder Characteristic on the Rheological Properties of Feedstock
Authors: Ren Shu Bin , He Xin Bo , Ye Bin , Qu Xuan Hui
Published: March 2009

In this study, the effect of SiC powder characteristic on the rheological properties of the feedstock was investigated. It was found that the viscosity of the feedstock decreased with the increase of the particle size. For the binary powder mixtures, the viscosity of the feedstock decreased with the increase of the particle size ratio of the larger particle to finer particle, which is attributed to the increase of the tap density of the powder.
Model of Start-Stop Control on Low Speed Moving
Authors: Chi Guan Xin , Di Shi Chun , Cao Guo Hui , Wang Zhen Long
Published: March 2009

This paper analyzes the cause of overshoot and retarded response in controlling
piezoelectric ceramic motor with PMAC card in micro WEDM. The model of start-stop control is
presented, and the servo control card with start-stop control is also developed. The model reserved
the advantages of traditional PID control, and overcome the problems of overshoot and retarded
response. It has been verified by machining that system overshoot is less than 3 pulses and response
time is less than 1 second.
A Framework of an Integrated Platform for Modelling and Measurement of Freeform Surface Generation in Ultra-Precision Raster Milling
Authors: Kong Ling Bao , Cheung Chi Fai , Lee Wing Bun , To Sandy
Published: March 2009

This paper presents an integrated platform for modelling and measurement of freeform
surface generation in ultra-precision raster milling. It is composed of several components which are
optics design component, tool path generator, modelling system, measurement system, evaluation
component, compensation component and optimization component, respectively. The research
emphasizes on modelling and simulation of freeform surface generation, the prediction of the cutting
performance and hence the optimization of cutting strategy in the ultra-precision raster milling of
freeform surfaces. A measurement system is also proposed to carry out a fast and efficient
measurement plan of freeform surfaces. Non-uniform Rational B-Spline (NURBS) will be employed
for the development of the integrated platform which will meet Standard for the Exchange of Product
model data (STEP).
Hysteresis Model for Superelasticity of Shape Memory Alloy Based on ANN
Authors: Li Hong Nan , Cui Di , Song Gang Bing
Published: March 2009

Superelasticity is one of the most important properties of shape memory alloy. In this
paper, the superelastic deformation behavior of NiTi shape memory alloy subjected to cyclic loading
with stable superelasticity is experimentally investigated. According to test data, a constitutive model
for the superelasticity of shape memory alloy is presented based on the artificial neural network
(ANN). Numerical results agree well with experimental observations that verified the constitutive
model being of high accuracy. This model can avoid the difficulties of other models on the
determination of the parameters and is suitable for practical engineering application. Thus, a new
method is provided for building the constitutive model of shape memory alloy.
Hydrophobically Modified Amphiphilic Cylodextrins as Novel Carriers for Controlled Delivery of Water-Soluble Drugs
Authors: Ganapathy Hullathy Subban , Lee Min Young , Woo Min Hee , Jeong Yeong Tae , Lim Kwon Taek
Published: March 2009

Hydrophobically modified derivative of a γ-cyclodextrin, functionalized with
perfluoro alkyl ester group, was prepared and investigated for its potential use as a
sustained release carrier for water-soluble drug molsidomine, a peripheral nitrovasodilator
used in the treatment of angina pectoris. The molecular encapsulation of molsidomine by
the amphiphilic cyclodextrin, octakis(6-O-perfluorobutanoyl)-γ-cyclodextrin (γ-CyD-F),
was confirmed by DSC and XRD studies. The in-vitro release of molsidomine from
peanut oil suspensions into aqueous phase was found to be significantly retarded by the
complexation with γ-CyD-F, mainly due to the hydrophobic properties of the γ-CyD-F.
Effect of Co-Content on the Corrosion of High Performance Stainless Steels in Simulated Bio-Solutions
Authors: Yoo Y.R. , Cho H.H. , Jang S.G. , Lee K.Y. , Son H.Y. , Kim Jung Gu , Kim Young Sik
Published: March 2009

This work focused on the effect of Co content on the corrosion resistance of high
pitting resistance equivalent (PRE), super ferritic, Ni-free stainless steels in simulated biosolutions.
The effect of Co in Ni-free alloys was evaluated by cytotoxicity test. Anodic
polarization test and AC impedance measurement were performed to evaluate the effect of Co
on corrosion resistance of the alloys. The cytotoxicity test result for 4 experimental alloys shows
non-cytotoxic but mild cytotoxic for 316L stainless steel due to relatively poor corrosion
resistance. However, the effect of Co on the passivity was positive in bio-solution but it was
negative in acidic chloride solution.
Force Measurement in Pyramid Shaped Parts with a Spindle Mounted Force Sensor
Authors: Szekeres Alexander , Ham M. , Jeswiet J.
Published: March 2009

Forces are measured in Single Point Incremental Forming with a spindle mounted sensor.
Results for AA3003 aluminum cones and pyramids are shown. Forces are measured for parts with a
75° forming angle, at which shear cracks are expected to occur. Forces in the three directions are
measured on the spindle with force spikes being observed when the tool changes direction at pyramid
corners, and reductions in force when stepping between contours. There is also a force variation as the
forming tool moves along the pyramid wall. A comparison is made between the forces measured for
cones and pyramids.
Single Point Incremental Forming Limits Using a Boxbehnken Design of Experiment
Authors: Ham M. , Jeswiet J.
Published: March 2009

Single Point Incremental Forming (SPIF) is a new method of forming sheet metal for
which not all forming limits and forming parameters are yet completely understood. In this paper, a
Box-Behnken design of experiment (DOE) is used to execute an experimental study used to
determine the forming limits in Single Point Incremental Forming (SPIF). The Box-Behnken
allows for good accuracy in defining a surface response for a relatively low number of experimental
runs – hence its usefulness in experimental work.
The Box-Behnken used in this paper solved five factors at three levels in forty six runs. The five
factors analyzed are based on the most critical factors effecting SPIF; they are material type,
material thickness, formed shape, tool size and incremental step size (depth of each step in form).
The data resulting from the Box-Behnken progressed into graphical response surfaces; the
response surfaces allow designers to determine what factors they need to select in order to
successfully form a part using SPIF.
Boss Forming, An Environment-Friendly Rotary Forming
Authors: Kawai K. , Koyama H. , Kamei T. , Kim W.
Published: March 2009

Boss forming, which is sometimes called hub forming, has attracted its attention as an
environment-friendly rotary forming process to form a circular plate with a hole into a boss shape.
An experimental study was conducted to survey the technological possibility of boss forming. Boss
forming of A1050-O commercially pure aluminum plate of 10 mm thickness was carried out at
room temperature under various working conditions. The effects of the working conditions on the
metal flow in boss forming were clarified experimentally.
Failure Mechanisms of TGV Brake Discs
Authors: Degallaix Gérard , Dufrénoy Philippe , Wong Jonathan , Wicker Paul , Bumbieler Frédéric
Published: March 2009

The CRISFIS project (supported by ADEME agency) consists in jointly studying the
squealing and cracking aspects of the high power disc brakes for TGV very high speed trains. This
paper deals with the progress concerning the cracking part. An experimental and modelling strategy
is adopted in order to better understand and predict brake disc cracking. Braking tests conducted on
an industrial scale-one test bench are presented. In a first step, the influence of the pad-type on the
thermal loading applied to the disc is studied by means of an infrared camera and thermocouples
embedded in the pads and in the disc. In a second step, the thermal maps extracted from
thermographic monitoring are used as input data for thermal-mechanical calculations. Finally, the
results of modelling and tests are compared to the damage observed on the brake discs.
Molecular Dynamics Simulation of Dislocation-Obstacle Interactions in Irradiated Materials
Authors: Lee Hyon Jee , Shim Jae Hyeok , Wirth Brian D.
Published: March 2009

The interactions of a dislocation with commonly observed irradiation induced defects such
as a stacking fault tetrahedron (SFT) and a void are studied using molecular dynamics (MD)
simulation methods. The simulation of an SFT interacting with a dislocation in face centered cubic
(FCC) copper (Cu) reveals that an SFT is a strong obstacle against a dislocation motion, with
dislocation detachment often involving an Orowan like mechanism. The resulting SFT generally
involves a shear step, although partial absorption is also observed in some specific interaction
geometries. Dislocation interaction with a void has been studied in body centered cubic (BCC)
molybdenum (Mo). The dislocation locally annihilates upon contact with the void and then
re-nucleates on the void surface as the dislocation glides past the void. The interaction results in the
simple shear of the void by one Burger’s vector. The obstacle strength of the void is measured using
conjugate gradient molecular statics (MS) method as a function of void size. A large increase in the
obstacle strength is observed for a void size greater than 3 nm in diameter.
Energy Harvesting for Autonomous Sensing
Authors: Inman Daniel J. , Farmer Justin , Grisso Benjamin L.
Published: March 2009

Autonomous, wireless structural health monitoring is one of the key goals of the damage
monitoring industry. One of the main roadblocks to achieving autonomous sensing is removing all
wiring to and from the sensor. Removing external connections requires that the sensor have its own
power source in order to be able to broadcast/telemetry information. Furthermore if the sensor is to
be autonomous in any way, it must contain some sort of computing and requires additional power to
run computational algorithms. The obvious choice for wireless power is a battery. However,
batteries often need periodical replacement. The work presented here focuses on using ambient
energy to power an autonomous sensor system and recharge batteries and capacitors used to run an
active sensing system. In particular, we examine methods of harvesting energy to run sensor
systems from ambient vibration energy using piezoelectric elements.
Crack Detection in Beams by Means of the Driving Force Parameters Variation at Non-Linear Resonance Vibrations
Authors: Bovsunovsky A.P. , Bovsunovsky O.
Published: March 2009

A closing crack causes the dynamic behavior of a vibrating system to be significantly
non-linear and, consequently, the appearance of non-linear resonances (that is super- and
subharmonic one). The main idea of the proposed procedure of crack location and size estimation is
based on the determination of the vibration response non-linearity around the superharmonic
resonance of order 2/1 and subharmonic resonance of order 1/2 at different parameters of driving
force.
First parameter of driving force under investigation is its point of application. It is shown both
numerically, with the use of the finite element model of a cracked beam, and experimentally that the
level of non-linearity of vibration response at non-linear resonances is strongly dependent not only
on the crack size but also on the driving force application point along the cracked beam. Moreover,
the abrupt change of the non-linearity of vibration response when driving force is applied close to
the crack clearly indicates its location. In such a way the procedure of damage detection is proposed
to estimate both the crack size and location in beams.
Second parameter is the level of driving force asymmetry. Addition of the static component to
the harmonic driving force varies the state of crack making crack more or fully open or closed. As a
result the level of non-linearity of vibration response at any non-linear resonance varies from
maximal value (in absence of static component) to practically zero value (when the static
component of driving force is so large that crack becomes permanently open or closed at vibration).
In such a way the presence of crack can be detected without preliminary information on the
vibration response of a structure in the intact state.
Using the Detection and Relative Damage Quantification Indicator (DRQ) with Transmissibility
Authors: Maia N.M.M. , Ribeiro A.M.R. , Fontul M. , Montalvão D. , Sampaio R.P.C.
Published: March 2009

The Detection and Relative Damage Quantification Indicator (DRQ) was presented
previously as a reliable damage detection indicator when used with Operational Deflection Shapes
(ODS). The DRQ was computed from the Response Vector Assurance Criterion (RVAC) between
the damaged and the initial ODS and the resulting value proved to be a good indicator of the
presence of damage.
The use of the ODS implies that the loads applied to the structure with and without damage are
either known or, at least, the same. If the forces are not deterministic but still ergodic, the power
spectrum could be used to evaluate the ODS, but still the above conditions hold, in a statistical
sense.
When a structure is subjected to ambient excitation, those conditions can hardly be assured. The
loads may vary quite significantly and the ODS changes may be due to those changes instead of the
presence of damage. To avoid this handicap, the authors explore here the use of the Transmissibility
functions. If properly defined, the Transmissibility is invariant with respect to the amplitude of the
loads. Since the Displacement Transmissibility is load invariant, a picked set of responses can be
measured in service and used to predict another set; the result will then be correlated to the actual
values using the RVAC and the DRQ will be computed. Numerical and experimental examples
illustrate the proposed technique.
An Updated Comparison of the Force Reconstruction Methods
Authors: Klinikov M. , Fritzen Claus Peter
Published: March 2009

For purposes of monitoring and damage prognosis it is important to know the external
loads which act on a structure. The knowledge of these loads enables us to make an assessment of
damage after extreme events and updated forecasts of the remaining life-time. In many practical
applications it is not possible to measure the forces e.g. resulting from wind loads or traffic directly.
Therefore, these forces are determined indirectly from dynamic measurements. In this contribution,
an updated overview of available time domain load reconstruction methods is presented. An attempt
of highlighting the main advantages and disadvantages of different approaches, which are used in
engineering is done. The importance of sensors type as well as their locations is considered for each
approach. Finally, the methods applicability to real structures, where the online reconstruction plays
an important role, is discussed.
Structural Health Monitoring of Aerospace Structures with Sol-Gel Spray Sensors
Authors: Ouahabi Abdelhakim , Thomas Marc , Kobayashi Makiko , Jen Cheng Kuei
Published: March 2009

A new approach is proposed for conducting structural health monitoring, based on newly
developed piezoceramic sensors. They are fabricated by a sol-gel spray technique. The potential
application of these sensors may be broad. These sensors have been evaluated for structural health
monitoring studies. The purpose of the present study aims the detection and the localization of
defects by the means of these new piezoceramic sensors. Nine sensors were integrated onto a
metallic plate with moving masses. The plate was excited by an impact at a specific location and the
vibratory signals from sensors were recorded simultaneously. The analysis of signals obtained from
nine locations was correlated with a numerical simulation in order to identify at each time the
location of the mass.
Influence of Temperature Fields on Wave Propagation in Composite Plates
Authors: Kudela Pawel , Ostachowicz Wiesław M. , Zak Arkadiusz
Published: March 2009

The aim of this paper is to investigate the influence of temperature fields on wave
propagation in composite plates (A0 mode of the Lamb wave has been used). This phenomenon is
modelled by the Spectral Element Method. For this purpose a spectral composite plate element,
which enables one to take into account thermal effects, has been developed. Different temperature
fields have been considered. Results of numerical simulations have been used as input data for
a special damage location algorithm. The proposed damage location algorithm utilises signals
registered by a clock-like sensor array. In the next step the results from crack location for different
temperature fields have been compared.
Locating Damage In Waveguides From Point FRF Measurements
Authors: Shone Simon P. , Mace Brian R. , Waters Tim P.
Published: March 2009

A method is presented for locating discontinuities in a uniform waveguide from two or
more point frequency response functions (FRFs). The phase of the FRF exhibits modulation when
plotted against wavenumber because of interference of waves reflected from the discontinuity, and
this is related to the distance of the excitation point from the discontinuity. Such discontinuities
might be known boundaries or unknown damage sites. An inverse Fourier transform is used to
transform from the wavenumber domain to the spatial domain in order to extract the locations of the
discontinuities. The use of the transform relies upon knowledge of the dispersion relation for the
waveguide. Experimental results are presented for several uniform isotropic beams which were
damaged to differing extents by sawing transverse slots in them. The results show the method to be
successful in locating the slots.