bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Simulation of Autogenous Shrinkage in High-Performance Cement Paste Based on a Multi-Component Hydration Model
Authors: Lim Seung Min , Lee Han Seung , Wang Xiao Yong
Published: March 2009

Autogenous shrinkage is the term for the bulk deformation of a closed, isothermal, cement-based material system not subjected to external forces. It is associated with the internal volume reduction of cement/water mixture in the course of the hydration process. However, addition of blended components to cement, especially such as fly ash or silica fume, for the high-performance concrete will lead to a densification of the microstructure. The autogenous shrinkage deformation will increase and the following autogenous shrinkage crack will do harm to durability of concrete structure. In this paper, numerical simulation is suggested to predict autogenous shrinkage of high performance cement paste. The simulation is originated from a multicomponent hydration model. The numerical program considers the influence of water to cement ratio, curing temperature, particle size distribution, cement mineral components on hydration process and autogenous shrinkage. The prediction result agrees well with experiment result.
Crash Tests of Tension Bolts in Light Safety Collision Devices
Authors: Kim Jin Sung , Huh Hoon , Choi Won Mog , Kwon Tae Soo
Published: March 2009

This paper demonstrates the jig set for the crash test and the crash test results of the tension
bolts with respect to an applied pre-tension. The tension and shear bolts are adopted at Light Collision
Safety Devices as a mechanical fuse when tension bolts reach designed failure load. The kinetic
energy due to the crash is absorbed by secondary energy absorbing devices after the fracture of tension
bolts. One tension bolt was designed to be failed at the load of 375 kN. The jig set was designed to
convert a compressive loading to a tensile loading and installed at the high speed crash tester. The
strain gauges were attached at the parallel section of the tension bolts to measure the level of the
pre-tension acting on the tension bolts. Crash tests were performed with a barrier whose mass was 250
kg and initial speed of the barrier was 9.5 m/sec. The result includes the load response of the tension
bolts during both the crash tests and finite element analysis.
Modeling of a Long-Term Creep Curve of Alloy 617 for a High Temperature Gas-Cooled Reactor
Authors: Kim Woo Gon , Yin Song Nan , Jung Ik Hee , Kim Yong Wan
Published: March 2009

This study aimed to model the long-term creep curves above 105 hours by implementing a
nonlinear least square fitting (NLSF) of the Kachanov-Rabotnov (K-R) model. For this purpose, the
short-term creep curves obtained from a series of creep tests at 950oC were used. In the NLSF of their
full creep curves, the K-R model represented a poor match to the experimental curves, but the
modified K-R one revealed a good agreement to them. The Monkman-Grant (M-G) strain represented
the behavior of a stress dependency, but the 􀁏 parameter was constant with a stress independency. The
􀁏 value in the modified K-R model was 2.78. Long-term creep curves above 105 hours from
short-term creep data were modeled by the modified K-R model.
Dimple Fracture Simulation under Mixed Mode Loading Condition
Authors: Kikuchi Masanori , Sannoumaru Shougo
Published: March 2009

Dimple fracture under mixed mode loading condition is studied experimentally and
numerically. By the mixed mode loading, it is found that fracture surface becomes much rougher
than that of mode I fracture. It is also found that ductile fracture growth direction deviates from the
original plane. It becomes clear that there are two factors affecting ductile fracture processes, one is
mixed mode ratio and another is thickness effect. Three-dimensional finite element analyses are
conducted to study effects of these factors. For the simulation of ductile fracture, Gurson’s
constitutive equation is used with large deformation theory. These numerical results agree with
experimental observation very well qualitatively.
The Enhancement of Corrosion Resistance of Titanium in High Temperature Acidic Solutions by Microarc Oxidation
Authors: Lu Jian Shu , Lu Chuang
Published: March 2009

Microarc oxidation technique (MAO) is an electrochemical process which can be used to
make ceramic coatings on the surfaces of titanium and its alloys. In this investigation samples of a
commercially pure titanium (TA3) were anodized in 30g/L NaAlO2 solution under 280V voltage for
75 minutes to form a 3-10µm coating. XRD analysis showed that the main phase of the coating is
TiAl2O5. Samples of the titanium and the MAO treated titanium were immersed in HCl and H2SO4
acid solutions at 250°C in an autoclave. Results show that in 0.1 mol/L concentration both the
titanium and the MAO treated titanium have good corrosion resistance in the acid solutions.
However, in 1 mol/L concentration the titanium samples completely dissolved in 24 hour immersion.
The MAO-treated titanium samples did not dissolved away although some degree of weight losses
took place. SEM shows that there are corrosion products on the surfaces of MAO treated titanium
samples. XRD analysis showed that the corrosion products are titanium oxides (rutile and anatase).
A corrosion resistance mechanism, which is based on the synergic protection of aluminum titanium
oxides and titanium oxides for the titanium substrate, is proposed for explaining the enhancement of
the corrosion resistance.
Effects of DLC on Fatigue Properties of Eutectoid Steel
Authors: Zhang Mian , Hattori Nobusuke , Nishida Shinichi
Published: March 2009

Diamond-like carbon (DLC) is an amorphous hard carbon, which has very high hardness,
high resistivity, and dielectric optical properties. Economically and technologically attractive
properties have drawn almost unparalleled interest towards the coatings. Eutectoid steel is a kind of
material that has been widely used in shafts and various kinds of industrial components. Three kinds
of fatigue specimens with different DLC conditions were used in this study. Fatigue test had been
performed to investigate the effects of DLC on fatigue properties of eutectoid steel. The
fractography was analyzed by a scanning electron microscope (SEM), and surface hardness was
also evaluated. The fatigue limits of the DLC coated specimens did notincrease after DLC process,
though the compressive residual stress which produced by DLC process can prevent fatigue fracture.
According to the results of fatigue test, the optimal DLC method for improving the fatigue
properties of eutectoid steel is determined and the relationship between fatigue limits and coating
bias are obtained.
Plastic Limit Analysis of an Elbow with Various Wall-Thinning Geometries
Authors: Lee Sang Min , Choi Young Hwan , Chung Hae Dong , Chang Yoon Suk , Kim Young Jin
Published: March 2009

A piping system including straight pipes, elbows and tee branches in a nuclear power plant is mostly subjected to severe loading conditions with high temperature and pressure. In particular, the wall-thinning of an elbow due to flow accelerated corrosion is one of safety issues in the nuclear industry. In this respect, it is necessary to investigate the limit loads of an elbow with a wall-thinned part for evaluating integrity. In this paper, three dimensional plastic limit analyses are performed to obtain limit loads of an elbow with different bend angles as well as defect geometries under internal pressure and in-plane/out-of-plane bending moment. The limit loads are also compared with the results from limit load solutions of an uninjured elbow based on the von Mises yield criteria. Finally, the effects of significant factors, bend angle and defect shape, are quantified to estimate the exact load carrying capacity of an elbow during operation.
A Study on Retrofit Methods of Shear Walls with New Openings
Authors: Choi Hyun Ki , Lee J.A. , Lee M.S. , Choi Yun Cheul , Choi Chang Sik
Published: March 2009

A series of five shear wall specimens were tested under constant axial stress and reversed
lateral cyclic loading in order to evaluate the seismic retrofit methods that had been proposed for
shear walls with new openings. The test results showed that the failed specimens had shear fractures
and two different retrofit methods had different effects on the strengths of each specimen.
Elastic-Plastic Torque Analysis of Notched Cross-Section Bars Using the Finite Difference Method
Authors: Liu Hui Peng , Fu Xiang Rong , Cen Song , Jiang Xiu Gen , Ju Jin San , Wang Wen Jie
Published: March 2009

A new strategy of finite differences method is proposed for analysis of notched cross-section bars under elastic-plastic torsion. Relation curves of the elastic-plastic torque responding with different positions, angles and lengths of the notches in one section are obtained by numerical tests. It can be seen that these relation curves exhibit obvious nonlinearity. Meanwhile, the stress intensity factors can also be easily calculated by utilizing the results of above finite differences method. It provides an effective way for solving such elastic-plastic fracture mechanics problem.
Epitaxial Growth of LSMO Film Prepared by Excimer Laser-Assisted Metal Organic Deposition (ELAMOD)
Authors: Tsuchiya Tetsuo , Daoudi Kais , Nakajima Tomohiko , Kumagai Toshiya
Published: March 2009

The La1-xAxMnO3 (A=Sr, Ca, Ba) film was prepared by excimaer laser-assisted metal organic deposition (ELAMOD). To understand the important controlling factor of the epitaxial growth using ELAMOD, the effects of the substrate temperature, substrate type, wavelength, and film thickness on the epitaxial growth were investigated. When the film thickness was 200nm with heating at 250°C, a polycrystalline LSMO film was formed on the LAO substrate. On the other hand, at 80nm, an epitaxial LSMO film was formed on the LAO substrate at 500°C. The epitaxial growth of the LSMO film was found to be dependent on the substrate materials and the laser wavelength. The formation of the epitaxial and polycrystalline LSMO films was discussed
Physical and Electrical Properties of (Ba0.6,Sr0.4)TiO3 Ferroelectric Thick Films Prepared by Aerosol Deposition Technique
Authors: Popovici Daniel , Tsuda Hiroki , Park Jae Hyuk , Akedo Jun , Okuyama Masanori
Published: March 2009

(Ba0.6,Sr0.4)TiO3 thick films have been fabricated on various substrates and their physical and
electrical properties were analyzed. The effect of primary powder condition on the quality of the
BST fabricated films using aerosol deposition technique has been investigated keeping in mind
results shown in the literature for BST films fabricated with classical deposition techniques.
Presence of carbonates and TiO2 has been demonstrated by XPS analysis and the leakage current
behavior has linked to the presence of TiO2 at the grain boundaries. The films showed good
insulating properties, with small leakage densities being on the order of 10-6 A/cm2 for an applied
electric field of 150 kV/cm.
Effect of Gel-Films-Thickness and Sintering Conditions on the Crystal Structure and Microstructure of Alkoxy-Derived BaTiO3 Thin Films
Authors: Tanaka Kiyotaka , Suzuki Kazuyuki , Kato Kazumi
Published: March 2009

Various BaTiO3 thin films were fabricated at 650oC by using different conditions such as the
heating rate and alkoxy-derived gel-film thickness. In this study, the spin-coating and calcination
step were repeated several times to control the gel-films thickness. And then the one-sintering was
carried out with various heating rates. BaTiO3 films with perovskite phase were obtained by using
the heating rate of 100oC/sec and the surface morphology became rough with increase of gel-film
thickness. We considered that the change of root mean square (rms) roughness and cross-sectional
profiles by various heating rates was caused by densification.
Dielectric Property of Poly- and Single-Crystalline BaTi2O5 Co-Substituted with SrO and ZrO2
Authors: Yue Xin Yan , Tu Rong , Goto Takashi
Published: March 2009

Poly- and single-crystalline BaTi2O5 co-substituted with SrO and ZrO2, Ba0.99Sr0.01(Ti1-xZrx)2O5
(BT2SZ) were prepared by arc-melting and floating-zone (FZ) melting, respectively. The
specimens showed a significant (020) orientation. The highest permittivity of poly-crystalline
BT2SZ was 3880 at x = 0.005 and that of single-crystal was 27000 at x = 0.005. The Curie
temperature (Tc) of poly-crystals decreased from 750 to 640 K with increasing x from 0 to 0.026 and
that of single-crystals decreased from 750 to 710 K with increasing x from 0 to 0.008. The
highest remnant polarization of single crystalline BT2SZ was 7.8×10-2 Cm-2 at x = 0.008, higher
than that of the poly-crystal.
Design of Composite Electromagnetic Wave Absorber Made of Soft Magnetic Materials Dispersed and Isolated in Polystyrene Resin
Authors: Sakai Kenji , Wada Yoichi , Yoshikado Shinzo
Published: March 2009

Composite electromagnetic wave absorbers made of a soft magnetic material (permalloy or sendust) and polystyrene resin were investigated [1]. The volume mixture ratio of magnetic material was varied in the range from 18 vol% to 75 vol%. The composites with the low volume mixture ratio of soft magnetic material absorbed more than 99 % of electromagnetic wave power in the frequency range from 1 GHz to 10 GHz. The values of the real part r’ of the relative complex permeability r * for both magnetic materials were less than unity at frequencies above approximately 6 GHz as the volume mixture ratio of magnetic material increased. This result suggests the possible realization of an electromagnetic wave absorber that can operate above 10 GHz.
Fuzzy Rules for Surface Roughness of Ground Steels
Authors: Ali Y.M. , Zhang Liang Chi
Published: March 2009

This paper presents a comprehensive model for predicting surface roughness due to grinding.
Fuzzy rules are provided, to estimate roughness for any practical combination of (1) wheel hardness
grade, (2) abrasive grain size, (3) dressing condition, (4) table speed, (5) wheel depth of cut, and (6)
coolant application. The rule-base can be adapted to account for the effect of (7) different workpiece
material hardness, (8) wheel rotational speed, and (9) equivalent wheel diameter. The 86 rules are
intuitive, and are particularly useful for production and/or embedded control applications.
High Speed Cutting of Titanium Alloy with PCD Tools
Authors: Ota Michiko , Okida Junya , Harada Takashi , Toda Naohiro , Sumiya Hitoshi
Published: March 2009

When cutting titanium alloy, the temperature of a cutting tool edge is easy to rise and the
tool edge is tend to be worn away quickly because the titanium alloy has the characteristics of low
thermal conductivity and high chemical activity. Therefore, it is difficult to achieve a balance between
the productivity and the tool life in cutting the titanium alloy, namely, low-speed cutting must be
carried out at present. To examine the possibility of the improvement in the cutting efficiency, a PCD
(polycrystalline diamond) tool having high thermal conductivity was adopted to the cutting of
titanium alloy and its cutting performance was investigated. The PCD tool was found to have
excellent flank wear resistance compared with conventional cemented carbide tools. It was also
revealed that unprecedented high speed cutting become possible by use of PCD tool with an
application of high pressure coolant.
Study on Two Kinds of Grinding Wheels for Dynamic Friction Polishing of CVD Diamond Film
Authors: Jin Zhu Ji , Yuan Ze Wei , Kang Ren Ke , Dong B.X.
Published: March 2009

This paper investigates two kinds of grinding wheels prepared by the combination of mechanical alloy and hot-press sintering (MA-HPS). Scanning electro microscopy, Optical microscope, Talysurf surface profiler, X-Ray diffraction and Raman spectroscopy were used to characterize two kinds of grinding wheels and identify the removal mechanism. It was found that FeNiCr matrix-TiC (FMT) grinding wheel yielded higher removal rate than TiAl abrasiveless carbophile (TAC) grinding wheel, which conversely owned good polishing quality; diamond was removed by transformation diamond to non-diamond carbons and then removed by mechanically or diffusion to grinding wheel during polishing process with FMT grinding wheel. While TAC grinding wheel polishing CVD diamond film mainly depended on the reaction between diamond carbon and titanium.
Grinding of Carbon/Epoxy Composites Using Electroplated CBN Wheel with Controlled Abrasive Clusters
Authors: Yuan H.P. , Gao Hang , Bao Yong Jie , Wu Yong Bo
Published: March 2009

Aiming at solving the problems of wheel loading in dry grinding of Carbon/Epoxy
composite materials, a novel electroplated grinding wheel with controlled abrasive cluster was
developed, in which the diameter of clusters is in Φ0.2 mm to Φ1.0 mm and the interspace between
them is about 0.5 mm to 1.0 mm. A conventional electroplated grinding wheel with abrasive grains
distributed randomly was fabricated in the same way. The comparison experiments involving C/E
composite were conducted on a vertical spindle grinder with the novel and conventional grinding
wheels. The results show that the grinding forces of novel wheel developed is more lower though
little larger surface roughness, and the wheel loading phenomenon is markedly decreased compared
with conventional electroplated wheel.
Actively Cooled and Activated Coolant for Grinding Brittle Materials
Authors: Gao Y. , Xin J. , Lai H.
Published: March 2009

An actively cooled and activated cooling approach is proposed and examined in this project
in order to deal with the problems associated with methods such as the cryogenic cooling method. It is
also aimed to further improve the surface quality of the workpiece after grinding by combining the
advantages of the existing cooling methods. Both computational and experimental studies were
conducted for grinding the brittle materials with the proposed approach. Optical examinations were
used to study the surface morphology. The experimental results show that the surface quality can be
improved by up to 23.75% on average in terms of surface roughness Ra. The computational test
reveals that the heat can be taken away more effectively by the proposed approach.
Study on Adhesion Removal Model in CMP SiO2 ILD
Authors: Guo Dong Ming , Liu Rui Hong , Kang Ren Ke , Jin Zhu Ji
Published: March 2009

In the process of CMP SiO2 ILD, the nano-particle with high surface energy in slurry has an essential impact on the efficiency and quality of CMP. In this paper the mode of nano-particle on the surface of SiO2 ILD is analysed and adhesion removal model corresponding to that is established. Through cycle polishing experiments, the change of nano-particle size and the state of particle surface before and after polishing is observed with TEM and Zeta potential analyzer, based on which the adhesion removal model is verified.
Effect of Conditioning Parameters on Surface Non-Uniformity of Polishing Pad in Chemical Mechanical Planarization
Authors: Qin N. , Guo Dong Ming , Kang Ren Ke , Huo Feng Wei
Published: March 2009

The calculating model of surface non-uniformity of polishing pad and the kinematical model between polishing pad and conditioner are initially established. Then the effects of several conditioning parameters were investigated by using the two models. The results of simulation and calculation show that the width ratio of diamond band of conditoner and the rotation speed at the same speed ratio between pad and conditioner have little effect on the surface non-uniformity of polishing pad, while at high non-integer rotation speed ratio, the surface non-uniformity of polishing pad is better than that at low integer speed ratio. The research results are available to select appropriate conditioning parameters especially for the stringent requirement of within-wafer non-uniformity in next generation IC.
Proposal of Pulverization Method Based on Grinding Process in Order to Recycle FRP Waste
Authors: Sakamoto Haruhisa , Nabata Shogo , Shimizu Shinji
Published: March 2009

In order to enable the recycling of FRP waste, the pulverization method is proposed based on surface grinding process. In the experiments, the pulverization characteristics are examined, and then, the change in the property of the FRP material pulverized to particles is confirmed. From the examination, the following were clarified: The FRP material can be pulverized with surface grinding process, and the sizes of the generated particles are almost 10μm or less. The size distribution of the generated particles hardly changes regardless of the change in grinding condition, such as depth of cut or feed rate. However, the increase in depth of cut or feed rate makes the particles easily cohere together. To improve the pulverization efficiency, the supply of the semi-cold-air is effective because this markedly prevents the particle cohesion. The pulverization improves the water suspension ability of FRP in water, and this gives FRP waste the possibility of recycling.
Grinding Burn and Chatter Classification Using Genetic Programming
Authors: Chen Xun , Griffin James
Published: March 2009

This paper looks at the multiple characteristics and investigations of two grinding anomalies: grinding burn and grinding chatter. A genetic programming (GP) of multiple classifications was investigated for different machining strategies and associated anomaly phenomena. Such a GP paradigm could evolve rules to provide the correlation between monitored signals and grinding phenomena. The investigation also looks at both Short-Time Fourier Transforms (STFT) and Wavelet Packet Transforms (WPT) to convert the raw acoustic emission (AE) signal into a time based frequency signal, segmented into different frequency bands. A set of encouraging results is presented.
Mesoporous Thin Films: An Example of Pore Engineered Material
Authors: Innocenzi Plinio , Soler Illia Galo
Published: March 2009

Self-assembly through supramolecular templates is an advanced process for preparing thin films with ordered mesostructure and tuned pore arrays; the overall process is a combination of sol-gel and supramolecular chemistry, while the organization is driven by solvent evaporation. Controlling of the process allows obtaining a nanomaterial whose ordered and open porosity can be exploited for applications in different fields. In the article we give a general overview of self-assembly during thin films deposition from a liquid phase and we present some possible fields of applications.
The Sol–Gel Production of Bioceramics
Authors: Salinas Antonio J. , Vallet-Regí Maria
Published: March 2009

Sol–gel synthesis is used for the fabrication of new materials with technological applications including ceramics for implants manufacturing, usually termed bioceramics. Many bioactive and resorbable bioceramics, that is, calcium phosphates, glasses and glass–ceramics, have been improved by using the sol–gel synthesis. In addition, the soft thermal conditions of sol–gel methods made possible to synthesize more reactive materials than those synthesized by traditional methods. Moreover, new families of bioactive materials such as organic–inorganic hybrids and inorganic compounds with ordered mesostructure can be produced. In hybrid materials, the inorganic component ensures the bioactive response whereas the organic polymeric component allows modulating other properties of the resulting biomaterial such as mechanical properties, degradation, etc. On the other hand, the sol–gel processes also allow the synthesis of silica ordered mesoporous materials, which are bioactive and exhibit – as an added value – a possible application as matrices for the controlled release of biologically active molecules (drugs, peptides, hormones, etc.). Finally, by combining the bioactive glasses composition with synthesis strategies of mesoporous materials, template glasses with ordered mesoporosity can be obtained. In this chapter, the advances that sol–gel technology has brought to the silica-based bioactive bioceramics are presented.
NanoStructured Sonogels
Authors: de la Rosa-Fox Nicolás , Morales-Flórez Victor , Piñero Manuel , Esquivias Fedriani Luis Maria
Published: March 2009

Acoustic cavitation effects in sol-gel liquid processing permits to obtain nanostructured materials, with size-dependent properties. The so-called “hot spots” produce very high temperatures and pressures which act as nanoreactors. Ultrasounds force the dissolution and the reaction stars. The products (alcohol, water and silanol) help to continue the dissolution, being catalyst content, temperature bath and alkyl group length dependent. Popular choices used in the preparation of silica-based gels are tetramethoxysilane (TMOS), Si(OCH3)4, and tetraethoxysilane (TEOS), Si(OC2H5)4. The resultant “sonogels” are denser gels with finer and homogeneous porosity than those of classic ones. They have a high surface/volume ratio and are built by small particles (1 nm radius) and a high cross-linked network with low –OH surface coverage radicals. In this way a cluster model is presented based on randomly-packed spheres in several hierarchical levels that represent the real sonoaerogel. Organic modified silicates (ORMOSIL) were obtained by supercritical drying in ethanol of the corresponding alcogel producing a hybrid organic/inorganic aerogel. The new material takes the advantages of the organic polymers as flexibility, low density, toughness and formability whereas the inorganic part contributes with surface hardness, modulus strength, transparency and high refractive index. The sonocatalytic method has proven to be adequate to prepare silica matrices for fine and uniform dispersion of CdS and PbS quantum dots (QDs), which show exciton quantum confinement. We present results of characterization of these materials, such as nitrogen physisorption, small angle X-ray/neutrons scattering, electron microscopy, uniaxial compression and nanoindentation. Finally these materials find application as biomaterials for tissue engineering and for CO2 sequestration by means the carbonation reaction.
Application of LabVIEW in Flame Cutter NC System
Authors: Wang Hong Yun , Guo G.F. , Li Y.X. , Zhu Xi Lin
Published: March 2009

In this paper, a system was introduced, which bases on Flame Cutter NC System and
software platform of LabVIEW which the USA NI company developed. Composing of NC machine,
partition of modules and assignments, functions confirming, data processing of machining and
control, structure of software by the numbers and realization method of two CPUs. The system makes
use of multitasking of LabVIEW to make the programmer realize easily the task, which is difficulty
to acquire in in tradition programme. It is a kind of comparatively convenient and swift thinking to
realize system interface and multitasking by the platform of LabVIEW.
Study for Laser Cladding of Ni60A on Copper Substrate by Laser
Authors: Tian Feng Jie , Liu Wei Jun , Shang Xiao Feng , Yang Guang
Published: March 2009

The Ni60A powder was clad on the copper by the laser through coaxial power feeding.
The hardness and erosion resistance of the substrate and the cladding layer were measured and
made contrasts. The morphology and the microstructures of the cladding layer were analyzed by
scanning electronic microscopy as well as the microstructure of bonding interface. The contents of
major elements in the bonding interface were studied by energy dispersive spectrometer. Moreover,
large amount of (Cu and Ni) solid solution formed a metallurgic and tight bonding with the good
dilution between the substrate and cladding layer.
Motion Analysis and Simulation of Complex Curved Surface WEDM System
Authors: Wang Tong , Jiang K. , Xie Shu Qiang , Hao Shuang Shuang
Published: March 2009

In this paper, the characteristics and general laws of cutting complex curved surface by
wire electrical discharge machining (WEDM) system are studied. Based on analysis of motion
parameters the universal mathematical model of polar coordinates is derived. Moreover, the
simulation of WEDM system is introduced, which is carried out by using language Visual C++ and
the three dimensional graph software OpenGL.This simulation method is helpful in improving
machining quality and productivity of complex curved surfaces, and is fundation for establishing
CAD/CAPP/CAM technology in WEDM.
Fundamental Experiment of Laminated Templates Electro-Deposition in Manufacturing Metal Part
Authors: Fan Hui , Tian Zong Jun , Huang Y.H. , Liu Z.D. , Wang X.C.
Published: March 2009

Laminated templates electro-deposition is an original manufacturing technology that is aimed at micro-scale metallic structures fabrication. Based on the discrete piling-up principal and electrodepositing method, it realizes a manufacturing simplification from the traditional machining to the repetition of template-assisted planar deposition in forming a three-dimensional complicated object. The ability to control the deposit surface nouniformity is a key to successful implementation for each planar depositing. Profile geometry and current configuration are alternated in experiment and thought as the major factors influencing deposit surface roughening. The results show that the surface of the deposits obtained by pulse electroforming has better performance in deposit thickness distribution and properties of the deposits. Optimized parameters have been obtained from the preliminary experiments in which 0.3millimeters-thick epoxy templates and 4~6A/dm2 current density were used at 40+ and a bulk of copper parts, section size 30mm×30mm and 7mm thick were produced and tested for their mechanical performance.
Tool Posture Optimization Subjected to the Rigidity of Multi-Axis Machine Tool
Authors: Yan R. , Peng F.Y. , Yang J.Z. , Lin Bin
Published: March 2009

In order to achieve higher product quality for sculptured surface productions, an advanced strategy are proposed for machining planning, namely a tool-posture-control strategy. In the tool-posture-control strategy, machining chatter is reduced by controlling the machine rigidity along cutting feed direction. This proposed strategy, which improved product quality of sculptured surface when subjected to both the part geometry and the machine rigidity constrains, is described in this paper. A new machining-planning aid called local stiffness index is developed to help tool posture planning. This proposed strategy subjected to multi-constrains help a part programmer to choice the optimum tool posture. In order to illustrate the application of stiffness index map and the proposed strategy, the applications of the proposed strategy to real three-dimensional complex surface (e.g. a turbine blade) are presented in this paper.
Development of a NC Servo System Based on Fuzzy Adaptive Control
Authors: Cao Jun , Li Z.W. , Meng Z.X.
Published: March 2009

According to BVXK20A NC machine servo system, a fuzzy controller is designed to achieve a faster response speed and better stability objectives. This controller is capable of automatically adjusting the three parameters of PID controller according to the tracking error E and the change in error EC. Simulation results shown the proposed control method could effectively achieve the goals of reducing the static error and improving response speed in the conditions of work condition altered.
Construction of a New Virtual Environment System for Assembly and Training of Complex Products
Authors: Lang Yue Dong , Xia Ping Jun , Chen P. , Yao Ying Xue
Published: March 2009

Virtual assembly (VA) is an important application for virtual reality (VR) technology in
manufacturing industries that can supply an effective solution to actual assembly problem of
products. According to the assembly characteristic of large-scale products such as airplane, rocket and
satellite, etc, a new interactive VA environment system is constructed, and its architecture and related
key techniques are studied. Considering human free activity in the system, a free-walking perception
machine is developed. And a stereo projection approach based on a video generator is proposed to
enhance real-time interaction and reduce hardware cost. Finally, those key techniques are successfully
applied in the process of satellite assembly planning and training.
Comprehensively Digital Descriptions Based on the Features of CAD and CAPP for the Typical Shaft-Like Component
Authors: Song J.L.
Published: March 2009

Based on the body element and topological features, studied and built up the fundamental system of feature-description of digital design and manufacturing for the typical shaft-like components, systematically researched and set up content tree of the feature description， two core sub-systems of spatial relationships of geometric elements orientated to the digital design and presentation of processing operation features faced to the digital manufacturing, followed by comprehensive-parameter method for the description of surface characteristics of the component. An example, supporting axis, from Quanhai Machinery Development Co. Ltd., was given for considerations taken in utilization of the feature-description system for the digital design and manufacturing. It is hoped that the current study and the construction of the system may lay the foundation for the unification of CAD/CAPP/CAM.
The Experimental Investigation of Face Grinding of Al2024/SiCp with Electroplated Diamond Wheel
Authors: Li D.P. , Yao Ying Xue , Yuan Z.J.
Published: March 2009

In this paper experiments of the face grinding of Al2024/SiCp through the use of
electroplated diamond wheel were carried out. The results indicated that high quality processed
surface was achieved by face grinding machining, under the experiment conditions of this paper, the
surface roughness was between Ra0.185 μm and Ra0.512μm, and the residual stress of processed
surface was compressive stress. Grinding parameter had little effect on tangential force and normal
force. Axial grinding force increased with the increasing of grinding depth and was stronger than
grinding forces in other two directions.
Research on Modeling of Bionic-Bone Tissue Scaffold for RPM
Authors: Ren B.Y. , Zhang J.W.
Published: March 2009

Modeling of bionic-bone tissue scaffold is the kernel of the structure design and bionic
manufacturing of bionic bone scaffold. According to the growth requirements of new bone tissue cell
on the porosity and pore size of bionic bone tissue model, an approach for modeling of bionic-bone
tissue scaffold based on the surface model of bone tissue is presented by filling the profile model of
bone tissue with the delamination of hollow unit cell. The hollow cubic unit cell is designed with
controllable porosity and pore size. The algorithm for filling the profile of bone tissue with
delamination of porous unit cell is provided for generating the model of bionic bone with pore
structure. The scaffold model is stored in Common Layer Interface (CLI) file for the Rapid
Prototyping Manufacturing (RPM) of scaffold.
Experimental Study on Intelligent Monitoring of Diamond Grinding Wheel Wear
Authors: Zhao Bo , Du Bao Yu , Liu W.D.
Published: March 2009

In order to research the relationship between grinding wheel wear and the signal of grinding
strength and grinding vibration, the grinding strength signal and grinding vibration signal under
different wear condition were carried on digital processing by time-domain, frequency-domain, and
wavelet-pocket analysis, and characteristic signal reflecting grinding wheel wear condition was
obtained. Grinding wheel wear was monitored by time-domain statistics average value of grinding
strength and energy value of three layers wavelet-pocket decomposition frequency band. The method
how to set design parameters of neural network is introduced, and their value in condition monitoring
network is determined. Mapping model of grinding wheel wear and characteristic signal is
established. Recognition effect is satisfied in the experiment of grinding wheel wear condition
monitoring. It confirmed the model is reliable and effective. The result shows that the new intelligent
monitoring method is effective on monitoring grinding wheel deactivation condition. One new
method of diamond grinding wheel wear condition monitoring under precision and ultra-precision
grinding is introduced.
Study on Path Planning for Industrial Robots in Free-Form Surfaces Polishing
Authors: Zhan Jian Ming , Zhou Xiao Qin , Hu Li Yong
Published: March 2009

Expected path of polishing tool is one of the most essential needs for movement scheduling and movement controlling of polishing robot in free-form surfaces polishing. By analyzing the expected movement and position of polishing tool and based on the traditional movement scheduling methods, this paper carries out systematic research works on contour-parallel-machining tool path planning method and direction-parallel-machining tool path planning method for polishing tool paths figuring out. Compared with contour-parallel-machining tool path planning method, the direction-parallel-machining tool path planning method needs one less number of degree of freedom and is much easier to avoid physical interventions and mechanic singularity, so it is an improved one.
Optimization of High Speed Milling Cutter Based on Critical Cutting Speed
Authors: Jiang Bin , Zheng Min Li , Xu Fang
Published: March 2009

Based on analyses of cutting heat and temperature in high speed milling, to construct a
model of critical cutting speed for high speed milling cutter, find out influencing factor of critical
cutting speed, and put forward optimization method of high speed milling cutter based on critical
cutting speed. The results indicate that chip conducts a majority of cutting heat along with increase
of cutting speed, feed speed and the rake of cutter. Cutting heat which workpiece conducts
gradually diminishes when heat source accelerates. When cutting performance of cutter satisfies
requirements of high speed milling, the proportion of cutting heat which workpiece conducts
approaches its maximum as cutting speed comes to critical cutting speed. To optimize high speed
face milling cutter for machining aluminum alloy according to critical cutting speed, the cutter takes
on better cutting performance when cutting speed is 2040m/min~2350m/min.
Precision Model of Predicting FDM Rapid Prototype Based on BP Neural Network
Authors: Shang G.Q. , Sun C.H. , Chen X.F. , Du J.H.
Published: March 2009

Fused deposition modeling (FDM) has been widely applied in complex parts
manufacturing and rapid tooling and so on. The precision of prototype was affected by many factors
during FDM, so it is difficult to depict the process using a precise mathematical model. A novel
approach for establishing a BP neural network model to predict FDM prototype precision was
proposed in this paper. Firstly, based on analyzing effect of each factor on prototyping precision,
some key parameters were confirmed to be feature parameters of BP neural networks. Then, the
dimensional numbers of input layer and middle hidden layer were confirmed according to practical
conditions, and therefore the model structure was fixed. Finally, the structure was trained by a great
lot of experimental data, a model of BP neural network to predict precision of FDM prototype was
constituted. The results show that the error can be controlled within 10%, which possesses excellent
capability of predicting precision.
Dental Ceramics Modified by Ternary Glass-Ceramic Coatings: Characterization and In Vitro Bioactivity Study
Authors: Chatzistavrou Xanthippi , Kantiranis Nikolaos , Papadopoulou Lambrini , Kontonasaki Eleana , Boccaccini Aldo Roberto , Koidis Petros , Paraskevopoulos Konstantinos M.
Published: March 2009

In this study new ternary bioactive mixtures were investigated, which are appropriate for applications as coatings on the surface of dental ceramics. The fabrication of mixtures based on the combination of dental ceramic, hydroxyapatite and bioactive glass was demonstrated. The mixtures were characterized by FTIR, XRD and SEM and their bioactive behavior was investigated by immersion in Simulated Body Fluid (SBF). The ternary mixture consisted of a high fusing leucite-feldspathic dental ceramic which exhibited the highest bioactive behavior assigned to the characteristic crystal phases occurring under the specific heat treatment investigated.
Investigation of the Bioactivity of Dental Ceramic / Bioactive Glass Composites Prepared by the Sol Gel Route
Authors: Goudouri Ourania Menti , Kontonasaki Eleana , Chatzistavrou Xanthippi , Papadopoulou Lambrini , Koidis Petros , Paraskevopoulos Konstantinos M.
Published: March 2009

Sol-gel derived glasses have been reported to express considerably higher bioactivity than melt-derived ones. The use of the sol-gel method for the fabrication of dental ceramic bioactive glass composites has resulted in composites consisting of an amorphous glassy network into which crystals of Calcium Silicate (CS), Wollastonite (W), leucite (Lt) and Fluorapatite (FAp) are dispersed. Thus, the aim of the present study was the investigation of the bioactivity of sol-gel derived dental ceramic/bioactive glass composites, in the form of powders and in thermally treated disk shaped specimens. Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were used to characterize the reacted products. The sol-gel derived dental glass ceramic composites present high bioactivity compared to the respective melt-derived ones, which is attributed to the higher CaO content and the crystallization of bioactive W and CS crystal phases during the fabrication process. However, the powdered samples presented faster HCAp formation compared to the respective specimens, due to their higher surface energy.
Surface Properties after Ageing of Dispersion Ceramic and its Influence on Strength
Authors: Begand Sabine , Oberbach Thomas , Herrmann Mathias , Sempf Kerstin
Published: March 2009

The primary purpose of this work was the examination of the surface and the strength of ATZ ceramic after hydrothermal treatment. Hydrothermal treatment of ATZ ceramic leads to changes of roughness and phase composition on the surface. The phase composition and the microstructure on the surface and within the peripheral zone were determined after applying a stepwise broad ion beam polishing technique and quantitative phase analysis. With this technique a penetration depth of the phase transformation of less than 14 µm was observed. Investigations of the cross sectional area by means of FESEM have shown a transformation zone of about 9 µm. Both methods lead to comparable results with a very small, morphologically changed peripheral layer. The study of the strength after ageing with different thickness of the samples showed that for a thickness of 2.0 mm there is no negative influence on mechanical behaviour. In consideration of this fact no significant change of tribological properties is expected.
The Effect of Collagen Matrix on Calcium Phosphate Mineralization
Authors: Allegretti L.J.M. , Bertran Celso A.
Published: March 2009

Mineralization of the proteic matrix composed mostly of collagen type I is controlled by specific interactions of ions Ca2+ and PO43-, present in the biological fluid, with the matrix, and by the diffusion of these ions. The specific interactions and the diffusion of ions combined; result in the nucleation and formation of calcium phosphate particles. Moreover, they control the morphology, size, crystallinity and composition of the particles In this work, precipitation of calcium phosphate particles in a collagen matrix type I was carried out through impregnation of the matrix with a Ca2+ and PO43- solution, with Ca/P ratio 1.67 and pH 2.5. Precipitation of particles associated with matrix structuring was carried out by adsorption of gaseous ammonia.
Brazilian Research Academy and Scientific Evidence on Calcium Phosphate Bone Grafts
Authors: Rodrigues Carla Valéria M. , Fernandes Ligia L. , de Almeida Soares Gloria Dulce
Published: March 2009

Different types of bone grafts are available in Brazil due to the increase of use of biomaterials for hard tissue replacement. This study was designed to evaluate the scientific production of Brazilian research groups on safety and efficacy of calcium phosphate bone grafts of commercial use in Brazil. The calcium phosphate bone grafts approved for commercial use in Brazil were searched at the National Health Regulatory Agency’s database (ANVISA). The main leaders’ names of the Brazilian Research Groups on these health technologies were obtained by applying the search strategies to the National Council of Technological and Scientific Development’s database (CNPq). Afterwards, it was performed a systematic search of studies conducted by these leaders on calcium phosphate bone grafts and published from 2000 to May 2008 at the following databases: Medline, Lilacs and Scielo. Twenty-nine bone grafts composed by calcium phosphates were registered at Anvisa in May 2008. From those products, 17 and 12 were from imported and national origin respectively. There were twenty-four Brazilian research groups on calcium phosphate bone grafts whose scientific production consisted of 5 studies on bone grafts registered at Anvisa: 3 experiments conducted in animals on the Brazilian bovine bone graft Gen-Ox®, one prospective comparative study and one case report both evaluating the clinical performance of a national biomaterial composed by BMP, demineralized bovine bone, inorganic bovine bone and bovine collagen with the commercial name Gen-Tech® for dentistry applications and 6 months of follow-up. However, all the included studies had poor methodological quality and could not be used for further recommendations despite their good results. The scientific evidence produced by the Brazilian research groups on safety and efficacy of calcium phosphate bone grafts of commercial use in Brazil is still scant. Additional studies are necessary to evaluate these technologies.
Control of the Injectability of Calcium Carbonate-Calcium Phosphate Mixed Cements for Bone Reconstruction
Authors: Tadier Solene , Le Bolay Nadine , Girod Fullana S. , Rey Christian , Combes Christèle
Published: March 2009

The purpose of this study was to improve injectability and cohesiveness of original calcium carbonate-calcium phosphate mixed (CaCO3-CaP) self-setting paste for bone filling and repair. With this aim in view dry co-grinding was implemented on the solid phase (vaterite and dicalcium phosphate dihydrate) of this cement. A protocol designed to quantify paste injectability has been established and pointed out the synergistic positive effects of solid phase co-grinding treatment on injectability, cohesiveness and setting time of the paste. The improvement of these properties are related to close and homogeneous association of reactive powders and to the decrease of specific surface area favoring the powders hydration process enhancing setting reaction rate. In addition, the particle size decrease and morphology modification improved flowability of the paste which results in a low and constant (320 g) force level to extrude the paste.
In Vivo Biological Behavior of Calcium Phosphate Cements with Different Ca/P Ratio
Authors: Saska Sybele , Nunes N.S. , Aveiro Emelly , Pavan Cristina A.C. , Santagneli S.H. , Campos J.A.D.B. , Gaspar Ana Maria M. , Ribeiro Sidney José Lima , Messaddeq Younes
Published: March 2009

Bioceramics with different Ca/P ratio were prepared from a mechanical mixture of NaPO3, CaCO3, Ca(OH)2 and phosphate buffer solution and implanted in rats subcutaneous tissues. The cements were characterized by Thermogravimetric analysis (TG-TDA), X-ray diffraction and 31P-NMR. The implant sites were excised after 1, 4 and 16 weeks, fixed, dehydrated, included in paraffin wax for serial cutting and examined under the light transmitted microscope. They were biocompatible and biodegradable when implanted in rat subcutaneous. None of the materials induced ectopic osteogenesis. According to the results, the studied materials seem to be able for manufacturing reabsorbable bone implants.