bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study of Inhomogeneous Schottky Diodes on n-Type 4H-SiC
Authors: Ewing D.J. , Wahab Qamar-ul , Tumakha Sergey P. , Brillson Leonard J. , Ma X.Y. , Sudarshan Tangali S. , Porter L.M.
Published: March 2009

In this study, we performed a statistical analysis of 500 Ni Schottky diodes
distributed across a 2-inch, n-type 4H-SiC wafer with an epilayer grown by chemical
vapor deposition. A majority of the diodes displayed ideal thermionic emission when
under forward bias, whereas some diodes showed ‘double-barrier’ characteristics with
a ‘knee’ in the low-voltage log I vs. V plot. X-ray topography (XRT) and polarized
light microscopy (PLM) revealed no correlations between screw dislocations and
micropipes and the presence of double-barrier diodes. Depth resolved
cathodoluminescence (DRCLS) indicated that certain deep-level states are associated
with the observed electrical variations.
High Temperature Operation of Silicon Carbide Schottky Diodes with Recoverable Avalanche Breakdown
Authors: Vassilevski Konstantin , Nikitina Irina P. , Bhatnagar Praneet , Horsfall Alton B. , Wright Nicolas G. , O'Neill Anthony G. , Uren Michael J. , Hilton Keith P. , Munday A.G. , Hydes A.J. , Johnson C. Mark
Published: March 2009

4H-SiC diodes with nickel silicide (Ni2Si) and molybdenum (Mo) Schottky contacts have
been fabricated and characterised at temperature up to 400°C. Room temperature boron
implantation has been used to form a single zone junction termination extension. Both Ni2Si and
Mo diodes revealed unchanging ideality factors and barrier heights (1.45 and 1.3 eV, respectively)
at temperatures up to 400°C. Soft recoverable breakdowns were observed both in Ni2Si and Mo
Schottky diodes at voltages above 1450 V and 3400 V depending on the epitaxial structure used.
These values are about 76% and 94% of the ideal avalanche breakdown voltages. The Ni2Si diodes
revealed positive temperature coefficients of breakdown voltage at temperature up to 240°C.
Nitrogen and Hydrogen Induced Trap Passivation at the SiO2/4H-SiC Interface
Authors: Dhar S. , Wang S.R. , Ahyi Ayayi Claude , Isaacs-Smith Tamara , Pantelides Sokrates T. , Williams John R. , Feldman Leonard C.
Published: March 2009

Post-oxidation anneals that introduce nitrogen at the SiO2/4H-SiC interface have been
most effective in reducing the large interface trap density near the 4H-SiC conduction band-edge
for (0001) Si face 4H-SiC. Herein, we report the effect of nitridation on interfaces created on the
(11 20) a-face and the (0001) C-face of 4H-SiC. Significant reductions in trap density (from >1013
cm-2 eV-1 to ~ 1012 cm-2 eV-1 at EC-E ~0.1 eV) were observed for these different interfaces,
indicating the presence of substantial nitrogen susceptible defects for all crystal faces. Annealing
nitridated interfaces in hydrogen results in a further reduction of trap density (from ~1012 cm-2 eV-1
to ~5 x 1011 cm-2 eV-1 at EC-E ~0.1 eV). Using sequential anneals in NO and H2, maximum field
effect mobilities of ~55 cm-2 V-1s-1 and ~100 cm-2 V-1s-1 have been obtained for lateral MOSFETs
fabricated on the (0001) and (11 20) faces, respectively. These electronic measurements have been
correlated to the interface chemical composition.
Interfacial Properties of SiO2 Grown on 4H-SiC: Comparison between N2O and Wet O2 Oxidation Ambient
Authors: Poggi Antonella , Moscatelli Francesco , Scorzoni Andrea , Marino Giovanni , Nipoti Roberta , Sanmartin Michele
Published: March 2009

Many investigations have been conducted on the growth conditions of SiO2 on SiC to
improve the oxide quality and the properties of the silicon carbide-silicon dioxide interface. In this
work a comparison between a wet oxidation and an oxidation in N2O ambient diluted in N2 is
proposed. The interface state density Dit near the conduction-band edge of SiC has been evaluated
by conventional C-V measurements obtaining results similar or better than the literature data.
Furthermore, the slow trapping phenomena have been studied and preliminary results are reported.
Low-Temperature Post-Oxidation Annealing Using Atomic Hydrogen Radicals Generated by High-Temperature Catalyzer for Improvement in Reliability of Thermal Oxides on 4H-SiC
Authors: Senzaki Junji , Shimozato Atsushi , Fukuda Kenji
Published: March 2009

Low-temperature post-oxidation annealing (POA) process of high-reliability thermal
oxides grown on 4H-SiC using new apparatus that generates atomic hydrogen radicals by
high-temperature catalyzer has been investigated. Atomic hydrogen radicals were generated by
thermal decomposition of H2 gas at the catalyzer surface heated at high temperature of 1800°C, and
then exposed to the sample at 500°C in reactor pressure of 20 Pa. The mode and maximum values of
field-to-breakdown are 11.0 and 11.2 MV/cm, respectively, for the atomic hydrogen radical exposed
sample. In addition, the charge-to-breakdown at 63% cumulative failure of the thermal oxides for
atomic hydrogen radical exposed sample was 0.51 C/cm2, which was higher than that annealed at
800°C in hydrogen atmosphere (0.39 C/cm2). Consequently, the atomic hydrogen radical exposure at
500°C has remarkably improved the reliability of thermal oxides on 4H-SiC wafer, and is the same
effect with high-temperature hydrogen POA at 800°C.
Evaluation of Mechanical Properties and Microstructure of a High Carbon-Vanadium Tool Steel Produced by Powder Metallurgy
Authors: Soares E.P. , Vatavuk Jan , Panelli Renato , Pillis M.F.
Published: March 2009

Tool steels have important participation in the worldwide market of steels. They are used by
metal-mechanical industry as cutting tools, molds, punches, etc. Because the use is of great
responsibility, it is important to discuss the relationship between microstructure and
mechanical properties. The starting material was powder of a commercial tool steel with the
composition (wt%) 2.5%C, 5.25%Cr, 0.9%Si, 9.75%V, 0.5Mn, 1.3%Mo and balance Fe. The
samples were obtained by hot isostatic pressing (hip) process, and than were austenitizing at
1120°C and submitted to tempering in the temperature range varying from 430° to 550°C.
The aim of this work was to evaluate the correlation between heat treatment, microstructure
and mechanical properties. Results of toughness and hardness are presented.
Effect of Grain Size,Lattice Defects and Crystalline Orientation on the Coercivity of Sintered Magnets
Authors: de Campos Marcos Flavio
Published: March 2009

The coercivity of sintered magnets like barium ferrite (BaFe12O19), samarium-cobalt (SmCo5) or neodymium-iron-boron (Nd2Fe14B) is largely affected by the grain size. A method to evaluate coercivity behavior as function of the crystalline orientation, including also the effects of grain size and lattice defects, is presented. Expressions were deduced to estimate the critical size of nucleus for spontaneous reversion of magnetization. The model indicates that the nucleation in grains of materials with high magnetocrystalline anisotropy only can begin by domain rotation. The model also predicts that the surface condition of grains is very important for the coercivity. A qualitative explanation is offered for the fact that materials with higher coercivity (or with smaller grain size) tend to follow an angular dependence of the coercivity similar to that given by the Stoner-Wohlfarth model, while materials with lower coercivity (or with larger grain size) tend to follow an angular dependence of the coercivity similar to 1 / cos theta.
Grain Size of Commercial High Speed Steel
Authors: Nogueira Rejane A. , Filho Oscar O. Araújo , Souza Leonardo F.M. , Liberati João Franklin , Salgado Lucio , Ambrozio Filho Francisco
Published: March 2009

The heat treatment of high speed steel tools consists of austenitizing, quenching
and tempering. The size of austenite grains formed during the hardening treatment is an
important factor in the final microstructure of the steel, and it also affects properties such as
wear resistance and toughness. This paper presents the austenite grain size, matrix
composition and hardness of commercial AISI M2, AISI T15, VWM3C and Sinter 23 high
speed steels that were austenitized and quenched from five distinct temperatures. This study
shows that increase in quenching temperature results in grain growth of steels such as AISI
M2 and VWM3C, obtained by the conventional method (cast to ingot and worked). The P/M
Sinter 23 high speed steel showed a slight grain growth (about 10%). This effect was not
observed in AISI T15 obtained by the powder metallurgy process.
Plasma Assisted Debinding and Sintering (PADS) – Metal Injection Molding Application
Authors: Machado Ricardo , Ristow Waldyr , Alba P.R. , Klein Aloísio Nelmo , Wendhausen Paulo A.P. , Fusão D.
Published: March 2009

this paper describes the PADS process and equipment, which has been developed to
produce PIM components. The use of a hybrid system of plasma discharge and Mo heating
elements makes debinding and sintering PIM components in the same heating cycle possible.
The use of an abnormal discharge between a cathode and anode under low-pressure provides
reactive specimens that break the polymeric chains of the binder of the molded parts. By the
combination of these features it was possible to use heating rates of 2,0º C/min during the
debinding step. The hydrocarbons, resulted from debinding, are pumped out through vacuum
pumps, without traps. The clean environment makes possible to sinter the parts in the same
cycle, as well as execute a surface treatment during cooling. The results present short process
times as 6 hours to Fe2Ni0,6C low alloy steel and 7 hours to 316-L stainless steel.
Characteristics as density, carbon content and mechanical properties are similar to traditional
PIM process. The reduction of energy and gas consumption and shorter lead-times are economic
advantages of PADS system. The clean environment of PADS is also an ecological advantage.
Study of the Recycling Grey Cast Iron Swarf by Powder Metallurgy: An Alternative for the Development of New Materials
Authors: Parucker M.L. , Costa César Edil da
Published: March 2009

This work is concerned with issues related to using grey cast iron swarf from dry
machining in powder metallurgy. In a first stage, a complete study on the characteristics of the
raw powder is performed, in which aspects related to the dilution in different proportion of
pure iron were studied. Low compacting pressure produces workpieces more resistant and that
the ideal sintering temperature is 1160 °C. In a second stage, aiming at reduction of the
powder, a heat treatment is performed. New dilutions using the decarburized powder were
made and results showed better structural homogeneity and an improvement in the
mechanical properties. The steel alloy 50/50% of swarf powder provided the best results. In a
third stage, a cylindrical bearing was produced. New dilutions were made. Based on the
control of the interconnected porosity, radial and wear resistance, the sample prepared with
100% swarf powder provided the best results.
Thermal Properties Measurement Photoacoustic Technique for Hardmetals
Authors: Machado F.A.L. , Faria Jr. Roberto da Trindade , Filgueira Marcello , Rodrigues M.F. , Bobrovinitchii Guerold Sergueevitch , Vargas H.
Published: March 2009

The open photoacoustic cell technique (OPC) was carried out in order to measure
the thermal diffusivity of hardmetal. Hardmetal is usually processed by the conventional
powder technology techniques: mix of WC + Co powders, compacting, and liquid phase
sintering A new method to process hardmetal parts is hereby described. Parts of WC-15%wt
Co were processed by using high pressure – high temperature sintering. It was used the
pressure of 5GPa, temperature of 1350 oC, and time of 2 minutes of sintering. In addition to
the thermal diffusivity, heat capacity was considered and the thermal conductivity achieved.
Results matched with the values of the literatures where others photoacoustic techniques have
been employed. It was achieved a thermal capacity of 3.34J/cm3K, thermal diffusivity of
0.35cm2/s, and thermal conductivity of 116.9W/mK. It reveals that the HPHT processed WC-
15%wtCo hardmetal is able to work as a cutting tool, in the thermal point of view.
Development of ZrO2-TiO2 Porous Ceramic as Soil Humidity Sensor for Application in Environmental Monitoring
Authors: Oliveira Rodrigo de Matos , Nono Maria do Carmo de Andrade , Kuranaga Carlos , Wada M.
Published: March 2009

Due to the necessity of the automation and control of processes in agriculture, as
well as to the crescent interest for the environmental monitoring, efforts have been demanded
in the development of more versatile, reliable sensors and sensor systems with smaller cost
[1-2]. In this sense, the search of new materials, the modeling study of sensor and the
development of new measurement techniques and processing of signs have been orientating
the progress in this area [3-4]. In this work, the results of the characterization analyses of
sensor elements of ZrO2-TiO2 porous ceramic for application as soil humidity sensor, are
shown and discussed. These ceramics were obtained from the mechanical mixture of ZrO2-
TiO2 powders and sintered at 1000, 1100 and 1200 oC, for obtaining different porosities. The
characterization of the ceramic was carried out using measurements of B.E.T.; nitrogen and
mercury porosimetry; scanning electronic microscopy and X-ray diffraction. The porous
ceramic characterization as soil humidity sensor element was accomplished through
capacitance and impedance measurements using a RLC bridge. The ceramic sensor elements
were immersed in the selected and previously characterized soils, the humidities of which
were defined in accordance with Atterberg limits, more exactly liquid limit. The results
obtained for specific surface area, distribution curves of pore size, microstructure, crystalline
phases and sensibility to the soil humidity showed that the ZrO2-TiO2 porous ceramic sintered
at 1100 oC presents a great potential to be applied as sensor element for soil humidity
monitoring.
X-Ray Diffraction Study of Particulate Tannery Waste Solidified in Cement
Authors: Pinto Carolina A. , Valenzuela-Díaz Francisco Rolando , Sansalone John J. , Dweck Jo , Cartledge Frank K. , Büchler Pedro M.
Published: March 2009

The leather industry creates a large quantity of organic and inorganic waste containing chromium. This research examines stabilization of particulate tannery waste in type II Portland cement. Several clays, Brazilian polycationic smectite modified in laboratory and commercial clays were used as additives with the aim of optimizing chromium adsorption. Tannery waste was added in quantities of 10, 15 and 20% relative to cement mass. The solidification components were analyzed separately and in combination in the solidified mixes using X ray diffraction. The analysis showed that reactions between the waste and the cement occurred, and that the tannery waste modified the final compounds of the system. Calcium sulfate present in the waste increased ettringite formation. Chromium also reacted with cement, since compounds with chromium and calcium were identified. Substitution of aluminum and silicon by chromium was also observed.
Effect of Quartz of Fine Particle Size on Porcelain Properties
Authors: Bragança S.R. , Bergmann C.P.
Published: March 2009

The mechanical properties of porcelain are strongly influenced by the generated thermal stress during processing. When quartz particle size is reduced its influence on the technical properties of ceramic products such as tiles and porcelains are changed. In this work, the properties of triaxial ceramics materials were evaluated using quartz of different particle size distribution. It was reported strong variations in mechanical strength and thermal shock strength. Although the cost of milling is increased to reduce quartz particle size, it can be compensated by its implicit advantages. The experimental results were very interesting showing the way that quartz particle size influences the analyzed properties. A significant improving in porcelain strength and thermal strength was obtained.
Separation of Effects due to Superimposition Using the Rietveld Method in Spectra Obtained by WDXRF
Authors: Salvador V.L.R. , de Lima Nelson Batista
Published: March 2009

This paper presents a new method to separate interfering spectra obtained in
wavelength dispersive x-ray fluorescence spectrometry (WDXRF). This method permits
improved results to be obtained, compared to conventional analytical results and enables the
determination of chemical species of the same element without chemical separation. This is
done by separation of the spectra due to electronic transitions of the valence electrons. The
Rietveld method [11] overcomes the problem of superimposed peaks of the species present in
the specimen and simultaneously enables determination of the species and does not require
standard specimens and calibration curves. This signifies a marked improvement in
comparison to other techniques. Specimen surface preparation to obtain spectra is a critical
stage and its effects can be minimized by using Rietveld refinement, which permits the
determination of intensity relationships of superimposed peaks with the aid of mathematical
models. This establishes the basic conditions to obtain more accurate results in quantitative
analysis. In the determination of chemical species, it is possible to separate, for example, Cr
(III) and Cr (IV), with almost 100% superimposition.
A Manufacturing Supply Chain Business Model and Its Implementation in a Plastics Manufacturing Company
Authors: Chu Ka Fu , Cheung Chi Fai
Published: March 2009

Effective inventory management strategies and their efficient implementation are recognized as important elements in a manufacturer’s business model. The targets are reduction of the level and value of inventory maintained, high speed in transforming them to orders delivered to customers and flexibility in dealing with demand changes. This paper proposes a business model for inventory management in a Hong Kong plastic products manufacturing company with production facilities located in the mainland. It shows how E-business technology applications have opened up the horizon for realization of such a business model. A supply chain strategy based on mutual trust and inventory information visibility is essential in the implementation of such a business model. The model has been found to be valid and feasible. The benefits attainable to parties in the supply chain are evaluated. It is proposed that the model can also be applied successfully for similar benefits in other companies.
Application of Ant Colony Algorithm and Grey Relation Theory in Selecting Cooperative Manufacturing Partner
Authors: Fang Ya Dong , He Wei Ping , Du Lai Hong , Chen Jin Liang , Zhao Feng , Zhang Guang Feng
Published: March 2009

According to requirement of cooperative manufacturing partner selection based on
networked manufacturing environment, the paper resolves cooperative manufacturing partner
selection problem by ant colony algorithm and grey relation theory: Firstly, manufacturing task is
divided into series of working procedure in time order by technologic planning. Secondly,
considerable candidate enterprises are selected in terms of multi-hierarchy grey relation coefficient at
each working procedure node to reduce the size of problem. Lastly, cooperative enterprise selecting
path is decided by making use of ant colony algorithm in light of transportation cost.
MMAP: An Intelligent Object Paradigm for the Monitoring and Control of Mobile-Enterprise
Authors: Jiang Xiao Nuo , Yung Kai Leung
Published: March 2009

The advances of wireless networking technologies and mobile devices has prompted many
modern enterprises to look for management information systems to remotely monitor and control of
their company operations in order to increase their flexibility and competitiveness in the market.
Multi-agent modeling has emerged as a powerful technology for dealing with cooperation and
decision-making processes in distributed information system applications. In this paper, we proposed
a Mobile-enterprise Multi-Agent Paradigm (MMAP) which is an intelligent multiagent-based system
combined with wireless VPN technology to provide various management operations to senior
executives by PDA (Personal Digital Assistant) with wireless data networks. To demonstrate how the
architecture can be built, the data collection agent, one of the primary component-ts of the proposed
paradigm, is developed into a prototype implementation for part of the MMAP.
Research on Material Removal Mechanism of Magnetorheological Finishing
Authors: Kang Gui Wen , Zhang Fei Hu
Published: March 2009

Magnetorheological finishing (MRF) is a novel precision optical machining technology.
MRF utilizes magnetic particles, nonmagnetic polishing abrasives in carrier fluid, and a magnetic
field to finish optical materials. Owing to its flexible finishing process, MRF eliminates subsurface
damage, corrects surface figure errors and the finishing process can be easily controlled by computer.
To achieve deterministic finishing, it’s necessary to know the mechanism of material removal.
Different magnetorheological fluids are used to finish optical glass on the same machining condition.
The material removal and surface quality are examined after finishing with no polishing abrasive,
aluminium oxide and cerium oxide. The results show that the hardness of polishing abrasive is not the
main factors to affect material removal.
Wear Characteristics of ID Saw Blade in Silicon Ingot Slicing Process
Authors: Wei Xin , Yuan Hui , Huang Rui Wei , Lai Shao Hui
Published: March 2009

In this paper, the wear behavior of the ID (inner diameter) saw blade in the cutting process of silicon ingot was observed with SEM. Its wear mechanism was discussed and the relation between the blade wear and vibration, deflection was analyzed. The results show that the blade worn manners include flatted diamond, micro-fractured diamond, macro-fractured diamond, pulled-out hole, tortoise-fractured bond, and polished bond. In the abnormal working stage of a blade, however, the working surface of the blade is displayed mainly with pulled out diamond, flatted diamond, macro-fractured diamond grains. Abnormal initial tension condition will induce severe vibration and deflection, and so then lots of diamond grits fractured or pulled out too early.
Study on the Multi-Phase and Multi-Scale Nanocomposite Ceramic Tool Material
Authors: Liu Han Lian , Huang Chuan Zhen , Wang Jun , Teng Xin Ying
Published: March 2009

An advanced ceramic cutting tool material Al2O3/TiC/TiN is developed by means of adding micro-scale TiC particle and nano-scale TiN particle dispersion. With an optimal dispersing and fabricating technology, this multi-scale and multi-phase nanocomposite may get both higher flexural strength and fracture toughness, especially the fracture toughness may reach to 7.8 MPa·m1/2. The micro-scale TiC particle will form the framework microstructure with other particle and the particles will inlay each other. That is why the flexural strength of Al2O3/TiC composite is improved. Another phase such as nano-scale TiN may lead to fining the grains further more, and promote the sintering to get higher density. The uniform and densified microstructure is obtained, the coexisting transgranular and intergranular fracture mode induced by micro-scale TiC and nano-scale TiN can result in remarkable strengthening and toughening effect.
Study on Finishing Cut with Dry WEDM
Authors: Wang Tong , Zhang Xin Fu , Zhao Xue Fang
Published: March 2009

Utilizing gas as the dielectric instead of dielectric liquid has enabled the development of
dry wire electrical discharge machining (WEDM) technology for finishing cut. This paper studies
on the surface quality of tool steel with WEDM method, which is conducted in gas to improve the
accuracy of finishing cut, and compares the surface quality in atmosphere and in water. Experiment
results showed that Low-Speed WEDM in atmosphere offers advantages such as better straightness,
lower surface roughness and shorter gap length, but WEDM in atmosphere has poorer material
removal rate than conventional WEDM in water. It was also found the removal rate in atmosphere
can be improved by increasing the wire winding speed.
Experimental Study of Micro-Flowing Characteristics of Liquid Transport in Round Micro-Channels
Authors: Ling Zhi Yong , Yang Ji Chang , Ding Jian Ning , Liu Yong , Zhuang Zhi Wen , Fan Zhen , Yang Ping
Published: March 2009

Micro-flowing technique gained popular applications in microdevices of microelectromechanical
systems (MEMS), and the performance of micro-devices is greatly determined by the
properties of micro-flow. This paper studied the characteristics of different viscosity fluid flowing
over microchannels with different diameters and lengths under low pressure driving, and the
influence of scale effects on the flowing characteristics of low viscosity fluids was also examined.
The experiments studied the flow rate–pressure characteristics of distilled water flowing over
microchannels with diameter of 13 μm, 20 μm, and silicon oil flowing over microchannels with
diameters of 50 μm, 100 μm. The results indicate that, when the diameter of micro-channel is more
than 20 μm, the flowing characteristics of distilled water and silicon oil agrees well with conventional
flow theory, and when the diameter of microchannels is 13μm, the flowing characteristics are related
to the length of micro-channel. When the length is relatively shorter, the flowing characteristics are
almost in agreement with the conventional flow theory. When the length reaches 100 mm, the flow
rate is much higher than the values predicted by theoretical calculation when the length reaches 100
mm. It is obvious that scale effect arises when the length arrives to 100 mm and the velocity slippage
results in the great increase of flow rate.
Research on the Cutting Track of Cutter and Fuzzy Comprehensive Evaluation for High Speed Ball-End Milling
Authors: Jiang Bin , Zheng Min Li , Gu Li Qiang , Yang Shu Cai
Published: March 2009

According to the principle producing the cutting track of cutter, to study the influence of
the cutting track of cutter on the process of high speed ball-end milling, the single-factor models for
evaluating the cutting track of cutter are established. Adopting four kinds of the typical cutting track
of cutter, the experiment of high speed ball-end milling is processed. The model of multi-ply fuzzy
comprehensive evaluation for the cutting track of cutter is established, fuzzy comprehensive
evaluation for the cutting track of high speed ball-end milling cutter is accomplished by the
application of fuzzy mathematics theory. Results show that the cutting contact curve of cutter
affects directly the process of high speed ball-end milling, fuzzy and uncertain properties exist in
the evaluation for the cutting track of cutter. The optimum cutting track can be selected by multi-ply
fuzzy comprehensive evaluation for the cutting track of high speed ball-end milling cutter.
Research on the Boring Chatter Suppression Based on MR Fluid
Authors: Kong Tian Rong , Yao Zhe He , Chen Zi Chen
Published: March 2009

Chatter during boring process is one of the main adverse factors influenced on the
machining accuracy of precision hole, surface quality and working efficiency. In order to suppress
chatter, an innovative controlling means of MR-intelligent-boring-bar with self-chatter-suppression is
proposed, which is composed of MR fluid, shell structure, excitation coil and boring bar. The MR
fluid’s mechanical characteristic can be adjusted by changing the intensity of magnetic field, thus the
system stiffness and damping will be modified, and then the boring chatter can be suppressed.
Otherwise, the dynamic model of MR-intelligent-boring-bar with self-chatter-suppression is built.
Lastly, the experimental system of MR-intelligent-boring-bar is established, and the experiments of
chatter suppression during boring process are performed. The results of experiments show that the
new means of chatter suppression is effective.
Performance of Brazed Diamond Wheel in Grinding Cemented Carbide
Authors: Li Shu Sheng , Xu Jiu Hua , Xiao Bing , Yan Ming Hua , Fu Yu Can , Xu Hong Jun
Published: March 2009

A kind of brazed monolayer diamond grinding wheel was developed with a relatively
regular distribution of grains on the wheel surface. Grinding performances of this kind of brazed
wheel in the surface grinding of cemented carbide were studied. The experiment results show that the
grinding forces ratio becomes higher with the increasing of the maximum undeformed chip thickness
and the specific energy falls with the material removal rate during grinding cemented carbide process.
Under certain grinding conditions, the material was removed almost through plastic deformation and
good surface quality is gained. Furthermore, the grits of the brazed diamond grinding wheel fail
mainly in attritious wear modes other than pull-out ones in conventional electroplated and sintered
diamond tools, which indicates that the strong retention of brazing alloy to the diamond grits and
longer service life of this kind of wheel.
Mechanism of Organic Grinding Fluid of Ceramics Based on Long Carbon Chain Alcohol and Halogenated Hydrocarbons
Authors: Tian Xin Li , Wu Zhi Yuan , Yang Jun Fei , Hu Zhong Xiang
Published: March 2009

This paper carries out grinding efficiency experiments on various formulas composed of
long carbon chain alcohol and halogenated hydrocarbons with the first principle of grinding fluid as
main evaluating index and finds via infrared spectrum testing that the conjugating ways of
lubricating films between alcohol-type grinding fluid and ceramics is based on chemical adsorption
or hydrogen bonding adsorption and generates alkoxy silane or polyalkoxy silane with perfect
anti-friction action under the condition of grinding high temperature. With adding of halogenated
hydrocarbons, it can further make grinding fluid with perfect extreme pressure property and
improves grinding efficiency. Furthermore, this dissertation firstly introduces heat capacity as
analysis means and discusses the influential factors on the removal rate of ceramics materials when
using abovementioned grinding fluid. It is shown from the result that the material removal rate
when silicon nitride ceramics grinding will increase with the augmentation of heat capacity.
Study on the Wear of Diamond Beads in Wire Sawing
Authors: Huang Hui , Xu Xi Peng
Published: March 2009

Diamond wire sawing has been used for many applications in stone industries and civil
engineering several decades ago. The wear of bead is a major factor that affects wire-sawing
performance in machining process. In this paper, seven diamond wires with different matrix system
and different structures are taken from the factory. The diameters in the front, middle and end of bead
along the moving direction of diamond wire, are measured respectively. The wear of diamond grits is
also observed using a digital video microscope system. It is show that the wear of bead varies along
the moving direction of diamond wire. The wear in the front of bead is greater than the others. The
diameter gaps are associated with the type of matrix and the wear of diamond grits. The diameter gaps
keep constant in the smooth sawing process.
Analyze and Correct Model for Machining Involute Spline
Authors: Cui Feng Kui , Li Yan , Zhou Yan Wei , Zhang Feng Shou
Published: March 2009

The rolling technic of involute spline has many advantages. This method can increase the production efficiency, has no cutting, can improve the metal structure of machining surface to increase the quality of surface and prolong the life of product, so the technic is used extensively in the industry of automobile and tractor. The design model of spline outline is built according to the formative theory of equidistant spiral surface by means of meshing principle of involute spline, roller is manufactured and machining spline is test according to the model. The correction of spline outline is accounted by means of measuring the outline of spline in three-coordinates measuring machine and comparing the measuring data and the data of ideal involute spline. The spline is remachined in corrected roller and ideal spline shape is gotten.
Manufacturing of a NbC Particulate Reinforced P/M Iron-Base Valve-Guide Cup
Authors: Xiao Zhi Yu , Ngai Tungwai Leo , Shao Ming , Li Yuan Yuan
Published: March 2009

The introduction of ceramic particulate into metallic powder will unavoidably lower the
compressibility and formability of the mixed powder. In order to overcome these problems, in this
study, warm compaction was introduced in the forming of an NbC particulate reinforced iron-base
valve-guide cup, which is used in a combustion engine. Warm compaction was used not only
because it can provide compacts with high green density but also it can increase the formability of
the mixed powder. The part composed of an iron-base material which possesses 10wt%NbC with a
relative density of 97.7%, a tensile strength of 815MPa, an elongation of 1.5%, a hardness of
HRC33 and an impact toughness of 11J/cm2. Its working surface composed of an iron-base material
which possesses 15wt% NbC with a high relative density of 98.2%, a tensile strength of 515MPa, a
hardness of HRC 58 and a remarkable tribological behavior. The sintered part successfully passed a
500 hours bench test. No serious wear on the working surface can be observed after the test. Results
indicated that the sintered part has excellent wear resistivity and the NbC particulate reinforced
iron-base composite is a suitable material for parts that work under severe wear condition.
A Practical Approach to Generating Accurate NURBS Tool Paths for CNC Machining of Sculptured Surface Parts
Authors: Chen Ze Zhong Chevy , Yang Xu Jing
Published: March 2009

This work proposes a practical approach to generating NURBS tool paths by accurately fitting ideal paths. A two-stage fitting process is included in this approach. Since NURBS paths can make accurate, smooth sculpture surfaces, this approach can promote the use of these paths in the manufacturing industry.
Using Gray Forecasting Estimates Cost of Aviation Project
Authors: Yang Ming , Li Yuan , Wang Yong Chao
Published: March 2009

China aviation project has little sample and the traditional method can not estimate the
project cost accurately. This paper proposes a method estimating aviation project cost based on gray
systematic theory. We divide aviation product into systems or parts and regard them as cost
estimation unit. The gray forecasting model GM (1, 1) was set up based on historical cost data of
cost estimation unit. If the model’s precision doesn’t meet with the requirement of aviation project
cost estimation, the revision model GM (1, 1) must be set up to raise the estimation precision The
experimental results show the method can get the more high-accuracy estimation value using the
little sample and is suitable for the cost estimation of the our country aviation project.
Research on Application Technology of Customer-Oriented Product Cooperative Design
Authors: Qu Li Gang , Gong Ya Dong , Wang Wan Shan
Published: March 2009

The system of customer-oriented product cooperative design(COPCD) provides a
platform for customers, on which the customer designers can participate in the cooperative design
activity. Through researching on the structure of cooperative design system platform based on
internet/intranet, the function, which is expressed with STEP standard file and online display via
network, modified as well , in the form of product model created in Pro/E, was achieved by making
use of VC++6.0 programming language and OpenGL technology. Moreover, the communication
tool NetMeeting was integrated in this platform interface for the communication in the process of
cooperative design activities. This system platform conceptually implements the cooperation
between customer and designer, the product design efficiency and its success rate would be
improved.
Application of Abductive Network and FEM to Predict the Maximum Forging Force and the Final Face Width of Spur Gear
Authors: Yang Tung Sheng , Hsu Yuan Chuan
Published: March 2009

The process of precision gear forging has been developed recently because of its
advantages of giving high production rates and improved strength. For complete filling up, predicting
the power requirement and final face width is an important feature of the forging process. A finite
element analysis is utilized to investigate the maximum forging force and final face width under
different process parameters such as modules, number of teeth, and the ratio of the height to diameter
of billet. The abductive network is then applied to synthesize the data sets obtained from the
numerical simulation, and a prediction model is established ultimately. Employing the predictive
model can provide valuable references in prediction of the forging force and final face width under a
suitable range of process parameters.
A New Method for Solving the Direct Kinematics of 6-DOF SPS
Authors: Li Qiang , Yan Hong Bo
Published: March 2009

A novel method is introduced. Simplify Stewart platform by using of group technology.
Six legs 6-6 Stewart Platform is transformed into three group legs Stewart platform by way of
geometrical knowledge and numerical analysis. Make emulational program of Matlab 6.5 to
validate the method of direct kinematics. Velocity and precision of computing are advanced by
repeatedly optimizing of method. The method is scientific and novel.
A Study on Titanium Alloys Deep-Hole Drilling Technique
Authors: Zhu Lin , Wang Jiang Ping
Published: March 2009

Focusing on the difficult-to-cut characteristic of titanium alloy, this paper selects several
cemented carbide tool materials in the tests of machining the titanium alloy workpieces. Different
sets of geometrical parameters of the drilling bits are grouped, chosen and optimized, and then
deep-hole drilling tests are carried out. The suitable cutter materials and the optimum geometrical
parameters of the cutter for drilling deep holes in titanium alloy have been determined through the
analysis of tested results.
Forming Simulation of Ti-TWBs at Different Elevated Temperatures
Authors: Cheng Chi Ho , Chan Luen Chow
Published: March 2009

Strong interest in producing ultra-light-weight, high corrosion-resistant, heat-proof and
tougher advanced products has prompted potential development of titanium tailor-welded blanks
(Ti-TWBs) to construct the critical parts of structures and panels in automotive applications and some
other advanced industries. However, the capability to predict the forming behavior of the stamped
TWBs without failure lags far behind the manufacturing technology. It is proven that the ductility for
most of the titanium alloy sheets can be significantly improved at elevated temperatures.
Nevertheless, such study of stress-strain behavior on the weldment of Ti-TWBs has not been fully
investigated. This paper aims to analyze the forming behavior of the Ti-TWBs at different elevated
temperatures using a finite element analysis. The distinctive mechanical properties of the base metals
and weldment for the forming simulations will be acquired experimentally. Finally, it is found that,
due to the increase of ductility, the forming behavior of Ti-TWBs will not be considerably improved
unless the forming temperature is kept between 500oC and 600oC.
A New General Equation of Mean Particle Size for Different Atomization Processes
Authors: Liu Yun Zhong , Li Yuan Yuan
Published: March 2009

In conventional studies, different empirical atomization equations are correlated for
different kinds of atomization methods or even in the same method. In the present study, it was
found that the basic law of melt breakup from bulky liquid into droplets can be universally applied
to all atomization methods. Based on theoretical analysis, a new general equation of mean particle
size applicable to both conventional atomization methods and new atomization processes is
presented. The mean particle size in melt atomization is mainly controlled and decided by two key
dimensionless parameter groups representing the liquid stability of melts and the breakup ability of
atomizer respectively. Different specific atomization mechanisms result in different formulae in
conventional atomization methods. In case of gas atomization, it is equivalent with and can be
changed into Lubanska Equation. In case of centrifugal atomization, it can be changed into the
equations that are currently the most widely used. In case of water atomization, it is similar to the
equation proposed by Grandzol and Tallmadge. According to the universal equation, new
correlations for mean particle size in novel atomization processes such as Hybrid Atomization and
Multistage Atomization were proposed and agreed with our experimental data well.
Biomimetic Deposition of Apatite on Zr-1Nb and Ti-6Al-4V
Authors: Kim J. , Choi Y.C. , Kim Hyoung Seop , Hong Sun Ig
Published: March 2009

Biomimetic apatite deposition behaviors on Zr-1Nb and Ti-6Al-4V plate with various
surface conditions were examined. Both alloys were polished with abrasive papers to have different
roughness and some of them were treated in NaOH before deposition of apatites in the simulated
body fluid. After, 10 days immersion in a SBF, NaOH treated Zr-1Nb and Ti-6Al-4V were
completely coated with apatite. The deposition rate of apatite was higher on NaOH-treated Ti-6Al-
4V than on NaOH-treated Zr-1Nb initially, but the deposition rate on Zr-1Nb accelerated after 2
days and the total weight gain due to the deposition on Zr-1Nb approached to that of Ti-6Al-4V.
NaOH treatment was found to enhance the deposition rate of apatite on Ti-6Al-4V significantly. On
the other hand, the deposition rate of Zr-1Nb was not influenced by NaOH treatment. Without
NaOH treatment, the polished Zr-1Nb with abrasive paper was found to induce more apatite
nucleation than the polished Zr-6Al-4V. The presence of apatite was confirmed by XRD analysis.
SEM observation revealed a conglomerated granular structure with elongate plates.
Characteristics of Pre-Alloyed Powders for Diamond Tools
Authors: Luo Xi Yu , Tang Ming Qiang , Kuang Xing , Huang Man , Ma Hong Qiu
Published: March 2009

In this paper, the fundamental attributes, phase composition of three pre-alloyed powders
for diamond tools by water atomization were investigated. The density, hardness, bend strength and
bending modulus of their sintered samples by hot pressing were examined under various
temperatures. The results showed that the three pre-alloyed powders have excellent low temperature
sintering characteristics. The physical and mechanical properties of the samples were found to be
nearly the same as those of ultra-fine cobalt powders.
Powder Metallurgy Diamond Tools – A Review of Manufacturing Routes
Authors: Konstanty Janusz
Published: March 2009

The methods of making diamond tools have undergone a fantastic development since the
invention of the synthetic diamond in the mid-1950’s. Over time, new production techniques based
on diamond tooling have been implemented into various areas of industrial activity enabling to do
the job faster, more accurately and at less cost. The recent statistics indicate that the consumption of
diamond abrasives reached an impressive volume of billion carats in 2000, as compared with 380
million carats in 1990 and 100 million carats in 1980. In the new millennium the market for
diamond tools continues to grow rapidly. The present decline in the price of industrial diamond
makes it a commoditised product capable of competing with conventional abrasives. In terms of
production volume, by far the largest group of diamond tools comprises the metal-bonded diamond
impregnated tools, such as circular and frame sawblades, wire saws, and core drills for cutting
natural stone and construction materials, and core bits for drilling in various rock formations. The
objective of this article is to provide a compendious coverage of the PM diamond tool-making
routes, and to identify the recent trends towards changing the tool design and composition to render
it cheaper and more efficient.
Research on Microstructure and Properties of TiN, (Ti, Al)N and TiN/(Ti, Al)N Multilayer Coatings
Authors: Quan Wang She , Li Chen , Fei Yin , Jia Li
Published: March 2009

Magnetron sputtered TiN, (Ti, Al)N and TiN/(Ti, Al)N multilayer coatings grown on
cemented carbide substrates have been characterized by using electron probe microanalysis (EPMA),
X-ray diffraction (XRD), scanning electron spectroscopy (SEM), nanoindentation, scratcher and
cutting tests. Results show that TiN coating is bell mouth columnar structures, (Ti, Al)N coating is
straight columnar structures and the modulation structure has been formed in the TiN/(Ti, Al)N
multilayer coating. TiN/(Ti, Al)N multilayer coating exhibited higher hardness, better adhesion with
substrate and excellent cutting performance compared with TiN and (Ti, Al)N coating.
Microstructure and Magnetic Properties of Nd2Fe14B/α-Fe Nanocomposite Prepared by HDDR Combined with Mechanical Milling
Authors: Hu Lian Xi , Wang Erde , Guo Bin , Shi Gang
Published: March 2009

Nd2Fe14B/α-Fe nanocomposite powders with a nominal composition of Nd12Fe82B6 were prepared by HDDR combined with mechanical milling. The microstructure of both the as-disproportionated and the subsequently desorption-recombination annealed alloy powders was studied by Mössbauer spectrometry and TEM. The magnetic properties were investigated by VSM using bonded magnet samples. The results showed that the annealing temperature had significant influence on both the recombination kinetics and the grain size of the Nd2Fe14B/α-Fe nanocomposite phases, and the bonded magnet samples presented the best magnetic properties when the nanocomposite powders were prepared by annealing at 760°C for 30 min.
Structure Peculiarities of Nanocomposite Powder Fe40Al/Al2O3 Produced by MASHS
Authors: Talaka Tatsiana , Grigorieva Tatiana F. , Vitiaz Piotr , Lyakhov Nikolay , Letsko Andrey , Barinova Antonina
Published: March 2009

Structure investigation results for MASHS powder Fe40Al/Al2O3 are presented. The
powder structure formation proceeds via two stages. On the first step (mechanical activation)
aluminothermal reaction takes plays in the system Fe+Al+Fe2O3, leading to formation of
nanocomposite precursor Fe-Al-Al2O3. On the second step (SHS), iron and aluminum reacts,
forming intermetallic FeAl. As-synthesized composite powder completely inherits the precursor
structural morphology in spite of the phase transformations taking place during the production
process. Such a production route provides the formation of intergrowth nanocomposite material
structure with improved interfacial strength.
Production of Dispersion-Strengthened Cu-TiB2 Alloys by Ball-Milling and Spark-Plasma Sintering
Authors: Kwon Dae Hwan , Kum Jong Won , Nguyen Thuy Dang , Dudina Dina V. , Choi Pyuck Pa , Kim Ji Soon , Kwon Young Soon
Published: March 2009

Dispersion-strengthened copper with TiB2 was produced by ball-milling and spark
plasma sintering (SPS).Ball-milling was performed at a rotation speed of 300rpm for 30 and 60min
in Ar atmosphere by using a planetary ball mill (AGO-2). Spark-plasma sintering was carried out at
650°C for 5min under vacuum after mechanical alloying. The hardness of the specimens sintered
using powder ball milled for 60min at 300rpm increased from 16.0 to 61.8 HRB than that of
specimen using powder mixed with a turbular mixer, while the electrical conductivity varied from
93.40% to 83.34%IACS. In the case of milled powder, hardness increased as milling time increased,
while the electrical conductivity decreased. On the other hand, hardness decreased with increasing
sintering temperature, but the electrical conductiviey increased slightly