bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Second Sintering on Intragranular Structure and Mechanical Properties of 10vol%Al2O3/3Y-TZP Composites
Authors: Li Xiu Hua , Men Rong Lei , Suo Guan Wei , Yang Zheng Fang
Published: March 2009

To study the effect of second sintering on intragranular structure and mechanical properties of
10vol%Al2O3/3Y-TZP composites, the composites were prepared by ball-milling nano-γ-Al2O3 and
nano-ZrO2(3mol%Y2O3), pressing unidirectionally, cold-pressing isostatically, then first sintering at
1400°C for 2h and second sintering at 1600°C for 5h in air. The composition and microstructure of the
composites were examined by X-ray diffractometer and scanning electron microscope, transmission
electron microscope. The results showed that the second sintering changed the microstructure and
fracture mode. After second sintering, the structure of fine grains was changed into the mixed one of large
grains and small grains . Many large grains contained small grains, forming intragranular stucture that
could be produced by the interblending of not only Al2O3 and ZrO2 but also ZrO2 itself. The intergranular
fracture after first sintering was changed into transgranular fracture and intergranular fracture after second
sintering . The second sintering led to grinds growing up and intragranular forming, which enhanced the
contribution of the phase transformation toughening. Although the second sintering resulted in abnormal
increase of grain size, the fracture strength and the fracture toughness of the composite were 667 MPa and
12.9 MPa⋅m1/2, respectively, due to the intragranular structure and the enhanced phase transformation
toughening.
Preparation of TiB2 Nanoparticles Reinforced Cu-Matrix Composite by Direct Combustion Synthesis
Authors: Xu Qiang , Zhang Xing Hong , Han Jie Cai , He Xiao Dong
Published: March 2009

Titanium diboride nanoparticles reinforced copper matrix composite by combustion synthesis
technology from titanium, boron and copper powders without other activated methods. Thermodynamics
of the system was calculated theoretically. It was found that TiB2 was stable phase in the composite and
TiCu interphase compound can convert into stable phase. The phases of the synthesized product were
identified using X-ray diffraction and the results showed that only TiB2 and Cu phases, no other phases
existed in the product. It is consistent with the calculated result of thermodynamics. SEM microstructural
characterization showed that a homogenous distribution of the titanium diboride nanoparticles in the
copper matrix.
Multilayer SiC/Si Composites Derived from Papers
Authors: Yang Gang Bin , Liu Yin Juan , Qiao Guan Jun , Jin Zhi Hao
Published: March 2009

The SiC/Si multilayer composites were fabricated successfully by reaction sintering method with normal stacked papers as the raw materials. Paper was cut into rectangular sheets and stacked, then infiltrated with phenolic resin to get a laminar structure. This paper /resin laminar composite was transformed into porous carbon with laminar structure after heating at 800 oC for 2h in N2 atmosphere. Finally this porous laminar carbon was reheated with silicon powder at 1450-1650oC for 1-2h in a vacuum furnace and SiC/Si multilayer composites can be obtained through the in-situ reaction between carbon and liquid silicon. The microstructure, reaction mechanism, phase composition and mechanical properties of these multilayer composites were researched. The final material shows a distingished laminar structure with alternating arrangement of SiC thick layers and silicon thin layers. SiC layer was composed by beta-SiC and a little of free silicon and carbon not reacted. The capillarity infiltration and in-situ reaction of liquid silicon act key roles in this process. Higher strength and non-catastrophic failure mode for this material were observed.
Reaction Path and Microstructures of Ti3SiC2/SiC Composite by Spark Plasma Sintering
Authors: Zhang Jian Feng , Wang Lian Jun , Jiang Wan , Chen Li Dong
Published: March 2009

Ti3SiC2/20vol%SiC composite was synthesized by spark plasma sintering (SPS) under a pressure of 50MPa at 1350°C using Ti, Si and C as starting powders. The phase constituents and microstructures of the composite were investigated. X-ray diffraction (XRD) results demonstrated that Ti reacted with C to form TiC firstly, then TiSi2 formed from Ti and Si. The formation of Ti3SiC2 might come from two reactions. One was that TiSi2, Ti and TiC reacted directly to form monolithic Ti3SiC2. The other one was that TiSi2, Ti and C reacted to form Ti3SiC2 and SiC. The EPMA results showed that the main phases were Ti3SiC2 and SiC with a minor content of TiC as impurity. TiC particles less than 1μm in diameter distributed in SiC phase.
Precision Machining of Si3N4 Refrigerator Friction Couple Based on FEA
Authors: Tian Xin Li , Tang Xiu Jian , Hu Zhong Xiang , Yu Ai Bing
Published: March 2009

The compressing piston and cylinder of refrigerating compressor frequently come into failures
as anti-wearability for metal material is weak. Engineering ceramics is appreciated by designers thanks to
its excellent performances. However, it is difficult to machining material because of high hardness. The
FEA modules for displacement and stress distributions of compressing piston and cylinder under declared
running conditions are established based on the theories of elasto-plasticity and aerodynamics, which
reveal the optimal precision conjugation clearance dependence of pressure distributions regularity
between friction couple. Based on the FEA analytical results, the feasibility of replacing metal material
with Si3N4 ceramics in the friction couple manufacture is researched. Special clamps have been designed
to guarantee the superficial quality as mirror surface and tolerances of form and position, technological
procedures are programmed, and with satisfactory machining effect.
Wear Characteristics of Twist Drills in Machining Fluorophlogopite
Authors: Ma L.J. , Yu Ai Bing , Mei Z.M.
Published: March 2009

The machinable fluorophlogopite was drilled with tungsten-cobalt carbide and high-speed
steel drill bits, respectively. The wear widths of major flank were measured, and the wear characteristic of
twist was analyzed during drilling fluorophlogopite ceramics.Drilling experiments were carried to
consider influence factors of drill bit wear, such as tool materials, cooling condition, spindle speed and
tool angles. Tool materials and cooling conditions are the major factors to affect wear of drill bits.
High-speed steel drill bits are not suitable for drilling fluorophlogopite ceramics. Cooling condition
affects wear remarkably. With the rising of spindle speed, the wear widths of major flank grows. But apex
angle has little affects on the tool wear rate. Research results indicate that low tool wear can be obtain
through optimizing tool material and machining parameters in drilling fluorophlogopite ceramics.
Properties of Sol-Gel Bonding Castables
Authors: Cao Feng , Long Shi Gang , Wu Xing Rong , Telle Rainer
Published: March 2009

The silica-alumina sol bonding agent, prepared by the sol gel route from ethyl silicate and
aluminium isopropanol, was characterized by X ray diffraction, infrared spectroscopy, thermogravimetric
analysis, particle size distribution. It was utilized in the corundum based refractory castables. The
properties and characters such as cold crushing strength, apparent porosity, hot modulus of rupture, pore
size distribution, scanning electron microscopy, energy dispersive spectral analysis, thermal shock and
slag corrosion resistance tests of the selected samples from both the sol-gel bonding castables and the
cement bonding castables were determined to identify the role of sol-gel additive in castables. The results
show that the sol-gel bonding castables have a lot of advantages compared with traditional cement
bonding castables and are more suitable for application in the ladles.
Effect of Cr2C3 Addition on Microstructure and Mechanical Properties of Ti(CN)-Based Cermets
Authors: Ni Xian Juan , Qi Long Hao , Pan Wei
Published: March 2009

In this paper, the Ti(CN)-based cermets were fabricated with ultrafine Ti(CN) powders,
additives WC, Cr2C3 and Mo, metal binder Ni by vacuum sintering and HIP treatment. The composition
of the mixture was Ti(CN)-10Mo-20WC-xCr2C3-20Ni. Effect of Cr2C3 addition on microstructure and
mechanical properties was investigated. Results indicated that with increasing Cr2C3 content, the relative
densities after vacuum sintering decreased and the grain sizes of cermets increased. Cr2C3 addition to the
cermets improved the hardness but had some negative effect on the performance of bending strength.
The Interface Reaction between an Ag+-Doped TiO2 Film and Stainless Steel Substrate
Authors: Ding Xin Geng , Gao Ji Wei , Shen Qian Hong , Liu Jian Xiang , Li Li
Published: March 2009

Ag+-doped TiO2 films on stainless steel were prepared by a sol-gel method and their
microstructures and compositions were studied with X-Ray Diffractometer, Scanning Electron
Microscope (SEM) and X-ray Photoelectron Spectroscopy. It was shown that Fe atoms in untreated
stainless steel react with Ag+ in the TiO2 film and form FeTiO3, which has an acicular crystal form under
SEM observation. As a result, Ag+ in the film is reduced to the silver atom, which degrades the
antibacterial property of the film. However, after an oxidization of the substrate, a layer of ferric oxide is
formed, which reacts with Fe atoms that would otherwise react with and reduce Ag+, and then forms
FeTiO3. Thus, the penetration of Fe atoms is stopped and Ag+ in the anatase-structure TiO2 film is
protected from the reduction, which enhanced antibacterial property of the film.
Biomimetic Fabrication and Characterization of BG/COL/HCA Scaffolds for Bone Tissue Engineering
Authors: Chen Xiao Feng , Wang Ying Jun , Yang Chun Rong , Zhao Na Ru
Published: March 2009

The bone tissue engineering scaffold was developed by compounded the type I collagen with
the porous scaffold of the sol-gel derived bioactive glass (BG) in the system CaO-P2O5-SiO2. The
resultant porous scaffold was treated in supersaturated calcification solution (SCS) to form the surface
layer of hydroxyl-carbonate-apatite (HCA) since the type I collagen possessed good biocompatibility and
bio-absorbability, and also, the ability of inducting calcium phosphates to precipitated inside and outside
the collagen fibers where the collagen fibers acted as bio-macromolecules template for formation of
bone-like inorganic minerals in nature bone such as: octo-calcium phosphate (OCP), tri-calcium
phosphate (TCP) and hydroxyl-carbonate-apatite (HCA). On the other hand, the sol-gel derived bioactive
glass also played an important role in formation of the above bio-minerals owing to its serial chemical
reactions with the body fluid. The in vitro study in supersaturated calcification solution SCS indicated
that the surface of the porous scaffold was able to induce formation of bone-like HCA crystals on the pore
walls of the scaffold which possessed satisfactory cells biocompatibility.
Microstructure Analysis of a Composite System Composed of Zirconia/Alumina Composites and Vita Alpha Coating-Glass for Dental Applications
Authors: Zhang Bin , Chen Ji Hua , Gao Ji Qiang , Qiao Guan Jun
Published: March 2009

The aim of this study was to analyze the microstructure and to observe the surface reactivity of
a composite system composed of two kinds of zirconia/alumina (Z/A) composites and Vita alpha
glass-ceramic, which would satisfy the biocompatibility and strength requirements for dental applications.
Two zirconia/alumina composites defined as specimen A and B were used as the substrate of fixed partial
denture, while commercial Vita alpha glass-ceramic as the coating-glass.From the experiment we can
find the following results. Zirconia particles migrated into grain boundaries and located at three or four
grain junctions of alumina particles. The crack pattern is consistently transgranular for the zirconia grains,
whereas it is intergranular for alumina grains. The mechanical properties of the composite with 66.6wt%
zirconia was superior to that of 33.3wt% zirconia-composed composite, while the homogeneous bond
between Vita alpha glass-ceramic and Z/A composites are distinct. Therefore, this system composed of
Z/A composites and Vita alpha glass-ceramic would satisfy matching properties of dental requirements
and it has a great future to be used as all-ceramic restoration materials.
Preparation of β-TCP/HAP Composite Bioceramics
Authors: Liu Tong Jun , Yang De An , Di Li Zhi
Published: March 2009

The β-TCP granules with the range of diameter from 314μm to 800μm were prepared. The
β-TCP/HAP composite bioceramics were prepared by dipping β-TCP discs made from the granules in
HAP sol. The component and morphology of the ceramics were observed by X-ray diffraction (XRD) and
scanning electron microscopy (SEM) respectively. The compressive strength of specimens was tested by
Testometric M350-20KN. The results show that the samples can be calcined at 1150°C without phase
transformation of β-TCP to α-TCP by doping the β-TCP with 1wt% MgO. And the compressive strength
of the composite ceramics reaches 24MPa.
Fabrication of Bi3NbTiO9 Thick Films by Air Flow Deposition
Authors: Barrel Jeremie , Stytsenko Eugene
Published: March 2009

Ferroelectric thick films of Bi3NbTiO9 (BNT) with Aurivillius type structure were
fabricated using the airflow deposition method at room temperature. The precursor powder for
deposition was prepared by a conventional mixed oxide route. The BNT films obtained from airflow
deposition had thickness between 25 and 90 μm. Subsequent sintering showed that the films were
sinterable at lower temperatures than bulk samples prepared from the same powder using isostatic
cold pressing technique. Thick films sintered at 900 0C displayed higher density and a higher
electrical breakdown field compared with bulk samples. SEM microscopy showed similar grain size
for the thick films sintered at 900 0C and corresponding bulk samples sintered at 1150 0C. A
pronounced preferential grain orientation of 70% along the c-axis was observed for thick films with
thickness of 252m sintered at 9000C. While the grain orientation in bulk samples was random the
grains in the thick films were aligned along the substrate plane. This significant microstructural
difference between thick film and bulk samples is believed to be associated with directional nature of
the deposition process. The novel method allowed anisotropic film formation without applying
pressure during sintering. Low sintering temperature allows reduction in bismuth losses and better
grain growth control, which also contributes to the advantages of the method.
Preparation of Bioactive β-Tricalcium Phosphate Scaffold with Bone-Like Structure
Authors: Xu Wei , Tian Jie Mo , Wang Chen , Dong Li Min , Zan Qing Feng
Published: March 2009

Porous β-TCP scaffold was prepared using three-dimensional gel-lamination technology with
foamy slurry. Then the sintered scaffolds were soaked in 1.5SBF solution to achieve scaffolds with
bone-like structure. After soaking, a low crystallized bone-like apatite layer containing CO3
-2 was formed
on the surface of the scaffold. With presoaking in NaOH solution, the formation of the bone-like apatite
layer on the surface of the scaffold in 1.5SBF solution was accelerated. In this way, a bioactive porous
β-TCP scaffold with bone-like structure could be prepared.
The Crystalline, Dielectric and Pyroelectric Properties of (1-x)Pb(Sc0.5Ta0.5)O3-xPb(Zr0.52Ti0.48)O3 Relaxor Ferroelectric Ceramics
Authors: Lan De Jun , Chen Yi , Chen Qiang , Jiang Yi Hang , Xiao Ding Quan , Zhu Jian Guo
Published: March 2009

The (1-x)PST-xPZT(PSTZT) complex perovskite relaxor ferroelectric ceramics were prepared
by wolframite precursor process(named two-step-sintering method, TSSM) and conventional oxides
mixing method (named one-step-sintering method, OSSM), respectively. The experimental results demonstrated
that pure perovskite PSTZT ceramics could be acquired by OSSM or TSSM. The temperature
dependence of permittivity and dielectric loss of PSTZT ceramics indicated that PSTZT ceramics are
relaxor ferroelectric ceramics with a complete diffusive phase transition. The pyroelectric properties of
PSTZT ceramics prepared by OSSM and TSSM were also investigated via quiet-state method. It was
found that the larger the x value of (1-x)PST-xPZT is, the lower the pyroelectric coefficient of PSTZT
ceramics is. The pyroelectric coefficient of 0.9PST-0.1PZT ceramics is about (8~25) × 10-8C/cm2·K at
room temperature. The pyroelectric figure of merit of PSTZT ceramics was also discussed.
Adhesion of Diamond Film to Co- Deficient Cemented Tungsten Carbide Substrate
Authors: Li Hong Lin , Gou Li , Ran Jun Guo
Published: March 2009

Diamond film was synthesized on Co-deficient (Co content is about 0.5%) WC-Co substrate
using microwave plasma chemical vapor deposition (MPCVD) equipment without special pretreatment.
SEM, XRD, Rockwell-indentation test and scratch test were used to analyze the structure and
morphology of the diamond film and its adhesion to the substrate. Co content was also measured by
EDAX. The results show that the film synthesized is of ideal diamond structure with perfect and uniform
grains, dense and continuous surface and strong adhesion. Co content on the surface of the substrate is
about 0.8% after 20h deposition, which is considered as one of the main causes to get good adhesion.
Wear Behavior of Plasma Sprayed Ni-WC Composite Coatings
Authors: Bao Chong Gao , Gao Yi Min , Xing Jian Dong , Zhang Guo Shang
Published: March 2009

Seal materials often lose their effectiveness due to the wear of surface under the combined
effect of environment and load. In this research, a metallurgical bonding composite coating reinforced
with nickel -coated tungsten carbide (Ni -WC) particles was produced on 40Cr carbon steel substrate by
plasma sprayed. The bond strength of the coating/substrate interface and the tensile strength of the coating
itself reached 260–330 and 100–132MPa, respectively. Effects of Ni and WC contents on the wear
behavior of the coating have been systematically investigated at two different wear conditions, namely the
high stress pin-on-disk abrasion and three-body abrasive wear. The results show that the higher the Ni
content in the coating, the lower the hardness and wear resistance. In stress pin-on-disk abrasive wear, the
mass percent of Ni in the coating having the lowest wear amount was 40%, and which was 60% in
three-body abrasion. In view of the above, the WC reinforcement of the composite coating plays an
important role in protecting the matrix from being worn-out, whereas in the abrasive wear, the wear
mechanism is mainly controlled by the scratching and micro-cutting of the matrix followed by the pull out
of WC particles due to the scratching action of abrasives. The wear resistance of the 40Cr carbon steel
composite coating (Ni -WC) is better than that of the flame overlaid coating.
Microstructure and Dry Sliding Tribological Behavior of Microarc Oxidation Coating Formed on Ti6Al4V against Steel
Authors: Wang Ya Ming , Lei Ting Quan , Jia De Chang , Zhou Yu , Ouyang Jia Hu
Published: March 2009

A nanostructured TiO2 dominated ceramic coating was fabricated on Ti6Al4V by microarc
oxidation (MAO). The coating with about 30 μm thickness is porous in the outer layer and compact in the
inner layer, mainly composed of rutile and a small amount of anatase TiO2, both in nano grain structure.
The hardness and elastic modulus of the compact layer in the coating are about 8.5 GPa and 87.4 GPa.
The adhesion strength is about 70MPa. The friction coefficient of the polished coating sliding against
GCr15 steel is as low as 0.2, which is clearly superior to that of the unpolished one. This is attributed to
the low surface roughness. However, the oxidation wear mechanism occurring at the later stage of wear
tests leads to a gradual increase of friction coefficient.
Electrical Properties of (1–x)(0.8PMN-0.2PNN)-xPT Ceramics near the Morphotropic Phase Boundary
Authors: Zhou Guo Yuan , Pan Jin Song , Zhang Xiao Wen
Published: March 2009

Ferroelectric ceramics of (1x)(0.8PMN0.2PNN)xPT (x = 0.280.43) were synthesized by
the columbite precursor method. Their phase structures as well as the dielectric, ferroelectric and
piezoelectric properties were investigated. X-ray diffraction (XRD) results demonstrate that the
morphotropic phase boundary (MPB) of this system lies in the composition range of x = 0.31–0.37.
Examination of the dielectric behavior indicates that the ceramics exhibit high dielectric constants
near the MPB compositions. In addition, the piezoelectric properties of the ceramics were found quite
well around the MPB. The interrelated mechanism was also discussed.
Interface Biomechanical Properties between Femora and Bioactive Ceramic Coatings Prostheses during the Initial Implant Stage
Authors: Tang Liu Ding , Zhao W.M. , Tian L.Y. , Li Bing Zhe
Published: March 2009

Biomechanical models of implanting prostheses into femora by means of press fit, i.e. the mechanics of non-homogeneous layer-like composites, have been used to quantify the press-fit strength and circumferential stress of the interface, when femora are partially replaced by different thicknesses of bioactive ceramic coatings on a prosthesis surface during the initial implant stage. The maximum press-fit strength appears on the interface between femora and Ti alloy prostheses with non-coating; the press-fit strength decreases with the increased thickness of the coating. The circumferential stress displayed as the large tensile stress at the femoral side of the interface; the compressive stress, appeared at the side of the coating and Ti alloy prosthesis. The shearing strength, jointing between the prostheses and femora would be bigger with the thinner bioactive ceramic coatings. Considering the biodegradability of bioactive ceramic coatings, e.g. hydroxyapatite, HA, it is concluded that the optimum thickness of the bioactive ceramic coatings will be about 50-60 microns.
Making Fluorophlogopite Ceramics through Ceramic Processing
Authors: Li Mao Qiang
Published: March 2009

Fluorophlogopite ceramics, which possesses very good machinability, high electrical
resistance and high dielectric strength, is very difficult to be sintered to fully dense state. It is usually
made through glass-ceramics processing. In this paper the effects of particle size distribution and
sintering agents on sintering of fluorophlogopite ceramics are investigated. The study concludes that
dense fluorophlogopite ceramics can be produced through ceramic processing, including careful
synthesis of fluorophlogopite powder as raw material, grinding with attrition mill, and pressureless
sintering with the help of plumbum contained boron silicate glass as sintering agent in the temperature
range of 1100 to 1200°C.
Preparation and Photocatalytic Performance of Ag-Doped Titanium Dioxide Whiskers
Authors: Jiang Xing Jun , Ling Yun Han , Li Hong Yi , Bai Xin De
Published: March 2009

Ag doped TiO2 whiskers were synthesized by calcining metatitanic acid with potassium car=
bonate to form tetratitanate whisker precursor, following by proton-exchanged and immobilized with Ag+.
The post treatment conditions for whiskers synthesis were investigated and the phase composition,
morphology and photocatalytic performance were characterized. The results showed that the TiO2
whiskers had an aspect ratio more than 15 and the absorption edge of Ag doped titania whiskers were red
shifted to 50 nm. The result of methylene blue degradation revealed that the photocatalytic performance of
Ag doped TiO2 whisker has been greatly improved.
Preparation and Photocatalytic Properties of Nanosized La3+ and Co2+ Co-Doped TiO2 by Microemulsions
Authors: Liu Wei Liang , Lu Dan Li , Ge Chang Chun , Chen Jian Hua , He Zhi Ping
Published: March 2009

La3+ and Co2+ co-doped titania nanoparticles were prepared from reacting TiOSO4, La(NO3)3 and Co(NO3)2 with NH4OH in water/Triton X-100/n-hexanol/cyclohexane microemulsions. The structure, surface morphology and the specific surface area of the samples were characterized. The photocatalytic efficiency of as-prepared TiO2 was tested by photodegrading methyl orange. The results showed that doping with La3+ and Co2+ could suppress the growth of TiO2 grains and increase the specific surface area; When the calcination temperature increased from 300°C to 900°C, the average crystallite size of the particles increased from 7.3nm to 35.6 nm andthe specific surface area of the particles decreased rapidly from 205.5m2/g to 41.2m2/g. The synthesized amorphous particles wer transformed into anatase phase at 300°C, and further into rutile phase at 900°C. UV-Vis diffuse reflectance spectrum revealed that La3+ and Co2+ co-doped TiO2 absorbed UV light and visible light, while pure TiO2 could only absorb UV light. In the experiments of photodegrading methyl orange, it was proved that La3+ and Co2+ co-doped TiO2 had high photocatalytic activity under UV light and visible light, while pure TiO2 showed photocatalytic activity just under UV light.
Dispersion and Electrophoretic Deposition of Titania Particles
Authors: Zhang Shao Hua , Xie Bing , Li Feng Yi
Published: March 2009

The dispersion of titania particles in different solvents and doping of dispersants at different levels were studied. Results showed butanol is a good solvent and triethanolamine(TEA) is a good dispersant at 3wt% level for TiO2. Based on the dispersion results, titania coatings were prepared by electrophoretic deposition in organic solvents with addition of PEG and without. The deposition amount and the photocatalytic activity of titania coatings were investigated.
Photocatalytic Degradation of Methylene Blue Aqueous Solution under Visible Light Irradiation by Using N-Doped Titanium Dioxide
Authors: Li Yan Hong , Cao Wen Bin , Ran Fan Yong , Zhang Xiao Ning
Published: March 2009

N-doped TiO2 powders with high photocatalytic activity under visible-light irradiation have
been prepared by calcining anatase nanocrystalline TiO2 powders and guanidine hydrochloride at 350 °C,
450 °C, 550 °C and 650 °C with the holding time ranged from 1.5 h to 3 h, respectively. The guanidine
hydrochloride content was varied from 1 to 6 M for the experiments. XRD patterns indicate that all the
powders are anatase crystalline phase. The specific surface area is 25~45 m2/g measured by BET method.
XPS results show that N atoms were incorporated into the lattice of TiO2 and the amount of N doped in
TiO2 is reached up to 8.26 at%. UV-Vis absorption spectra show that the absorption edge of the
synthesized N-doped TiO2 powders, calcined at 350 °C for 2.5 h, has red-shifted well into visible region
up to 700 nm. Degradation of methylene blue (MB) aqueous solution has been investigated by UV-Vis
light spectrophotometer. The 400-mL 10 mg/L aqueous solution of methylene blue could be degraded
completely with 4 g N-doped TiO2 within 4.5 h of visible light irradiation.
Preparation of Nanosized Ca-Zn Ferrite Particles by a Sol-Gel Method and its Magnetic Properties
Authors: Xao Xi , Qian Cheng , He Zhen Qiu
Published: March 2009

A sol-gel process was used to synthesize nanosized Ca-Zn ferrite powders. DTA-TG, XRD and SEM techniques are employed to investigate the thermal decomposition of the dry gel, phase composition and microstructure of nanosized ferrite particles. The results revealed that the Ca0.4Zn0.6Fe2O4 phase appeared while calcined the gel powders at 300 °C for 2 hrs, and the Ca0.4Zn0.6Fe2O4 crystalline can be formed completely at 400 °C. Hysteresis loop indicated that the nanocrystallites size has great influence on the magnetic properties, which leads to the increase of the specific saturation magnetization and the decrease in coercivity of the samples with increasing the particle size.
Synthesis of LaMnO3 via a Mechanochemical Activated Process
Authors: Wu Hao , Xu Qi Ming , Li Qiang , Zhang Cheng , Jiang Dan Yu
Published: March 2009

LaMnO3-based perovskite oxides are typical functional materials applicable to various devices
for its chemistry and physics properties. The conventional method solid-state reaction method has some
drawbacks of high reaction temperature, large particle size and limited degree of chemical homogeneity.
So, an easy, low cost and environmental method of synthesizing fine and homogenous powders of
LaMnO3 is required. This paper discusses the synthesis of LaMnO3 via a mechanochemical activated
process. The mixtures of La2O3 and Mn2O3 were used as starting powders. The specific surface of starting
materials was measured by BET method. A planetary ball mill was used to grind the starting mixtures.
During the grinding process, XRD analysis was employed to make clear the phase changes, and BET
analysis was used to test the specific surface changes. After being grinded for different time, the mixtures
were annealed at different temperatures. After this, the phase identification of mixtures was conducted by
XRD. At the same time, a pre-mixing of starting materials with ethanol as solvent by normal ball-milling
for 8 hrs was proceeded to obtain homogeneous mixture and improve the efficiency of grinding. All
obtained LaMnO3 powders via the mechanochemical activated process were characterized by SEM
imaging. Finally, an optimized powder processing was proposed.
Effects of Processing Conditions on the Dielectric Properties of CaCu3Ti4O12 Ceramics
Authors: Wang Chih Ming , Kao Kuo Sheng , Lin Shih Yuan , Chen Ying Chung , Weng Shang Chih
Published: March 2009

In this present work, we adopt conventional solid state reaction techniques to obtain
CaCu3Ti4O12 (CCTO) ceramics and the dielectric properties of polycrystalline CCTO samples sintered in
the temperature range 900 − 1100°C were investigated. X-ray diffraction (XRD) patterns show no
obvious change in crystal phase with various sintering temperature. However, experimental results show
that the dielectric properties of CCTO ceramics are very sensitive to processing parameters and the
dependence of dielectric constant and loss tangent of CCTO ceramic on processing can be obtained. The
effect of sintering conditions on the surface microstructures and the electrical properties of CCTO
ceramics are also discussed in this study.
Preparation of Nano-Ag Particles and Antibacterial Dope Loaded Silver
Authors: Yin Jie , Zhang Yun , Yin Guang Fu , Zhang Ping
Published: March 2009

The nano-size silver particles were prepared in polymer-protecting colloidal dispersion with
silver nitride as the raw material, hydrazine hydrate as the reduction reagent and polyvinyl pirrolidone
(PVP) as the protective solvent. The optimal conditions for the preparation process were studied
experimentally as well. The influences from main factors, such as Ag+ concentration and ratio of
hydrazine/AgNO3, on the particle size, appearance shape, particle aggregation condition and size
distribution of nano-silver particles were also investigated. The results showed that the size of Ag
particles prepared in this polymer-protecting system is less than 50 nm, and PVP can reduce the growing
tendency of nano-size silver particles. Meanwhile, the antibacterial dope loaded nano-silver particles
were prepared by wetting agent, dispersant, defoamer, etc. The antibacterial and bacteriostatic effects of
the dope with or without nano-silver particles were tested with bacilli as the tested bacteria. The
experiment results showed that the dope loaded nano-silver particles are of high practicality. Its antibacterial
ratio is also up to 91.9% in one hour when the added dosage of nano-silver is 0.02%.
Synthesis of Yttrium Oxide Hydroxide Nitrate Nanorods by Hydrothermal Method
Authors: Peng Li Xia , Hong Zhang Lian , Li Guang Hui , Wang Min Quan
Published: March 2009

Yttrium oxide hydroxide nitrate nanorods were prepared via a facile hydrothermal method
using PEG-6000 as template in Y(NO3)3 and KOH reactant system. The effect of hydrothermal treatment
time on the crystallite structure, the crystallite shape and size was investigated by XRD and FE-SEM
measurements. XRD results showed that the main phase of the as-prepared product was Y4O(OH)9NO3
crystal of monoclinic phase. FE-SEM images displayed that the size of the nanorods grows large with
increasing time from 5h to 24h. Furthermore, no shape change was found, demonstrating that the as
grown nanorods are stable when the reaction time increased from 1h to 24 h. Dissolution recrystallization
process was proposed to explain the growth process of Y4O(OH)9NO3 nanorods.
Large-Scale Fabrication of ZnO Hexagonal Rods Arrays by a Simple Chemical Solution Method
Authors: Du Yi , Hao Wei Chang , Zhang Jun Ying , Wang Tian Min
Published: March 2009

In this paper, nanostructure zinc oxide (ZnO) hexagonal rods arrays on ZnO granular films
coated substrates were fabricated by a simple chemical solution method. The shapes and structures can be
controlled by changing the reactants and experimental conditions. X-ray diffraction (XRD),
field-emission scanning electron microscopy (FESEM) equipped with energy dispersive spectrometer
(EDS), and fluorescence spectrum were used to characterize the structures and luminescent properties.
The best reacting condition has been discussed. Urea was found playing an important role in forming rods.
The granular films acting as the seed films were proved.
Surface Morphology of Thin Film Deposited on Rotating Substrate by EB-PVD
Authors: Shan Ying Chun , He Xiao Dong , Li Ming Wei , Li Yao
Published: March 2009

The thin film deposited by electron beam physical vapor deposition (EB-PVD) on rotating substrate was approached via a kinetic Monte Carlo (KMC) algorithm on a “surface” of tight-packed rows. The motivation is to study the surface morphology distribution of thin film along the substrate radial. Effective deposition rate model and effective incident angle model were established along the substrate radial. Two phenomena are incorporated in the KMC simulation: adatom-surface collision and adatom diffusion. The KMC simulations show that the surface roughness of thin film is small and the changing of surface roughness is small near the side of rotation axis, however, the surface roughness is big near the side of substrate edge, and the surface roughness increases quickly with the increasing of substrate radius when r>300 mm. The simulation results indicate that the effective incident angle is the main factor to cause the changing of surface roughness: the effective incident angle does not reach critical value and the deposition rate difference is small when the radius is less than 300 mm, so the surface roughness of thin film in the scope is small and its changing is small, but when r>300 mm, the effective incident angles increase sharply with radius increasing and all of them are above the critical value, which cause surface roughness of thin film to increase quickly. Experiments reveal that the KMC method can predict surface roughness distribution of thin film deposited by EB-PVD on rotating substrate.
Effect of TiO2 Nanopowders on the Sintering and Electric Properties of Lead Zirconate Titanate Ceramics
Authors: Li Guang Hui , Hong Zhang Lian , Peng Li Xia , Wang Min Quan
Published: March 2009

XRD, SEM, bulk density and dielectric properties measurements were used to investigate the effect of TiO2 nanopowder substitution for conventional TiO2 micro-powder on the sintering and electric properties of PZT ceramics. Results revealed that the sintering temperature of dense Pb(Zr0.53Ti0.47)O3 ceramics was lowered about 50°C ~ 100°C when 20% and 40% of conventional TiO2 micro-powder was substituted by TiO2 nanopowder. The electric properties were kept or even enhanced in the PZT ceramics adopted the TiO2 nanopowder.
Influence of Binder Additives on the Sintering of Nano-3Y-TZP
Authors: Liu Xian Xian , Zeng Zhao Qiang , Chen Bo Jun
Published: March 2009

Nanosized yttria stabilized tetragonal zirconia powders were prepared by chemical co-precipitation. By adding certain amount of wax emulsion, we obtained green compacts with the relative density ranged from 47% to 60%. Then the green compacts were sintered in air at the temperature from 1350°C to 1550°C. It turned out that the 3Y-TZP compacts were nearly fully densified after sintering at 1350°C and the grain sizes were between 200 to 300 nm. This result suggested that the addition of wax emulsion could improve the wettability between powders, elevated the density of the green compacts so that the coordination number and the contact points between particles were increased. With more transfer passages, the sintering behavior is remarkably improved.
Analysis of the Surface Adsorbed Organics of Nanosized TiO2 Photocatalyst with High Visible-Light Photocatalysis Activity by Ultrasonic Treatment under Water and Ethanol Solution
Authors: Chen Guan Qin , Hong Zhang Lian
Published: March 2009

Low frequency ultrasonic treatment was applied to desorb surface organics from the surface of nanosized TiO2 photocatalyst, which was prepared by hydrothermal method using a mixture of different amounts of Ti(OBu)4, ethanol, acetone and pyridine raw materials. The UV-Vis, TG-DTA and GC-MS analysis were used to investigate the surface organics. It was found that the absorption intensity around 250nm in UV-Vis spectra of the upper transparent solution, which represents the amount of organics desorbed from the TiO2 surface, increased with increasing treatment time. Along with the TG-DTA and GC-MS analysis, the kinds and amounts of partial surface organics were roughly clarified, and these organics may correspond with the photocatalytic degradation rate for methyl orange (MO) solution under visible light irradiation (≥450nm).
Joining of SiC Ceramic by High Temperature Brazing Using Ni-Cr-SiC Powders as Filler
Authors: Li Shu Jie , Mao Yang Wu , He Yue Hui
Published: March 2009

Joining of ceramics is of importance from both technical and economical points of view.
Brazing is a widely used process to join ceramics. In order to increase the working temperature and weld
strength of joints, a high temperature brazing process using Ni-Cr-SiC powders (consisting of Ni, Cr and
SiC powders) as filler to join recrystallized SiC ceramic has been investigated. The obtained optimized
technological parameters are joining temperature of 1360°C, holding time of 5min and filler mass of
280mg. Under these conditions the maximum relative bending strength of joints, 70.5%, is achieved.
Microstructure and phase analysis reveals that interdiffusions and chemical reactions take place in the
weld zone. A reaction layer, of which the major phase is Ni2Si, exists between the welding base material
SiC ceramic and the filler reaction product layer, called as interlayer, of which the major phase is Cr23C6.
Fractal Dimension of Al(OH)3 Particle and Fractal Simulation of Boundary Micro-Topography
Authors: Gai Guo Sheng , Li Jin Ping , Zheng Zhou Shun , Hao Xiang Yang , Yang Yu Fen
Published: March 2009

Based on the fractal theories, using image processing software (IPS) to handle the scan electron
microscope photos of particles, this paper gives a simple and applied method to pick up the boundary
line’s fractal dimension (FD) of particles’ projective numerical images. Take example for Al(OH)3
material particles, adopting respectively relative Box-counting (BC) method and relative C-S method, we
have calculated the boundary FD values of the research objects and compared FD with other quantitative
token parameters, which shows FD is a sort of more refined quantitative token parameter. Finally,
utilizing the method of Generator, we get some fractal figures which have nearly same FD values with
Al(OH)3 material particles, utilizing that we can simulate and analyze the complexity of the boundary and
surface micro-topography of Al(OH)3 material particles.
Description of the Nanoindentation Unloading Behavior of Brittle Ceramics with a Modified Surface
Authors: Li Zong Huai , Gong Jiang Hong , Peng Zhi Jian , Miao He Zhuo
Published: March 2009

The nanoindentation unloading behavior of some brittle ceramics with modified surfaces was analyzed. It was found that the unloading data may be described well with a quadratic polynomial. The physical meaning of the quadratic polynomial in describing the nanoindentation unloading behavior was then discussed by considering the effect of residual contact stress on the force-displacement relationship. It was suggested that the quadratic polynomial may be considered as a modified form of the basic forcedisplacement relationship for the contact of an isotropic elastic half-space by a rigid conical punch.
Dynamic Fatigue of Y-TZP Ceramics at the Room Temperature
Authors: Li Chun Guang , Si Wen Jie , Zhang Wei Fang
Published: March 2009

Dynamic fatigue behavior of two kinds of Y-TZP ceramics was investigated at room
temperature. The results showed that dynamic fatigue and slow crack growth behaviors exist in zirconias.
Crack growth exponents of original and pre-cracked samples were obtained. Crack growth exponents of
the two original zirconias are 15.60 and 21.00, respectively. Crack growth exponents of annealed
pre-cracked samples are close to the original samples, indicating that the pre-crack experimental method
is reasonable and effective. Because of the influence of residual stress indcued by indentation, crack
growth exponents of unannealed samples are different from that of original samples. So residual stress
should be removed.
Fracture Enhancement of Mixed Mode I-II Transformation Toughened Ceramics
Authors: Liu Yun Ting , Liu Xie Quan , Ni Xin Hua , Zhang Shu Qin
Published: March 2009

The pressure sensitive transformation criterion is used to determine the constitutive relation of
transformation toughened ceramics. By the use of the strain energy release rate criterion and the method
of weight function, the fracture enhancement of mixed-mode I-II crack in transformation toughened
ceramics is predicated. The theoretical expressions of the toughening effect for both the stationary and
steady-state growing crack are given respectively. The result show there is no toughening effect for the
stationary crack and the toughening effect for the steady-state growing crack is associated with the
modulus of elasticity, the width of transformation and its volume fraction.
Corrosion Resistance of the Ceramic Coating Formed by Micro-Plasma Arc Oxidation on AZ91D Alloy
Authors: Li Shu Hua , Wang Fu Chi
Published: March 2009

The ceramic coating was formed by micro-plasma arc oxidation (MPAO) on AZ91D
magnesium alloy. The surface and section morphology of coatings were observed using scanning electron
microscopy. The phase composition of coatings was analyzed by X-ray diffraction. The method of salt fog
experimental was carried out to proof-test performances of anti-corrosion of material. The results showed
that the ceramic coating was composed by loose layer and compact layer. The coating surface has a large
number of grains with various sizes. In addition, there is also a lot of pore in the loose layer, but the
compact layer is tighter than the loose layer. Compact layer has a good combination with substrate
magnesium alloy. The MPAO coating is mainly composed of silica oxide (MgAl2Si3O12 and β-Mg2SiO4
and (Mg4Al14) (Al4Si2)O20) and composite oxide of Mg and Al (δ-MgAl28O4). The performance of
resistant corrosion of AZ91D coved by ceramic coating is higher than AZ91D magnesium alloy. The
corrosion ratio of AZ91D alloy coved by ceramic coatings to AZ91D alloy is 1:8.61.
Preparation and Wet Erosive Wear Characteristics of Porous Al2O3 Ceramics
Authors: Liang Xiao Ping , Neville Anne , Wang Xiao Hui , Xin Shao Bo
Published: March 2009

Porous Al2O3 ceramics were produced by a dry pressing technique and their characteristics were assessed. In terms of their microstructure the results showed that the open porosity varies with the type of pore-making agents. The open porosity is increased but fracture strength is decreased with an increase in the amount of pore-making agent. The fracture strength of Al2O3 ceramic matrix is increased by adding 5-15wt% ZrO2 particles (ZTA). In terms of their wet erosive wear characteristics the results from liquid-solid impinging jet tests can be used to determine the weak aspects of their microstructure. From examination of worn surfaces it is apparent that grain pull-out is the dominant mechanism of erosive wear. For the porous ceramics, wet erosive wear rate depends on strength, porosity and pore size. For porous Al2O3 ceramics having the same level of porosity, the larger the biggest pore size the higher the erosive wear rate. ZTA composite ceramic has a higher erosive wear resistance than that of Al2O3 ceramic with an equivalent level of porosity primarily due to its higher strength.
Influences of Calcination Ambiences on Phase Composition and High Temperature Oxidation Resistance Property of Ceramic Coatings on Ti–6Al–4V Alloy by Micro-Plasma Oxidation
Authors: Hao Guo Dong , Jiang Zhao Hua , Yao Zhong Ping , Xian Heng Ze , Jiang Yan Li
Published: March 2009

Compound ceramic coatings with the main crystalline of Al2TiO5 (as-coated samples) were
prepared on Ti-6Al-4V alloy by pulsed bi-polar micro-plasma oxidation (MPO) in NaAlO2 solution. The
coated samples were calcined in Ar and air at 1000oC, respectively. The phase composition, morphology
and element content of the coatings were investigated by XRD, SEM and XRF. The samples treated in Ar
and the as-coated ones were calcined in air at 1000oC to study the oxidation resistance of the samples. The
results showed that Al2TiO5 decomposed and transformed into corundum and rutile TiO2 during the high
temperature calcination. Al2TiO5 decomposed very quickly in air and the proportion of Al2O3 to TiO2 was
44:55 after a complete decomposition. On the contrary, Al2TiO5 decomposed very slowly in argon with
the final proportion of Al2O3 to TiO2 of 81:18 on the coating surface. The morphology of the ceramic
coatings after the calcination was also different. The coatings calcined in argon were fined: the grains and
pores were smaller than those of the coatings calcined in air. The weight gains of both coatings changed in
the form of parabola law, and the weight gains of the coated samples treated in argon were comparatively
lower than that of the as-coated samples. During the high temperature calcination, the samples treated in
argon cannot distort easily, compared with the as-coated ones.
Geometric Design of Cycloidal Drives with Ceramic Ball Meshing Elements
Authors: Zhou Jian Jun , Hu J.X. , Huang Min
Published: March 2009

Geometric design procedures for the cycloidal drive with ceramic ball meshing elements were
introduced. Using the theory of conjugate surfaces, the equations of meshing of the cycloid drive and the
cycloid raceway profiles were derived. Design examples were presented to demonstrate the design
procedure and feasibility. The ceramic balls were used as the meshing elements. Prototype of this
research was made and tested with satisfying results. The results of this work are suitable for computeraided
design and manufacture of industrial applications.
Phase Development and Microwave Dielectric Properties of Ba4(Sm1−yNdy)9.33Ti18O54
Authors: Yu X.H. , Zhou Dong Xiang , Gong Shu Ping , Zhao Jun , Zhang X.L.
Published: March 2009

In order to study the effect of coexistence of Nd2O3 and Sm2O3 on phase development in Ba4
(Sm0.7Nd0.3)9.33Ti18O54 ceramics, the calcination process was applied in one-step and two-step way.
From the XRD patterns of one-step calcinated powders, the solid-state reactions were deduced. And the
results indicated the coexistence of Nd2O3 and Sm2O3 would be helpful to form secondary phase
Nd2Ti2O7, which would worsen the properties. The final tested results of sintered samples confirmed the
advantages of two-step calcination. The εr was improved from 72.1 to 82.4 and Q.f was improved from
7200 GHz to 8300 GHz, while τf was still near zero.