bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical Properties of High Reinforcement Content TiB2p/Al Composites under Quasi-Static and Dynamic Loading
Authors: Zhu De Zhi , Wu Gaohui , Chen Guo Qin , Zhang Qiang
Published: March 2009

High reinforcement content TiB2/2024Al composites (Vp=55, 65%) were fabricated by
squeeze casting technology, and their microstructures as well as mechanical properties under
quasi-static and dynamic loading were evaluated. For 55 vol.% TiB2/Al composite, the bending
strength and elastic modulus were as high as 623.5MPa and 218.1GPa. When compressed at a strain
rate of 1050s-1, both composites exhibited a higher compressive flow stresses and compressive
moduli than those under quasi-static loading. The micro-damage of high reinforcement content
composites was mostly dominated by the large particle cracking. In addition, some evidence of
aluminum alloy melting was observed on the fracture surfaces of dynamic compression, it was
ascribed to the adiabatic heat accumulated in a local region transferred by plastic work.
Plastic-Factor for the Fracture Toughness Test of the SA508Cl.1a Narrow-Gap Welding Part
Authors: Huh Yong , Cho Sung Keun , Kim Hyung Ick , Seok Chang Sung
Published: March 2009

In this study, the plastic η -factors of the SA508Cl.1a narrow-gap welding part, which is
used for the primary piping system in a nuclear power plant were obtained by using finite element
analysis and the modified fracture toughness testing method was suggested for the narrow-gap
welding part. Also, we have performed the fracture toughness test for the SA508Cl.1a narrow-gap
welding part by applying the new testing method and then we compared the results with those from
the ASTM fracture toughness test.
Mechanical Properties of Interpenetrating Graphite/2024Al Composites Produced by Improved Squeeze Exhaust Casting
Authors: Su Chen , Wu Gaohui , Qiao Jing , Jiang Long Tao
Published: March 2009

The graphite/2024Al composites have been fabricated by improved Squeeze Exhaust
Casting (SQEC) method. Two kinds of graphite preforms with porosities of 13% and 17%
respectively were infiltrated with 2024Al (Al-5Cu-2Mg) alloy under the pressure of 73MPa. The
disadvantages of traditional Squeeze Casting (SQC) were avoided and the distribution of aluminum
alloy appeared homogenous 3D network in the composites. Flexural strength and Young’s modulus
were determined at room temperature. Compared to graphite preform, the composites exhibited a
significant enhancement of mechanical properties. The flexural strength and Young’s modulus of
X-Y direction of G186/2024Al composites increased from 38.6MPa to 99.7MPa and from 10.1GPa to
19.7GPa, respectively. The fracture mechanism of the composites was discussed on the basis of
fracture surfaces.
Thermal Physical Properties of Bulk Materials from ZrO2 Nanoparticles by Sintering Process
Authors: Feng Yi Jian , Gui Chang Lin , Chen Ji Gui , Hu Xian Guo
Published: March 2009

Nanoparticles can be made into bulk material by sintering process in order to obtain some
excelled properties of nanomaterials. Because ZrO2 has a good thermal-resistance property, it has
been widely used as thermal-barrier material, including functionally graded material (FGM) and
thermal barrier coating (TBC). In the present paper, ZrO2 nanoparticles with a size of 10, 50, 80 and
100 nm were fabricated into bulk material respectively with the help of cold and isostatic pressing
processes. The thermal diffusion coefficient, the hot expand coefficient and the specific heat of
these bulk materials were measured. The experimental results showed that after ZrO2 nanoparticles
being pressed and sintered, the nanoparticles were found in a state of aggregation in the bulk
materials, but there are some nanometer size effects in their thermal physic properties. It was found
that the thermal diffusion coefficients between 100-150oC were obviously different, as the samples
were made of ZrO2 with different nanometer dimensions. The less the nanometer size of particles,
the higher the thermal diffusion coefficient. The hot expand coefficient of the sample from 100 nm
ZrO2 particles was 96.9741×10-7 K-1 between 30-300 oC. However, the hot expand coefficient of the
sample from 10 nm ZrO2 particles was 100.2345×10-7 K-1. On the other hand, the specific heat of
the bulk material from ZrO2 nanoparticles was much higher than that of the bulk material from
micron ZrO2 particles. When the temperature was over 350 oC, the size of ZrO2 nanoparticles
influenced the specific heat of bulk material even more. With the decreasing of size of ZrO2
nanoparticles the specific heat of bulk material increased continuously.
Influence of Sintering Aids on the Nitridation of Reaction Bonded Si3N4/BN Ceramics
Authors: Lin Tie Song , Jia De Chang
Published: March 2009

The influences of different sintering aids, including Fe2O3, Fe(NO3)3·9H2O, Y2O3+Al2O3
and MgO+Al2O3+SiO2, on the nitridation of reaction bonded Si3N4/BN ceramics were conducted at
1350°C for 2h. Results indicate that the addition of sintering aids could facilitate the nitridation
process resulting in higher nitridation percent due to the reactions between sintering aids and surface
silica on silicon powder. When 5wt. % of Y2O3 and 2wt. % Al2O3 were added, the nitridation percent
reached to 94.4%. The addition of sintering aids has obvious effect on the ratio of α-Si3N4/β-Si3N4.
The increase of β-Si3N4 ratio was attributed to the direct reaction of silicon with nitrogen.
Synthesis and Properties of AlN-SiC-TiB2 Ceramics by SHS-HIP
Authors: Zhou Li Juan , Zheng Yong Ting , Du Shan Yi
Published: March 2009

AlN-SiC-TiB2 ceramics were synthesized by self-propagating high temperature synthesis
(SHS) and hot isostatic pressing (HIP) methods. The powder mixtures of Al, 6H-SiC and TiB2 were
shaped by isostatic cool pressing method, and then combustion reaction was carried at the pressure of
100-200 MPa N2 by an ignitor. The solid solution of AlN and 2H-SiC in AlN-SiC-TiB2 ceramics was
formed. The phase composition and microstructure were investigated by XRD and SEM. The
mechanical properties of composite were measured as functions of composition. The maximum value
of flexural strength and fracture toughness of composites were 430 MPa and 3.9 MPa⋅m1/2
respectively.
Mechanical Properties of ZrB2-Based Ceramics Reinforced by Nano-SiC Whiskers
Authors: Wang Hai Long , Wang Chang An , Zhang Rui , Hu Xing , Fang Dai Ning
Published: March 2009

In this paper, ZrB2-based ceramics containing up to 15 vol% nano-SiC whiskers were
prepared by hot pressing at 1950°C under 20MPa pressure in flow argon. SEM and XRD
techniques were used to characterize the sintered compacts. A fine and homogeneous
microstructure was observed. The relative density of ZrB2-based ceramic containing 10vol% SiC
whiskers reached to 97.7%. The bending strength and fracture toughness of the composite were
550 MPa and 8.08 MPa·m1/2 respectively, while those of the monolithic ZrB2 ceramic (0 vol% SiC
whiskers added) were 424 MPa and 4.52 MPa·m1/2 respectively. The grain size of the ZrB2-based
ceramics was reduced greatly by the addition of nano-SiC whiskers during the sintering process.
Effect of Sintering Process on Fabrication of Porous Si3N4/SiC Composites
Authors: Vu Cong Hoa , Phan Quoc Thai , Seo Do Won , Lim Jae Kyoo
Published: March 2009

Porous SiC/Si3N4 composites were fabricated by reaction between Si3N4 and C powder in
0.5 MPa nitrogen atmosphere at 1700oC, 1800oC and 1900oC for 0.5h, 1h and 2h, respectively. The
characteristics of in situ porous Si3N4/SiC composites were further investigated by X-ray diffraction
(XRD) and scanning electronic microscopy (SEM). Results show that the SiC particles are very fine.
And the transformation from α-Si3N4 to β-Si3N4 is obvious at 1800oC for 2h and at 1900oC.
Otherwise, at 1700oC, the formation of rod-like β-Si3N4 is inhibited. The compressive test was
conducted at a cross-head speed of 0.5 mm/min to get the basic mechanical performance of the
porous ceramics. The highest value of strength of these composites was obtained when sintered at
1800oC for 1h.
Uniform Design and its Application in the Chemical Composition Design of Hot Work Die Steel
Authors: Xie Hao Jie , Wu Xiao Chun , Min Yong An , Luo Yi
Published: March 2009

According to the conditions that hot work die steels, for example H13 and HOTVAR,
were used, the main chemical compositions and the ranges of their contents were determined as
follows: 0.25~0.6%C, 0.5~1.5%Si, 0.2~1%Mn, 2~6%Cr, 1~3%Mo and 0.3~1.5%V. Based on
uniform design, six kinds of steels and the following heat treatment schemes were designed. The
tempering resistance and the impact toughness at room temperature were measured. The results
were analyzed by quadratic stepwise regression analysis, the relationships between the chemical
compositions, the heat treatment processes and the properties were studied in detail, the influence
coefficients and the influence tendencies of the main variables were also given in this paper.
Effect of Hot Treatment Process on High Performance Alloy Spring Steel D701 Mechanics Properties
Authors: Gao Hui Ju , Liu Pan , Ai Jia He , Dong Jian Xin , Xie Xi Shan , Shen Yong Xiang , Wang Yu , Liu Yu
Published: March 2009

High performance alloy spring steel D701 for accelerated railway wagons is improved
60Si2CrVA steel. Its properties have been better than 60Si2CrVA steel.The difference between
of them is using controlled rolling process for D701 steel.The affect of hot treatment process was
studied by orthogonal test on D701 steel property in the article. The mechanical property σs is
1800MPa; σb is 1925MPa; δ is 9.5%, ψ is 36.5%.
Investigation of the Anti-Corrosion Ceramic Coating Formed on AZ91D Magnesium Alloy by Micro-Arc Oxidation
Authors: Chen Dong Chu , Li Wen Fang , Jie Jun
Published: March 2009

A new micro-arc oxidation method with a home-made asymmetric alternating-current
(ac) power supply for forming an anti-corrosion ceramic coating on AZ91D magnesium alloy was
presented, and two different silicate-based and aluminate-based preparing solutions were introduced
to coating formation. The effect of many processing parameters on the growth and performance of
the formed ceramic coating was investigated. It was found that the electrolyte concentration, current
density, treating time duration and other parameters have significant influence on the coating
morphology and anti-corrosion performance. Through the polarization curve test, it showed that the
coating oxidized in silicate solution has better corrosion-resistance due to its continuous and
compact structure than that formed in aluminate solution. The morphology and microstructure of
the coating were analyzed through SEM, XRD technology. The coating consists of two layers, i.e.,
loose layer and compact layer. The compositions and phase structures varied with electrolytes, and
it was found that the micro-arc oxidation coating prepared in silicate solution is composed of MgO
and Mg2SiO4, while the coating prepared in aluminate is mainly composed of MgAl2O4.
Thermodynamic Analysis of EB-PVD Preparing SiC Coating
Authors: He Xiao Dong , Yi Jian , Sun Yue , Li Yao
Published: March 2009

The process of Electron Beam-Physical Vapor Deposition (EB-PVD) preparing SiC
coating by Electron Beam evaporating 3C-SiC ingot on stainless steel (SS) substrate was firstly
discussed as a preliminary estimation from thermodynamic viewpoint. The results show that, with the
temperature increasing from 2500 to 3400 K, the purity of SiC coating increases from 0.58 to 0.734.
Effect of Mean Stress on Fatigue Strength of Non-Combustible Magnesium Alloy
Authors: Morishige K. , Noguchi Hiroshi
Published: March 2009

Effect of mean stress on fatigue strength at N=107 of non-combustible magnesium alloy
AMX602B(X=Ca) was investigated. Rotating bending fatigue test and tension-compression fatigue
test were carried out on specimens with a small hole or crack. It was clarified that the fatigue
strength at N=107 of the specimen with the small hole was about 30-150% higher than that of the
specimen with the small crack within the range of σm=0~100MPa. This is the reason why the
fatigue strength at N=107 of the specimen with the small hole can be not threshold condition for
crack propagation but crack initiation. The fatigue strength at N=107 of the specimens with the
small hole decreased within the range of σm=100~195MPa due to a static small crack initiating from
the small hole at first loading. The effect of mean stress on fatigue strength at N=107 both oh the
specimens with the small hole and crack could be estimated using modified Goodman diagram.
The Microstructure and Mechanical Properties of Ti/TiN Multilayer Film Synthesized by Unbalanced Magnetron Sputtering Deposition on 17-4PH Stainless Steel
Authors: Zhang Qi , Qi Feng , Leng Yong Xiang , Huang Nan , Cai Zhen Bing
Published: March 2009

Ti/TiN multilayer films were synthesized on 17-4PH stainless steel using unbalanced
magnetron sputtering. The modulation periods is ranged from 100nm to 350 nm. The microstructure
of the multilayer films was analyzed by X-ray diffraction. The cross-section views of the multilayer
films were studied by scanning electron microscope (SEM). The microhardness and wear resistance
of the films were measured by a HXD-1000 microhardness tester and ball-on-disk wear tester. The
corrosion resistance of the multilayer films was evaluated by potentiodynamic polarization scans in
a 3% NaCl solution. The results showed that there was TiNx intergradation layer in the films. The
microhardness and the wear resistance of the multilayer films increased with the layer number. The
Ti/TiN multilayer can improve the corrosive resistance of the 17-4PH stainless steel.
Preparation and Wear Resistance of TiN/Ti Deposition and Diffusion Multi-Layers by Plasma Alloying Process
Authors: Liu Yan Ping , Xing Fei
Published: March 2009

High quality TiN/Ti multi-layers have been successfully obtained on a carbon steel
substrate by double glow plasma surface alloying technique (DGP). The TiN/Ti multi-layers
consists of deposition layer and diffusion layer, and then on its surface TiN film (PVD) is deposited
to form TiN/TiN/Ti compound multi-layers. In addition, studies were carried to compare TiN/Ti
multi-layers, TiN/TiN/Ti compound multi-layers and TiN film (PVD) directly deposited on the
surface of the carbon steel and their microhardness and dry friction-abrasion properties were also
investigated. The results show that the thickness of TiN/Ti multi-permeated layers is above 10*m;
Ti and N concentrations change gradually along the depth of alloying layer. TiN/Ti multi-layers and
substrates are metallurgically bonded. Preferred orientation of TiN/Ti multi-layers is crystal surface
(200). The hardness of the TiN/Ti multi-permeated layers ranges up 2200HV, its average friction
coefficient is lower, abrasion crack is shallower and wear resistance better.
Study on Properties of Plasma Sprayed CoCrAlYCoating on TiAl Alloy Surface
Authors: Zhou Hai , Fei Chen , Yao Bin , Wang Yin Xia
Published: March 2009

The CoNiCrAlY thermal barrier coating was prepared on the surface of TiAl alloy by
plasma spraying technique. SEM observation shows that the bonding between thermal barrier
coating and substrate is good. The surface hardness of TiAl alloy is improved, the microhardness of
the coating surface is about 673HV after the oxidation test at 850°C. The oxidation tests at 850°C
show that the oxidation resistance of the samples is improved remarkably. The surface morphology
and microstructure of the thermal barrier coating are determined by SEM.
A Special Method to Evaluate the Strong Adhesion between Brittle Coating and Ductile Substrate
Authors: Zhang Kun , Peng Qing , Chen Guang Nan
Published: March 2009

The evaluation of the interfacial adhesion of coating system has always been a rough task.
In this paper, a special testing method of cross-sectional indentation is applied on a model coating
system, i.e. electroplated chromium on a steel substrate which is generally regarded as an example
of materials pair with strong adhesion. Based on fractography analysis with SEM and interfacial
stress simulation with FEM, it is found that interfacial shear stress may induce coating spalling.
More interestingly, spalling location is sensitive to substrate pretreatment process. This shows the
feasibility of cross-sectional indentation to distinguish interfacial strength at a high level.
Application of Wear Resistant Coating Technology on Coating Blade
Authors: Wang Can Ming , Sun Hong Fei , Song Qiang , Yan Qiong Qiong
Published: March 2009

Coating blade wears seriously in paper coating process. Wear mechanism was analyzed
in this article. A new technology of surface coating process was introduced to increase the hardness
of the edge of coating blade and thus to prolong its service life. Surface coating preparing process
on blade was studied and metal-ceramic compound coating prepared successfully on the edge of
coating blade with AT13 (Al2O3+13%TiO2) wear resistant material by plasma spraying process.
NiCrAl alloy powder was used as under coat material. Microstructure of the coating is dense. The
coating bonds well with the matrix and have high hardness. Results of grain-abrasion testing show
that wear-resisting property of the metal/ceramic compound coating is about 7-8 times as that of
steel blade.
CrN Coating on Magnesium Alloy AZ91 by Arc-Glow Plasma Depositing Process
Authors: Miao Qiang , Cui Cai E. , Pan Jun De , Zhang Ping Ze
Published: March 2009

Magnesium alloys exhibit great application potential in industries such as automotive,
electronics, aerospace and others. But poor wear resistance and corrosion resistance have
restricted their actual uses. In this study, a CrN film had been prepared on magnesium alloy AZ91
by arc-glow plasma depositing. The composition and microstructure of the coating had been
analyzed by X-ray diffraction (XRD) and glow discharge spectrum (GDS). The morphology of
CrN film has been surveyed through scanning electronic microscopy (SEM) and atom force
microscopy (AFM). The wear behavior was investigated through ball-on-disc test. The corrosion
behavior in 5 wt% NaCl solution was also studied. The results indicate that the specific wear ratio
decreases greatly and the corrosion potential also increases relatively comparing to AZ91 matrix.
Surface Plasma Molybdenized Burn-Resistant Titanium Alloy
Authors: Zhang Ping Ze , Xu Zhong , Zhang Gao Hui , He Zhi Yong , Wu Hong Yan , Yao Zheng Jun
Published: March 2009

Conventional titanium alloy may be ignited and burnt under high temperature, high
pressure and high gas flow velocity condition. In order to avoid this problem, a new kind of
burn-resistant titanium alloy-double glow plasma surface alloying burn-resistant titanium alloy has
been developed. Alloying element Mo is induced into the Ti-6Al-4V substrate according to double
glow discharge phenomenon, Ti-Mo binary burn-resistant alloy layer is formed on the surface of
Ti-6Al-4V alloy. The depth of the surface burn-resistant alloy layer can reach about 100 microns
and alloying element concentration can reach 59%. High energy laser ignition experiments reveal
that the ignition temperature of alloyed layer with Mo concentration about 10% is about 200°C
higher than ignition temperature of Ti-6Al-4V.
Influence of Temperature on Characteristics of TiAl Plasma Surface Niobiumizing
Authors: Liu Xiao Ping , Tian Wen Huai , Guo Chao Li , Chen Dong Dong , He Zhi Yong , Xu Zhong
Published: March 2009

In this study, plasma niobium alloying of the TiAl based alloys has been carried out at
1050, 1100 and 1150°C. The effect of the alloying temperature on the characteristic of the alloyed
layer was investigated by optical microscopy, scanning electronic microscopy (SEM), glow discharge
spectrum (GDS) and energy dispersive spectrum (EDS). The results show that the surface
roughness, chemical composition and thickness of the alloyed layer increased with the alloying
temperature which is dependent on the sheath potential. A deposition layer formed on the TiAl surface
at 1150 °C was resulted from the larger sheath potential or the stronger sputtering of source
electrode.
Microstructure and Resistivity of Low Temperature Deposition ITO Films on PET Substrate by Magnetron Sputtering
Authors: Weng Xiao Long , Tang Wu , Wu Yu Tao , Deng Long Jiang
Published: March 2009

Sn doped indium oxide (ITO) films were fabricated on polyethylene terephtalate (PET)
substrate by magnetron sputtering at low deposition temperature using a 10 wt % SnO2-doped In2O3
target applied in the infrared regions as low emissivity materials. The microstructure and surface
morphology of ITO films was studied using X-ray diffraction (XRD) and atomic force microscopy
(AFM); the resistivity was investigated by four-point probe technology. It was found that the film
with amorphous microstructure has highest resistivity to 1.956×10-3 2.cm at low deposition
temperature and the surface roughness and resistivity increase with the increasing Ar sputtering
pressure from 0.5Pa to 1.4Pa. The most interesting is that the resistivity increases with the
increasing surface roughness, it indicates that there are internal correlation between roughness and
resistivity.
XPS Analysis of Silicon Oxycarbide Formed on the Surface of Rf-Sputter Deposited SiC Thin Films
Authors: Xue Kun , Niu Li Sha , Shi Hui Ji , Liu Ji Wen
Published: March 2009

Sputter deposited SiC films with and without annealing were characterized using X-ray
photoelectron spectroscopy (XPS). A complex transition layer, containing silicon oxycarbide
(SiCxOy), between the SiO2 layer grown during extended exposure to ambient air or annealing and
SiC substrate was investigated. Furthermore, the presence of excessive amorphous carbon was
detected in the near-surface region for annealed sample. We justified the differences of composition
and chemical bonding in these two oxide layers in terms of different oxidation kinetics involved.
Microstructure and Properties of Microarc Oxidation Ceramic Coatings on Aluminum Alloy
Authors: Liu Wan Hui , Bao Ai Lian , Mao Xin Yu , Zheng Guang Hai
Published: March 2009

The paper discusses structure and property aspects of oxide films formed on 7075
aluminum alloys by microarc oxidation in alkali-silicate electrolytic solution. Microstructure, surface
morphology and phase composition of the ceramic coatings were investigated by SEM and XRD.
Distribution of hardness along the coating thickness was determined by microhardness analyses. The
friction and wear behavior of the oxide films against steel counterparts was evaluated with a friction
and wear tester. The results showed that the microarc oxidation coatings composed mainly of α-Al2O3
and γ-Al2O3 phase are dense and uniform, which indicates that the wear resistance of Al alloy could
be improved obviously by microarc oxidation. The films possess a beneficial combination of 25~45
μm thickness, HV0.11500 microhardness and provide a low wear rate but a relatively high friction
coefficient against GCr15 steel under dry friction condition.
Mo-Si-C-N Multi-Layer Anti-Oxidation Coating on C/C Composites
Authors: Lai Zhong Hong , Jeon Jae Ho , Zhu Jing Chuan , Yin Zhong Da
Published: March 2009

A Mo-Si-C-N multi-layer anti-oxidation coating was in situ fabricated on C/C composites
by fused slurry and reaction-sintering method in nitrogen atmosphere using Mo and Si element
powders, and characterized by X-ray diffractometry, optical microscopy, X-ray photoelectron
spectroscopy, and scanning electron microscopy with energy dispersive spectroscopy. It is shown that
the coating contains three distinctive layers, namely, SiC inner-layer, MoSi2/Si middle-layer and
Si3N4/SiC/Si thin surface-layer. The MoSi2/Si middle-layer, whose thickness could be controlled by
dipping process, is the main portion of coating. Oxidation test reveals that the Mo-Si-C-N multi-layer
coating significantly improves the oxidation resistance of the C/C composites. Compared with the
Mo-Si-C coating, the oxidation temperature is extended up to 1450°C. After oxidation pre-treating at
1400°C, the anti-oxidizing temperature of the Mo-Si-C-N multi-layer coated C/C composites can be
raised to 1500°C and the weight loss is less than 1wt% after 12-hour oxidizing test.
Static and Dynamic Force Analysis to Large-Scale Bed of Leather Cutting Machine Tool
Authors: Ji Guo Shun , Wang Wen , Huang Yan Jun , Chen Zi Chen
Published: March 2009

The leather is cut by hand or by hand with some help of semiautomatic machine in general
leather cutting technology. In order to enhance the cutting efficiency and quality, the machine tool to
realize high speed automatic leather cutting was developed. The final goal of the design is to cut a
piece of hide on a working table with cutting velocity 2 meters per second, the dimension of the
machine tool is big. It is very difficult to design the frame of this machine tool to meet the
performance index for high speed cutting, so the static and dynamic force analysis to the body of it
was implemented.
First, the digital model of the body of it was built with AutoCAD software, then, the digital model
in IGES format was transmitted to the Ansys software and the finite element analysis to it were carried
out. Because the static force and vibration from driving system have great influence on the
deformation of this machine tool and this deformation will affect the cutting precision and the whole
performance of it. So the static force analysis and modal analysis were carried out. Finally, the results
of finite element analysis were discussed, corresponding modification to the design was proposed.
The analysis results indicate the mechanical property of the body of the developed machine can
meet the requirements for high speed cutting.
Study on the Process Parameters of MPAW-Based Rapid Prototyping
Authors: Aiyiti Wurikaixi , Zhao Wan Hua , Tang Yi Ping , Lu Bing Heng
Published: March 2009

A direct metal RP (rapid prototyping) process based on micro-plasma arc welding
(MPAW) is presented. The impact of R (ratio of width to height of the deposited track’s
cross-section) on part quality is investigated. Taguchi method is adopted to analyze the effect of
each process parameter on R, and the optimized process parameters are obtained. The results show
that the quality of the parts with larger R is better than that with smaller R, and the peak current,
duty cycle of pulse duration, wire-feeding speed, scanning speed and plasma gas flow rate all exert
significant effects on R. The overlapped surface smoothness, tensile strength and elongation of the
parts fabricated with optimized parameters are measured to show obviously better performances
than those of the parts fabricated with ordinary process parameters.
Effects of Adhesive Joint on the Failure Strength Properties of Natural Fiber Reinforced Composite
Authors: Yoon Ho Chel , Wang Ren Liang , Jeon Yang Bae , Choi Jun Yong , Lee Sang Yong , Thai Phan Quoc , Lim Jae Kyoo
Published: March 2009

This research was concerned with study of failure strength of natural fiber reinforced
composites. Tensile-shear tests were carried out with single-lap-adhesive-joined specimens
consisting of polyester lap and composite lap. Composites were manufactured using the polyester as
matrix and bamboo natural fiber layer as reinforcement. Two types of specimens with different
reinforcement positions were tested to evaluate the failure strength of adhesive-single-lap-joined
natural fiber reinforced composites. The test results were presented by tensile-shear strength graph
comparing with finite element analysis. The failure mechanism was discussed in order to explain the
lower tensile-shear strength of composite, and effect of position of bamboo natural fiber layer on the
failure strength properties were explained.
A Study on Mechanical Properties and Durability Evaluation of Structure Adhesived and Spot Welded Joints
Authors: Yoon Ho Chel , Dewidar Montasser , Lim Jae Kyoo
Published: March 2009

Structure adhesive bonding method is widely used in the industry because it is possible to
joint complex shape and dissimilar materials. Especially in the car industry, requests of lightweight
car have adhesive bonding method be applied in the many parts. Also it is possible for stress to
distribute uniformly through the adhesive layer, and stress concentration is released. Since strength,
stiffness durability is much better, this method is determined as the technique replaced weld defect.
But, it has much shorter history then other joint method such as spot weld and mechanical joint
method. Evaluation of strength and durability is not established. As the fundamental research of
design of adhesive bonding joints, considers over-lap length, adhesive thickness, surface treatment
and environment which affect strength and durability of single-lap joints. In this research, a real part
of bus folding door was used and tested to compare durability of spot welding and adhesive bonding.
A Study of Self-Loosening and Fatigue Failure of Bolted Joint under Transverse Vibration - Influences of Property Class of Bolt and Plastic Region Tightening
Authors: Hashimura Shinji
Published: March 2009

In our previous study, loosening-fatigue tests under small transverse vibrations had been
performed to elucidate bolt behavior and loosening-fatigue mechanism in the long life region. In this
study, the influences of bolt property class and the plastic region tightening on loosening-fatigue
characteristics under transverse vibration have been investigated. Result shows that bolt property
class has little influence on the loosening-fatigue limits under transverse vibration. Result also shows
that the transverse loosening-fatigue limit of the bolt which has been tightened to within the plastic
region is lower than the transverse loosening-fatigue limit of the bolt that has been tightened to within
the elastic region. This result is the opposite of the result of the axial fatigue characteristics of bolted
joints.
Thermal Fatigue Mechanism of Welding Deposited Metal of Dies Steels
Authors: Liu Ren Pei , Wei Yan Hong , Chen Wen Hua
Published: March 2009

This paper conducted the outer constraint test of Coffin thermal fatigue and studied the
deformation behaviors of microstructure for two kinds of welding deposited metals, they are
3Cr2W8 and HM3. The experimental results show that the thermal fatigue deformation belongs to
multiple slip systems and the heterogeneous deformation mainly concentrates around the second
phase particles. Moreover, it is found that the cracking initiation relates to the separation between
the second phase particles and base body, void and micro-cracking formation.
Study on the Evolution of Welding Residual Stress under Tension Loading Condition
Authors: Niu Ji Tai , Jin Cheng , He Shi Yu
Published: March 2009

In this paper, the welding residual stress state and the distribution of 5A06 aluminum
alloy welded plate were determined before and after tension loading by means of hole-drilling
method. Results show that the applied load can reduce the residual stress obviously and drive it to
an even state. But the local strain near the weld is higher than other positions far from the welding
central line relatively.
Joining of SiC Ceramic to High Strength Graphite Using Polysiloxane with Active Additive
Authors: Li Shu Jie , Yuan Xiao Kun , Zhang Ting , Mao Yang Wu , Yan Lian Sheng
Published: March 2009

In order to contribute to the development of the joining technique of Cf/SiC, joining of
SiC ceramic to high strength graphite was investigated. This joining has been successfully realized
by reaction joining process using a preceramic polymer, polysiloxane, mixed with the active
additive Al-Si powder as joining material. The weld strength is strongly affected by the
technological parameters and the ingredient ratio (polysiloxane:Al-Si powder). The optimized
factors have been obtained by orthogonal experiments, under which the achieved three-point
bending strength of the joints is 96.8% of the strength of the welding base material graphite. The
microstructure and composition of the weld zone were analyzed by SEM, EDX and XRD. The
results show that the joining material has transformed into a densified interlayer with the thickness
of about 15μm. Also, diffusion takes place in the interfacial area, which contributes to a sound
interfacial bonding. The interlayer is composed of SiC, Al2O3 and Si.
Heating Characteristics of Gas Tungsten Arc Welding of Copper Thick Plates with Shielding Gas of Argon, Helium or Nitrogen
Authors: Yan Jiu Chun , Li Yi Nan , Zhao Wei Wei , Yang Shi Qin
Published: March 2009

The welding temperature patterns of gas tungsten arc welding for copper thick plates
during Ar, He or N2 shielded arc welding were simulated, and the size of weld pools and
heat-affected zones have been compared. It was predicted that the heat-affected zone in the welded
joints during Ar arc welding is the widest and that during N2 arc welding is the narrowest, while the
size of weld pools using Ar (preheating at 400°C), He and N2 (without preheating) shielding arc
welding is very similar. Among the three kinds of gases shielded arc welding, the temperature
gradient of welded joints during Ar arc welding is the least and that during N2 arc welding is the
greatest. The temperature rise velocity at the arc center during N2 arc welding is the highest, and
those at the zone close to the weld pool of welded joints during He arc and N2 arc welding are a few
higher than that during Ar arc welding.
Fabrication and Fracture Properties of Nano-Sized HAP-TZP (3Y) Bioceramic for Artificial Joints
Authors: Han Wen Bo , Wang Zhu Ju
Published: March 2009

Hydroxyapatite is a kind of ideal biomaterials for bone and teeth replacement, but its low
strength and brittleness need to improve. As bone replacing materials, hydroxyapatite (HAP) and
zirconia both have advantage and disadvantage. Nano-sized HAP-ZrO2 powders and HAP-TZP (3Y)
(3mol% yttria - stabilized cubic zirconia) bioceramic for artificial joint have been fabricated in this
paper. The nano-sized HAP-ZrO2 powders with homogeneous distribution could be synthesized by
two-step precipitation method. The HAP-TZP bioceramic with small grain size could be obtained by
using hot-press sintering technology, and the sintering parameters are: sintering temperatures
T=1300°C, sintering pressure p=30MPa and sintering time t=30min. The mechanical properties,
microstructures and fracture pattern that were analyzed by SEM and optical microscopy of the
HAP-TZP bioceramic were investigated systematically. The results show that no reaction between
HAP and ZrO2 powders, which could be attributed to the very short sintering time of hot press
sintering.
Adhesion Evaluation of Titanium Oxides Films on 316L Stainless Steel Substrate
Authors: Wang Zhi Hao , Leng Yong Xiang , Huang Nan , Zhu Min Hao
Published: March 2009

Titanium oxides films were deposited on tensile sample and vascular stents made of 316L
stainless steel by unbalanced magnetron sputtering. The effects of structures, deposition temperature,
Ti interlayer and thickness on the adhesion of titanium oxide films were investigated by tensile tests.
The results revealed that the structure of the Ti-O films affect their adhesion dramatically. TiO film
is brittle and fragile, lacking ability of deformation. Therefore its adhesion was worse than that of
TiO2 film. The higher substrate temperature was helpful to improve adhesion of film, the adhesion
of the TiO film deposited at 673K was better than those of the TiO films deposited at 323K and
473K. The adhesion of the TiO film with Ti interlayer was better than the one without interlayer.
The introduction of Ti interlayer was beneficial to adhesion of film. The adhesion of thinner TiO2
film was better than that of thicker one. TiO2 film deposited on stents had good adhesion. After
expansion, the film didn’t crack and peel off. TiO2 film has potential application on the vascular
stents for improving its blood compatibility.
Ultrafine TiO2 Powders Prepared from Aqueous TiCl4 Solutions at Room Temperature
Authors: Yi Hong Liang , Zhang Jie , Ma Ming Tu , Zhang Hao , Lee Bong Ho , Huh Jeung Soo
Published: March 2009

Ultrafine TiO2 powders as rutile and anatase phase were simply precipitated at room
temperature for only tens of hours by simply controlling the pH value and Ti4+ concentration via
aqueous TiCl4 solution. Under the optimal pH value and Ti4+ concentration, the average particle size
of powders with rutile phase was 3.7nm, while that of powders with anatase phase was 3.0nm. The
average particle size was calculated from the broadening of corresponding X-ray spectral peaks by
Scherrer formula. In addition, 3.0 mol.l-1 are suggested to be used as concentration of stock solutions
instead of the current concentration 2.0 mol.l-1.
The Synthesis and Properties Studying of 1-D TaS2 Nanostructure
Authors: Li Chang Sheng , Liu Yan Qing , Li Jun Mao
Published: March 2009

large-scale and elegant one-dimension tubular nanostructure TaS2, have been generated
successfully employing solid-phase reaction growth with tantalum and sulfur powders. Detailed
experimental procedures, and the characterization of associated product, have been evaluated using
transmission electron microscopy (TEM) and other techniques. The results show that the reaction
yielded a lot of one dimension nanostructures of TaS2 with average diameter of one hundred
nanometers and length of several micrometers (or several ten micrometers). Moreover, effect of
TaS2 nanostructure, as additive in commercial lubricating oil T40, was initially measured by UMT
Multi-specimen Test System (UMT-2). The results show, as additive, antiwear and bearing weight
ability of 1-D TaS2 nanostructure, excelled ordinary lubricating oil at atmosphere.
Lactose Modified Chitosan Scaffold for Hepatocytes Culture
Authors: Pan Ji Lun , Bao Zhi Ming , Chen Wei , Li Li , Li Jie Liang , Yu Yao Ting
Published: March 2009

The chitosan scaffold we prepared have a high porosity of about 90% with pore sizes
from 50 to 200m. Lactose was conjugated onto the inner surface of the highly porous chitosan
scaffold. It was used as substrate for rat hepatocytes culture. The cell attachment ratio was much
higher than on monolayer membrane and non-modified porous scaffold. Metabolic activities of the
cells were evaluated in terms of albumin secretion and urea synthesis. It was found that hepatocytes
cultured on the modified scaffolds showed an increase in albumin secretion during the first 4 days
and were more stable than that on non-modified scaffold. The results showed that the microstructure
of porous scaffolds provides large surface for cells to adhere and facilitates nutrient and oxygen
transportation. Such lactose modified scaffold has a potential application in bioartificial liver
support system.
Effects of Temperature and Concentration on the Nano-Sized Hydroxyapatite Whisker Prepared by Chemical Precipitation Method
Authors: Bai Yun Qiang , Li Mu Sen , Lu Yu Peng , Cao Ning
Published: March 2009

Chemical precipitation is a popular method for the preparation of hydroxyapatite(Ca10
(PO4)6 (OH)2, HA) because of its simple operation. In this work, nano-sized HA whiskers were
synthesized at various synthetic temperatures and concentration by chemical precipitation with Ca
(NO3) 2·4H2O and (NH4) 2HPO4 as raw materials. Heat treatment was carried out after they were
synthesized. The HA powders were analyzed by using X-ray diffraction (XRD), transmission
electron microscope (TEM) and strength test in order to find the favorable growing condition for
HA whiskers. The results show that the HA prepared at different synthetic temperatures show no
impurity diffraction peak, indicating that they have a high purity. Prior to heat treatment, the
crystallinity and length/diameter ratio of the HA whiskers become larger with the increasing of
synthetic temperature. So a higher synthetic temperature can promote the growth of the HA
whiskers. There is no obvious difference in crystallinity after the heat treatment. Besides, a lower
reaction concentration can also promote the growth of HA whiskers. The strength test results show
that the compressive strength of the HA prepared gets a maximum value at 50°C.
Effective Structural Parameters of Armchair Carbon Nanotubes
Authors: Oh Hyu Kjin , Lee Usik
Published: March 2009

Due to exceptionally high strength and stiffness, carbon nanotubes have been attracted as
promising materials for the applications to many nanoscale devices such as the ultrahigh frequency
actuators and sensors. In this study, a dynamic continuum modeling method is used to evaluate the
effective structural parameters of the armchair single-walled carbon nanotubes. The effective
structural parameters obtained by the present dynamic continuum modeling method are shown to be
in very good agreement with the results computed by using the Young’s muduli reported in the
existing references.
Development of High Technology for Improvement of Fatigue Strength in the Intervertebral Disc Herniation's Cervical Attachment System
Authors: Kim Cheol Woong , Lee Sang Hoon , Lee Jin Yi , Kim Kee Joo
Published: March 2009

The fixation of the vertebral column using transpedicular screws is a well-establish
technique. Multi-axial pedicle screw designs allow deviation of the screw away from the
perpendicular to the longitudinal rod, which facilitates application of a screw-rod system such as
Cervical Attachment System (CAS) into the curved spine. This study was performed a static
(compression bending and torsion) and dynamic (compression bending fatigue) empirical analysis
of CAS component such as pedicle screw, rod and set screw based on the guideline of ASTM F136-
98 using Ultra-high Molecular Weight Polyethylene (UHMWPE) blocks as test vertebral bodies.
Stress Analysis of the Swelling and Deswelling Process of Thermo-Responsive Gel
Authors: Kuhara Kei , Enoki Manabu
Published: March 2009

Poly-N-isopropylacrylamide (PNIPA) gel is a typical thermo responsive gel which
undergoes a large volume change from the low-temperature swollen phase to the high-temperature
shrunken phase. In this study, the mechanical behavior of PNIPA gels was investigated by the
experiment and simulation. The cylindrical shaped specimens of PNIPA gel were prepared and
tensioned at various temperature. Swelling ratio at equilibrium state was calculated by diameter of
swelling gels. Young modulus was obtained from stress-strain curve plotted using tensile load
measured by semiconductor gauge. Also swelling and deswelling behavior of thermo sensitive gel
were simulated by using finite element method. Polymer-solvent interaction parameter, χ was used as
a function of temperature. Calculated swelling ratio at equilibrium was compared with experimental
result and theoretical swelling curve. Furthermore, change of volume fraction and stress distribution
in swelling process were evaluated.
Molecular Modeling of the Dimers from Cyclo-[(1R, 3S)-γ-Acc-D-Phe]3
Authors: Cheng Jie , Zhu Jing Chuan , Liu Bo
Published: March 2009

Four kinds of dimers from cyclic peptide [-(1R, 3S)-γ-Acc-D-Phe]3 were investigated
using molecular modeling based on the density functional theory (DFT), molecular mechanics (MM)
and molecular dynamics (MD). The equilibrium dimer structures reveal that these dimers can be
divided into two different types according to stacking formation, in which one type dimer is more
stable due to the effect of side chain groups. In each type of dimers, only one can transport CHCl3.
When the terminal N-substituent methyl is introduced, the transport character is reversed. Analysis
of 500 ps MD trajectory suggests that the inner and terminal sizes of the dimers are the main factor
that affects the transport of CHCl3. The modeling results can provide a new way for designing and
synthesizing cyclic peptide transport channels.
Mechanical Properties on Nanoindentation Measurements of Osteonic Lamellae in a Human Cortical Bone
Authors: Joo W.K. , Kim B.I. , Bae Sung In , Kim Chae Sil , Song Jung Il
Published: March 2009

The mechanical properties of bone have been found varying at different structural levels.
The different mechanical properties might indicate some important information, such as the
ultrastructure of various bone tissue. Descriptions of the structural features of bone are intensive in
current studies. However, the mechanical properties of bone, in particular those at the micro-and
nanostructural level (material level) remain poorly understood. To probe the mechanical properties
at the microstuctural level, the nanoindentation technique is applied. Nanoindentation as a
promising technique is widely used in the materials science community for probing the mechanical
properties of thin films, small volumes, and small microstructural features. Nanoindentation has
been shown to be an effective method to probe the mechanical properties of microstructures at the
micron scale.
Research and Development of Calcium Phosphate Cement
Authors: Liu Chang Sheng
Published: March 2009

Hydroxyapatite (HAP)-forming calcium phosphate cement (CPC), due to the high
biocompatibility, easy-to-shape characteristic, and the capacity to self-setting under ambient
conditions, has been widely used for the repair of hard tissue defects. To satisfy the different
clinical need, some modified CPC, including porous CPC, fast-biodegradable CPC, injectable CPC,
water-resistant CPC, and rhBMP-2/CPC, have been designed and fabricated in recent years. This
paper attempts to give an overview of different types of CPC that have being developed at the
present time. Meanwhile, the application perspective of these modified CPC is also explored.
The Quantitative Measurement Model of ACFM Based on Swept Frequency Method
Authors: Kang Zhong Wei
Published: March 2009

The alternative current field measurement (ACFM) technique is a new non-destructive
testing (NDT) method to evaluate the surface flaws, and in contract to other methods it has
advantages of non-contacting and non-calibrating. Precise locating and crack length measurement
can be easily achieved. But it is rather difficult to measure the crack depth with the complicated
mathematic model. Its application is thus limited. On this ground, the swept frequency method is
introduced to make up of this shortage. The penetration depth of eddy current that is theoretically
different for different operational frequencies is the principle of crack depth measurement of the
swept frequency method. By means of measuring the switching-frequency of the characteristic
curve, the information of flaw depth is achieved by sweeping frequency. The paper introduced the
physical model of ACFM and assayed the errors of measurement. Some methods were introduced
to decrease the errors. The crack depth is proportional to the interval of the switching-frequency of
flaw and of no-flaw, which is detected at the position of minimum value of Bz.
Ultrasonic Fast-Identification Expert System of the Auto Stick-Weld Defect Based on Echo-Characteristics Analyzing
Authors: Lai Xin Min , Zhao Xin , Zhang Yan Song , Chen Guan Long
Published: March 2009

The current inspection methods of spot-weld quality are difficult to achieve an ideal result
especially for the stick-weld defect which is one of the most important types of spot-weld defect in the
automotive body. This paper thus developed one fast-identification method to identify the joint
defects quickly and efficiently based on quantitative analyzing the echo characteristics of ultrasonic
curves that could reflect the spot-welding joint defects. The echo-characteristic parameters were
analyzed quantitatively through the decision-making bintree of defects and ART networks. After
knowledge acquiring and information processing, a fast-identification expert system (FIES) was
developed to identify the automotive body spot-weld defects, through collecting the standard
ultrasonic curves and quantitatively analyzing. Finally, a series of experiments were conducted to
verify the proposed methods and the results showed that FIES is credible and the identification rate
can exceed 95% in total test samples.