bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical Characteristics and Microstructures of Gd-Doped Bi4Ti3O12 Ceramics
Authors: Liu X.B. , Sun Y.H. , Chen Min , Huang Chong Qing , Liu J. , Wan Z.M.
Published: March 2009

The electrical properties of Gd-doped bismuth titanates (Bi3.25Gd0.75Ti3O12, BGT) prepared by a conventional ceramic technique have been investigated. At applied d.c. field below 200V/mm, the current-voltage curve of the BGT ceramic exhibits a negative differential resistance behavior. The impedance spectrum indicates that the sample consists of semiconducting grain and moderately insulating grain boundary regions. XRD, SEM and EPMA analyses reveal crystalline phase characterized by a Bi-layered perovskite structure of Bi4Ti3O12 (BIT) and the distribution of every element is uniform. The BGT sample exhibits randomly oriented and plate-like morphology.
AFM Study on the Surface Dissolution of Hydroxyapatite
Authors: Seo Dong Seok , Kim Hwan , Lee Jong Kook
Published: March 2009

The surface dissolution of hydroxyapatite ceramics in distilled water was investigated by using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The disks made of hydroxyapatite powder were sintered at 1200oC for 2 h in air with under moisture protection. After sintering, the disks were polished to smoothness using 1 μm diamond and they were soaked in 40 ml of pH 7.4 distilled water at 37oC for certain period of time. The morphological change of hydroxyapatite surface, specifically at the initial stage of immersion, and related surface roughness were observed with immersion time. The present study suggested that an artificial fact like surface scratch in this case initiated to be eliminated prior to the surface dissolution along grain boundary. That is, the surface roughness decreased at the initial stage of immersion, and then increased due to the surface dissolution.
Repairing the Dog's Femoral Defect with the Autologous Osteoblast Integrated the Nano-Calcium Phosphate/Zirconia Scaffold
Authors: Xu Guo Hua , Ye Xiao Jian , Yuan Wen , Cai Shu , Shi Jian Gang , Xiao Jian Ru
Published: March 2009

In this paper, we study the effect of repairing the dog's femoral defects with the artificial bone
integrating the nano-calcium phosphates/zirconia porous artificial bone scaffold with the autologous
osteoblasts. We transplanted the artificial bone to the femoral defect of the dog, and at the same time,
simple scaffold and the autologous cancellous bone were implanted as the control group. 3 months after
the transplantation, the specimen was taken out with complete integration with the bone in these 3 groups
and the bone defect got the complete bone union. The mechanics strength test showed that the group of
the artificial bone was the strongest, followed by the cancellous bone group, and the simple material
group was lower, but the strength was stronger than that before the transplantation. In the sixth month, the
complete femoral defect repair was found in each group and the complete formation of the Haversian
canal can be found on the histology examination. According to the mechanics strength test, there was no
significant difference (P<0.05).
Microstructure of Ceramic Layer in Composite Pipe Made by SHS-Gravitational Process
Authors: Lin Tao , Cui Fen Ge , Yin Sheng , Guo Zhi Meng
Published: March 2009

SHS-gravitational process was developed to synthesize the ceramic lined steel pipe, especially
for elbow, conical pipe, three-way and four-way pipe and pipe with a small diameter. In
SHS-gravitational process, the molten ceramic, which separated out from the reaction products due to
their density difference, solidified to form the ceramic lined layer in the steel pipe when contacted with
the steel pipe wall. With an X-ray diffractometer and a scanning electron microscope, it can be found that
the ceramic layer is composed of α-Al2O3 and FeAl2O4. A small amount of iron also remains in the
ceramic layer. There is a thin equiaxed grain area of alumina near the steel pipe wall, and then alumina
was grown in form of dentrite to the surface of ceramic layer. FeAl2O4 distributes among alumina dentrite.
Although the ceramic layer was solidified from one end to another end of a pipe, the microstructure of
ceramic layer was almost uniform throughout the whole length of the pipe.
Thermal Cycling Behavior of Lanthanum-Cerium Oxide Thermal Barrier Coatings Prepared by Air Plasma Spraying
Authors: Ma Wen , Ma Yue , Gong Sheng Kai , Xu Hui Bin , Cao Xue Qiang
Published: March 2009

Lanthanum-cerium oxide (La2Ce2O7, LC) is considered as a new candidate material for thermal barrier coatings (TBCs) because of its low thermal conductivity and high phase stability between room temperature and 1673K. The LC coatings with different La2O3 contents were prepared by air plasma spraying (APS) and their lifetime was evaluated by thermal cyclic testing from room temperature to 1373 K. The structures of the coatings were characterized by XRD and SEM and the deviation of the composition from the powder was determined by EDS analysis. Long time annealing for the freestanding coating at 1673K reveals that the near stoichiometric LC coating is stable up to 240h, and the stability decreases with increasing the deviation from stoichiometric LC composition. During thermal cyclic testing, spallation was observed within the top coat near the bond coat. It is considered that the effect of intrinsic stress caused by the coefficient of thermal expansion (CTE) mismatch between top coat and bond coat is larger than that of thermally grown oxide (TGO) and the bond adherence of top coat with TGO.
A Promising Sm1.9Ca0.1Zr2O6.95 Ceramic for Thermal Barrier Coatings
Authors: Xu Qiang , Pan Wei , Wan Chun Lei , Qi Long Hao , Miao He Zhuo
Published: March 2009

Sm1.9Ca0.1Zr2O6.95 ceramic was sintered at 1600°C for 10 h in air by solid-state reaction method. The phase structure and thermal expansion coefficient were measured by XRD and a high-temperature dilatometry, respectively. The results show that the crystal structure of Sm1.9Ca0.1Zr2O6.95 ceramic is still pyrochlore. The doping with calcium cation leads to a shift of the X-ray spectrum of Sm1.9Ca0.1Zr2O6.95 ceramic to lower 2θ values. The experiments also show that the thermal expansion coefficients of Sm1.9Ca0.1Zr2O6.95 ceramic are higher than those of Sm2Zr2O7 ceramic. These results are related to the vacancy induced by doped calcium cation in the samarium lattice.
Effect of Heat Treatment on Coloration of Ag Doped TiO2-SiO2 Films
Authors: Bi Wen Yue , Wang Li , Yu Xin Gang , Zhang Xing Dong , Bao Hong Quan , Zhao Hui Feng
Published: March 2009

Silver doped titania-silica films were fabricated by two-step route of sol-gel method using
Ti(OC4H9)4, Si(OC2H5)4 and AgNO3 as the precursor materials. The films were annealed at temperature
from 350°C to 560°C for a period of time ranging from 15min to 90 min. Optical properties of the films
were characterized by UV-visible spectroscopy and the state of silver in the titania-silica films was
investigated by XRD patterns. It was found that the annealing temperature and time have considerably
influenced the coloration of the films, and with the increase of annealing temperature the [111]
orientation of silver crystal occurred which make the color of silver doped titania-silica films deepened.
The coloration stability of the silver doped titania-silica films was also investigated.
Photo-Hydrophilicity and Photo-Catalysis of TiO2-SiO2 Coating on Ceramics
Authors: Cai Hong Hua , Luo Zhong Kuang , Liang Xun , Li Hai Yang , Li Run , Xu Xiao Dan , Liu Jian Hong
Published: March 2009

Sol-gel coatings of mixed TiO2-SiO2 had been deposited on ceramic substrates by spraycoating
technique to study their hydrophilic and photocatalytic behavior on exposure to sunlight or
ultraviolet illumination. The range of the films heat-treatment temperature is from 300°C to 500°C. AFM
and XRD analysis were used to characterize the crystal structure and surface morphology of these
coatings. Hydrophilic property was evaluated by water contact angle measurement under sunlight
illumination condition, and photocatalytic activity by decomposition rate of aniline blue under ultraviolet
illumination. Attrition resistance experiment was also carried out to test the hardness and adherence
strength of these films. The experimental results demonstrate that this coating possesses high
photo-activity and excellent adhesion to ceramic substrates.
Method for Estimating the Critical Cooling Rate for Glass Formation from Isothermal TTT Data
Authors: Zhu Dong Mei , Zhou Wan Cheng , Ray Chandra S. , Day Delbert E.
Published: March 2009

A method is proposed for estimating the critical cooling rate for glass formation and continuous
cooling transformation curve (CCT) from isothermal TTT data. The critical cooling rates and CCT curves
for a group of lithium disilicate glasses containing different amount of Pt as nucleating agent estimated
through this method are compared with the experimentally measured values and it shows this method can
give a reasonable estimation.
Influence MnO2 on the Properties of (LixNayK1-x-y)NbO3 Ceramics
Authors: Chen Qiang , Lan De Jun , Chen Yi , Lin Du Min , Yue Xi , Xiao Ding Quan , Zhu Jian Guo
Published: March 2009

Lead-free piezoelectric ceramics lithium sodium potassium niobate (LixNayK1-x-y)NbO3
(LNKN100x/100y) have been synthesized by a conventional solid state process. The effects of MnO2
addition on the properties of (LixNayK1-x-y)NbO3(x=0.06, y=0.5)(LNKN6/50) ceramics were investigated.
It was found that a morphotropic phase boundary (MPB) between orthorhombic and tetragonal phases is
in the composition range 0.05<x<0.07. The piezoelectric constant d33 and the planar electromechanical
coefficient kp of LNKN6/50 ceramics reach 222pC/N and 39%, respectively. As the amount of MnO2-
doped increases, dielectric constant, piezoelectric constant and Curie temperature Tc of LNKN:Mn
ceramics decreased, while mechanical quality factor Qm of LNKN6/50:Mn increased prominently
compared to pure LNKN6/50 ceramics. The addition of MnO2 can also decrease the sintering temperature
effectively of LNKN6/50 ceramics.
Preparation and Characterization of LiNbO3 Thin Films Derived from Metal Carboxylate Gels
Authors: Zhao Jiu Peng , Liu Xiang Rong , Qiang Liang Sheng
Published: March 2009

Lithium niobate thin films have been deposited on Pt/Ti/SiO2/Si substrates by the Pechini
method from metal carboxylate gels and heat-treated at temperatures ranging from 400 to 600°C. The
thermal decomposition of the metal carboxylate precursor gels has been studied by differential thermal
analysis and thermogravimetry. The products derived from calcination of the gels at different
temperatures have been characterized by Fourier transform infrared, Roman spectrum and X-ray
diffraction. Scanning electron microscopy analysis shows the surface of the films to be smooth, dense and
crack-free. Electric properties measurement indicates that the LiNbO3 films demonstrate a ferroelectric
hysteresis loop. The remanent polarization (Pr) and coercive field (Ec) are 17.89 μC/cm2 and 35.23 kV/cm,
respectively.
In Situ Template Synthesis of TiO2 Nanotube Array Films
Authors: Jiang Wu Feng , Ling Yun Han , Hao Su Ju , Li Hong Yi , Bai Xin De , Cang Da Qiang
Published: March 2009

Anodic aluminum oxide (AAO) is commonly used as a starting template for fabrication of several kinds of functional nanoscale devices due to its homogeneous nanohole structure with high aspect ratio. In this paper, high density and uniform titanium dioxide nanotube array films were prepared via liquid phase deposition method by immersing the AAO templates in an aqueous ammonium hexafluorotitanate solution. The phase and microstructure of the nanotube array films were characterized by X-ray diffraction and field-emission scanning electron microscopy. It was found that the mean inner diameters of nanotube are 40-100 nm, mainly depended on different templates and post treatment condition; the phase of as-deposited TiO2 array film was amorphous, while it became anatase at above 400°C.
Microstructure and Mechanical Properties of Cr-C-N, Cr-Si-N and Cr-Si-C-N Coatings by a Hybrid Coating System
Authors: Jang Chul Sik , Cho Young Rae , Kang Myung Chang , Chung Won Sub , Kim Kwang Ho
Published: March 2009

CrN-based multi-component coatings were deposited by a hybrid coating system combining
the arc ion plating (AIP) and sputtering technique. In this work, comparative studies on microstructure
and mechanical properties of microhardness and wear behaviors among Cr-C-N, Cr-Si-N, and Cr-Si-C-N
coatings were systematically conducted. Adding carbon and silicon atoms into CrN coatings had large
effects on microstructural change and mechanical properties of CrN coatings. The hardness value of
Cr-Si-C-N coatings showed about 44 GPa, while those of Cr-Si-N and Cr-C-N coatings were 34 and 23
GPa, respectively. The average friction coefficient of CrN-based coatings decreased from 0.65 to 0.4 with
the incorporation of silicon and carbon content.
Nanocomposites – Toughened Ceramics
Authors: Awaji Hideo , Matsunaga Takuya , Choi Seong Min
Published: March 2009

In order to improve fracture toughness of ceramics, an intrinsically small frontal process zone
(FPZ) size must be expanded. An intra-type nano-structure, where nano-particles are embedded within
matrix grains, yields dislocations around the dispersed particles due to residual stresses. These dislocations
become sessile dislocations at room temperature, operate as origins of small stress concentration in
the matrix, and create nano-cracks in the FPZ. To produce the intra-type nano-structure, we developed a
soaking method. This method makes it possible to produce nano-sized metallic particles dispersed within
ceramic powders. In this research, alumina-nickel nanocomposite powder was obtained using the soaking
method. The powder mixed with α-alumina as a seed was sintered using a pulse electric current sintering
technique. The sintered nanocomposites are then annealed to disperse dislocations around the nanoparticles
into alumina grains. Results showed that the maximum fracture toughness was 7.6 MPam1/2,
which was two times higher than that of alumina.
Erosion Wear Characteristics and Mechanism of Si3N4 Ceramics: Effect of Impact Angle
Authors: Bao Chong Gao , Pan Wei , Miao He Zhuo , Qi Long Hao
Published: March 2009

Erosion wearing regulation with different erosion angel for Si3N4 ceramics were systematically
studied by liquid-solid dual phase erosion wearing test with rotation disk through comparing with
Cr15Mo3 high chromium cast iron for pumps in industry. Besides the micro failure mechanism and the
relationship between mechanical behavior and anti erosion wearing have been analyzed for the
experimental materials. The experimental results were concluded as following: the erosion resistance of
Si3N4 ceramic is about 20 times better than that of Cr15Mo3 high-Cr cast ion in erosion test angle, and the
effect of erosion angel on the erosion wearing volume lose features as N-shaped curve with the biggest
volume lose at 45° erosion angle while most erosion wearing volume at 90° angle, which indicates that it
should avoid 45° or 90° erosion angle during materials designing. Obvious direction and erosion trace are
revealed and volume lose mainly featured with tiny cutting, pear ditch and erosion hole, and micro crack
and grain falling off at high angle erosion on the surface of Cr15Mo3 materials, besides smooth surface,
high ductile, compact structure, fine grain and fine cylinder grain explaining main reason for excellent
anti erosion wearing for Si3N4 ceramic.
The Microwave Characteristics of Glass-Ba2Ti9O20 Ceramics
Authors: Lin Hui Xing , Zhao Xiang Yu , Yang Ai Min , Li Hua Xin , Chen Wei , Luo Lan
Published: March 2009

In this study, 2BaO-3B2O3 (BB) glass was used as a sintering aid to lower the sintering
temperature of Ba2Ti9O20 ceramics. Microwave Characteristics of the BB-added Ba2Ti9O20 ceramics
sintered at different temperatures were investigated. The crystalline phases of BB-Ba2Ti9O20 ceramics are
Ba2Ti9O20, BaTi(BO3)2 and TiO2. Good microwave dielectric properties (εr = 26, Q*f = 28770GHz and τf
= 14.6ppm/oC) were obtained by sintering the BB-added Ba2Ti9O20 ceramics at 1040oC for 2 h.
Structure and Dielectric Properties of Zn Doped PST Thin Films Prepared by Sol-Gel Method
Authors: Zheng Zan , Li Xiao Ting , Han Gao Rong , Weng Wen Jian , Du Pi Yi
Published: March 2009

(PbySr1-y)ZnxTi1-xO3-x thin films were prepared on ITO/glass substrate by sol–gel process
using dip-coating method. The phase structure, morphology, and dielectric properties of thin films
were investigated by XRD, SEM and impedance analyzer, respectively. The perovskite phase
structure was exhibited in the Zn-doped PST thin films. The formation ability of the thin films of the
perovskite phase and its grain size decreased with the increase in doping Zn. The dielectric constant of
the thin film was influenced by oxygen vacancies which could be controlled by Zn doping.
On the Sealing Materials for SOFC
Authors: Han Min Fang , Wang Zhong Li , Wang Yu Qian
Published: March 2009

Processing of sealing materials is a key technology in planar SOFC. In this paper, compositions of sealing materials were determined and then mixed and milled for 7~8 h. Glass materials were obtained by melt at 1300 ~ 1600°C and quenched in cold water. The powder materials were made by milling and screening. Properties of thermal expansion of sealing materials were on the same level to both electrolyte and interconnect. Experiments using 7 kinds of materials were carried respectively at 900°C and 1300°C. The most suitable sealing temperatures related to sealing materials were then determined. Thermal cycle experiments were carried and hermetical properties were tested by red-absorption. Microstructure were observed with SEM and it revealed that the prepared sealing materials joins well with YSZ but not so good with metal.
Preparation of Pb(Mg1/3Nb2/3)O3 Relaxor Ferroelectric by Sol-Gel Route
Authors: Xia Wen , Xu Li Hua , Zhang Han , Song Jun Jun
Published: March 2009

Without addition of any thermodynamically stable perovskite compound such as PbTiO3, Pb(Mg1/3Nb2/3)O3 was fabricated by a new sol-gel route, and the processing parameter was studied. The result showed that the chelating effect of ammonium citrate was relatively better than that of citric acid in this system. When the ratio of ammonium citrate to Nb2O5 was 8.33, the colloid of Nb2O5·nH2O was in state of transparency. The effects of heat treatment on the formation of perovskite phase of Pb(Mg1/3Nb2/3)O3 powders were characterized by X-Ray Diffraction (XRD) method. With increasing heat treatment temperature or holding time, pyrochlore phase turned into perovskite phase gradually, and after second calcination, the content of perovskite phase increased significantly from 54% to 72%.
Luminescence Properties of MO-Re2O3-B2O3:Eu3+ (M= Mg, Sr; Re=Y, Gd ) under VUV Excitation
Authors: Zhou Dan , He Da Wei , Liang Zhong Yi , Hou Tao
Published: March 2009

The phosphors of MO-Re2O3-B2O3:Eu3+ (M = Mg, Sr; Re = Y, Gd) were prepared by
conventional solid-state reaction. Red-emitting MO-Re2O3-B2O3:Eu3+ (M=Mg, Sr; Re=Y, Gd) phosphors
had the highest luminescence intensity under vacuum ultraviolet (VUV) excitation. They had sharp
emission peak lines at 591 and 613nm, which were assigned to the transitions of 5D0→7F1 and 5D0→7F2.
By the introduction of Sr into MgO-Re2O3-B2O3:Eu3+ (M=Mg, Sr; Re=Y, Gd), the intensity of absorption
peaked at 172nm and the emission peak intensity were enhanced.
Application of Rare Earth Permanent Magnet on Magnetic Abrasive Machining
Authors: Chen Y. , Ju Dong Ying
Published: March 2009

Because of the raw material elements and its purity and so on, the Nd-Fe-B permanent magnet,
the strongest magnetic material, which needs artificial synthesis, can hardly be used directly. The
performance of the permanent magnet has not yet been greatly developed owing to the limitation of the
artificial synthesizing technology, of the powder sintering technology and that of the application. In this
paper, the magnetic abrasive machining method as a new application is put forward, and from this
viewpoint, are discussed the performance and the processing technology of the permanent magnet and the
magnetic abrasive machining method. A sintering route combining the direction heat treatment technique
to increase the magnetic energy is suggested.
Preparation of BaRuO3 and BaIrO3 Films by Laser Ablation
Authors: Masumoto Hiroshi , Ito Akihiko , Kaneko Y. , Goto Takashi
Published: March 2009

BaRuO3(BRO) and BaIrO3(BIO) thin films were prepared by laser ablation, and the effects of
preparation conditions on the structure, morphology and electrical conductivity were investigated. BRO
thin films deposited at oxygen partial pressure (PO2) = 13 Pa and substrate temperature (Tsub) < 573 K
were amorphous. At Tsub = 573 K, the rhombohedral BRO thin films with (110) orientation were obtained.
BRO thin films prepared at Tsub = 773 K and PO2= 13 Pa exhibited the resistivity of 5x10-6 m and
showed metallic conduction. BIO thin films deposited at PO2= 40 Pa and Tsub < 623 K were amorphous.
Tsub > 623 K, the BIO thin films crystallized into a 6H structure were obtained. The resistivity of the BIO
films at PO2= 40 Pa decreased from 1.4x10-2 to 4x10-4 m with decreasing Tsub from 1073 to 573 K.
Preparation and Properties of Zinc Oxide and Titanium Oxide Ultra-Fine Composite Particles for Attenuation of Ultraviolet Radiation
Authors: Ran Jing , Zhang Ping , Yang Wei Zhong , Zhou Da Li , Liu Heng , Li Zhe
Published: March 2009

A co-precipitation preparation method and the properties of an ultraviolet (UV)-attenuating
agent are described in this paper. The composite particles of ultra-fine zinc oxide and titanium oxide are
used to attenuate UV radiation. Preparation of TiOSO4, ZnCl2 solution and the co-precipitation of the
composite particles by alkali are included during the process. Various types of surfactants have been used
to modify the composite particles. Particle sizes are determined by laser particle analyzer, and reflectance
and absorption coefficient are determined by UV-VIS spectrophotometer. Results show that particle size
of the composite particles as well as total reflectance and absorption coefficient depend on the surfactants,
pH value, and carline temperature. The average sizes of zinc oxide and titanium oxide ultra-fine particles
range from39 to 65 nm. Attenuation capability of ultraviolet radiation becomes stronger when the particle
average sizes becomes smaller. Composites less than 40 nm with titanium oxide of rutile phase attenuate
most effectively the ultraviolet radiation ranging from 280 nm to 390 nm.
Annealing Effects on Powder Metallurgy Based Pb1-xSnxTe Materials for Thermoelectric Applications
Authors: Gelbstein Y. , Dashevsky Z. , Kreizman R. , George Y. , Gelbstein M. , Dariel M.P.
Published: March 2009

Lead tin telluride based alloys are known p-type materials for thermoelectric applications,
in the 50-600oC temperature range. These alloys combine desired features of mechanical and
thermoelectric properties. The electronic transport properties of PbTe and Pb1-xSnxTe materials may
be strongly dependent on the preparation technique. Powder metallurgy process is known to introduce
defects and strains, that may alter carrier concentration. Under such non-equilibrium conditions the
thermoelectric properties are instable at the operating temperature. An appropriate annealing
treatment can eliminate this effect.. The present communication describes the annealing treatment
applied to cold compacted and sintered Pb1-xSnxTe materials.
Tribochemical Effects of MoSi2 Powder in Ball Milling
Authors: Zhou Qi , Ma Qin , Zang Shu Jun , Liu Jian Jun , Wang Cui Xia
Published: March 2009

The tribochemical effects of MoSi2 powder in the ball milling process have been studied by
X-ray diffraction (XRD) and QM-4H milling machine. It has been found that the intensity of diffraction
peak of MoSi2 powder is continuously decreased and the width increased with the increase of milling time.
Specifically, the crystallite size decreased largely in the early stage of milling. Contrary to the above, the
microstrain and the effective temperature factor increased considerably. After ninety hours of milling, the
crystallite size had little changes. The relations among the tribochemical effect factors are as follows: the
microstrain and the effective temperature factor increase with the decrease of the crystallite size. The
microstrain increases with the increase of the effective temperature factor.
EDM Properties of a Low Wear Electrically Conductive CVD Diamond Electrode
Authors: Iwai Manabu , Sharma A. , Pan Wei Li , Sano Sadao , Uematsu Tetsutaro , Suzuki Kiyoshi
Published: March 2009

It has been reported in our previous report that electrically conductive CVD diamond
(hereafter, EC-CVD diamond) having specific resistance of the order of 1x10-3 Ω⋅m shows almost
zero electrode wear even at the short pulse duration of 3μs on a die-sinking EDM machine. In this
research EDM properties are investigated in the context of the pulse on time in oil and water. It is
found that the electrode polarity has an effect on the electrode wear of the EC-CVD diamond
electrode in oil. In the test in oil, EC-CVD diamond shows zero wear at positive [+] electrode
polarity but a higher wear at negative [-] electrode polarity than that of the copper electrode.
Furthermore, the EC-CVD diamond electrode showed very less wear than copper even in
water. These results in oil and water may be due to the high thermal diffusivity, an increased rate of
carbon adhesion and the high thermal stability of the EC-CVD diamond electrode. Workpiece
surface roughness using the EC-CVD diamond electrode is about 20~50% lower than using the
copper electrode under the same EDM conditions. From the single pulse discharge experiment with
EC-CVD diamond and copper electrodes, the improvement in roughness is explained by the
dispersion of the discharge in the case of EC-CVD diamond due to its rather high specific resistance.
A Study on the Grinding Temperature Field for Titanium Alloy
Authors: Li W. , Xing Tong , Qiu Bao Xiang , Hu Gang Xiang , Jin Yang Fu
Published: March 2009

A reasonable finite element (FE) model of grinding temperature field has been developed
on the basis of analysis of the transient temperature field， and three kinds of boundary conditions
are loaded on the element of a moving heat source. The study, which is based on the finite element
principle, has been carried out using the numerical simulation software ANSYS. Many results have
been obtained including three dimensional temperature distribution map. The simulated results
under different conditions show good agreement with the experimental results. With the comparison
of the dry-grinding and wet-grinding, the result shows that the wet-grinding temperature with a
proper grinding fluid is rather lower than the dry-grinding temperature. Finally, the variable
coefficient of convective heat transfer and the different form heat source have been discussed in
detail.
Porous Polymer Prosthesis for Meniscal Regeneration
Authors: Lee Sahng Hoon , Seong Sang Cheol , Lee Jin Ho , Han Il Kyu , Oh Se Heang , Cho Kwang Joon , Han Hyuk Soo , Lee Myung Chul
Published: March 2009

Meniscus is the most commonly injured structure in the knee joint. Resection of the
meniscus as well as the torn menisci is known to induce the degeneration of the articular cartilage.
Replacement of the resected meniscus by allograft is limited by its availability and potential disease
transmission. Artificial prostheses are being tried in an attempt to regenerate the meniscal tissue and
we developed the biodegradable porous polycaprolactone(PCL) scaffold, which acts as a temporary
scaffold to enable the regeneration of a new tissue in time. We report the results of rabbit
implantation model. Biodegradable PCL scaffold coated with type I collagen with pores sized
100~150 +m and with compression modulus 400 kpa were fabricated by melt-molding particulate-
leaching method. The molds were made using the native meniscus of the rabbit. Medial meniscus of
right knee was partially removed through arthrotomy, leaving anterior 1/5 of the meniscus, after
sectioning medial collateral ligament. The implant was attached to the peripheral capsule and
remnant anterior meniscus with sutures. The medial meniscus of the left knee was removed and
served as a control without replacement. The regenerated meniscus was harvested at 4 & 12wks
after implantation. In addition to the routine histology of the tissue regenerated and remnant
scaffold, junction between the normal meniscus and the regenerated tissue, and cartilage surface
degeneration was observed. After 4 and 12 weeks the scaffolds, although considerable amount of
the materials remained, were largely filled and covered with fibrous tissue which was assumed to be
derived from synovial tissue of peripheral capsule. The tissue grossly resembling the native
meniscus was maintained and spindle shaped cells with extracellular matrices were observed
histologically. Neither cells with chondrocytic phenotype nor distinct cartilage matrices were
observed until 12 weeks. The bonding between the regenerated tissue and the peripheral synovial
capsule was firm and solid in all cases. The tissue bridges between the native meniscus and the
regenerated tissue were found in 9/10 operated knees. Articular surface degeneration was not
different between experimental and control groups except one case. More or less, the extrusion of
the meniscus was found in almost all knees. This study revealed that meniscal replacement with
PCL polymer prosthesis was feasible and led to adequate tissue formation. Long term studies on
adaptive remodeling will be required.
Analysis of Size-Effects in the Miniaturized Deep Drawing Process
Authors: Justinger H. , Hirt Gerhard
Published: March 2009

With the increasing trend towards miniaturization and the enhanced demand for small
components, reliable processes for mass production are needed. Today the deep drawing process is
already used to produce large numbers of small parts (diameter < 1 mm) at low costs per part. But a
better understanding of the process in relation to miniaturization is required to improve process
stability, because several aspects of the process change when scaled down. For example, product
accuracy and process parameters can be influenced by changing the ratio of surface to volume or the
ratio of grain size to foil thickness. For the analysis of these effects experiments with geometrically
scaled deep drawing tool sets from 8 mm to 1 mm punch diameter have been carried out, using
CuZn37 foils in different annealed conditions and a foil thickness ranging from 0.3 mm to 0.04 mm.
Additionally, the deep drawing process is simulated via FE-methods to consider influences that
cannot be measured using the available experimental setup, such as temperature conditions resulting
from the heat generated due to plastic dissipation and friction.
Superplasticity of Nanocrystalline ZrO2-Spinel Composite
Authors: Morita Koji , Hiraga Keijiro , Kim Byung Nam , Yoshida Hidehiro
Published: March 2009

The effect of nanocrystalization on superplastic flow was examined in ZrO2-30vol%spinel composite. The nanocrystalization can increase the strain rate by one order of magnitude or lower the deforming temperature by about 100 K. Irrespective of the lowered flow stress, however, the tensile elongation to failure of nanocrystalline composite is lower than that of submicrom-grain composite. The limited tensile elongation in nanocrystalline composite can be ascribed mainly to accelerating cavity damage accumulation.
Preparation of Bi4Ti3O12 Based Thick Films by Screen Printing
Authors: Futakuchi Tomoaki , Kakuda Tatsunori , Sakai Yuichi , Iijima Takashi , Adachi Masatoshi
Published: March 2009

Bi4Ti3O12 based thick films were prepared by screen printing and firing using Pt bottom electrodes and ZrO2
substrates. The influence of excess Bi2O3 as sintering aid was investigated. Furthermore, substitution of Ti-site
and Bi-site for V5+ and Nd3+ was performed. Screen-printable pastes were prepared by kneading the Bi4Ti3O12
based powder and Bi2O3 powder in a three-roll mill with an organic vehicle. The microstructures and
ferroelectric properties of the thick films were examined in comparison with bulk ceramics. The remanent
polarization of 9.6 μC/cm2 and coercive field of 64 kV/cm were obtained for the Bi3.0Nd1.0Ti2.99V0.01O12 thick
film with 10 wt% of excess Bi2O3 fired at 1200OC.
Preparation of Three Dimensionally Ordered Macroporous LiCoO2 Cathode for Lithium Batteries
Authors: Woo Sang Wook , Nakano Hiroyuki , Dokko Kaoru , Kanamura Kiyoshi
Published: March 2009

Macroporous LiCoO2 was prepared by a colloidal crystal templating method. Colloidal crystal consisting of monodisperse polystyrene particles was used as the template for the synthesis of macroporous LiCoO2. A Li-Co-O sol was injected into the template, and it was calcined at high temperatures. A porous membrane of LiCoO2 with three dimensionally ordered macroporous (3DOM) structure was obtained. The prepared material had a rock-salt type crystallographic structure with R3m space group. The interconnected macropores with relative uniform size (0.8~0.9 ;m) were observed on entire part of the membrane. The electrochemical properties of the 3DOM LiCoO2 were characterized with galvanostatic charge-discharge measurements in an organic electrolyte containing a lithium salt. The 3DOM LiCoO2 exhibited charge and discharge capacities of 136 and 107 mA h g-1, respectively, at around 3.9 V vs. Li/Li+, indicating that 3DOM LiCoO2 electrode had solid state redox reaction accompanying with Li+ ion insertion and extraction to CoO2 frameworks.
Synthesis and Characterization of Li[Ni(1/3-x)Mn(1/3-x)Co(1/3-x)Mx]O2(M=Fe,Mg,Al) Particle by Aerosol Process
Authors: Myoujin Kenichi , Ogihara Takashi , Nakane Koji , Ogata Nobuo
Published: March 2009

Spherical Li[Ni(1/3-x)Mn(1/3-x)Co(1/3-x)Mx]O2 (M=Fe, Mg, Al) precursor powders were synthesized by ultrasonic spray pyrolysis using aqueous solution of metal nitrate. X-ray diffraction (XRD), scanning electron microscope (SEM), BET method using N2 adsorption analysis and Battery tester were used for determination of the composition, morphology, particle size, surface area and electrochemical properties. SEM observation showed that the size of as-prepared particles were about 0.9 μ with narrow size distribution. The crystal phase of Li[Ni(1/3-x)Mn(1/3-x)Co(1/3-x)Mx]O2 (M=Fe, Mg, Al) was resulted in layered rock salt structure with R3m space group by calcinations at 1023 K for 10 h. No impurity-related peaks are observed from the XRD pattern with various doping metals. Mg and Al doped Li(Ni1/3Co1/3Mn1/3)O2 showed very good cycling stability. The Mg substitution for Ni led to the most excellent. On the other hand, the capacity degradation during cycling was observed by Fe substitution for Mn doped Li(Ni1/3Co1/3Mn1/3)O2.
Recent Developments in SiAlON Research in New Zealand
Authors: MacKenzie Kenneth , White G.Vaughan , Rumsey Ben , Woolf Hayley
Published: March 2009

An important aspect of previous sialon research in NZ has been the development of new synthesis methods, including refinements in carbothermal reduction and nitridation (CRN) methods and the use of mechanochemical activation of sialon precursors (either Al and Si nitrides and oxides or CRN mixtures). Mechanochemical activation of CRN mixtures of clay and carbon heated in N2 formed β-sialon (z = 2) at 1300oC (100oC lower than in unground mixtures) but 21R polytypoid and corundum were also formed. More recently, our attention has focussed on the technique of silicothermal reduction and nitridation (SRN) to synthesise other sialons, including the AlN polytypoids and Na and Li α-sialons. The interest in the polytypoids springs from their expected physical properties (thermal conductivity and good electrical insulation similar to AlN), their covalent bonding and relatively light weight arising from their high Al and N contents and their elongated crystal morphology which may improve the crack resistance of polytypoid composites with α-sialon. This paper describes the development of SRN single-step synthesis of high-purity dense 15R sialon from clay, Si and AlN, and the effect of additives on the synthesis and sintering of the product. A method is also described for SRN synthesis of Na and Li α-sialons from clay, Si and AlN using fluoride additives. Fluorides have the advantage of small size, high electronegativity, leading to their known facilitation of AlN synthesis. Furthermore, they do not readily enter the sialon structure but may toughen it by formation of glassy phases. Fluorides allow use of clay in this SRN synthesis by introducing M+ without additional oxygen, but have the disadvantage of generating SiF4 as a byproduct. The reaction using LiF proceeds readily at the very low temperature of 1200oC via an O-sialon intermediate by a mechanism which probably involves Si migration assisted by the formation of SiF4.The effect of mechanochemical activation (high energy grinding) on the SRN formation and sintering of Na and Li α-sialons, O and β-sialon has also been studied.Grinding the SRN O-sialon precursor promotes O-sialon formation in powders but not in pellets due to pre-reaction sintering, which is facilitated by the smaller particle size. Grinding Na and Li α-sialon SRN precursors forms a mixture of sialons rather than the target monophase product, while sintering of all the sialons is assisted by grinding their SRN precursors.
Theoretical Tensile Deformation of Σ13 Pyramidal Twin Grain Boundary in Alumina
Authors: Nakamura Kaoru , Mizoguchi Teruyasu , Shibata Naoya , Yamamoto Takahisa , Ikuhara Yuichi
Published: March 2009

First-principles grain boundary (GB) tensile deformation simulations were performed to investigate the atomic-scale mechanism of GB fracture of the Σ13 pyramidal twin GB in α-Al2O3. It was found that the specific Al-O bond broke at the GB core in the early stage of tensile deformation. From chemical bonding analyses, the first breaking bond was the weakest bond in the GB core. However, when the catastrophic GB fracture started, initially strong Al-O bond broke. This indicates that local atomic bonds should determine the microscopic GB fracture behavior.
Electric Loading-Induced Cracking Behavior at Electrode Edges in PZT Ceramics
Authors: Kusukawa Kazuhiro , Shiozaki Yohei
Published: March 2009

Fatigue damage behavior under repeated electric loading was investigated on two kinds of
PZT ceramics with discontinuous electrodes. Intergranular cracking was observed at the electrode
edge in soft PZT under electric fields greater than ±400 V/mm. However, under the same loading
conditions, no damage was observed in hard PZT. When cracking occurred, permittivity of specimens
decreased with the number of cycles corresponding to the amount of mechanical damage. FEM
analyses of the electroelastic field of the specimens showed that cracking due to cyclic electric loading
was related to 180˚ domain switching caused by concentrated electroelastic field.
Melt Spinnable Blend Polymers of Polycarbosilane and Polysiloxane for Synthesis of Silicon Carbide Micro Tube Structures
Authors: Kita Kenichiro , Narisawa Masaki , Mabuchi Hiroshi , Itoh Masayoshi
Published: March 2009

Silicon carbide base ceramic tubes were synthesized from blend polymers of
polycarbosilane (PCS) and methylhydrogen silicon oil (H-oil) by polymer precursor method. This
precursor method consisted of melt spinning, thermal oxidation curing and pyrolysis processes. Pore
structure observed at cross sections of obtained tubes depended on H-oil content, melt-spinning
temperature and oxidation curing conditions. At 578K for melt-spinning, however, a considerable
amount of H-oil was decomposed during the spinning process. The resulting H-oil contents were
usually lower than the starting H-oil contents. In the case of the 578K melt spinning, however, unique
single pore structures were often observed in the tubes by adjusting the curing conditions. At 40% of
the H-oil content, large pores with thin walls were observed at the cross-section, while such structures
were difficult to be controlled. By reducing the melt-spinning temperature to 543K, the starting H-oil
contents could be maintained during the spinning process. The cross sections of the tubes often
showed multi pores in this case.
Preparation of Characterization of Calcium Carbonate/Titanate Composite Material by Mechano-Activated Method
Authors: Du Ya Li , Ding Hao , Liu Yan Gai , Deng Yan Xi
Published: March 2009

The effects of technology condition and performance of calcium carbonate/titanate
composite material (CCTCM) prepared by mechano-activated method were studied in this paper.
The results show that CCTCM can be prepared by the surface modification of calcium carbonate
using titanate as a modification agent incorporated with the simultaneous wet ultra-fine grinding,
and the modification results and performance of composite material are affected by the grinding
condition of calcium carbonate. CCTCM has good application characteristics from its physical
property and the performance of packing polyethylene (PE).
Precipitation Behavior of Warm-Rolled Ti-Stabilized Interstitial-Free (IF) Steel Sheets
Authors: Han Fu Tao , Wang Zuo Cheng , Jing Cai Nian , Zhang Wen Ping
Published: March 2009

Precipitates have great influence on the recrystallization, texture evolution and thus the
final mechanical properties of the Interstitial-Free (IF) steel sheets, however, very few studies have
dealt with the precipitation behavior of IF steels warm rolled in ferrite region. In the present work, the
precipitate characteristics (type, morphology, size and amount) of warm-rolled ordinary Ti-stabilized
Interstitial-Free (Ti-IF) steel and p-added high-strength Ti-IF steel were investigated by Transmission
Electron Microscope (TEM) and Energy Dispersion Spectrometer (EDS). The results show that most
precipitates in warm-rolled ordinary Ti-IF steels are TiN, TiS, Ti4C2S2 and TiC. Besides these
precipitates, a great amount of FeTiP precipitates exist in warm-rolled P-added high-strength Ti-IF
steel. The precipitation of FeTiP retards the migration of grain boundary in the recrystallization
annealing, so the {111} texture and thus deep drawability of warm-rolled high-strength Ti-IF steel is
deteriorated.
A Study on Grinding Performance of Porous NiTi Shape Memory Alloy
Authors: Tao Yi Yi , Xu Jiu Hua , Ding Wen Feng
Published: March 2009

The machining performance of porous NiTi shape memory alloys prepared using powder metallurgical production technique has been investigated experimentally in the grinding operation. Grinding force ratio, specific grinding energy, surface characteristics were detected. The result reveals that, much difference of grinding characteristics exists among three kinds of NiTi alloy because of the pore rate and the mechanical performance induced by TiH2. Under the experimental conditions, the integrated effects of predominant plastic flow and slight brittle fracture were taken for porous NiTi alloy during grinding. Additionally, the grinding parameters should be chosen carefully, otherwise the surface quality deteriorates and even the microcrack perhaps appears.
Study on Contact Mechanism of Interface in Wafer CMP Based on Abrasion Behavior
Authors: Su Jian Xiu , Zhang Xue Liang , Chen Xi Qu , Du Jia Xi , Guo Dong Ming
Published: March 2009

Right getting hold of the contact form between the wafer and the pad is the precondition of fully understanding the material removal mechanism in wafer chemical mechanical polishing (CMP) process. In this paper, according to friction and abrasion theory, the differentiating method of contact form between the wafer and the pad has been obtained firstly. Then, the material removal rate (MRR) produced by mechanical action, chemical action and their interaction has been achieved by test results of MRR. According to analysis on test results of MRR, it is concluded that the mechanical action produced by abrasives is the main mechanical action, the MRR produced by the interaction between the mechanical action of abrasives and chemical action of slurry is the main MRR and the contact form between the wafer and the pad is solid-solid contact in wafer CMP. These results will provide theoretical guide to further understand the material removal mechanism of in wafer CMP.
Technique Optimization of Dual Rotation Plates Lapping Method for Ceramic Ball
Authors: Lv Xun , Yuan Ju Long , Dai Yong
Published: March 2009

Dual rotation plates lapping method can effectively solve the limitations of traditional
ceramic ball machining methods. This paper focuses on the application of Taguchi method to
optimize the technique parameters to lap ceramic ball. The main objective is to study impact degree
of the process parameters (lapping load, lapping speed combination and slurry concentration). The
results show that the experimental design based on Taguchi method can determine the optimum
machining conditions which improve the surface quality and geometrical precision of ceramic ball.
Influences of Ultrasonic Assistance in High Speed Lapping of Nano ZTA Engineering Ceramic on the Surface Machining Quality
Authors: Jiao Feng , Zhao Bo , Liu Chuan Shao , Zhu Xun Sheng
Published: March 2009

Ultrasonic aided high speed lapping with solid abrasive material was put forward aimed at the
precision finishing of nano ZTA engineering ceramic. Through theoretical analysis and contrast lapping
experiments, the influences of ultrasonic assistance on the surface machining quality were clarified. Research
results show that the maximum undeformed chip thickness in ultrasonic aided lapping is smaller than that in
conventional lapping under the same conditions; ultrasonic assistance is beneficial to enlarging the range of
ductile lapping regime and improving the surface quality of nano ZTA ceramic; with the application of
ultrasonic vibration, smaller surface roughness and more regular surface profile can be obtained.
High Performance Grinding Zirconia Ceramics by Brazed Monolayered Diamond Wheels
Authors: Li Shu Sheng , Xu Jiu Hua , Xiao Bing , Fu Yu Can , Xu Hong Jun
Published: March 2009

A new segmented grinding wheel of the brazed monolayer diamond was developed with
a defined grains pattern on the wheel surface. Results of grinding zirconia using brazed segmented
diamond wheel were presented. The experiment results showed that the grinding forces ratio
becomes higher with the increasing of the specific material removal rate and the specific energy
falls with the increasing of the maximum undeformed chip thickness during grinding zirconia
process. In this investigation, brazed diamond wheels with defined distribution patterns was
conditioned by touch-dressing method so that grit tips get micro-conditioned and allow the
underlying grits to participate and consequently improve the quality of finish. All the ground
surfaces of zirconia were generated by the combined removal modes of brittle and ductile.
Fractal Tool-Path Planning for Free-Form Surface Polishing System
Authors: Li Yu Hao , Feng Jing Chun , Wang Yu Han
Published: March 2009

This paper presents a reasonable method for generating the tool-path of free-form surface
polishing using the fractal curves. Free-form surface polishing processes as a finishing process are
used to reduce the roughness of surfaces and smooth the surface form by eliminating the surface
waviness left by tool marks, EDM spark erosion and so on. In the interest of realizing this aim
without introducing undesirable surface waviness and time efficiency, a tool-path should provide
even coverage of free-form surface during polishing. A fractal curve is suitable to cover the
free-form surface uniformly at any complexity due to its plane-filling and self-similar
characteristics. A method of generating the fractal path for free-form surface polishing is presented,
and also an automatic polishing system is installed to confirm the path planning method’s validity.