bluuebunny/crossref_metadata_2025 huggingface dataset:
Analyzing the Microstructure and Tensile Properties of an Al8Si0.35Mg Cast Alloy with Prolonged Aging
Authors: Wang Gui Qing , Zhao Zhong Kui , Liu Yan
Published: March 2009

This paper examined the microstructure and tensile properties of an Al8Si0.35Mg cast
alloy during several prolonged aging treatments. The results show that there is a improvement in
ductility for solution treated Al8Si0.35Mg samples aging at 150 °C more than about 20 h to 48 h or
ageing at 200 °C more than about 10 h to 20 h, but no significant reductions in UTS are observed.
There is a substantial improvement in ductility at long aging times at the cost of UTS decreases.
The morphology changes and distribution characteristics of precipitates and its effect on tensile
properties in prolonged aging conditions have been analyzed.
Young’s Modulus of In Situ TiB Whiskers in Ti Metal Matrix Composites
Authors: Meng Qing Chang , Feng Hai Bo , Jia De Chang , Zhou Yu
Published: March 2009

The TiB/Ti metal matrix composites (MMCs) with different volume fractions of in situ
TiB reinforcements were spark plasma sintered at 1000 °C with a pressure of 20 MPa for 5 minutes
in vacuum. The in situ synthesized TiB is whisker shape with a hexagonal transverse section and
distributes uniformly and randomly in the Ti matrix. The Young’s modulus of TiB was
back-calculated from the elastic properties of the composites using the Halpin-Tsai model. The
Young’s moduli of all the composites were found to increase with the increase of TiB volume
fraction. The calculated value of TiB Young’s modulus is about 489±83GPa. Values of Young’s
moduli of TiB whisker obtained according to different methods were compared and discussed.
A Proposed Thickness Distribution of Elbow Resisting Ratcheting
Authors: Gao Bing Jun , Chen Xu , Zhang Shao Feng , Li Jin Hong
Published: March 2009

With the analysis of thickness distributions of elbow by the equal-strength criterion and
plastic deformation by pushing bending process, an ideal thickness distribution is proposed with the
consideration of elbow processing characteristics to improve its ratcheting resistance. Ratcheting of
elbows under internal pressure and reversed in-plane bending is analyzed with Chaboche model by
finite element method, which shows that elbows with the proposed thickness distribution have great
resistance to ratcheting compared with equal thickness elbows.
Experimental Studies of Non-Equilibrium Grain-Boundary Segregations of Phosphorus under Low Tensile Stresses
Authors: Fu Yu Dong , Wang Gang , Liu Chen , Li Qing Fen
Published: March 2009

In the present paper, the non-equilibrium grain-boundary segregation of P atom was
studied in low alloy steels subjected to a low tensile stress at different temperatures. The AES
(Auger electron spectroscopy) experiments and dynamic analyses were conducted to study on the
non-equilibrium grain-boundary segregation of P atom. The research results show that
non-equilibrium segregation of phosphorus occurred at the grain boundaries of the steels
2.25Cr1Mo and 12Cr1MoV, while the critical time reached about 0-1 hour at constant temperatures
773 and 813K. The relationship between the diffusion rate and the diffusion time for the complex
and the phosphorus atom was investigated based on the experimental results. Eventually the
diffusion coefficients of complex and P were calculated with using a proposed dynamic model.
Stress Relaxation Testing For Analysis of 12Cr1MoVG Steel for Creep Strength Evaluation
Authors: Sun Wei Ming , Chen Bing Bing , Jin Wei Ya , Gao Zeng Liang
Published: March 2009

The design of pressurized components at elevated temperature is limited by available
mechanical properties that often do not span appropriate range of stress, time, strain and temperature.
To improve the design process, a new approach based on short-time stress relaxation test (SRT) is
introduced in steel tensile creep analysis. The experiments are implemented using SRT and tested for
creep properties of 12Cr1MoVG steel at 560 °C. The results of creep curves agree well with the
traditional constant load creep test data. The possibility to apply SRT approach is shown promising in
the design of the pressurized component at elevated temperature.
Impact Toughness of Titanium Alloys with Different Strengthening Methods
Authors: Sun Qiao Yan , Xiao Lin , Sun J.
Published: March 2009

In present paper effect of alloying elements and strengthening particle on the impact
toughness were investigated. Load and energy in the impact tests were also discussed in detail for
Ti-2Al, Ti-2Sn,Ti-2Zr, Ti-1Mo and Ti/TiC. Impact tests were carried out at room temperature (293K)
and low temperature (83K) using a 300J capacity impact machine. Ti-1Mo, Ti-2Zr,Ti-2Sn alloys
exhibit high impact toughness even at low temperature, while Ti-2Al and Ti/TiC only have high
toughness at room temperature. At room temperature, general yielding occurred in all the materials,
but it occurred only in Ti-1Mo, Ti-2Zr and Ti-2Sn at low temperature. It seemed that strengthening
titanium couldn’t affect the elastic energy (Ei) effectively, but bring about more changes to Ep
(propagation energy of crack) than to Ei (initiation energy of crack). As for the effect of alloying
elements on the impact toughness, it seems to be related to the comprehensive result of the
concentration and electronegative property of alloying elements. The interface between the TiC
particles and matrix resulted in low toughness, especially at cryogenic temperature.
The Effect of Heat Treatment on the Properties of LF9 Alloy
Authors: Cheng Shi Chang , Fu Xiao Yang , Wang Li Min , Liu Zheng Dong , Wang Bao Feng
Published: March 2009

The paper experimentally investigated the change of LF9 properties, including strength at
room temperature and 350°C, plasticity and impact toughness, under various heat treatment
schedules. Results show that the strength of LF9 decreases and plasticity and toughness increase
after secondary aging, with the increase of solid solution temperature. Meanwhile, with the increase
of aging time, the strength of LF9 increase and plasticity and toughness decrease. The investigation
of optical metallography, TEM and phase analysis indicate that the phenomena are mainly caused
by the precipitation of η, γ’and γ’’.
Experimental Study on Residual Stress of K24 Superalloy in Laser Cladding Zone by Laser Shock Processing
Authors: Lu Jin Zhon , Zhang Yong Kang , Xu Y.Y. , Kong De Jun , Yao H.B. , Ren Xu Dong
Published: March 2009

The surface of K24 superalloy was processed with laser cladding & LSP (laser shock
processing). Residual stress in the laser cladding zone by LSP was measured with X-ray stress tester
X-350A, and the variational rule of residual stress in the cladding zone by tempering treatment of 8
hours and 16 hours was measured, respectively. The experimental results show that compressive
residual stress of K24 superalloy surface by laser cladding & laser shock processing is above
-600MPa, which exceeds residual stress by mechanical peening treatment; and there is no clear effect
on residual stress by tempering treatment at 600°C for 8 hours and 16 hours, respectively, which can
improve fatigue life of K24 superalloy.
Effect of Tungsten Addition on Properties of Ni-Based Alloy Sheet Prepared by EB-PVD
Authors: Song Guang Pin , He Xiao Dong , Sun Yue , Li Ming Wei
Published: March 2009

Large scale Ni-based alloy sheets are prepared by electron beam physical vapor deposition
with and without tungsten added into melting pools respectively. Addition W increased vapor rate and
decreased compositional transformation during deposition. Chemical constitution of the sheet
prepared through tungsten is more similar to that of the ingot. Microstructure of two alloy sheets is
observed by scanning electron microscope (SEM) and atom force microscope (AFM). The results
show that both of the sheets consist of columnar grains, whose major axes are almost parallel to the
normal direction of the sheet. However, the average diameter of grains of the sheet through tungsten is
larger than that of the sheet not through tungsten in minor axis direction. Mechanical properties and
failure mechanisms of both sheets are studied. Tensile tests are conducted on a number of specimens.
Strength, strain-to-failure are estimated under loading condition. The results show that the sheet
prepared by EB-PVD through tungsten has a superior strength and an elongation percentage than that
of the one prepared without tungsten.
Influence of Oxidation to Small Punch Creep Test
Authors: Shan Jian Hua , Qian Zhen Mei , Ling Xiang
Published: March 2009

In order to validate a procedure for creep rupture tests using small punch specimens, the
influences of oxidation on the creep deflection curve, rupture time and ductility of miniature
specimens were investigated. Using disc test specimens of 10mm in diameter and 0.5mm in thickness,
a variety of small punch creep (SPC) tests for Cr5Mo steel at the condition of 550°C-404N and
650°C-189N under the protection of different Argon flow and in air atmosphere were firstly carried
out. Metallographic observations, micro-hardness testing and measurement for these specimens of
SPC test were performed. It indicates that the oxidized layer of specimens integrates and the residual
thickness of specimens increases, while the hardness of specimens increases with the increment of the
Argon flow. Moreover, the different oxidation degrees of specimens with the surface morphology
were compared in this paper. The test results show the rupture time of specimens can be effectively
prolonged by the protection of different Argon flow.
Compressive Properties of Quartzite Microcrystallite Glass Ceramics
Authors: Zhang Qiu Ming , He Xiao Dong , Li Yao
Published: March 2009

Quartzite microcrystallite glass ceramics is one of the most promising machinable
ceramic materials due to its many outstanding properties. The density of quartzite microcrystallite
glass ceramics is smaller than the aluminum alloy and its thermal conductivity approaches to the
zirconia and its elastic module is also very small; All these advantages meet the requirements for
structural components to work at higher temperature; Compressive properties of quartzite
microcrystallite glass ceramics had been studied at room temperature and 500°C in this paper; The
specimens had been aged at 1000°C for 5, 10, 20, 30 hours, respectively. Through SEM
observations of the fracture surface of the specimens, the microstructural changes had been
determined; The tests showed: the compressive property of the machinable glass ceramic declined
as the ageing time increasing; but the compressive property of the specimen aged for 10 hours was
inferior to that aged for 20 hours; Then compressive property declined as the ageing time
increasing. The SEM observation indicated that with the extend of ageing time, the grains grew
bigger and microporous and microcracks increased in the specimens; Comparing the compressive
property at room temperature with that at 500°C, one found that the change of compressive property
was very small when the ageing time was the same; With the extend of ageing time, the curve of the
compressive property changed from smooth curves to broken lines.
Microstructural Evolution during Tensile Creep of a Single-Crystal Nickel-Base Superalloy
Authors: Li Ying , Yu Hui Chen , Wu Xue Ren , Yang Xiao Guang , Shi Duo Qi
Published: March 2009

Tensile creep tests were conducted at 980°C under a constant stress on a single crystal
nickel base superalloy. Some tests were interrupted at different stages during the creep process. The
strain-time curves indicated that this alloy exhibited conventional primary, steady-state and tertiary
stages at this temperature. The transmission electron microscope (TEM) observations of foils taken
from the gauge sections of specimens were made to interpret the microstructural evolution that
occurred during the creep process. It was found that the γ′ particles were rafted in the direction
perpendicular to the applied stress. The acceleration of the creep rate was related to the change of the
dislocation density.
An Experimental Investigation on the Tensile Behavior of Silane-Modified MMT/Epoxy Nanocomposites
Authors: Ha Sung Rok , Rhee Kyong Yop , Shin H.H.
Published: March 2009

It is well-known that the mechanical properties of nanocomposites are better than those of
conventional composites. One of problems in fabricating nanocomposites is a dispersion of
nanoparticles in the composites. In this study, the effect of MMT content on the tensile characteristics
of trifunctional silane-treated MMT/epoxy nanocomposite was investigated. It was found that the
tensile strength and the elastic modulus increased by over 24% and 83%, respectively, as the content
of MMT increases from 2wt% to 10wt%. The improvement of tensile strength and modulus with
increasing content of MMT occurs because the reinforcing effect of MMT becomes greater than the
deteriorating effect due to the interfacial debonding between MMT and epoxy as the MMT content
increases.
Formability Analysis of the Mg-Alloy AZ31
Authors: Sakamoto Hidetoshi , Fournier Olivier , Kawabata Kousuke , Hiwatashi Tetsuya , Fukagawa Kazuyoshi , Takahashi Kousei
Published: March 2009

Formability of AZ31 (aluminium 3%, zinc 1%) magnesium alloy sheets was studied by
tensile test and deep drawing test. Effects of the working anisotropy and temperature on the alloy’s
mechanical properties were first investigated. Test temperatures are 160, 180, 200 and 220°C, and
specimens’ directions are 0°, 45° and 90° to the rolling direction. The deep drawing of cylindrical
cups of 100mm in diameter were done for the same temperatures in order to discuss the effects of
the test conditions (temperature, punch speed, lubricant and blank holding pressure) on the
formability. The experimental results show that the formability of AZ31 alloy sheets (1mm in
thickness) at 200°C is better than that of other tested temperatures. The highest drawing speed was
also achieved for an operating temperature of 200°C.
Influence of Collision Velocity and Angle on Bullet Deformation Investigated by Reconstruction and FEM Analysis
Authors: Sakamoto Hidetoshi , Hiwatashi Tetsuya , Sato Kensuke , Yamaguchi Toshihiko
Published: March 2009

In this paper, the effects of collision velocity and collision angle on bullet deformation
were discussed and performance of protection board made of PC (polycarbonate) plate was
estimated. After gun firing experiments, the shape of the bullet and PC were measured using three
dimensional measurement machine and deformed the bullet and PC plate shapes were reconstructed
by using 3D-CAD as digital data. Furthermore, crash simulation of the bullets were performed by
FEM analysis code “LS-DYNA”, and the results of simulation and measurement were discussed.
Effect of Extruding Technology on Microstructure and Properties of Al-Li Alloy
Authors: Shi Qi Nian , Xiong Wei Hao
Published: March 2009

By the test of Al-Li-Cu-Mg-Zr Alloy’s mechanical property and microstructure in various
kinds of extrusion technology, the effect of extrusion processing parameter on the structure and
property of the alloy was analyzed, and the parameter’s range for obtaining proper compromise of
strength and toughness was discussed.
Grain Orientation Dependence of Extended Planar Dislocation Boundaries in Cold-Rolled Polycrystalline Aluminium
Authors: Lin Feng Xiang , Godfrey Andrew , Liu Qing
Published: March 2009

The dependence on the grain orientation of the alignment of planar dislocation
boundaries in plastically deformed metals has been investigated by examining grains of S
orientation ({123}<63-4>) in cold-rolled polycrystalline aluminum. For the ideal S orientation the
{111} slip plane associated with the highest resolved shear stress lies either at +40° or -40° to the
rolling direction in the longitudinal section, with two S variants corresponding to each case.
Boundary traces in S orientation grains in the rolled sample were examined by the combined use of
electron channeling contrast imaging and electron backscatter diffraction orientation mapping. In
each case the +/- sense of the observed planar boundary traces matched that of the {111} slip plane
with the highest resolved shear stress showing that the alignment of the boundaries is
predominantly controlled by crystallographic rather than macroscopic considerations.
The Effect of Heat Treatment on Microstructure and Mechanical Properties of ZK60 Alloy
Authors: Zhang Ding Fei , Liu Rong Shen , Peng Jian , Yuang Wei , Zhang Hong Ju
Published: March 2009

With different heat treatment, the microstructure and mechanical properties of ZK60
magnesium alloy were investigated. It can be concluded that heat treatment has great effect on
mechanical properties of ZK60. With artificial aging after extruding, the precipitation of the second
phase from the supersaturated solid solution significantly improved mechanical properties. It can
greatly increase yield strength of ZK60 alloy, while the tensile strength has little change. For the
combination of solid solution strengthening and age hardening, two opposite factors must be
considered. On one hand, the solid solution strengthening and the later precipitation strengthening is
good for alloy’s strength; on the other hand, the properties decrease as the grains grew under high
temperature for a long time during solution heating.
The Mechanical Property and Microstructure of Ti-4Al-2V Alloy after High Speed Shot Peening Treatment
Authors: Zhang Xi Yan , Jia Chong , Zhao Xin Chun , Liu Zhi Nong , Yi Jin
Published: March 2009

The microstructure characteristic and wear behavior of the severe deformation surface
constitution of Ti-4Al-2V alloy were studied in this paper. The results show that the wear resistance
of the deformed surface is much better than that of the coarse grain surface. And the wear mechanism
of the nanocrystalline surface is different from that of the coarse grain surface. The former is particle
wear mechanism of harder material and the latter is adherence wear mechanism. The influence factors
on the wear resistance of the nanocrystalline surface have been discussed.
The Estimation of Barrel-Rifle Surface Wear Based on Fractal Theory
Authors: Jing Chang , Wang Bing Cheng , Ren Zhao Hui , Yu Tao , Song Nai Hui
Published: March 2009

In this paper, the theory of fractal geometry was used to study the barrel-rifle surface
topography and correlation dimension method was adopted to calculate the fractal dimensions of
the projectile worn marks shot from the barrels with different worn. The study showed that the
different wears of barrel-rifle surface resulted in different fractal dimensions of the projectile wear
surface and there was a correlation between the fractal dimensions of the projectile wear surface
and the change of the barrel rifle surface. Therefore, through the rifle marks on the projectiles, not
only the wear of the barrel’s internal surface can be analyzed, but the gun life also can be further
estimated. The paper provided a new tool for analyzing the barrel-rifle surface wear.
Analysis of Fretting Problems Using a Numerical Method Based on Cauchy Singular Integral Equation
Authors: Lee Choon Yeol , Tian Li Si , Bae Joon Woo , Chai Young Suck
Published: March 2009

Numerical analysis by influence function method (IFM) is demonstrated in this study in
order to investigate the fretting wear problems on the secondary side of the steam generator, caused by
flow induced vibration. Two-dimensional numerical contact model is developed in terms of Cauchy
integral equation. The distributions of normal pressures, shear stresses and displacement fields are
derived between two contact bodies which have similar elastic properties. The work rate model is
adopted to find the wear amounts between two materials. The results are compared with the solutions
by finite element analyses, which validates the application of the present method to fretting wear
problems.
Effect of Sliding Speed and Applied Load on the Wear Behavior of Thermally Sprayed Ni-Based Self-Flux Alloy Coating
Authors: Kim Yeong Sik , Kim Kyun Tak
Published: March 2009

This study aims at investigating the effect of the sliding speed and the applied load on the
dry sliding wear behavior of thermally sprayed Ni-based self-flux alloy coating. Ni-based self-flux
alloy powders were flame-sprayed onto a carbon steel substrate and then these coatings were
heat-treated at temperature of 1000 oC. Dry sliding wear tests were performed using the sliding speeds
of 0.2, 0.4, 0.6 and 0.8 m/s and the applied loads of 5, 10, 15 and 20 N. AISI 52100 ball (diameter 8
mm) was used as counterpart material. Wear behavior of Ni-based self-flux alloy coatings was studied
using a scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX). It was
revealed that microstructure and wear behavior of the Ni-based self-flux alloy coatings were much
influenced by the sliding speed and the applied load.
Tribological Behavior of Phosphor Bronze against SAE52100 Steel under Different Lubricants
Authors: Xia Yan Qiu , Sasaki Shinya , Murakami Takashi , Nakano Miki
Published: March 2009

The friction and wear properties of phosphor bronze discs sliding against SAE52100 steel
balls were evaluated using an Optimol SRV reciprocating friction and wear tester under the
lubrication of pure poly-alpha-olefin (PAO) and PAO containing commercial phosphite ester, zinc
dialkyldithiophosphate (ZDTP) and oleic acid additives. The morphologies of the worn surfaces of
the phosphor bronze discs were observed using a scanning electron microscope (SEM). In addition,
the elemental compositions and chemical states of several typical elements on the worn surfaces of
the phosphor bronze discs were examined by means of X-ray photoelectron spectroscopy (XPS). The
findings indicated that the phosphor bronze discs exhibited higher wear resistance under the
lubrication of PAO containing phosphite ester than pure PAO, PAO containing ZDTP, and PAO
containing oleic acid. Also, the phosphor bronze discs exhibited stable friction coefficients as low as
0.09-0.11 when lubricated with PAO containing phosphite ester. According to the XPS analyses, it
was considered that the formation of CuO and phosphate led to lower friction coefficient and high
wear resistance of phosphor bronze specimens lubricated with PAO containing phosphite ester. In the
case of the phosphor bronze specimens lubricated with PAO containing ZDTP and oleic acid, the
formation of organic compounds seemed to lead to lower friction coefficient, but did not seem to
affect the wear resistance.
Stress Analysis of Bonded-Interface Technique on Subsurface Damage Observations of Brittle Porcelains
Authors: Yu Hai Yang , Sun Zhen , Zhao Hua , Zhu Min Hao
Published: March 2009

In the subsurface damage observations on the wear behavior of brittle dental porcelains,
it still remains unsolved that how to distinguish the cracks that develops accidentally during the
preparing sample process from those actually produced in the tests. In the sliding friction tests, the
bonded-interface technique (BIT) was successfully used for subsurface damage evaluations. The
profile of wear scar was easily observed on the cemented section of the blocks without inducing any
cracks. The stresses on the surface and internal of dental porcelains were calculated with the contact
element method (CEM) by ABAQUS software. The model of rectangular dental porcelain and Si3N4
ball were developed based on sliding friction tests. The Si3N4 ball modeled in this study was of the
diameter of 4mm and 12 mm. The size of Vita VMK 95 porcelain blocks was 5 mm wide, 2 mm
thick and 15 mm long. The glue layer thickness values are 10 .m, 20 .m and 30 .m. The loading
of the Si3N4 ball was modeled as a constant distributed vertical load applied across the bonding line
of the porcelain. Stresses and displacements of all nodes of the model, especially at the bonding
interface, were analyzed and compared. The results of the study indicated that stress values
correlated strongly to the applied loads. Stress distribution was symmetric about the
bonded-interface plane. The maximum occurred in surface layer and the minimum on the bottom
line in the porcelain blocks. Along the interface, stresses decreased with the distance from the
surface of porcelain. On the other hand, high stresses focus on the surface part and go sharply down
in the internal region along the depth direction. Among the parameters of sliding test on the stresses,
the load effect is prominent. The BIT model experiences a different, non-axisymmetric stress field
than that of real work-piece. So the BIT should not be considered as a reliable source of quantitative
analysis but as a qualitative method for observing the form of the damage modes with more visible
information than the conventional tools.
Composite Fretting Wear of Aluminum Alloy
Authors: Zhu Min Hao , Zhou Zhong Rong
Published: March 2009

A complex relative motion of fretting combined by dual motions of radial and tangential
fretting was achieved on a modified fretting tester. The composite fretting motion was induced by
the action of an oscillating normal force in a sphere-on-inclined flat contact (52100 steel ball
against 2091 aluminum alloy). Two types of inclined angles (45° and 60°) were used in the tests.
Variations of veridical force vs displacement have been recorded and analyzed as a function of
cycles. Effects of the cyclic normal force and the inclined angle were discussed. The test results
showed that wear, cracking and plastic deformation accumulation with a strong dissymmetry in
damage morphology was observed. A transformation of fretting mode from composite to radial
fretting mode occurred due to a strong modification at local contact configuration. As a conclusion,
a physical model for wear mechanism of composite fretting was presented.
Fretting of Human Axial Cortical Bone
Authors: Yu Hai Yang , Gao Shan Shan , Cai Zhen Bing , Wang Min , Chen Xin Min , Zhu Min Hao
Published: March 2009

Under imitating human physiological solution, the fretting behaviors of flat cortical bone
specimen from fresh human femur in the axial orientation against TA2 titanium ball with diameter
of 40 mm had been investigated. The coefficients of friction (COF) and fretting logs were
calculated automatically. The worn surfaces of the cortical bone were analyzed by means of laser
confocal scanning microscopy. The results showed that the fretting logs for the cortical bone varied
with the increase of the cycles from the elastic partial slip (D=5 (m), the elastoplastic partial slip
(D=15 (m) to gross slip (D=30 (m), respectively. The fretting regime transformed from the partial
slip regime directly to the gross slip regime without the mixed fretting regime. And the evolution of
the COF in each fretting condition was also compared statistically. The fretting damage in the
elastic partial slip state was slight. But the abrasive wear and micro-fracture were observed in the
plastoelastic partial slip state and gross slip regime. The wear depth increased with cycles and well
related to the COF of the cortical bone in each fretting condition. To reduce the fretting damages of
bone, it is advisable to control the displacement amplitude at bone-implant interface.
An Experimental Study of Excavation Damaged Zone in Anisotropic Rock
Authors: Wang Shu Hong , Lee Heek Wang , Zhao Xing Dong , Bashir Ahmad
Published: March 2009

When a tunnel or an underground structure is excavated in rock mass, rock disturbed or
damaged zone (EDZ) is formed around the excavation due to the stress concentration resulting from
stress redistribution. Recent studies on the rock EDZ revealed it’s important to structural stability
around underground opening. In this study, the fracture and damage mechanisms of rock induced by
the accumulation of microcracks were investigated by AE tests. The results of the experiments
showed that tensile failure was the major microscopic failure mechanism of rock in excavation
damaged and disturbed zone. The expression of the damage magnitudes in each AE source leads to
accurate prediction of macroscopic failure mechanisms. In addition, the orientation of the
macroscopic failure plane could be estimated by the orientational distribution of microcracks.
Simulation on the Short Fatigue Crack Initiation of LZ50 Axle Steel for Railway Vehicles
Authors: Xu Yan Hai , Zhao Yong Xiang
Published: March 2009

The short fatigue crack initiation of LZ50 axle steel for railway vehicles was investigated
by numerical simulation in this paper. The microstructure of LZ50 steel was constructed with the
application of 2D Voronoi tessellation. The stress and strain distributions in the microstructure were
obtained by FEM under the boundary condition shifted from loading level applied in fatigue
specimen of this steel. Finally, the probability of short fatigue crack initiation was given with
different loading cycles to illustrate the process of crack initiation of LZ50 steel under the given
loading cycles based on the S-N curve of the material. The further work on the research of crack
growth and collective evolution of short fatigue cracks can be conducted with the simulated results
of crack initiation in the microstructure of LZ50 steel.
A New Numerical Method for General Failure Probability with Fuzzy Failure Region
Authors: Chen Lei , Lu Zhen Zhou
Published: March 2009

For general reliability analysis with fuzzy failure region F % , the general failure
probability F P% is defined as the integral of product of μF% [g( y)] , the membership of performance
function ( ) g y to F % , and joint Probability Density Function (PDF) f ( y) over , the total
variable space, i.e. [ ( )] ( ) F F P μ g f d % = ∫ ∫ % y y y L . On the basis of line sampling, an efficient method
for random failure probability analysis with clear failure region, a new numerical method is
presented to calculate F P% . In the presented method, the total integral region is split into m clear
sub-regions i F in a way that the value of g( y) in i F can be approximately viewed as i g , a
constant independent of y , and the value of [ ( )] F μ % g y in i F can be viewed as a constant
( ) F i μ g % subsequently. Due to the closely invariant property of [ ( )] F μ g % x in i F and
1 2 m = F I F ILI F , F P% is transformed into the sum of ( ) F i μ g % ( )
i F ∫L∫ f y dy , where
( )
i F ∫L∫ f y dy is the random failure probability with the clear failure region i F and can be
obtained by line sampling. The high efficiency of the presented method resulted from that of the
line sampling is demonstrated by the illustration.
A New Technology of Improving Surface Quality of Engine Cylinder
Authors: Zhu X.J. , Xu Hong Jun , Gao Yan Xia , Lu Zhi Meng
Published: March 2009

This paper introduces the new technology of ultrasonic vibration honing, and analyzes
the cutting principle of ultrasonic honing in terms of cutting motion, grain performance and cutting
quantity. Then, the applied effect used in the cast-iron cylinder of DY90 is introduced. The principle
and the structure of this device are discussed. This new technology can further be used in
micro-car’s cylinder, can provides a high-productivity, high-quality for cast-iron cylinder.
Dynamic Intelligent Prediction Control in Slender Cylindrical Grinding
Authors: Ding Ning , Li Xiao Mei , Ding Yuan , Li Guo Fa , Wang Long Shan
Published: March 2009

A dynamic intelligent prediction control system is built in slender cylindrical grinding.
Elman network is used in the dynamic size prediction control model, and the first and the second
derivative of the actual amount removed from the workpiece are added into the network input,
which can greatly improve the size dynamic prediction accuracy. Moreover, a surface roughness
equation with vibration data is proposed. Based the equation, the surface roughness dynamic fuzzy
neural network prediction subsystem is built. Experiment verifies that the developed prediction
control system is feasible and has high prediction and control accuracy.
Study on Self-Configuration Method of Neural Network Model for Grinding Troubles On-Line Monitoring
Authors: Liu Gui Jie , Wang Qiang , Shi Xiao Long , Kang Ren Ke
Published: March 2009

A grinding trouble on-line monitoring mode is presented based on the nonlinear building
mode principle of neural network. The input units were the peak of the FFT, the peak of RMS, and
the standard deviation of AE signals. The outputs were the troubles of the grinding burning,
grinding chatter, and grinding wheel dull. The structure of neural network is established by
self-configuration method. The network mode is trained and tested by using the experiment data,
and the results indicate that the neural network mode obtained by self-configuration method has
high recognize rate for grinding troubles, and can be used to monitor grinding troubles on-line.
Study on Tribological Performance of Fine-Grained Diamond Films
Authors: Shen Bin , Zuo Wei , Sun Fang Hong , Chen Ming
Published: March 2009

Friction and wear behavior of fine-grained diamond (FGD) films were investigated in the
ambient air, deionized water and paraffin oil lubricating environment. The FGD films were deposited
on WC substrates using HFCVD method and the tribologcial tests were conducted in a ball-on-plate
type reciprocating friction tester where the mating balls were made of ball-bearing steel. Scanning
electron microscopy (SEM), surface profilometer and Raman spectrascropy were used to study the
characterizations of the deposited FGD films, and after sliding tests, the worn areas on both mating
balls and FGD films were investigated and the wear debris layer adhered to the friction area of FGD
films were analyzed with EDX. The experiment results suggested that FGD films exhibited steady
friction coefficient as about 0.25 in water, lower than that in open air, which is up to 0.40; but the
mating ball in water suffered much severer wear lost and its specific wear rate was more than two
times higher than that in air, up to 3.6E-4 mm3N-1m-1. As while, a thick and compact layer of wear
debris was observed on the worn area of FGD films sliding with water lubrication while only little
debris existed in the diamond grain boundaries, which might dominate the friction process and
attribute to the lower friction coefficient and higher specific wear rate in water environment. In oil
environment, furthermore, both the friction coefficient and specific wear rate reached minimum value
as low as 0.1 and 1.1E-4 mm3N-1m-1, no observable wear scar could be measured on the sliding
surface of the FGD film.
Lapping Process of Diamond Cutting Tool by Molecular Dynamics Simulating
Authors: Li Zeng Qiang , Sun Tao , Yan Yong Da , Zhang Jun Jie , Liang Ying Chun , Dong Shen
Published: March 2009

Molecular dynamics is a rapidly developing field of science and has become an established
tool for studying the dynamic behavior of material machining. A three-dimensional molecular
dynamics (MD) model about the atoms of the diamond cutting tools and the diamond grits is built by
using the molecular dynamics. The Tersoff potential function is used to calculate the force and potential
energy among the atoms of the diamond tools and the atoms of the diamond grits. The lapping
processes at a special cutting depth are simulated. The variety of the specimen potential energy in the
lapping process is observed. The mechanism of the diamond micro machining and the form of the
surface formation are given by comparing the distribution maps of atoms in initial and cutting states.
This study will give a strong support to the diamond cutting tools’ lapping.
Research on the Hydrodynamic Electro-Chemical Mechanical Polishing for Silicon Wafer with Suspension Fluid
Authors: Zhan Jian Ming , Zheng Di
Published: March 2009

Silicon wafer is one of the key materials of LSI and SLSI and has been widely used in
the electronic industries and IT products. In the new century of nano times, silicon wafer needs
higher geometry accuracy, lower surface roughness and higher precision machining effecency, but
no disfigurement in its surface layer. Nowadays, non-contact polishing still seems to be most
efficient method to achieve nano-scale geometry accuracy and maintain surface roughness in the
nanometer level even for silicon wafer, but it is still not easier to control its machining course and to
obtain well-pleasing machining effecency. In this paper, a hydrodynamic electro-chemical polishing
system based on CNC is established with micro-displacement compensating for nano-scale
polishing. A new type of compliant polishing tool system is developed, which can turn orthogonal
force control subspace and position control subspace to isomorphic position servo space. Moreover,
it convert force control deflection to position servo deflection and in this way the polishing force is
controlled by micro-displacement compensating with piezoelectricity. Polishing experiments on
silicon wafer, in hydrodynamic polishing fluid mixed with nano-scale SiO2 abrasive particles, have
been conducted to investigate the fundamental machining mechanism.
Study on Pad Conditioning Parameters in Silicon Wafer CMP Process
Authors: Zhou Zhao Zhong , Yuan Ju Long , Lv Bing Hai , Zheng Jia Jin
Published: March 2009

Polishing pad plays a key role in determining polish rate and planarity of a chemical
mechanical planarization (CMP). The properties of the pad would deteriorate during polishing
because of pad surface grazing, which results in reduced removal rates and poorer planarity of
wafer surface. Pad conditioning and its influence on pad surface structure and CMP process is
introduced and discussed in this paper. The study shows that the surface structure can be
regenerated by breaking up the glazed areas with conditioner, MRR(Material Removal Rate) can be
maintained at high level with proper pad conditioning, and UN(Non-uniformity)can also improved.
Orthogonal experiments design is employed in this study to determine the best conditioning
parameters.
Researching and Manufacturing of Endless Diamond Wire Saws and the Cutting Experiment
Authors: Gao Wei , Ma Bo Jiang , Cao Tong Kun , Liu Zhen Chang
Published: March 2009

The research and manufacture of endless diamond wire saws have been reported in this
paper. The matrix of saws was 65Mn steel wire whose diameter was o.8mm, and was welded as a ring
by argon arc welding. The endless diamond wire saws were made by setting diamond abrasives on
endless steel matrixes using nickel-plating method. The cutting experiments were carried out using
the diamond wire saws on the homemade test equipment. The characteristics of the saws are narrow
slot, high cutting speed, low noises and good surface quality. The surface cut could be finishing
grinding or polishing directly, so the productivity could be improved greatly. Endless diamond wire
saws can cut not only rock, but also valuable hard and brittle materials such as ceramic, boulder, and
silicon etc.
Detection of Grinding Surface’s Quality Based on Image Technique
Authors: Liu Xian Li , Wu Chun Ya , Liu Yi Zhi , Yan Fu Gang , Li Yu Fu , Wang Peng
Published: March 2009

Aiming at different grinding surfaces of hardened bearing steel GCr15, this paper made
experimental research on detection method of surface roughness based on image technique.
Adopting cold light source and five kinds of LED light sources, such as low-angle light, collimated
light and coaxial light, we analyzed image characteristics of grinding surface under different
processing conditions and found that there was a good correlation between standard deviation of
gray variance and roughness of grinding surface. In comparison with the results from traditional
surface roughness measuring instrument, we gained the corresponding relation between different
grinding surface roughness and standard deviation of image gray variance. It was proved by
calculating that they have a good correlativity.
Grinding Process Fuzzy Control on CNC Tool Grinder
Authors: Kang Jing , Feng Chang Jian , Hu Hong Ying , Shao Qiang
Published: March 2009

In order to improve form cutter accuracy in grinding process, a closed-loop control system was designed to accomplish adaptive control of constant force in grinding process. Since it is a complicated dynamic process with severe nonlinear and much stochastic disturbance, fuzzy adaptive controller was used which can adjust parameters online. By measuring grinding force, characteristic information of grinding process was acquired. Regulation factor of feed rate is determined by grinding force ratio, and force deviation and its change rate are used as evaluation indexes. Thus, adaptive control of constant force in grinding process is accomplished. Simulation and tool grinding test indicate that the system has high precision and stability, and reduces cutter error efficiently.
Precision form Grinding of Ceramic Materials with Diamond Grinding Wheel
Authors: Cui Zhong Ming , Zhu Deng Jie , Du Lei
Published: March 2009

Ceramic is difficult to cut with normal machining method in precision intricate profile.
The grinding process with diamond abrasive wheel is an effective process to machining ceramic
materials. In this paper, a precise form-grinding method of ceramic materials with diamond
grinding wheel is introduced. The tolerance of intricate profiler precision degree by this grinding
process is less than 0.005mm. The machining process contains many techniques as high efficiency
of profiler dressing technique of diamond wheel and form grinding process of ceramic. It gives
some references on the developing of ceramic precision intricate profile machining techniques
forward.
In Vivo and In Vitro Response to a Gelatin/α-Tricalcium Phosphate Bone Cement
Authors: Bracci Barbara , Fini Milena , Panzavolta Silvia , Torricelli Paola , Bigi Adriana
Published: March 2009

We recently developed a new biomimetic calcium phosphate bone cement enriched with
gelatin (GEL-CP) which exhibits improved mechanical properties with respect to the control
cement (C-CP) and a good response to osteoblast-like cells. In this work, we have extended the
investigation to primary culture of osteoblasts derived from normal (N-OB) and osteopenic (O-OB)
sheep bones cultured on samples of GEL-CP, and their behavior was compared to that of cells
cultured on C-CP as control. Cell morphology, proliferation, and differentiation were evaluated at 3
and 7 days. Preliminary in vivo tests were carried out onto critical size defects in the radius
diaphysis of rats.
Study of Hydroxyapatite Osteoinduction with Osteo-Specific Gene Expression of Stem Cells
Authors: Lin Li Wen , Chow King L. , Leng Yang
Published: March 2009

Osteoinductivity of hydroxyapatite (HA) was investigated using uncommitted pluripotent mouse stem cells, C3H10T1/2 in an in vitro differentiation assay. HA exhibited impressive ability to induce expression of osteo-specific genes in C3H10T1/2, including alkaline phosphatase (ALP), type I collagen (COL1) and osteocalcin (OCN); compared with its insignificant up-regulation of the same genes in osteoblast-like cells, Saos-2. HA osteoinductivity exhibited in C3H10T1/2 was comparable to that of a bone morphogenetic protein (BMP) with reference to up-regulating osteo-specific genes except the core binding factor 1 (Cbfa1, Runx). This result implies a difference in osteogenic induction pathway initiated by HA and BMP. HA osteoinductivity was also demonstrated in the stem cells culture using conditioned medium derived from cells cultured on HA substrates. The medium exhibited excellent ability to up-regulate ALP without the presence of HA and BMP. The result suggests that the HA can interact with the cells and generate potent inductive substance released into the medium. Such substance in turn is able to induce uncommitted cells to differentiate into the osteolineage.
Application of Newly Developed Globular-Shaped Granules of β-Tricalcium Phosphate for Bone Substitute
Authors: Gonda Yoshinori , Ioku Koji , Okuda Takatoshi , Kawachi Giichiro , Yonezawa Ikuho , Kurosawa Hisashi , Ikeda Tohru
Published: March 2009

Globular-shaped beta-tricalcium phosphate (β-TCP) granules were synthesized using a unique
dropping slurry method and the biological response was analyzed by implantation into the rat femur. Two
kinds of globular-shaped β-TCP granules, composed of either rod-shaped particles or conventional
non-rod-shaped particles were synthesized, implanted into the left femurs of 8-week-old female Wistar rats,
and analyzed histologically. Commercially available β-TCP granules composed of conventional
non-rod-shaped particles were also implanted as a control experiment. Four weeks after the operation,
part of each implant was already resorbed and the resorbed area was replaced by newly formed bone tissue
and bone marrow. Eight weeks after the operation, the resorption and replacement were advanced in each
implant. At 12 weeks after the operation, residual globular-shaped β-TCP granules composed of
rod-shaped particles were resorbed into compact petrotic bone tissue almost completely. The formation of
less compact petrotic bone tissue was observed in specimens implanted with globular-shaped β-TCP
granules composed of conventional non-rod-shaped particles. Commercially available β-TCP granules
composed of conventional non-rod-shaped particles were mostly resorbed into trabecular bone and the
formation of compact petrotic bone tissue was rarely observed. These data suggested that both the unique
spherical shape and microstructure of β-TCP particles affected bone-forming activity after the operation.
Variations in the Compression Strength of Cylindrical Samples Made of Dense Hydroxyapatite
Authors: Dorozhkin Sergey V. , Gunduz Oguzhan , Oktar Faik N.
Published: March 2009

Dense bioceramics made of pure hydroxyapatite (HA) was prepared and characterized.
The cylindrical samples were compacted from HA powders of diverse pretreatments; namely, from
spray-dried HA, calcined HA and mixtures thereof. The samples were prepared by a hydraulic press
under different compaction loads both with and without auxiliary compounds (a binder and a
lubricant). Both the total mass and geometrical dimensions of the prepared cylinders were
measured. Then, the cylindrical samples were sintered at 1200 °C for 4 hours. After cooling down
to ambient temperature, the sintered cylinders were weighed and their geometrical dimensions were
measured once again. Mass decreasing and the shrinkage degree were calculated as a result.
Afterwards, the compression strength of the sintered cylinders was measured by an Instron 5587
machine. Preparation of dense HA bioceramics possessing the highest possible compression
strength was the purpose of this study. The necessary processing parameters were discovered.
Preparation and Biological Evaluation of Si-Substituted HA Ceramics with Controlled Composition
Authors: Palard Mickael , Combes J. , Champion Eric , Bernache-Assollant Didier
Published: March 2009

This work aimed at preparing dense and monophasic silicated hydroxyapatite ceramics
over the range 0 ≤ x ≤ 1.0 mol of silicon. The synthesis of the powder via an aqueous precipitation
process followed by an adapted thermal treatment showed that it was possible to obtain dense
single-phased apatite ceramics containing up to 0.6 mol of silicon. The in vitro biological
characterization of these materials was performed.