bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure and High Temperature Stress Rupture Properties of Ru-Containing Directionally Solidified Ni-Base Superalloy
Authors: Zheng Liang , Li Shu Suo , Xiao Cheng Bo , Tang Ding Zhong , Gu Chen Qing
Published: March 2009

In this investigation, 3wt.% Ru was added to a low Cr and high W content superalloy
with a nominal composition of Ni-10Co-1.5Cr-2.0Mo-1.0Nb-5.5Al-1.2Ti-0.1C-0.02B (wt.%) and
both the Ru-free and the Ru-bearing alloys were directionally solidified. The multi-step heat
treatment, thermal exposure and stress rupture test were performed. The results indicate that Ru is a
weak positive segregation element (k’=Cinterdendrite / Cdendrite= 1.03). The solubility of Ru in γ phase
is 30% higher than that of in γ' phase. Ru hardly enters into MC carbides, but can effectively retard
the formation of M6C carbides. Ruthenium reduces the amount of eutectic (γ+γ'), decreases solid
solution temperature of γ' phase, and promotes the rafting tendency of γ/γ' at elevated temperatures.
Ru-bearing alloy possesses rather higher life at 1100°C/118MPa due to decrease of the film-like
M6C carbides. The addition of Ru can inhibit the formation of M6C and eutectic γ', which hinder the
initiation and propagation of cracks.
Microstructure Reconstruction and Numerical Simulation of Deformation in Particle-Reinforced Composites
Authors: Cai Wen Zhong , Tu Shan Tung , Zheng Yang Yan , Gong Jian Ming
Published: March 2009

A new methodology of computer simulation is proposed to perform finite element (FE)
calculations of uniaxial tensile deformation on the three-dimensional (3D) complex microstructures,
through its application to the microstructure of aluminum matrix containing randomly distributed
and oriented SiC particles of highly variable and angular geometry. Compared with the simplified
microstructure model, the complex microstructure model shows significant differences in terms of
micromechanical fields and macroscopic uniaxial deformation. The results reveal that a quantitative
and convenient reconstruction of microstructure of particulate composites is crucial for both the
prediction and design of material properties.
Texture Evolution of Rolled AA3003 Alloy Sheets after Annealing
Authors: Kim Kee Joo , Kim Joo Sung , Kim Cheol Woong , Sohn Il Seon , Lee Jin Yi , Kim Joong Bae
Published: March 2009

To fabricate the aluminum alloys with good drawability, the textures evolution of the 3003
aluminum alloy sheets after rolling and subsequent annealing was studied. The measurement of the
deformation textures was carried out for the sheets in which were cold rolled with high reduction ratio
by using the symmetric roll. In addition, the change of the recrystallization texture was investigated
after heat-treatments of the rolled sheets with various heat treatment conditions. Rolling without
lubrication and subsequent annealing led to the formation of favorable rot-CND {001}<110> and
γ-fiber ND//<111> textures in 3003 aluminum alloy sheets. From the results, the γ-fiber ND//<111>
component well evolved during rolling at high reduction ratio (reduction over 90%, l/d parameter
over 6.0). Among shear deformation textures, the γ-fiber ND//<111> was not rotated during
recrystallization (350°C) in special condition.
Research on the Effect of Entry Angle and Pressure-Pad Force on Deep-Draw Thermo-Rheological Forming of a TC1 Ti-Alloy Sheet
Authors: Yin Shui Ping , Luo Ying She , Cao Zheng , Luo Shu Ling , Liu Wen Bin
Published: March 2009

Numerical simulation can be successfully applied to evaluate product manufacturability
and predict, while material wrinkling and splitting are associated with entry angle and pressure-pad
force during sheet metal stamping process. In this paper, the influence of entry angle and pressure-pad
force on deep-drawing thermal forming of TC1 titanium alloy was analyzed by using explicit dynamic
finite element software STAMPACK, two kinds of main invalidation, including wrinkling and
splitting, and obtained that the entry angle is an important factor for deep-draw thermal forming. By
analyzing the forming operation and optimizing the entry angle and the pressure-pad force of the die,
the best range of the entry angle and the suitable pressure-pad force without wrinkling were obtained
and splitting phenomena were controlled effectively. The researched results of numerical simulation
provided some parameters for die design.
Effect of an Electric Field on the Texture and Microstructure Evolution during Annealing of High Reduction Cold-Rolled Ni
Authors: Li Xiao Ling , Liu Wei , Godfrey Andrew , Liu Qing
Published: March 2009

The influence of an electric field on the annealing of high purity (99.999%) cold rolled
nickel has been investigated. Annealing was carried out for 2 hours at temperatures between 300oC
and 800oC with and without an electric field of strength 2.0KVcm-1. The microstructure and fraction
of cube texture resulting were characterized using electron backscattering pattern (EBSP) technique.
Annealing in an electric field leads to somewhat smaller average values of the cube fraction and grain
sizes compared to annealing without an electric field. The highest temperature (800oC) annealing in
an electric field results in microstructures with a lower fractional twin boundary length.
Study on Cavity Growth in Uniaxial Tension of ZK60 Magnesium Alloy
Authors: Yu Yan Dong , Yin De Liang , Zhang Bao You
Published: March 2009

Cavity growth is a typical microstructure feature in superplastic forming (SPF) of
materials. Substantial growth and interlink of cavities in superplastic deformation usually lead to
reduction in elongation, even to failure. Consequently, it is necessary to investigate the
mechanism and model of cavity growth. In this paper, experimental studies on cavity growth were
carried out by means of superplastic tension of ZK60 magnesium alloys. Scanning electronic
microscope (SEM) was employed for observation of fractography. Experimental cavity radius and
volume fraction were determined by optical microscopy and corresponding picture-based analysis
software. It is found that, the fractured surfaces after a superplastic elongation have a mixed
characteristic of intergranular cavities and dimples. Further, the cavity growth is identified to follow
a exponentially increasing mode.
Deformation and Annealing Textures of Extruded and Cold Rolled Pure Ni Single Crystals of Cube Orientation
Authors: Li Kun , Godfrey Andrew , Liu Wei , Liu Qing
Published: March 2009

A pure Ni single crystal of Cube orientation (001)/[100] have been deformed by
reversible cold rolling to a reduction of 98% following an initial extrusion treatment. The
microstructure in the as-deformed samples and in partly recrystallized specimens have been
characterized in the scanning electron microscope using electron backscattered diffraction (EBSD).
Line scans along the normal direction across the sample thickness show some evidence for a
macroscopic pattern of subdivision. The EBSD measurements show that the deformed sample is
characterized by large jumps in orientation between alternating S and Br orientations, related by
misorientation angles of 50°~60°. In part of the sample a background cumulative change in
orientation is seen, though local large change in orientation are also still seen. In annealed samples
it is found that the orientations of the new grains
Researches on Microstructures and Mechanical Properties of Extruded Mg-Zn-Zr-Y Alloy
Authors: Peng Jian , Liu Rong Shen , Zhang Ding Fei , Song Cheng Meng
Published: March 2009

The microstructures and mechanical properties of Mg-Zn-Zr-Y alloy extruded bar with
different heat treatment processes were investigated, including solution treatments of 400 oC, 450 oC
and 500 oC for 3 hours followed by 170 oC×24h aging treatment, and solely aging treatments of 160
oC, 180 oC for 24hours without solution after extruding. By comparing the grain size, strength and
elongation of the samples, the heat treatment processes for extruded products with high strength and
with medium strength were recommended.
Three-Dimensional Elastic Stress Fields of Finite Thickness Plates with Elliptical Hole
Authors: Yang Zheng , Cho Chong Du , Su Ting Ya , Kim Chang Boo , Beom Hyeon Gyu
Published: March 2009

Based on detailed three-dimensional finite element analyses, elastic stress and strain field
of ellipse major axis end in plates with different thickness and ellipse configurations subjected to
uniaxial tension have been investigated. The plate thickness and ellipse configuration have obvious
effects on the stress concentration factor, which is higher in finite thickness plates than in plane stress
and plane strain cases. The out-of-plane stress constraint factor tends the maximum on the mid-plane
and approaches to zero on the free plane. Stress concentration factors distribute ununiformly through
the plate thickness, the value and location of maximum stress concentration factor depend on the plate
thickness and the ellipse configurations. Both stress concentration factor in the middle plane and the
maximum stress concentration factor are greater than that under plane stress or plane strain states, so
it is unsafe to suppose a tensioned plate with finite thickness as one undergone plane stress or plane
strain. For the sharper notch, the influence of three-dimensional stress state on the SCF must be
considered.
Fracture Toughness Calculation by Movable Cellular Automata Method
Authors: Pak Mik Hail , Lee Choon Yeol , Chai Young Suck
Published: March 2009

Fracture toughness calculation by Movable Cellular Automata (MCA) method is
demonstrated in this study in order to verify the validity of application of MCA method to the
fracture problems. Two different geometries: edge-cracked strip and center cracked plate tension
specimen have been considered to simulate numerically, which make place in real experiments.
Soda-Lime silica glass for brittle material, AISI 1040 Steel and Aluminum Alloy 2024 for ductile
materials were used, respectively. Fulfillment of basic principles of fracture mechanics has been
checked. In MCA method, special fracture criterion is used to describe the process of crack
propagation and critical stress and displacement was obtained, which are used as input data for
evaluating the fracture toughness. In comparisons with table data, the results showed the sufficient
agreement, which states the facility of the MCA method in application to the fracture problems.
Tribological Properties of MoS2-Coated Gray Cast Irons with Some Different Matrix Phases under the Boundary Lubricating Conditions
Authors: Murakami Takashi , Inoue T. , Shimura H. , Sasaki Shinya , Nakano Miki
Published: March 2009

In this study, Fe-2.0Si-4.6C (mass%) gray cast iron disk specimens with three different
matrix phases were coated with MoS2 using pressure spraying, and the friction and wear properties
of the specimens were investigated against AISI52100 steel and polytetrafluoroethylene balls under
the lubrication of oil using an Optimol SRV friction tester. When AISI52100 steel balls were used
as the paired material, all of the MoS2-coated gray cast iron specimens showed lower friction
coefficients and higher wear resistance than the non-coated disk specimens. On the other hand,
MoS2-coated gray cast iron specimens exhibited higher friction coefficients than non-coated disk
specimens for the most part, when polytetrafluoroethylene balls were used as the paired material.
Influence of Laser Micro-Mesh Texturing on the Tribological Performance in an EHL Point Contact
Authors: Wang Xiao , Li Jian , Chen Wei , Cai Lan , Zhu Jian Ying
Published: March 2009

Fabricating surfaces with controlled micro-geometry may be an effective approach to
improved tribological performance. In this paper, the effect of laser surface micro-mesh texturing
on the tribological performance is investigated theoretically with numerical solution of EHL point
contact. In the theoretical model, the Reynolds equation is used as the governing equation. Well
controlled micro-mesh texturing is described in film thickness equation. By Full Multi-Grid (FMG)
method, the solutions of film thickness profile and pressure distribution map are present over a wide
range of texturing parameters. The influence of width, depth and orientation of mesh texturing on
the friction coefficient is analyzed. Result shows that, the film thickness profile and pressure
distribution are sensitive to the parameters of micro-mesh texturing. The curve result of friction
coefficient under two load conditions indicated that the parameters of mesh are key factor for
texturing design. Solutions demonstrate the ability of numerical simulation on the design and
optimization of surface mesh texturing.
Effect of Tempering on the Wear Characteristics of Induction-Hardened SPS5 Steel
Authors: Kim M.H. , Rhee Kyong Yop , Hong Jai Sung , Ham Young Sam
Published: March 2009

In this study, the tempering effect on the wear characteristics of induction-hardened SPS5
steel was investigated. For this purpose, three tempering conditions were applied to control the
hardness and microstructure of heat-treated SPS5 steel. Ball-on-disk wear tests have been
performed using zircornia balls on the tempered specimens to determine the variation of wear
characteristics. The results showed that friction coefficient decreased with increasing hardness for
induction-hardened SPS5 steel. This seems to occur because real contact area between specimen
and mating ball was affected by the specimen hardness. Also, we observe the wear type changes
from the plowing wear to the adhesive wear as the hardness increases and the adhesive wear
particles act as an obstacle to the transmission of the force of friction, reducing the coefficient of
friction and the wear rate.
An Effective Energy Criterion on Fatigue Crack Growth of Metal Materials
Authors: He Yu Ting , Li Feng , Fan Chao Hua
Published: March 2009

An effective energy criterion is presented and can be narrated as follows: only the effective
release energy has an immediate effect on fatigue crack growth characteristics, and the crack
extension in each load cycle is decided by the effective release energy. The effective release energy is
considered as the energy released for crack extension after the fatigue crack fully opens and it is equal
to the consumed energy in the same crack extension. And the consumed energy can be obtained by the
cracking resistance of materials. An approach for determining cracking resistance curve is proposed
and validated by experimental results. Based on effective energy criterion, a model for fatigue crack
growth is presented. And fatigue life can be predicted by recourse to the model. Validation against
calculations by the model and experimental data shows good agreement.
Fretting Fatigue Strength and Life Estimation Considering the Fretting Wear Process
Authors: Hattori Toshio , Nishimura Naoya , Yamashita Minoru
Published: March 2009

In this paper we present the estimation methods of fretting wear process and fretting
fatigue life using this wear process. Firstly the fretting-wear process was estimated using contact
pressure and relative slippage. And then the stress intensity factor for cracking due to fretting
fatigue was calculated by using contact pressure and frictional stress distributions, which were
analyzed by the finite element method. The S-N curves of fretting fatigue were predicted by using
the relationship between the calculated stress intensity factor range ( #K) with the threshold stress
intensity factor range ( #Kth) and the crack propagation rate (da/dN) obtained using CT specimens
of the material. Finaly fretting fatigue tests were conducted on Ni-Mo-V steel specimens. The S-N
curves of our experimental results were in good agreement with the analytical results obtained by
considering fretting wear process. Using these estimation methods we can explain many fretting
troubles in industrial fields.
Fatigue Analysis and Life Prediction of Dumpers with Cumulative Fatigue Damage Approach and Finite Element Model
Authors: Li Shou Ju , Liu Ying Xi
Published: March 2009

A fatigue damage model is developed for evaluating accumulative fatigue damage of
dumpers. The loading spectrums acted on dumpers are created according to measured strain data in
field. The finite element model is meshed for assessing and calculating stress distribution and strength
characteristics of dumpers. The stress distribution and stress concentration factors of main
components of dumper at different loading cases are numerically simulated. A fatigue damage model
is developed for evaluating accumulative fatigue damage of dumpers. Fatigue damage indexes and
service life are calculated by a modified Palmgren-Miner rule. The investigation shows that fatigue
notch factor has a significant influence on the calculation of fatigue damage of dumpers.
Influence of Duration of Stress Wave on the Spallation Process in Inhomogeneous Material
Authors: Zuo Yu Jun , Tang Chun An , Zhu Wan Cheng , Li Lian Chong
Published: March 2009

Based on mesoscopic damage mechanics, a numerical code RFPA2D (dynamic version) is
developed to simulate the spallation process of inhomogeneous medium induced by reflection of
stress wave, and the influence of duration of stress wave on spallation is discussed. For convenience
of description and discussion, the failure area in the immediate vicinity of loading position of model
is divided into two zones, i.e. comminution zone and fracture zone; and the failure area caused by
spalling in model is defined as spalling zone. The comminution zone is affected little by the
duration of stress wave, but the fracture zone and the spalling zone are affected to a greater extent
by duration, also, the stability of specimen is affected by the duration of stress wave. Furthermore,
if the duration becomes significantly long, the fracture zone corresponding to the maximum
extension of the radial tensile cracks will be dominant in specimen. If the duration of stress wave
becomes short to some extent, the spalling zone corresponding to the maximum extension of the
tangential tensile cracks will be dominant in specimen. In addition, if the duration of stress wave is
long enough, the specimen may lose stability.
Hot Spot Stress Analysis of Fatigue for Tsing Ma Bridge Critical Members under Traffic Using Finite Element Method
Authors: Zhou Tai Quan , Chan Tommy Hung Tin
Published: March 2009

The suspension bridge has more flexibility and repetitive vehicles produce stress cycles
in members. Then fatigue of the member is accumulated with the daily traffic loadings. In order to
evaluate the working condition of the Tsing Ma Bridge, the online monitoring health system has
been installed in long suspension bridge. The location of the strain sensor is not exactly at the
critical member locations. The hot spot stress analysis for critical members is necessary for accurate
fatigue evaluation of the bridge. The global finite element analysis of the Tsing Ma Bridge under
traffic loading is performed to determine the critical fatigue member locations. A detailed local
finite element analysis for the welded connections is performed to determine the hot spot stress of
critical fatigue location. As a case for study, the calculated stress concentration factor is combined
with the nominal representative stress block cycle to obtain the representative hot spot stress range
cycle block under traffic loading from online health monitoring system. The comparison result
shows that the nominal stress approach cannot consider the most critical stress of the fatigue
damage location and the hot spot stress approach is more appropriate for fatigue evaluation.
The Influence of Stress Ratio on the Fracture Behavior of Brittle Materials
Authors: Li Wei Hong , Chen Xiong , Zhao De Shen , Bao Yi Wang
Published: March 2009

The fracture behavior of brittle materials under different stress ratio has been investigated
by means of numerical simulation method with software RFPA2D (Realistic Failure Process
Analysis). The fracture dependence of brittle material on biaxial plane stress state was confirmed.
The results show that the critical stress intensity factor under biaxial stress increases with the
increase of biaxial stress ratio. The simulation tests reveal that the biaxial stresses have strong
influence on the fracture properties of glass. The results confirmed that the strain criterion of
fracture is feasible while brittle materials under complex stress state.
Numerical Model for Thermal Cracking of Concrete
Authors: Tang Shi Bin , Tang Chun An , Liang Zheng Zhao , Yu Qing Lei
Published: March 2009

Thermal stresses are identified as one of the major causes of concrete failure. In order to
consider the heterogeneity of concrete at mesoscopic level, and to simulate its failure processes
during temperature change, a coupled thermo-mechanical model, which is on the basis of statistical
damage model, is proposed. The model revealed the effect of the heterogeneity on concrete, and by
analysis one of the important thermal stresses, i.e. thermal mismatch stresses, which are caused by
thermal mismatch between the aggregate and mortar due to uniform change in temperature, it
indicate that the presence of thermal mismatch causes stress concentration along the interface
between aggregate and mortar, and the superpose of those stresses cause the crack propagation in
the line of the two aggregate. The crack patterns, simulated by the proposed model, show a good
agreement with the experimental results.
Study of Interface Problems Using Finite Element Method
Authors: Su Li Jun , Liao Hong Jian , Wang Shan Yong , Wei Wen Bing
Published: March 2009

In numerical simulation of engineering problems, it is important to properly simulate the
interface between two adjacent parts of the model. In finite element method, there are generally three
methods for simulating interface problems: interface element method, surface based contact method
and the method by using a thin layer of continuum elements. In this paper, simulation of interface
problems is conducted using continuum elements and surface based contact methods. The results
from each method are presented and compared with each other.
Numerical Simulation on Fracture Formation on Surfaces of Bi-Layered Materials
Authors: Ma Tian Hui , Yang Ju Ying , Liang Zheng Zhao , Zhang Yong Bin , Xu Tao
Published: March 2009

Fracture formation on surfaces of bi-layered materials is studied numerically. A simplified
two-layered materials model like growing tree trunk is present. This work is focused on patterns of
fractures and fracture saturation. We consider the formation of crack pattern in bark as an example of
pattern formation due to expansion of one material layer with respect to another. As a result of this
expansion, the bark stretches until it reaches its limit of deformation and cracks. A novel numerical
code, 3D Realistic Failure Process Analysis code (abbreviated as RFPA3D) is used to obtain
numerical solutions. In this numerical code, the heterogeneity of materials is taken into account by
assigning different properties to the individual elements according to statistical distribution function.
Elastic-brittle constitutive relation with residual strength for elements and a Mohr-Coulomb criterion
with a tensile cut-off are adopted so that the elements may fail either in shear or in tension. The
discontinuity feature of the initiated crack is automatically induced by using degraded stiffness
approach when the tensile strain of the failed elements reaching a certain value. The different patterns
are obtained by varying simulation parameters, the thickness of the material layer. Numerical
simulation clearly demonstrates that the stress state transition precludes further infilling of fractures
and the fracture spacing reaches constant state,i.e. the socalled fracture saturation. It also indicates
that RFPA code is a viable tool for modeling fracture formation and studying fracture patterns.
High-Efficiency and Precision Grinding Technology of HIPSN All-Ceramic Bearing Race
Authors: Li Song Hua , Wu Yu Hou
Published: March 2009

This paper deals with the development of a high-efficiency and precision grinding
technology for producing HIPSN ceramic bearing races. A new high-speed CNC grinding machine
has been developed, which is equipped with a high-speed ceramic spindle with a built-in motor.
Extensive experiments have been performed with this new machine to investigate the influence of
various process parameters such as wheel speed, work speed, depth of cut, and wheel grit size on
material removal rate, surface finish, grinding forces, and so on. The results of these investigations
are presented in this paper. With the application of this technology, a low cost production of ceramic
bearings race was realized with the most optimized process parameter.
Removal Process Technology of Precision Grinding for Complicated Surface Part of High Performance Hard and Brittle Materials
Authors: Ji Tian , Guo Dong Ming , Bian Gui Hong
Published: March 2009

Some key parts used in such area as the national defence are made of high performance
hard and brittle materials, and they should meet not only the requirement of geometry accuracy but
also that of specified physical performance in manufacturing. The Radome is one of such key parts in
the active homing guidance weapon, with a typical complicated surface. In order to meet the electric
thickness requirement, a controlled removal grinding point-by-point is needed for the radome during
its precision machining. A special 3-coordinates equipment with spherical diamond grinding wheel is
adopted; the grinding paths are generated in the planes normal to the cutter axis with a Z-level profile
machining method; the feed step is determined by step screening method; and the stepping between
layers is carried out according to the remaining scallop crest height. Process conditions including the
grinding depth and the workpiece speed are determined through experiments, and the process errors
under different processing conditions are analyzed to put forward an optimized processing tactics. As
a result, a basis for precision removal process of any other part of high performance hard and brittle
materials with complex surface is established, and a technology support for precision machining of
key parts in the national major projects is provided.
Analysis of Influence Factors for the Contact Length between Wheel and Workpiece in Surface Grinding
Authors: Mao Cong , Zhou Zhi Xiong , Zhou De Wang , Gu Du Yi
Published: March 2009

In order to understand the grinding mechanism and analyze the grinding operation, it is necessary to study the contact phenomena between wheel and workpiece during grinding operation. The contact length, the grinding temperature distribution within the contact zone, and the grinding forces are measured in-process by using Critical Contact State mode, thermocouple method, and 3-axis piezoelectric dynamometer, respectively. It is found that the grinding conditions and the properties of work material have effects on the contact length, moreover, the mechanism of which is discussed in this paper. The results show that the contact length significantly interacts with grinding force and grinding temperature in the grinding zone.
Design of Surface Finish Using Synchronous Process of Grinding and Electrochemical Finishing
Authors: Pa Pai Shan
Published: March 2009

In order to elevate the efficiency of the surface finish to reach the fast improvement of the
surface roughness of the workpiece, so as to reduce the residual stress on the surface efficiently. The
present study discusses the surface after traditional machining, of which the plane surface used a
design of finish tool includes an electrode and a nonconductive grinding wheel to execute the
synchronous process of grinding and electrochemical finishing. The electrode form and the
machining process are obviously different from electrochemical grinding (ECG). In the experiment,
the design electrode is used with continuous and pulsed direct current. The controlled factors
include die material, and chemical composition and concentration of the electrolyte. The
experimental parameters are flow rate of electrolytes, position of plate electrode, electrode
thickness, electrode rotational speed, electrical current rating, feed rate of workpiece, and pulsed
period. The experimental results show that the supply of current rating is near concern with the
position and thickness of the plate electrode. The use of large electrolytic flow rate and thick
electrode is advantageous to the finish effect. High rotational speed of finish tool produces better
polishing. The finishing effect is better with longer off-time because discharge of polishing dregs
becomes easier. Higher current rating with quicker workpiece feed rate effectively reaches the fast
improvement of the surface roughness of the workpiece is recommend in current study.
Study of Finishing Internal Surface Using Magnetic Force Generated by Rotating Magnetic Field in Electromotor
Authors: Yao Xin Gai , Wang Shi Ying , Ding Yan Hong , Ya Gang , Zhang Jie
Published: March 2009

In the paper, a new method of using rotating magnetic field generated by a stator of alternative electromotor to polish the inner surface of tube-type workpieces is proposed; a finishing device using the stator construction and inverter is designed; the finishing mechanism is analyzed and experiments are carried out. Experimental investigations show that filling amount of magnetic abrasive influences the surface roughness of workpiece directly and have an optimal value. The higher magnetic conductivity is, and the finer finishing effect is. The attraction force of magnetic particles depends on intensity of magnetic induction directly and has the optimal value. The higher the rotation speed is, and the lower the value of surface roughness. Under the optimal experimental condition, the new method can reduce the value of surface roughness more than 2 grades. Therefore, this technique has prospective application future.
Experimental Study on Increasing Magnetic Abrasive Finishing Efficiency of Finishing Nonferromagnetic Materials
Authors: Zhang Shu Ren , Yang Li Feng , Wu Guo Xiang
Published: March 2009

Magnetic Abrasive Finishing (MAF) is relatively a new finishing technique which employs the magnetic force for finishing. In this paper, the influence of the magnetic flux density on the finishing pressure and the finishing efficiency during finishing is analyzed. With the cylindrical magnetic finishing apparatus developed by the author, a series of experiments on finishing the cylindrical surfaces of nonferromagnetic materials and ferromagnetic materials are carried out. To solve the problems of low finishing efficiency and abrasive particles escaping easily because of lack of finishing pressure during finishing nonferromagnetic materials, a new method of increasing the finishing pressure by using the “pressure-increasing bag” in the finishing system is put forward. A lot of comparative experiments on finishing nonferromagnetic materials with the “pressure-increasing bag” and without the “pressure-increasing bag” are performed. Under the same experimental conditions, the amount of diameter-reduction d is increased from 1μm to 1.88μm and the surface roughness is improved from Ra0.315μm to Ra0.250μm by using the “pressure-increasing bag”. The results show that the finishing pressure is increased obviously and the MAF efficiency of finishing nonferromagnetic materials is improved dramatically by using the “pressure-increasing bag”.
Research on Design Knowledge Expression Method of Abrasive Machine Tool Based on Axiomatic Design
Authors: Feng Yi Xiong , Zheng Bing , Wei Zhe , Tan Jian Rong
Published: March 2009

The axiomatic design theory is applied with the product design knowledge expression of abrasive machine tools, making it possible to convert the implicit knowledge created in the study process into the explicit knowledge that will be shared all over the organization. The design knowledge created in the design and developing processes is divided into functional requirements, design parameters, design constraints and design coupling. In this paper, not only has the function-structure knowledge information mapping been analyzed, but also the implementation steps of product knowledge expression have been provided. Moreover, the matter-element model of the product design heterogeneous knowledge of the abrasive machine tool is established and the heterogeneous knowledge semantic rule is described. Finally, through a case of product design knowledge expression which is applied to the MLL60 abrasive flow machining tool, the correctness and practicality of this method are verified.
Is Hydroxyapatite Ceramic Included in the Bone Remodelling Proccess? An In Vitro Study of Resorption and Formation Processes
Authors: Detsch Rainer , Mayr Helmar , Seitz Daniel , Ziegler Günter
Published: March 2009

Bone remodelling is a coupled process of bone formation and resorption. This process is
physiologically controlled and involves the synthesis of bone matrix by osteoblasts and bone
resorption by giant cells called osteoclasts. It includes a complex interaction of cells, with specific
chemokine signalling. In order to study bone remodelling in vitro, we cultivated two precursor cellline
types in a model coculture system on synthetic hydroxyapatite ceramic (HA) for 14 days. The
monocytes have the capacity to differentiate into osteoclast-like cells, and the bone marrow stromal
cells can differentiate into osteoblast-like cells. This coculture was used to analyse the in vitro cell
interaction between monocytes and stromal cells. Furthermore, the attachment of the bone marrow
stromal cells to the resorbed HA-surfaces was studied. In this in vitro study we demonstrated
osteoclast-like differentiation and bone marrow stromal growth in a coculture system on a synthetic
bone substitute material. Under optimal conditions, HA can be resorbed and bone marrow cells can
grow into the lacunas to form new bone. These results give important cues for the adjustment of
synthetic bone substitute materials for optimal remodelling behaviour.
Cell Growth on TiAlNb Alloy as a Function of Bioactivation Method
Authors: Sovar M.M. , Aldea E. , Mitran V. , Miculescu Florin , Demetrescu Ioana
Published: March 2009

This paper it supposed to demonstrate how to obtain the hydroxylapatite on the surface of TiAlNb biomaterial used as dental implant. The bone-forming bioactivity of TiAlNb is associated with its chemical and structural properties, including composition, porosity, specific surface area and particle size. After different bioactivation surface treatments as chemical and electrochemical treatments, it was observed a better stability for the TiAlNb alloy that was treated electrochemically.
Characterization of Bone Cell Behaviors on Collagen Grafted Hydroxyapatite Surfaces
Authors: Chun S. , Shin D.H. , Kang I.K. , Ahn M.W. , Kim Suk Young
Published: March 2009

In order to enhance bone cell adhesion on hydroxyapatite (HA), collagen was used as a surface-grafting material on HA substrates because the collagen is a major constituent of connective tissues and has been regarded as one of the most excellent coating materials for bone bonding. First, HA disks (10mmΦ x 1mm) were prepared and then collagen was immobilbized on the HA surface using an 3-APTES coupling agent on HA disk surfaces. MC3T3-E1 osteoblasts were seeded on the collagen-grafted and non-grated HA disks and cultured in a Dulbecco’s modified eagle medium containing 10% fetal bovine serum for 4 hrs to evaluate the cell adhesion on the HA samples. The osteoblasts on the collagen-grafted sample were more spread than those on the non-grafted sample. It is believed that collagen-grafted HA surface provides suitable sites for cell attaching due to the high biocompatibility of collagen
Isolation Yield and Osteogenic Potential of Human Bone Marrow Stromal Cells are Maintained Irrespective of Age or Gender
Authors: Yoo Jeong Joon , Bang Jeon Hyun , Koo Kyung Hoi , Yoon Kang Sup , Kim Hee Joong
Published: March 2009

The relationships between donor age and gender and initial isolation yield and the
osteogenic potentials of human bone marrow stromal cells (hBMSCs) have not been clearly
elucidated. The authors investigated whether isolation yields and the osteogenic differentiation
potentials of hBMSCs are indeed dependent on donor age or gender. Fresh bone marrow was
aspirated from iliac crest of 72 donors (mean age 54.1 years; range, 23-84 years; 39 men and 33
women) undergoing total hip arthroplasty. Numbers of mononuclear cells, numbers of colony
forming unit-fibroblasts (CFU-Fs) and alkaline phosphatase (ALP)-positive CFU-Fs, and numbers
of BMSCs after isolation culture were not found to be significantly dependent on donor age or
gender. Moreover, no significant age- or gender-related differences were observed in terms of the
proliferation activities, ALP activities, and calcium contents of BMSCs during in vitro osteogenic
differentiation. The data obtained from 72 human donors revealed no significant age- or genderrelated
differences among hBMSCs in terms of isolation yields, proliferation activities, and
osteogenic potentials.
Fabrication of Encapsulated Ag Microsphere with Hydroxyapatite for Sustained-Release
Authors: Yabutsuka Takeshi , Tsuboi Shinichiro , Hibino Mitsuhiro , Yao Takeshi
Published: March 2009

Apatite nuclei were synthesized by raising pH of simulated body fluid (SBF). The apatite
nuclei were attached to surfaces of Ag microspheres. Hydroxyapatite (HAp) was induced from the
apatite nuclei and spread over whole surface area of the Ag microspheres in SBF, then encapsulated
Ag microspheres with HAp were fabricated. The encapsulated Ag microspheres with HAp were
soaked in saline and changes in Ag ion concentration in saline were measured. The encapsulated Ag
microspheres with HAp showed sustained-release of Ag ion.
ATLANTIK Genta, a New Concept of Gentamicin Loaded HAP/TCP Bone Substitute for Prophylactic Action-In Vitro Releasing Mechanisms Study
Authors: Bignon Aurélien , Laurent F. , Goldnadel J. , Chevalier Jérôme , Fantozzi Gilbert , Viguier E. , Roger T. , Boivin Georges , Hartmann D.J.
Published: March 2009

Despite systemic prophylaxis, infection rates after orthopedic surgery can reach more
than 1%. A new HAP/TCP bone substitute loaded with 125 mg of gentamicin was designed for
prophylactic use. Its aim was to enhance the efficacy of systemic prophylactic treatments by
increasing the local antibiotic concentration. For prophylactic applications, release had to take place
within 48 hours not to select antibiotic-resistant bacterial strains. The purpose of this study was to
investigate the releasing mechanisms of gentamicin from the porous HAP/TCP matrix. The release
rate of gentamicin trough the porosities of the bone substitute was investigated in vitro, in 0.9%
sodium chloride solution. The rate appeared to be related to the bone substitute volume and fit
classical diffusion laws. All the gentamicin was released in less than 48 hours: this rate corresponds
to the recommendations for the prophylactic use of antibiotics.
Calcium Phosphate Powder for Cancer Vaccination
Authors: Frayssinet Patrick , Ciocca Daniel , Rouquet Nicole
Published: March 2009

Cancer cells synthesize abnormal proteins and peptides which are associated to heat shock proteins being overproduced by these cells due to the stress induced by the particular biology of cancer tissue. We have purified on hydroxylapatite powder heat shock proteins using the HAparticles as purification bed, vectors for the proteins and vaccination adjuvant. The powder make possible that the purified HSPs and their associated peptides are transfected to the antigen presenting cells and presented to the T cells for the destruction of the cancer cells bearing the antigens.
Calcium Phosphate Ceramic Blasting on Titanium Surface Improve Bone Ingrowth
Authors: Goyenvalle Eric , Aguado Eric , Cognet Ronan , Bourges Xavier , Daculsi G.
Published: March 2009

Surface roughness modulates the osseointegration of orthopaedic and dental titanium implants. High surface roughness is currently obtained by blasting of titanium implants with silica or aluminium abrasive particles. This process includes into the surface abrasive particles and may cause the release of cytotoxic silica or aluminium ions in the peri implant tissue. To overcome this drawback, we currently develop an innovative gridblasting process using Biphasic Calcium Phosphate (BCP) particles (RBBM Resorbable and Biocompatible Blast Media) to generate biocompatible roughened titanium surface. This work present the technique of blasting using RBBM particles to provide a roughened surface which does not release cytotoxic elements and (ii) to assess the effects of such a roughened surface for bone osteointegration in critical size rabbit defect. Our results demonstrate that resorbable biphasic calcium phosphate abrasive particles can be used to create titanium surface roughness. This grid blasting process increases surface roughness of titanium implants and offers a non cytotoxic surface for rapid and efficient osteointegration.
Validation of an Analytical Model Describing Mechanical Properties of Porous BCP Ceramics
Authors: Pecqueux François , Payraudeau Nathalie , Tancret Franck , Bouler Jean Michel
Published: March 2009

Macroporous biphasic calcium phosphate bioceramics, for use as bone substitutes, have
been fabricated by cold isostatic pressing and conventional sintering, using naphthalene particles as
a porogen to produce macropores. The resulting ceramics, composite materials made of
hydroxyapatite and β-tricalcium phosphate containing various macroporosities and microporosities,
have been submitted to compression and three-point bending tests. The mechanical tests performed
on the sintered ceramics tend to validate the modelling approach and its hypothesis, i.e. the material
can be considered as a microporous matrix containing isolated macropores, and the critical flaw is a
macropore.
Production and Characterization of Zinc Substituted Hydroxyapatite
Authors: Shepherd David , Best Serena
Published: March 2009

Zinc substituted hydroxyapatite of varying wt% was produced using a precipitation
method based on reacting calcium and zinc nitrate with ammonium phosphate. Characterisation
results from X-ray diffraction (XRD) and X-ray fluorescence spectroscopy (XRF) showed that zinc
was successfully substituted up to 0.8wt% using this method. Rietveld analysis showed that the alattice
parameter was reduced and c-lattice parameter was increased with increasing zinc content.
Initial mechanical test results showed samples with a zinc content of 0.4% had the greatest
compressive strength.
Development of Multisubstituted Apatites for Bone Reconstruction
Authors: Landi Elena , Sprio Simone , Sandri Monica , Tampieri Anna , Bertinetti Luca , Martra Gianmario
Published: March 2009

Hydroxyapatite powders characterized by substitutions of Mg2+, SiO4
4-, CO3
2- ions in
biological like amounts, in the crystallographic site of calcium and phosphates, ions in biological
like amounts, in the crystallographic site of calcium and phosphorus, were successfully prepared by
synthesis in aqueous medium. The chemico-physical properties of the powders were investigated
through several analytical techniques, among them: XRD, FTIR, TG-DTA, ICP-OES, HR-TEM. The
entering of silicon in the HA structure progressively reduces its crystallinity, as also carbonate ions
do. Silicate and carbonate ions can enter simultaneously into the HA structure, in biological-like
amounts, although they compete for the occupation of the phosphate site. Solubility tests, carried
out at physiological conditions, reveal an increased calcium release in the HA powders containing
silicon compared to the silicon-free HA.
Preparation of Porous Synthetic Nanostructured HA Scaffold
Authors: Strnadová Marie , Protivinsky Jiri , Strnad J. , Vejsicka Zdenka
Published: March 2009

The low temperature macro and micro porous hydroxyapatite scaffold was synthesized.
The synthetic nanostructured HA powder was prepared by the reaction of Ca(OH)2 and H3PO4. The
ultrasound apparatus was used for the separation of the particles during the precipitation process.
Hydrogen peroxide (H2O2) was used as a foaming agent. The samples were dried for 3 hours at
120°C. HA (hydroxyapatite) granules exhibited interconnected macro and micro porosity with the
micro pore size in the order of 0.01 'm. The specific surface area of the precipitate reached the
average value 64.8 ± 11.9 [m2.g-1]. The compressive strength of the low temperature porous HA
scaffold granule was very similar to deproteinized bovine bone and other calcium phosphate
ceramic materials used in bone regeneration and prepared by high temperature processes. The
porosity of the scaffolds 50-75% was determined by mercury porosimetry. In-vitro cytotoxicity test
proved the granules to be non toxic.
Preparation and In Vitro Characterization of Wollastonite Doped Tricalcium Phosphate Bioceramics
Authors: García Carrodeguas R. , De Aza A.H. , Jimenez J. , De Aza P.N. , Pena P. , López-Bravo A. , De Aza S.
Published: March 2009

In this work a new kind of CaSiO3-doped α-Ca3(PO4)2 ceramic materials, with
compositions lying outside the field of the Ca3(PO4)2 solid solution in the system Ca3(PO4)2-
CaSiO3, were obtained and some of their properties, relevant for bone repairing, were studied in
vitro. Crystalline α-Ca3(PO4)2 solid solution and minor amounts of non-equilibrium residual glass
were the only phases in the materials containing 2 and 5 wt% of CaSiO3. α-Ca3(PO4)2, crystalline
eutectic-like phase and residual glass were observed for sample containing 15 and 20 wt% of
CaSiO3. The mechanical strength improved for all the doped ceramics with regard to un-doped
Ca3(PO4)2. The release of ionic Ca and Si in simulated physiological conditions increased with the
content of CaSiO3 and favored α-Ca3(PO4)2 surface transformation. The soluble components
extracted from the CaSiO3-doped α-Ca3(PO4)2 bioceramics were not cytotoxic to human fibroblastlike
cells. Initial cell adhesion onto the surface of the materials seemed to be partially hindered by
surface reactivity and remodeling, however those cells adhered to the experimental bioceramics
were viable and proliferated normally.
Bioresorbable Phosphate Scaffolds for Bone Regeneration
Authors: Vitale-Brovarone Chiara , Verné Enrica , Baino Francesco , Ciapetti Gabriela , Leonardi Elisa , Baldini Nicola
Published: March 2009

In this work, a new bioresorbable phosphate glass (I-CEL2) was prepared in order to use
it for the production of 3D-bioresorbable scaffold for bone regeneration. I-CEL2 was characterized
to assess its thermal characteristics as well as its bioresorption rate in different medium such as
distilled water, Tris-HCl and Simulated Body Fluid (SBF). 3D-macroporous scaffolds were
prepared by mixing and pressing I-CEL2 powders and an organic phase and by treating the compact
of powders at 550°C for 3 hours. The obtained scaffolds showed a very high porosity and a high
resorption rate and are thus suitable candidates for a scaffold to be used as a temporary guide for
bone regeneration. The initial response of human marrow stromal cells (hMSCs) has been tested on
I-CEL2 surface to describe its biological potential.
Porous Biphasic and Triphasic Bioceramics Scaffolds Produced by Gelcasting
Authors: Mendonça Flavia , Louro Luis Henrique Leme , de Campos Jose B. , Prado da Silva Marcelo Henrique
Published: March 2009

The present work suggests a modified gel casting process, including polyethylene wax spheres addition to the suspension with the objective of creating uniform and interconnected pores in the body of samples. In the present study, apatite powders were synthesized at pH 10 and pH 12 in order to give rise to biphasic and triphasic bioceramics after sintering.