bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Hierarchical Design Method of Open Modular Architecture CNC System
Authors: Wu Z.Y. , Wang Tai Yong , Li H.W. , Wang Wen Jin , Dong T.J.
Published: March 2009

One reason for the delay of open-architecture control system in industry action is that no clear and hierarchical design method has evolved. Different application environment and object should have different open levels, applying platforms, system architectures and integration method. Abstract open control concepts or characters must be converted into specific and practical applying objects and contents of one designing of open-architecture CNC system. Then through analysis of the hierarchy or level of system open character, practical system functional objects to be realized, technical and non-technical issues to be considered, implementation contents and process and the method of component and system validation, a hierarchical design method of open modular architecture CNC system is established.
A Combined Model of the Active Vibration Control of the Coupled Flexible System
Authors: Niu Jun Chuan , Zhao Guo Qun , Song K.J.
Published: March 2009

A novel general model of the coupled flexible system is presented. Based on the
description of state-space equation of the coupled system, the transmission channels of the power flow transmitted into the foundation are discussed in frequency domain, and then combined into a single function. The transmission characteristics of power flow and control strategies are discussed in detail. From numerical simulations presented, it is clear that the analytical model is effective and
moment controls are able to achieve vibration cancellation substantially.
Internet-Based Physical Simulation of Drilling Process
Authors: Dong Li Hua , Zhao Yan Ling , Fan C.H.
Published: March 2009

This paper presents the implementation of an internet-based facility for the drilling
process simulation, which complies with TCP/IP and is supported by Browser/Server model. The process simulation is one of pivotal technologies and implemental techniques of the internet-based agility manufacturing technology. A network architecture model is developed with the WebServer toolbox of MatLab. The complicated drilling process is studied. Semi-experimental mathematic models of drilling force and torque are established. Users input different machining parameters in client-side and then they will get the simulation curves of cutting forces and torques and can evaluate the simulation results. At last, optimum machining parameters can be chosen by users via internet.
Study on the Semi-Active Suspension Control System and Its Stability Based on T-S Fuzzy Neural Control Strategy
Authors: Long Chen , Jiang Hao Bin , Yang M.C.
Published: March 2009

A semi-active vehicle suspension model is built, and semi-active suspension control
system based on T-S fuzzy neural control strategy is designed. Then, the stability of the control system is analyzed and the condition of stability of the system is deduced. Simulations and experiments are carried out and their results accord with each other, which shows that the controller is stable, valid and has strong robust performance.
Finite Element Simulation of the Orthogonal Metal Cutting Process
Authors: Chen Shi Jin , Pang Q.L. , Cheng K.
Published: March 2009

In this paper, a finite element model of a two-dimensional orthogonal metal cutting
process is used to simulate the chip formation, cutting forces, stress, strain and temperature distributions. Two deformable parts are involved in this model: the workpiece and the cutting tool. To make the results of the simulation agree the orthogonal cutting test better, the separation surface between the chip and the machined surface is not predefined in this simulation. The chip-separation criterion is based on the Johnson and Cook law. This work will help as a reference to tackle more complex cutting processes such as oblique and discontinuous cutting.
The Objectives Decision Making Study in Product Innovation Development Process Based on TRIZ Technology Evolution Theory
Authors: Zhang F.Y. , Xu Yan Shen , Hu D.J.
Published: March 2009

The TRIZ theory of technology evolution is introduced and its limitations in new product development is assessed in this paper, Based on the multiple approaches evolution patterns of TRIZ Theory, a decision-making procedure model for new product development is proposed and a sample product is used to demonstrate how to use new model to the real developing procedure of a new product.
An Experimental Study of Specific Energy in Grinding Granite
Authors: Yu Yi Qing , Li Yuan , Xu Xi Peng
Published: March 2009

An investigation is reported of the characteristics of specific energy in grinding of granite using diamond abrasives. The effects of many parameters, such as the types of diamond tools, the types of abrasives, the properties of granite, the conditions of lubrication, and the working conditions of diamond tools, were studied. The power consumed in grinding was measured in order to obtain the specific energy, which is defined as the energy expended per unit volume of material removal. It is found that the specific energy for grinding of granite was closely related to the removal mechanisms of granite, the failure modes of diamonds and the interactions of the swarf with the applied fluid and bond matrix.
Study on Hole Making in EACVD Thick Diamond Film
Authors: Zuo Dun Wen , Lu Wen Zhuang , Li Xiang Feng , Chu X.Q. , Wang Min
Published: March 2009

Few research works have been reported on hole making in EACVD thick diamond film, though many papers have been published on the preparation and smoothing of the film. In this paper, YAG laser and EDM were used to make holes in un-doped and Boron-doped diamond film respectively. Fundamental investigation was carried out on the effects of processing parameters on the holing efficiency and processed surface quality. The film surface was analyzed by means of Raman spectrum before and after holing. It is shown that YAG laser has a higher processing efficiency than EDM, but the latter can get a rounder hole.
Application of the Hilbert-Huang Transform to Pick up Surface Roughness
Authors: Wu Jian Hua , Yao Zheng Qiang , Jin Y.
Published: March 2009

The surface roughness is evaluated by decomposing micro-errors from irregular surface image. The wave of surface is designated as signals including high-frequency, mid-frequency, and low-frequency signal, that denote roughness, waveness and the geometry shape error. Hilbert-Huang transform is a promising revolutionary technique for spectral data analysis, which is used to extract roughness from surface. It overcomes the imprecise result of the traditional surface roughness calculation and avoids the complication of the Wavelet analysis. Theory of Empirical Mode Decomposition (EMD) is given in the paper. This method is initially applied in picking up surface roughness, and it is proved to be of very high efficiency and simplicity.
The Mechanism of Ultrasonic Vibration Improving MRR in UEDM in Gas
Authors: Zhang Qin He , Du Ru , Zhang Jian Hua , Yang J.Y. , Ren Sheng Feng
Published: March 2009

A new machining method, ultrasonic vibration aided electrical discharge machining
(UEDM) in gas, is proposed in this paper. It is shown that electrical discharge machining with ultrasonic vibration aid can be achieved well in gas medium. In the process of UEDM in gas, the tool electrode is formed to be thin-walled pipe, high pressure gas medium is supplied from inside, and ultrasonic vibration is applied to workpiece. The property of ultrasonic is introduced. The same to other sound waves, ultrasonic have the characteristics of reflecting, refracting, intervening and
resonance. The mechanism of elastic pole keeping in resonance with ultrasonic transferring from one end to the other end is explained with characteristics of ultrasonic. During the process of UEDM in gas, ultrasonic vibration of workpiece can improve the machining process. The theories of ultrasonic vibration increasing materials removal rate (MRR) are introduced. One theory is that the adhere strength between the metallic liquid drops and workpiece is not enough for the
accelerative vibration, so metallic liquid drops will be ejected off easily. Another theory is that ultrasonic vibration increases the number of the effective discharge.
Robust Position Controller Design for Linear Servo Units Used in Noncircular Machining
Authors: Huang S.T. , Zhi Jing Feng , Cheng Hao Bo , Zuo W.
Published: March 2009

This paper presents the design and implementation of a robust motion control structure for linear servo units used in noncircular machining. Compared with ball/screw driven system, the controller of the linear motor driven system must provide a high level of disturbance rejection performance, as the system is more
sensitive to force disturbances and parameter variations. Thus, in this paper, a robust feedback controller based on disturbance observer is applied to enhance the stiffness and robustness. A magnitude and phase regulating control scheme (MPRC) is proposed to improve the system tracking accuracy, and a simple error
feedforward compensator (EFC) further reduces the feedforward control error that result from inaccurate frequency response data. The effectiveness of the proposed controller is demonstrated by experiments.
Dispersion and Stability of Nanodiamond in Clean Oil
Authors: Xu Xiang Yang , Yu Z.M. , Zhu Y.W. , Wang B.C.
Published: March 2009

Nanodiamond prepared by detonation synthesis using explosives as the precursor exhibits serious agglomeration characteristics in non-polar medium such as clean oil. Mechanochemical measures were introduced to modify nanodiamond (ND) surface, improve its dispersion behavior and actualize suspension stability. Hyperdispersants’s adsorption can be intensified with the participations of mechanical forces, and the main mechanism of hyperdispersant may lie in the steric
stabilization of its adsorption layer founded on ND surface. After the eagglomeration and dispersion treatments, a suspension containing ND particles with the average diameter of around 55 nm can be prepared and it can be reserved for over 6 months without any sedimentation.
A New Fabrication Method of Neutron Fresnel Lens
Authors: Guo Jian Qiang , Ohmori Hitoshi , Lin Wei Min , Adachi T. , Shimizu H.M.
Published: March 2009

In order to improve the application of neutron scattering technique, a new neutron optical device, which optical system consists of an array of several ten neutron Fresnel lenses, is designed by the researcher engaging in the study of neutron optics. Neutron Fresnel lenses for this new device have the same symmetric concave form. Its center is a spherical surface and the other surfaces are conic section. MgF2 single crystal glass is selected as the material for making neutron
Fresnel lens because of its high transparence. Considering the form complicity and the brittle properties of MgF2 material, the fabrication of neutron Fresnel lens is of very difficulty. Form ELID (electrolytic in-process dressing) grinding was used for grinding the neutron Fresnel lens in this first study. The optima of grinding conditions for #325, #1200 and #4000 cobalt bonding diamond abrasive wheels are obtained through a series of tests. The MgF2 material is removed at the ductile
mode by using #4000 abrasive wheel. Thus, the neutron Fresnel lens fabricated has low roughness and high transparence. The transmission of an array of 50 pieces of neutron Fresnel lens is 92.5 percents to neutron beam with wavelength 5Å and 79.3 percents to 16Å.
Advanced Materials Science Applied in the Restoration of Outdoor Bronze Statues
Authors: Sajó István E. , Buza Gábor , Madarassy W. , Kálmán Erika
Published: March 2009

In the heart of Budapest, an ensemble of nearly 40 large size bronze statues and reliefs were restored in the years of 1995 – 2002. In this paper it is shown, how the achievments of materials science were used to restore the original look and ensure long term integrity of the monument.
Coating of SWNTs with Nickel by Electroless Plating Method
Authors: Zeng Qiang , Bayazitoglu Y. , Zhu Jiang , Wilson Kenneth , Imam M. Ashraf , Barrera Enrique V.
Published: March 2009

This study considers a method for producing SWNTs reinforced lightweight
metal-matrix composites. In this research, fluorination has been applied to achieve
considerable improvement in the dispersion of purified single-walled carbon nanotubes. It has been demonstrated that surface fluorination is a possible approach to entrap catalytic nucleation centers along the walls of SWNTs. The results show that nickel could be successfully plated onto the activated surfaces of fluorinated SWNTs (F-SWNTs) through electroless plating which is an effective way for producing nanotube/metal systems. It was observed that high surface coverage of Pd-Sn catalytic nuclei is needed to form high quality coatings. A two-step approach was used and the coating mechanism is described in this paper.
Study on a Novel Radar Absorbing Structure Composite
Authors: Jiang Shicai , Xing Li Ying , Li Bin Tai
Published: March 2009

A radar absorbing structure composite (RAS) which contains circuit analogue structure (CAS) made from conductive foil was studied in this paper. The results show that CAS acting as a reflection screen can cause the interference of incident EM wave with reflection EM wave. So, through rational composite material design and preparation, the radar absorbing structure composite with CAS can exhibit good radar absorbing property. The results also show that in the composites with gradually changed impedance, when other design parameters are not changed but
only increase the size of CAS, the electromagnetic parameter and the thickness of the medium laminate, the maximum absorbing peak of the reflectivity will move to the direction of the lower frequency. The above research results show that the introduction of CAS into the radar absorbing structure composites can improve the wave-absorbing properties. Therefore the radar absorbing structure composite with CAS is a promising radar absorbing structure composite form.
Optimizing Analysis in the Bending Rigidity of CFRP Circular Plate with Multiple Holes
Authors: Zhong Xiang Yu , Ding Xin , Bao Jian Wen , Li Ye , Chen Xiang Bao
Published: March 2009

Being subjected to the bending load, the structure of plate often has the high demand of bending rigidity. Fiber reinforced composites are used in an increasing number of structural applications, this due to their higher specific strength and specific stiffness compared to homogenous structural materials. For the orthotropic carbon fiber reinforced plastics (CFRP) plate with multiple holes, the application of the classical stress-strain analysis is very difficult because of the anisotropism and the effect of the holes. Therefore, the finite element method (FEM) is used to
investigate the effect of a plate with multiple holes on the bending rigidity. The bending rigidity in the situation that stiffeners are fixed firmly to the plate is much higher than they are separated. The computation results are consistent to the experiment results. Based on the computation, a FEM model to optimize the bending rigidity of this kind of laminate circular plate with multiple holes is established. The placement of holes, the form and number of stiffeners are optimized in this paper.
The computation results show if the number of stiffeners change to 6 and are matched with holes the bending rigidity will be increased remarkably and the weight of plate is reduced simultaneously. The computation results are consistent to the experiment results. The resolution of this study provides a reference for the design of this kind of laminate circular plate with multiple holes.
Preparation and Characterization of Tin Doped Tetra-Pod Shaped Zinc Oxide
Authors: Liu Jing Jing , Zhou Zuo Wan , Wang Kai , Li Yanxia
Published: March 2009

Tin doped tetra-pod shaped ZnO (T-ZnO) were fabricated by equilibrant airflow reaction method. The microstructure of tin doped T-ZnO was characterized by X-ray Diffraction analysis and Scanning Electron Microscope. The results demonstrated that most of tin acted as a catalyst during the ZnO crystal growth process and the others reacted with ZnO to generate Zn2SnO4. Tin had catalytic influences on the morphology of T-ZnO, which promoted predominant growth on the c axis of ZnO crystal at the addition of 15% in weight and advanced the growth on the a axis at higher weight proportion.
Preparation and Characterization of Antibacterial Titanate Whiskers
Authors: Ling Yun Han , Jiang Xing Jun , Bai Xin De
Published: March 2009

Antibacterial titanate whiskers were synthesized by calcination of titanium dioxide with potassium carbonate, following by ion-exchanged and immobilized with Ag+ and Cu2+. The pretreatment conditions for whiskers synthesis were investigated; the microstructures of as-prepared whiskers were characterized by XRD and SEM. The antibacterial performance of cation-doped titanate whiskers was tested and evaluated by Escherichia Coli. and staphylococcus aureus.
Laser CVD Process for High Speed Deposition of YSZ Films
Authors: Goto Takashi
Published: March 2009

Thick oxide coatings have wide ranged applications such as oxidation protection, abrasives and thermal barrier coating (TBC). Yttria stabilized zirconia (YSZ) has been used for TBC in gas turbines. Generally, atmospheric plasma spray (APS) and electron-beam physical vapor deposition (EB-PVD) have been utilized in practical applications. Although chemical vapor deposition (CVD)
provides high quality coatings, the deposition rate of CVD could have been too small for TBCs. We have recently developed a new laser CVD process achieving an extremely high deposition rate up to 660 ım/h for YSZ coatings on Al2O3 substrates and Ni-based super alloy substrates using Zr(dpm)4 and Y(dpm)3 precursors. An Nd:YAG laser with a high power of 250 W was introduced in a CVD
chamber as a defocused beam in a diameter of 20mm covering a whole substrate surface. The YSZ coatings had a well-grown columnar structure with significant (200) orientation. Other oxides such as Y2O3, Al2O3 and TiO2 films were also prepared by laser CVD at high deposition rates around 1 mm/h.
Preparation of Rutile and Anatase TiO2 Films by MOCVD
Authors: Tu Rong , Goto Takashi
Published: March 2009

Titanium dioxide (TiO2) films were prepared on quartz substrates by using
Ti(O-i-C3H7)2(dpm)2 and O2 gas. The crystal structure, morphology and deposition rate of TiO2 films were investigated by changing deposition temperatures (Tdep) from 700 to 1100 K and total pressures (Ptot) from 0.6 to 1.0 kPa. The structure changed mainly with deposition temperature. Rutile TiO2 films with (200) orientation and anatase TiO2 films with (004) orientation both in a
single phase were obtained at Tdep = 873 K and 723 K, respectively. At Tdep > 873 K, the TiO2 films had a columnar microstructure consisting of mainly anatase and a small amount of rutile. At Tdep = 723 to 873 K, the TiO2 films were the mixture of non-oriented rutile and slightly (004) oriented anatase having dense and fine-grain microstructure. The deposition rate of TiO2 films increased with increasing Tdep showing the maximum of 30 µm h-1 at Tdep = 973 K and Ptot = 0.6
kPa.
Influence of Deposition Processing Conditions on Polycrystalline Silicon Thin Film for Solar Cells on Ceramic Substrates
Authors: Li Hai Feng , Huang Yong , Wan Zhi Jian , Zhang Hou Xing , Xu Y.
Published: March 2009

Various polycrystalline silicon thin films were deposited on Al2O3 ceramic substrates by RTCVD processing under different deposition conditions. The influence of deposition conditions on thin film quality was studied and a set of typical processing parameters were obtained, which would direct the RTCVD processing of thin film silicon solar cell technique.
Study on Thermal Conductivity of SPS-Sintered Si3N4 Ceramics after Heat-Treatment
Authors: Lu Xin , Ning Xiao Shan , Xu Wei , Zhou He Ping , Chen Ke Xin
Published: March 2009

α-Si3N4 ceramics were sintered at a low temperature of 1773K by using a
spark-plasma-sintering (SPS) method with different heating rates, and then they were further heat-treated at different temperatures from 1773K to 2273K, to study the effect of the heating rate of SPS on the microstructure and the thermal conductivity of Si3N4 ceramics after the heat-treatment. Results show that the heating rate of SPS has great influence on the phase transformation and the microstructure of the β-Si3N4, but it has little influence on the thermal conductivity of the ceramics. This proves that the thermal conductivity of the ceramics does not
have an obvious relationship with the ratio and the size of the columnar β-Si3N4 grain.
The Aging Behavior for Low Carbon Bainitic Steel Bearing Cu-Nb
Authors: Wang Xue Min , Zhou G.F. , Shang Cheng Jia , Yang Shan Wu , He Xin Lai
Published: March 2009

By the aid of optical microscope, Hardness measurement, SEM, TEM and the chemical quantitative phase analysis technique, the influence of copper, niobium, and chromium on the aging hardness has been investigated. The aging precipitation behavior and the interaction between various precipitates have also been discussed. The results indicate that since there are multi aging-hardening elements in the steel the aging hardening behaviors are complicated. During the aging the ε－copper， and carbides containing iron and chromium will precipitate. Also, new
niobium carbonitride precipitation occurs. These precipitation processes cause marked hardening effect and various hardness peaks. The ε－copper can precipitate at dislocation and lath boundaries preferentially. During the aging the bainite lath united and became wider and then gradually vanished.
Fast Uniform Mixing & Controllable Colloidal Forming of Ceramics
Authors: Ma Tian , Huang Yong , Yang Jin Long , Zhang Li Ming
Published: March 2009

A process of fast uniform mixing & controllable colloidal forming of ceramics was
invented to thoroughly avoid the crucial effect of temperature on colloidal forming of ceramics. The ceramic suspension was divided into two components A and B. The monomer was added into A, and the initiator was added into B. Under this condition, there were no reactions in separate A or B because of segregation of the monomer and the initiator. Both of the suspensions could keep good fluidity until they were mixed quickly and uniformly. The mixture would fast solidify under a determined pressure. The highly automatic equipment also had been developed for this process.
Study on Elimination of Surface-Exfoliation and Crack of ZrO2 Green Body of Gelcasting with Water-Solubility Macromolecule
Authors: Yi Zhong Zhou , Wang Shi-en , Huang Yong
Published: March 2009

Ceramic gelcasting has to be performed in nitrogen to avoid surface-exfoliation and
crack of the green body. The rapid drying of gelled bodies can cause nonuniform shrinkage. Non-uniform drying in various regions due to the solvent gradient, induces structural and residual stresses which cause defects, such as cracking, warpage and the other malformations. These malformations can be minimized or eliminated via adding a proper amount of water-soluble polymer polyethylene glycol(PEG).This study concentrates attention on dispersion, rheological property and gelation behavior in the new system, The flexural strength and microstructure of ZrO2 green bodies were measured and observed.
Surface Nanocrystallization of Low Carbon Steel Induced by Circulation Rolling Plastic Deformation
Authors: Fan Xin Min , Zhou Bosen , Zhu Lin , Wang Heng Zhi , Huang Jie Wen
Published: March 2009

In this paper, the circulation rolling plastic deformation(CRPD) surface nanocrystallization technology is proposed based on the idea that the severe plastic deformation can induce grain refinement. The equipment of CRPD is designed and manufactured. A nanocrystallization surface layer was successfully obtained in a column sample of low carbon steel. The average grain size in the top surface layer is about 18 nm, and gradually increases with the distance from the surface. The
hardness increases gradually from about 200HV0.1 in the matrix to about 600HV0.1 in the surface layer.
Tensile Properties and Creep Behavior of SiC-Based Fibers under Various Oxygen Partial Pressures
Authors: Sha Jan Ji , Park J.S. , Hinoki Tatsuya , Kohyama Akira , Yu J.
Published: March 2009

Three kinds of atmospheres (air, highly-pure Ar and ultra highly-pure Ar gas) with different oxygen partial pressures were applied to investigate the tensile properties and creep behavior of SiC fibers such as Hi-NicalonTM and TyrannoTM-SA. These fibers were annealed and crept at elevated temperatures ranging from1273-1773 K in such environments. After annealing at 1773 K, the room
temperature tensile strengths of SiC-based fibers decreased with decreasing the oxygen partial pressure and the near stoichiometric fiber TyrannoTM-SA shows excellent strength retention. At temperatures above the 1573 K, the creep resistance of SiC fibers evaluated by bending stress relaxation (BSR) method under high oxygen partial pressure was lower than that of in low oxygen partial pressure. The microstructural features on these fibers were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD).
Effect of Impurities on Vacancy Mobility in V-4Cr-4Ti
Authors: Xu Qiu , Yoshiie Toshimasa , Nagasaka Takuya , Muroga Takeo
Published: March 2009

To investigate the effect of impurites, such as O, N and C, on migration behavior of
vacancies in several types of V-4Cr-4Ti vanadium alloy with different amount of impurites from 207wppm to 866wppm were irradiated with 28 MeV electrons using an electron linear accelerator at 100 K. After irradiation, positron lifetime measurements were carried out. Single vacancies were produced in all samples. The vacancy clusters were formed at 348 K and 433 K in samples with lowest and highest impurites, respectively. The temperature forming vacancy clusters incresased with increaisng amount of impurites. The vacancy migaration is depended on the amount of impurities rather than the kind of impurity.
Development of an Innovative Carbon-Based Ceramic Material Application in High Temperature, Neutron and Hydrogen Environment
Authors: Wu C.H.
Published: March 2009

In the framework of the European Fusion Research Program, a great effort has been made to develop an innovative carbon-based ceramic material to meet all of all operational requirements. After a decade of research and development, It is succeeded to develop an advanced material: namely, a 3D CFC, contains about 8-10 at% of Silicon with porosity is about 3-5% . This advanced ceramic material possess very high thermal conductivity, dimensional stability under the neutron irradiation, lower chemical erosion (longer life time), lower tritium retention and lower reactivity with water and oxygen (safety concern) . This innovative ceramic materials seems very promising for application in the high temperature, neutron and hydrogen environment. A detailed discussion on development , properties and application of material is presented.
TiB2/Cu Electrode Material Fabricated via SPS
Authors: Jin Song Zhe , Zhang Hai Long , Jia Shu Sheng , Li Jing Feng
Published: March 2009

TiB2 and copper are difficult to be sintered together by conventional sintering process. In this article, the TiB2/Cu functionally graded materials (FGMs) were successfully fabricated via spark plasma sintering (SPS) method, in which a temperature gradient was achieved by using a specially designed mold and a two-step sintering was performed. The SEM observations show that the TiB2/Cu FGMs have dense microstructures. The XRD analysis suggests that no new phases
were introduced into the TiB2/Cu composites after mechanical milling or SPS process. The TiB2/(TiB2+Cu)/Cu FGMs are promising electrode materials of solar thermoelectric modules.
Models for Static and Metadynamic Recrystallisation of Interstitial Free Steels
Authors: Zahiri Saden H. , Kim S.I. , Byon Sang Min , Hodgson Peter , Lee Y.
Published: March 2009

We have investigated the static and metadynamic behaviour of the interstitial free steels and in particular the effects of the steeling elements (phosphorous and boron) on kinetics of recrystallisation. The results showed that the strain for the initiation of strain independent softening (often referred to as metadynamic recrystallisation) varies with the Zener-Hollomon parameter and steel composition. Strain rate had a strong influence on kinetics of metadynamic recrystallisation. An
increase in temperature from 930oC to 1100oC led to a decrease in time for 50% softening (about one order of magnitude) in the SRX region. However, for the same temperature range, the time for 50% MDRX did not change significantly.
Plasma Sputtering and Optical Properties of Au/SiO2 Nano-Composite Films
Authors: Zhang Bo Ping , Jiao Li-Shi , Masumoto Hiroshi , Goto Takashi
Published: March 2009

Au/SiO2 nano-composite thin films with 3 to 65 vol% Au content were prepared by
induction-coil-coupled plasma sputtering. Au particles dispersed in the SiO2 matrix can be prepared by controlling the deposition time of one Au layer and the thickness of the one SiO2 layer. The Au nano-particle dispersed Au/SiO2 multilayer with an uniform nano-layered microstructure showed the absorption peak at the wavelength of 560 nm. The heat-treated Au/SiO2 films containing 3 to 65 vol% Au showed absorption peaks at the wavelength of 540 to 560 nm, while no absorption peak was observed in the as-deposited multilayers containing more than 12 vol% Au.
New Progress on SHS of Silicon Nitride with High α-Phase Content
Authors: Ge Chang Chun , Wang Fei , Shen Wei Ping
Published: March 2009

Silicon nitride (Si3N4) is one of the most important advanced ceramics due to its high wear resistance, corrosion resistance, and especially high thermal shock resistance at high temperature. It has been used as cutting-tools, high-temperature bearings and turbochargers for car engines etc. But its applications are still limited by the relatively high cost of Si3N4 powders which are now mostly produced by direct nitridation at high temperature for long time with high energy consumption.
Self-propagating high-temperature synthesis (SHS) shows potential as an advanced technology for synthesizing Si3N4. One of the reasons of why SHS Si3N4 powder has not been widely used commercially is that most SHS Si3N4 powder reported in literatures are of high b-phase content and SHS Si3N4 with high a-phase content is very difficult to be made, especially for large samples. Since
1990’s C.C.GE and his group in Laboratory of Special Ceramics and Powder Metallurgy (LSCPM) has been working on the structure formation mechanism of SHS Si3N4 and the nitridation mechanism of large samples of SHS Si3N4. Recently, great effort has been put on the SHS of homogeneous high a-phase Si3N4. In the present work, the effect of nitrogen pressure and purity, the type and amount of
diluents on the a-phase content and microstructure of the product synthesized in a reactor of 10 liter capacity are investigated. Through optimization of processing parameters, SHS Si3N4 powder with high a-phase content up to 96% was synthesized.
Effect of Copper Content on the Microstructures and Properties of TiB2 Based Cermets by SHS
Authors: Xu Qiang , Zhang Xing Hong , Han Jie Cai , Pan Wei
Published: March 2009

TiB2 based cermets with different copper content were produced from titanium powder, boron powder and copper powder by Self-propagating High-temperature Synthesis under conditions of Pseudo Hot Isostatic Pressing (SHS/PHIP). In order to obtain the optimal copper content, the effect of copper content on the microstructures and properties of TiB2 based cermets was investigated. The
size of the TiB2 particles in the products decreased with increasing amounts of copper. The hardness (HRA) and bend strength increased firstly, then decreased with copper increasing. Their maximum values appeared at 20 wt.% and 40 wt.% copper, respectively. The porosity of TiB2 based cermets decreased with the copper content increasing due to good fluidity of copper. With the addition of
copper, the fracture toughness of TiB2 based cermets increased gradually. Crack-tip plastic blunting by a ductile metallic phase and crack deflection are the principal mechanisms of toughness improvement of TiB2 based cermets. The range of optimal copper content in the TiB2 based cermets is between 40 wt.% and 50 wt.%.
Effect of La2O3 on the Properties of Combustion-Synthesized Molybdenum Disilicide
Authors: Gao Jian Ying , Jiang Wan , Wang Gang
Published: March 2009

The phase constituent of MoSi2 with 2.0 wt.% La2O3 synthesized by self-propagating high-temperature synthesis (SHS) was studied. It was observed that the addition of La2O3 as a doping agent significantly influences the thermodynamics and kinetics of combustion process when compared with the combustion synthesis of molybdenum disilicide alone. The morphology of the combustion product was investigated using scanning electron microscopy (SEM). The results showed that the addition of La2O3 could obviously decrease the particle size of the
combustion product. Hardness and fracture toughness of the material were directly obtained from the sintered product by using micro-indentation technique. The fracture toughness was found to be significantly enhanced with the addition of La2O3.
Immobilization of Radioactive Wastes into Perovskite Synrock by the SHS Method
Authors: Zhang Rui Zhu , Guo Zhi Meng , Jia Cheng Chang , Lu Guangfeng
Published: March 2009

This paper researched the fabrication of perovskite synrock by self-propagating high temperature synthesis (SHS) and the characterization of the products. This synthesis process is simpler, the fabricated synrock can immobilize waste loading up to 35wt% SrO with satisfied physical properties (density>4.2g•cm-3, open porosity<0.2%, Leach rate<1.0 g•m-2•d-1). The structure analyses by XRD and SEM/EDS show that the major phase is perovskite which well agrees with the design. It proves that SHS offer a suitable Sr-waste synroc which is favorable for
geological disposal.
Synthesis Ba3(Ca1.18Nb1.82)O9-δ with Sol-Gel Auto-Ignition Process and Its Electrical Conducting Property
Authors: Su Xin Tai , Yan Qing Zhi , Ge Chang Chun
Published: March 2009

Ba3(Ca1.18Nb1.82)O9-δ (BCN18) is a novel complex perovskite structure proton conductor. Nanocrystalline BCN18 was synthesized by means of sol-gel method. The solid oxide electrolyte was prepared by using this powder, and its sintering behavior was studied. SEM and XRD were performed to demonstrate its sintering properties. Its electrical conductivity was systematically investigated at
intermediate temperature (400～600°C).
Thermal and Solute Transportation Effects during Bridgman Crystal Growth of II-VI Compounds
Authors: Jie Wan Qi
Published: March 2009

The bulk crystal growth of II-VI compounds, such as HgCdTe, CdZnTe etc., is usually carried out by Bridgman and modified Bridgman methods. Optimizing the growth process relies mainly on the understanding of the fundamental problems of solute and thermal transportation principles, which determines the composition segregations and other defects, including point defects, dislocations, precipitates, stacking faults, etc. In the last few years, the present author studied the coupling effects of the convection, thermal and solute transportation phenomena during the growth processes through both theoretical modeling and experimental methods. Several important phenomena, such as effects of ACRT forced convection on the thermal and solute field and the growth interface morphology, the shift of the growth interface due to the solute redistributions, solute segregation behaviors during the growth process, etc, are discussed. Based on these researches, technologies for growing high quality CdZnTe and other II-VI compounds have been developed.
Silica and Alumina Thin Films Grown by Liquid Phase Deposition
Authors: Sun Jie , Hu Lizhong , Wang Zhaoyang , Du Guotong
Published: March 2009

This work demonstrates the condition optimization during liquid phase deposition (LPD) of SiO2/GaAs films. LPD method is further applied to form Al2O3 films on semiconductors with poison-free materials. Proceeding at room temperature with inexpensive equipment, LPD of silica and alumina films is potentially serviceable in microelectronics and related spheres.
Characteristic of Nanoporous SiO2 Thin Film Prepared by Sol-Gel Method with Catalyst HF
Authors: He Z.W. , Liu Xing Qin , Xu D.Y. , Su Qiang , Guo D.F. , Wang Y.Y.
Published: March 2009

The characteristic of nanoporous SiO2 thin film prepared by sol-gel method with
catalyst HF was studied by scanning electron microscopy, Fourier transform infrared, HP analyzer series and ellipsometry. Results showed the incorporation of HF effectively adjusted the pore size and distribution, and lowered the leakage current density and dielectric constant. This might be related to the weak acidity of HF, which properly controlled the velocity of chemical reaction in solution, and to the introduction of strong Si-F bonds, which had the lower electronegative and the larger volume.
Fabrication and Properties of Lead-Free Sn-Ag-Cu-Ga Solder Alloy
Authors: Chen Guohai , Ma Ju Sheng , Geng Zhi Ting
Published: March 2009

Sn-Pb solder alloys, widely used in electronic industry, will be restricted because of the toxicity of Pb. That is paramount importance that developing viable alternative lead-free solders for electronic assemblies. Sn-Ag-Cu alloys are better alternative because of its good performance. But they have a melting temperature of 217-225°C that is much higher than that of Sn-Pb eutectic alloy, 183°C. It may be very difficulty to realize industrialization. Sn-Ag-Cu-Ga solder alloys have been studied in this paper, including a series of properties tests, such as melting point, hardness, shear
strength and solderability. The best composition of Sn-Ag-Cu-Ga lead-free solder alloy has been obtained.
A Study of the Degradation Mechanism for Carbon Nanotubes in Field Emitter Applications
Authors: Kim D.H. , Kim T.S. , Ahn B.K. , Shin H.Y. , Lee Dong-Gu , Cho H.K. , Cho Young Rae
Published: March 2009

Carbon nanotubes have attracted considerable attention because their high aspect ratio leads to a large electric field enhancement and a low operating voltage. The dependence of environmental gases such as Ar, O2 on the emission current from carbon nanotube emitters was examined in this study. Based on our experiments, the current density is decreased in single-wall carbon nanotubes (SWNTs), but is increased in multi-wall carbon nanotubes (MWNTs) as the vacuum level decreases from 10-7 Torr to 10-4 Torr by the inflow purging gases. The current density subsequently recovered as the vacuum level increased to 10-7 Torr when gas inflow stopped. From those results, we conclude that the MWNTs have completely different degradation characteristics in comparison to SWNTs. The increased current density of an MWNT in the high-pressure range of 10-4 Torr is a significant finding and would be widely applicable to low cost vacuum packages.
Interface-Related In-Plane Optical Anisotropy of Quantum Wells Studied by Reflectance-Difference Spectroscopy
Authors: Chen Y.H. , Ye X.L. , Xu Bo , Zeng Yi Ping , Wang Z.G.
Published: March 2009

The in-plane optical anisotropy of three groups of GaAs/AlGaAs quantum well structures has been studied by reflectance-difference spectroscopy (RDS). For GaAs/Al0.36Ga0.64As single QW structures, it is found that the optical anisotropy increases quickly as the well width is decreased. For an Al0.02Ga0.98As/AlAs multiple QW with a well width of 20nm, the optical anisotropy is observed not only for the transitions between ground states but also for those between the excited
states with transition index n up to 5. An increase of the anisotropy with the transition energy, or equivalently the transition index n, is clearly observed. The detailed analysis shows that the observed anisotropy arises from the interface asymmetry of QWs, which is introduced by atomic segregation or anisotropic interface roughness formed during the growth of the structures. More, when the 1 ML InAs is inserted at one interface of GaAs/AlGaAs QW, the optical anisotropy of the QW can be increased by a factor of 8 due to the enhanced asymmetry of the QW. These results demonstrate clearly that the RDS is a sensitive and powerful tool for the characterization of semiconductor interfaces.
Effect of Austempering Process on the Properties of TRIP-Steel
Authors: Wang Li , Hsu T.Y.
Published: March 2009

Transformation-induced-plasticity (TRIP) –aided steels are a promising solution for producing lighter, crash-resistant car bodies, due to their high-strength and large uniform elongation. The influences of the austempering temperature and time on the microstructure mechanical properties and the transformation behavior of a Si-Mn TRIP steel are investigated in this paper.
High-Efficient Non-Doped Type White Organic Light-Emitting Devices Using an Electron/Exciton Blocker
Authors: Xie Wenfa , Liu Shi Yong
Published: March 2009

Non-doped type white organic electroluminescent (EL) devices have the following
structure ITO/m-MTDATA (30nm) /NPB (20-dnm) /rubrene (0.1nm) /NPB (dnm) /DPVBi (20nm) /TPBi (20nm) /Alq (10nm) /LiF/Al were fabricated. The EL spectrum of the devices are dependent on the d and when d=3, the CIE coordinates of the device were well within the white region for voltage raging from 3V to 15V. This device has a luminance of 18950cd/m2 at 15V and maximum power efficiency of 5.65cd/A at 6V.
UV-Irradiation-Induced Refractive Index Increase of Ge-Doped Silica Films
Authors: Zhang Letian , Xie Wenfa , Hou Yong , Li Aiwu , Zheng Jie , Zheng Wei , Zhang Yushu
Published: March 2009

Ge-doped silica glass films were fabricated on Si (100) substrates for core materials of waveguide using flame hydrolysis deposition. Then the films were hydrogen loaded and irradiated to KrF excimer laser. The refractive indices and extinction coefficients of the samples before and after irradiation were determined using M-2000 variable angle incidence spectroscopic ellipsometer (VASE) and obtain the maximum increase about 0.3% at 1550 nm.
Investigation of the Optical Properties of CdZnTe by IR Transmission and PL Spectra
Authors: Li Guo Qiang , Jie Wan Qi
Published: March 2009

The optical properties of CdZnTe crystals grown by vertical Bridgman method were
investigated in detail by infrared (IR) transmission spectra and photoluminescence (PL) spectra. IR transmission measurements showed that according to the trends of the IR transmission with the wavenumbers, IR transmission spectra could be classified into four types, i.e. descending, ascending,
low straight and high straight. Each of them indicated one type of CdZnTe crystals with specified properties. PL measurements revealed that the low-temperature PL spectra consisted of three emissions: the near-band-edge emission (I0) situated at 1.66eV related to the free and bound excitons, the donor-acceptor emission (I1) centered at 1.62eV related to the impurities, and a defect band emission (I2) centered at 1.50eV due to the dislocations. The full width at half maximum (FWHM) of I0 and the PL intensity ratios of I1/I0 and I2/I0 could be used to evaluate the properties of the crystals.
Application of TLP (Transient Liquid Phase) Bonding Method to the High Tm Lead-Free Solder
Authors: Lee Jung Suk , Bang Woong Ho , Jung J.P. , Oh Kyu Hwan
Published: March 2009

TLP method was applied to the lead free soldering process; Sn-3.5Ag core solder (Tm of 221°C) / Sn-Bi coating layer (Tm of 139°C at eutectic) was reflowed on UBM pad. Sn-Bi was formed by electroplating method at current range of 2~6A/dm2, which had varied the coating layer composition from 96wt% to 28wt% Bi. Specimens were reflowed on copper pad at temperature range of 200 and 220°C, and then interface reaction was examined. It was claimed that high Bi adding in the plated layer improved the wetting performance on Cu. Even at the reflow temperature of 200°C, SEM observation revealed well-defined interface junctions between solder and copper pad, i.e. nucleation and growth of CuxSn intermetallic compound. After heating for 5min at 220°C, Bi was resolved into Sn-3.5Ag core solder and completely homogenized, which is favorable from the viewpoint of long term fatigue reliability.
Effects of Bias Springs on Actuation and Transformation Behaviors of TiNi Wires
Authors: Huai Limin , Cui Li Shan , Zhang Lai Bin , Zheng Yan Jun
Published: March 2009

The effects of bias springs with different coefficient on the actuation and transformation behaviors of TiNi wires were studied. Results showed that the maximum output stress increases with increasing spring coefficient. The reverse martensitic transformation starting temperature of the TiNi wires does not change with spring coefficient, but the reverse transformation finishing temperature increases with increasing spring coefficient.
Self-Tension of Martensite during Constrained Transformation
Authors: Cui Li Shan , Zheng Yan Jun
Published: March 2009

In a constrained martensitic transformation of shape memory alloys, a fraction of
martensite is always retained in the materials. Experimental results showed that the remaining martensite could be plastically deformed by the generated recovery stresses. The self-tension process elevated the reverse transformation temperatures of the remaining martensite, and the external constraint conditions had no significant effect on the self-tension process of the remaining martensite.
Effect of Ti on Formability of IF Steels
Authors: Kim Su Young , Choi Il Dong , Park Ik Min , Cho Kyung Mok
Published: March 2009

The influence of the texture development in Ti-added (0.03, 0.05 and 0.07wt%) IF
(Interstitial Free) steels on physical properties, especially ř -value was investigated. It was intended to determine the proper Ti content for the promotion of deep drawability as well as mechanical properties of IF steels. The precipitation behavior in the IF steels was clarified with the aid of computer simulation. The quantitative X-ray analysis on the texture development of IF steels was performed using pole figure and orientation distribution function measurement. For the IF steel with the composition of 0.025C, 0.070Mn, 0.002N and 0.007S, the optimum Ti content was found to be 0.05wt%.
The Dynamic Impact Behavior of Ti50Ni47Fe3 Shape Memory Alloys
Authors: Liu Fu Shun , Qian Yanping , Xu Hui Bin
Published: March 2009

Static and dynamic mechanical behavior of Ti50Ni47Fe3 shape memory alloy was
investigated by mechanical tensile test and instrumention impact test under a wide temperature range from -196°C to 20°C. The instrumention impact test was carried out under different temperatures at which the alloys are with martensite, austenite and R phase, respectively. It is found that the alloy with austenite performed the best ductility, the samples with martensite and R phase exhibit superior and inferior ductility, respectively.
Anisotropy in Elastic Properties of Textured TiNbAl Shape Memory Alloy
Authors: Inamura Tomonari , Hosoda Hideki , Wakashima Kenji , Miyazaki Shuichi
Published: March 2009

Anisotropy in elastic properties of Ti-24mol%Nb-3mol%Al (TiNbAl), a new biomedical shape memory alloy developed by our group, was characterized in a temperature range from 133K to 413K. A well developed <110>{112}-type recrystallization texture is formed by an annealing at 1273K for 1.8ks after a severe cold-rolling. Young’s modulus of the -phase exhibited a strong anisotropy depending on the loading direction. Young’s modulus along  of -phase of TiNbAl around room temperature was estimated to be , with assuming that the texture is perfectly developed.