bluuebunny/crossref_metadata_2025 huggingface dataset:
The Corrosion Behaviour of a Hypereutectic Al-Si Alloy Obtained by Spray Forming in Acid, Neutral and Alkaline Solutions
Authors: Santos H.O. , Kunioshi Clarice Terui , Rossi J.L. , Costa Isolda
Published: March 2009

Al-Si hypereutectic alloys produced by spray forming represent an important
technological development for application in the aeronautical and automotive industries. Due to
some special properties these alloys find application as cylinder liners, mainly due to their high
strength and wear resistance. Much research has been carried out to evaluate the mechanical
properties of these alloys but the literature on their corrosion performance is still very scarce. In this
study, the corrosion behaviour of a spray formed Al-Si-Cu hypereutectic alloy was investigated by
electrochemical impedance spectroscopy (EIS) in acid (pH 3.3), neutral (pH 7) and alkaline (pH 11)
solutions. Intense localized attack occurred in the acid electrolyte and the impedance decreased with
time of immersion. In the neutral medium, the alloy was passivated but localized attack also
occurred on weak areas of the passive film. In the alkaline medium, precipitation of corrosion
products occurred during the first hours of immersion causing the increase of impedance but
thickening of this layer led to cracks growth with time and, consequently, to the exposure of
metallic substrate, resulting in the decrease in impedance for longer periods.
Microstructure of Plasma-Sintered Aluminum Bronze Powder Compacts
Authors: Frota T.M.P. , Brito R.A. , Alves Jr. Clodomiro , Hajek V.
Published: March 2009

Porous materials are successfully utilized for fabrication of many industrial
components such as filters and selflubricating bearings. These products are made by powder
metallurgy, where mixtured or prealloyed powders can be used. The aluminum bronze is one
of the most wanted due its excellent properties in combination with low cost of the raw
materials. In this work, single action compacted (100 MPa) prealloyed aluminum bronze (Cu-
9wt%Al-1wt%Fe) cylinders were sintered using a hollow cathode discharge at temperatures
between 400 and 750°C with duration on the isotherm for 12 min. Microstructure changes,
homogeneity, porosity and composition were analyzed after the treatment. Sintering below
550° C led to uniform but porous structure. Above 550 °C it was observed a solidified central
region and a porous structure that changes slightly through out the cross-section. The diameter
of the central region increased with treatment temperature. It is concluded that due to the
intense plasma heating and subsequent surface melt formation a mass flow direction to the
center of compacts occurred.
Continuous Binder-Powder Coating for the Production of Ti/SiC/C Composites
Authors: Ferreira Ricardo Arthur Sanguinetti , Yadava Yogendra Prasad , Arvieu C. , Quenisset J.M.
Published: March 2009

Continuous Binder-Powder Coating (CBPC) is a new fabrication route for the titanium metal matrix composites reinforced with continuous SiC filaments. Based on powder-cloth process, this alternative fabrication route is characterised, analysed and application viability is discussed considering the other related routes. In addition, effects of the pressure and temperature on the Ti/SiC/C composites were considered for matrix consolidation. Results have shown that the titanium matrix composites processed by Continuous Binder-Powder Coating present, simultaneously, good matrix densification, consolidation and also a weak interaction between matrix and fibers, when the hot pressing is performed under 150 MPa at temperature below β-transus. Most important characteristics of the CBPC process and its application viability are reported, in this paper.
Effects of Operational Variables on the Performance of Venturi Scrubbers with Circular Section
Authors: Meili L. , Fernandes M.O. , Ataíde Carlos Henrique , Damasceno João Jorge Ribeiro
Published: March 2009

The Venturi scrubbers have a high collection efficiency to remove very small
particles from gaseous streams. The main purpose of this work is to determine the overall
collection efficiency of Venturi scrubbers with circular section under different operation
conditions. The experimental system consisted of a Venturi scrubber with circular section and
liquid injection in the throat. A factorial experimental design was carried out; the overall
collection efficiency was the response. Three variables were analyzed: the throat length, the
air velocity and the liquid flow. The best values for efficiency were obtained for 15 m/s of air
velocity and 300 mL/min of liquid flow and the throat length did not have influence.
Sintering of AISI M3:2 High Speed Steel – Part II
Authors: Araujo Filho Oscar O. , das Neves Maurício David Martins , Liberati João Franklin , da Silva Luís Carlos Elias , Salgado Lucio , Ambrozio Filho Francisco
Published: March 2009

Liquid phase sintering of high speed steels seems to be a cheaper processing route in the
manufacturing of tool steels if compared to the well-known and expansive hot isostatic pressing
high speed steels process. In a previous work a M3:2 high speed steel was vacuum sintered from
irregular water atomized powders and had its sintering temperature determined. In this work the
same powder was uniaxially cold compacted and vacuum sintered by adding some small quantity of
graphite (0.3%C in weight) to prevent porosity and loss of carbon which result from the sintering
cycle. The samples from all these experimental procedures were uniaxially cold compacted and
vacuum sintered at five different temperatures and had its densities evaluated. The microstructure
was evaluated using optical-electronic techniques in order to investigate the best range of sintering
temperature. At least five parallel samples were tested to each condition of sintering.
Effects of Raw Materials on the Technological Properties of Brick Compositions Using a Statistical Design Approach
Authors: Correia Sivaldo Leite , Grun Elayne , Denardi Christian D. , Hotza Dachamir , Folgueras Marilena Valadares
Published: March 2009

The simultaneous effect of raw materials (A, B and C) on physical and technological properties of brick compositions was studied. This investigation was carried out using the statistical design of mixture experiments. Ten mixtures of three raw materials were selected and used in the experiments design. Those mixtures were processed under conditions similar to those found in the ceramics industry. Fired body characterisation results were then used to iteratively calculate statistically significant and valid regression equations (trace plots), relating linear firing shrinkage, open porosity, fired bending strength and water absorption with the proportions of raw materials. The microstructures of some selected samples were studied using scanning electron microscopy. Mixtures with high clay B contents were most adequate to produce, under constant processing conditions, a brick with specified properties. The microstructures are characterized by a low closed porosity and absence of vitreous phase.
Anelastic Behavior due to Interstitial Oxygen in SmBa2Cu3O7-δ
Authors: Nascimento Rubens Maribondo , de Albuquerque Gimenez Juliana Maria , Grandini Carlos Roberto , Cunha Alfredo Gonçalves da
Published: March 2009

The composite SmBa2Cu3O7-δ (Sm-123), obtained by the substitution of the ion Y
for Sm in the very well known and studied YBa2Cu3O7-δ (Y-123), is potentially attractive for
better understanding superconductivity mechanisms and for its applications as electronic
devices. Sm-123 samples show higher critical temperatures than Y-123 ones do and a larger
solubility of Sm in Ba-Cu-O solvent, which makes their growth process faster. When oxygen
is present interstitially, it strongly affects the physical properties of the material. The
dynamics of oxygen can be investigated by anelastic spectroscopy measurements, a powerful
technique for the precise determination of the oscillation frequency and the internal friction
when atomic jumps are possible. Anelastic spectroscopy allows determining the elasticity
modulus (related to the oscillation frequency) and the elastic energy loss (related to the
internal friction) as a function of the temperature. The sample was also investigated by X-ray
diffraction (XRD), scanning electronic microscopy (SEM), and electric resistivity. The
results obtained show a thermally activated relaxation structure composed by at least 3
relaxation processes. These processes may be attributed to the jumps of oxygen atoms
present of the Cu-O plane in the orthorhombic phase.
Ceramic Bonding to Biocompatible Titanium Alloys Obtained by Powder Metallurgy
Authors: Bottino M.C. , Oyafuso D.K. , Coelho Paulo Guilherme , Taddei Elisa B. , Henriques Vinicius André Rodrigues , Silva Cosme Roberto Moreira , Bottino M.A. , Bressiani Ana Helena A. , Bressiani José Carlos
Published: March 2009

The shear bond strength between a ceramic material (Titankeramik®, Vita Zahnfabrik, Germany) and two biocompatible titanium alloys was investigated. Ti-13%Nb-13%Zr (TNZ) and Ti-35%Nb-7%Zr-5%Ta (TNZT) alloys were obtained based on the blended elemental technique followed by a sequence of cold uniaxial and isostatic pressing and sintering. Characterization involved microstructural analysis (SEM) and crystalline phase identification (XRD). Subsequently, samples were machined to 4 x 4 mm with a base of 5 x 1 mm. The base metals were blasted with Al2O3 particles followed by the application of a coupling agent and opaque ceramic. After ceramic firing, the specimens were loaded in a universal testing machine (0,5mm/min). XRD revealed the presence of α and β-phases for TNZ, and peaks related to β phases and Nb and Ta for the TNZT alloy. SEM evaluation (TNZ) depicted remaining pores and biphasic microstructure formation. SEM micrographs of the TNZT alloy revealed good densification and a homogeneous β structure. Shear bond strength data (MPa) were statistically analyzed (one-way ANOVA and Tukey test, α=.05) revealing that TNZT (37.6 ± 2.91) presented significant higher values (p=0.0002) compared to TNZ (26.03 ± 2.92). In conclusion, it seems that Ti alloy composition plays a significant role on ceramic bonding.
Zirconium Titanate: Synthesis and Processing of Fine Powders Prepared by Chemical Route
Authors: Ussui Valter , Lazar Dolores Ribeiro Ricci , de Lima Nelson Batista , Bressiani Ana Helena A. , Pascoal José Octavio A.
Published: March 2009

A process for synthesis of fine zirconium titanate powders by chemical route is
described. Zirconium/titanium molar ratio was varied from 0.67 to 1.5 and the powders
produced were analyzed. The precipitation process comprises the mixture of zirconium and
titanium metal salt solutions to ammonium hydroxide solution, followed by washing of the
precipitate, calcination and grinding to result in zirconium titanate. The ceramic powder is
then uniaxially pressed as cylindrical samples and sintered at 1400°C for 5 hours. The
microstructure of fractured and thermally etched ceramic was observed by scanning electron
microscopy, and crystal phase identifications were done by X-ray diffraction. At least two
different zirconium titanate phases, ZrTiO4 and Zr5Ti7O24, were identified. Ceramic hardness
was measured by Vickers indentation.
A Case Study of the Ceramic Matrix Sintering of Sewage Sludge when Fired at High Temperatures
Authors: Morais L.C. , Dweck Jo , Gonçalves E.M. , Büchler Pedro M.
Published: March 2009

This study shows a possibility of using sewage sludge after thermal treatment (at
1050°C for 3h) in the production of a building material. The use of dehydrated sewage sludge
as a component in building materials, like in the sludge-clay mixture employed in the
manufacture of bricks, tiles and cements, has been frequently done around the world. During
sludge-clay mixture firing, which was done by controlled heating at a temperature above of
1000°C for 3h, organic substances of the sludge were completely eliminated. After thermal
treatment, the micropores formed due to the released expansive gases, are responsible for the
acoustic and thermal isolation properties of the resulting material. A problem found in the
ashes was the high concentration of toxic compounds like Zn, Ni, Cr, Cu, Al oxides. The aim
of the present work was to observe through scanning electron microscopy (SEM), X-ray
fluorescence (XRF) and inductively coupled plasma optical emission spectrometer (ICP-OES)
the integration of these oxides into the sintered ceramic matrix of sludge. Oxide integration is
an important factor in brick manufacturing used as building materials.
A Study on Driving Interference-Fit Fastener Using Stress Wave
Authors: Cao Zeng Qiang , Qin Qing Hua
Published: March 2009

Interference-fit fasteners are used in large numbers throughout aircraft structures.
Conventional installation methods are driving fasteners into aperture using pneumatic or hydraulic
tooling, installation damage always occurs using these methods. This paper introduces a new
method of driving interference-fit fastener using stress wave, reports on a comparison of driving
quality between stress wave driving and hydraulic force driving. The experiments completed by
authors indicate that stress-wave method can drive the fasteners with larger interference which
conventional installation method can not implement; stress wave driving method provides high
installation quality and repeatable results compared with the conventional driving method; and
stress wave driving method is convenient to be used. The experiments prove that the protuberant
material produced by stress wave method is less than that of conventional installation methods, this
is advantaged to improve the fatigue strength of joint.
Green Manufacturing of Suspended Bio-Carriers
Authors: Jiang Fan , Chen Wei Ping , Mai Ming Ren , Zhang Tao
Published: March 2009

The suspended bio-carrier is an important environment material for the biological
contact oxidation of sewage treatment technology. And it is produced by mould manufacture and
plastic production. In order to reduce the resource consumption and environment pollution, the
green manufacturing technology is introduced; it is certified that the technology is beneficial to
produce the bio-carriers. In the two stages of producing, the synthesis use of resource and the
environment protection are acted as the objectives; then the multiple objective optimization models
are put forward based on material selection, mould machine, and plastic injection process. The
variables and constrains in those models are analyzed in detail. For models of multiple objectives,
the genetic algorithm is used, and is improved by adaptively adjusting the crossover probability Pc
and mutation probability Pm, and assisting gradient descending method.
A New Approach to Achieve Lean Production in Workshop-Production Preparation Package
Authors: Li Tao , Wang Run Xiao , Song Li Jun , Luo Zhi Qing
Published: March 2009

According to idea of lean production, in order to shorten production preparation time,
production preparation package is brought forward. The concept, flow and performance
management about production preparation package is introduced. Production efficiency is improved
and cost of production is reduced in the aeronautical manufacturing enterprises.
Research on Web Based Remote Monitor and Control System for Grinding Process
Authors: Liu Gui Jie , Mei Ning , Tan Jun Zhe
Published: March 2009

A web based remote monitor & control system for grinding process is presented. In this
system, OPC/Socket drive technology, CAN bus technology, B/S structure, Java Applet and ActiveX
etc. are used to realize the remote monitor & control, and grinding processes in different place can be
monitored and controlled by remote grinding expert only through browser, so it overcomes the
shortage that the grinding quality depends on skilled workers and variants with grinding operators.
The data processing and feature releasing method of AE signals in grinding process also be discussed.
The grinding state feature information can be updated automatically, and be browsed by remote
experts through running the ActiveX in the browser. Therefore, it is of important significance for
improving workers’ working environment and work-piece quality.
One Kind of Integrated Scheme of Regional Networked Manufacturing Systems
Authors: You Jia , Liu Fei , Wang Jun , Song Yu Chuan , Yin Chao
Published: March 2009

How to effectively and efficiently integrate regional networked manufacturing systems is
very important, and essential for speeding up agile collaboration between enterprises. The paper
presents one kind of integrated framework of regional networked manufacturing systems, including
software layer, business and application layer and coordination layer. Meanwhile, some key
problems are analyzed. Furthermore, the paper studies a running mode of the systems integration.
At last, the primary application situation of the framework in Chongqing of China is introduced, as
well as some effects acquired.
Implementation of Decision-Making Model System for Autonomous Vehicles in Virtual Environment
Authors: Liang Yan Fei , He Han Wu , Zheng De Tao , Chen Xin
Published: March 2009

This paper established the framework of the decision-making model system for
autonomous vehicles. Based on virtual reality environment modeling technology, the virtual scene
was obtained. The driving performance of autonomous vehicles in real environment was simulated
with that of the virtual vehicle in virtual environment. It was studied the influence of driver’s
aggressiveness on lane-changed performance through considering human factors, and several
longitudinal driving modes were classified and discussed. Three-power B spline function was used
in this paper to plan path by interpolating characteristics points. The driving framework and the
driving models described in this paper serve to address the problem of building more realistic traffic
at the microscopic level in driving simulators. The autonomous vehicles based on this system can be
used as the vehicles in simulators and help to design traffic or help to verify the performance of
vehicles.
Modeling of Back Pressure Distribution on the Wafer Loaded in a Multi-Zone Carrier in Chemical Mechanical Polishing
Authors: Sun Yu Hui , Kang Ren Ke , Guo Dong Ming
Published: March 2009

The within-wafer non-uniformity (WIWNU) of material removal rate in chemical
mechanical polishing (CMP) is important for IC manufacture. The non-uniform distributions of
polishing pressure and the relative speed between the wafer and the polishing pad are main factors
affecting the WIWNU. In this paper，based on the contact mechanics and the elastic plate theory, a
compensate pressure computing model is presented, in which the effects of kinematic parameters are
taken into acount. By modelling and calculating, the desired compensate back pressure distribution is
obtained. In the last section the design of a schematic carrier with multi-zone, in which the
compensate back pressure can be applied, is presented. The model and the design can be used for
providing theoretical guide to the development of CMP equipments and selection of the kinematic
variables in CMP process.
Performances of HSK Spindle/Toolholder Interface for HSM
Authors: Zhang Song , Ai Xing , Li Jian Feng , Fu Xiu Li
Published: March 2009

With the rapid development of high-speed machining technology, more and more
machining centers have been equipped with the HSK toolholders. In this paper, the performances of
the HSK spindle/toolholder interface, such as the axial movement, the radial deflection and the
contact stress distribution, were simulated by means of the finite element method and compared
with the traditional BT interface. From the simulated results, it was pointed out that the
performances of the HSK interface were obviously superior to that of the BT interface, and the
HSK interface was much more suitable for high-speed machining.
The Influence of Acoustic Cavitation to Microscopic Material Removal in Polishing Process Based on Vibration of Liquid: A Numerical Study
Authors: Guo Zhong Ning , Huang Zhi Gang , Chen Xin
Published: March 2009

In Polishing Process based on Vibration of Liquid (PVL), abrasive particles driven by
polishing liquid will brush and etch workpiece to achieve material removal. Because the liquid is
vibrated in ultrasonic frequency, polishing process will be greatly affected by cavitation phenomenon.
The critical thermal conditions and high-speed liquid jet produced by bubble dynamics may damage
workpiece. A refined Dissipative Particle Dynamics method is applied to study the effect of acoustic
cavitation on PVL. Validity of the numerical simulation is tested according to experimental results.
Study on the Thermal Properties of Phenolic Resin Mix-Modified by Nano-Alumina
Authors: He Lin , Yu Li Hua , Yan Jian Wei , chen Chun Yan , Bian Xiu Fang
Published: March 2009

In the present research the thermal properties of phenolic resin 2123-P mix-modified by
nano-alumina are investigated. The nano-alumina employed in the research can be classified two
kinds, one is treated by 1%wt. silane coupling agent KH-550 relative to the weight of alumina, and
the other is commercial alumina untreated. DTA-TG results show the thermal stability and
anti-weight loss ability of the mix-modified phenolic resin 2123-P with KH-550 treated alumina are
increased relative to those of the pure 2123-P and those of the mix-modified 2123-P with
commercial alumina, and the results are to be proved by the constant speed friction and wear tests.
It can be observed from SEM that KH-550 treated nano-alumina particles are dispersed equably in
phenolic resin.
Microstructure and Performance of Porous Ni-Cr Alloy Bonded Diamond Grinding Wheel
Authors: Su Hong Hua , Xu Hong Jun , Xiao Bing , Fu Yu Can , Xu Jiu Hua
Published: March 2009

Although the porous metal bonded diamond grinding wheel, which has recently been developed, had an excellent grinding performance for hard-brittle materials, its applications were only in precision grinding in past study. A new method for fabricating the new porous metal bonded diamond grinding wheel by Ni-Cr alloy as bond and vacuum loose powder sintering was proposed in this paper. The morphology of cross section of the segments and microstructure of interface between diamond grits and bond were analyzed. The wetting mechanism between Ni-Cr alloy bond and diamond is reacting wetting. Machining performance experiments about grinding ratio and surface roughness have been carried out. The testing results show that the porous Ni-Cr alloy bonded diamond grinding wheel has certainly fine machining performance in high grinding force occasion, and the maximal grinding ratio and best surface roughness were 6660 and 1.08 m, respectively.
Study on the Fabrication of Blazed Grating with Sub-Micrometer Space on Aluminum Film
Authors: Lun Shi , Hao De Fu , Qi Xiang Dong
Published: March 2009

The saw tooth grooves of blazed grating ruled by ruling engine are formed by diamond
tool which presses on the aluminum film evaporated on the substrate of optical glass or metal. The
real shape of ruled saw tooth groove is different from that of the ideal groove and the ruling process
indicates that there are the zero order planes, similar to the flat tops, on the grating grooves. The
results of Fourier analysis for the real ruled grating featuring the zero order plane structure shows
that the flat top width is an important factor for grating efficiency. Additionally, bigger pressure
value loaded on the diamond tool and bigger lateral pressure value on the aluminum film will be
benefit to the improvement of grating diffraction efficiency. Based on the grating interferometer,
the high precision positioning control system of ruling engine guarantees the accuracy of the
grooves space. High density blazed grating whose space is 0.83μm is manufactured and its’ grooves
spaces are very equidistant and uniform under the view field of AFM. And the infrared blazed
grating, whose diffraction efficiency in the first order is up to 97 percent, is ruled successfully also.
Prediction and Design of the Optimal Punch Shape for Recess Forging
Authors: Wu Chun Yin , Hsu Yuan Chuan , Yang Tung Sheng
Published: March 2009

In this study, the finite element method was used to analyze comprehensively the effects of punch shape on forming the forging recess. Then, the polynomial network and genetic algorithm were combined to construct the predicted and designed system. Through this approach, we can predict the forging results formed from arbitrary shaped punches, and design the optimal punch shape for forging recess. Through the interactive verifies of modeling repeatedly, the errors resulted from modeling analysis, network prediction and genetic algorithm optimal design are extremely limited. Consequently, the predicted and designed approach of optimal punched shape for forming recess in this study could be extended to the design of more complicated and difficult formed forging die.
A Study of Double Sided Polishing Process for Ultra-Smooth Surface of Silicon Wafer
Authors: Li Wei , Hu Xiao Dong , Jin Yang Fu , Hu Gang Xiang , Hu Xiao Zhen
Published: March 2009

Double sided polishing process has become a main machining method for silicon wafer finishing process, but it is difficult to get ultra-smooth surface with the very stringent machining conditions. In this paper, the mechanism of ultra-smooth surface machining process was studied, the main parameters affecting the surface quality of silicon wafer, such as the polishing pad and carrier rotation speed, polishing press, polishing slurries etc. , were discussed and optimized, then ultra-smooth surface of silicon wafer with Ra 0.4nm has been obtained based on the above study. A new double sided polishing machine with computer control system equipped with a digital controlled press valve was developed, and the ultra-smooth machining process of silicon wafer was established in this paper.
Study of Fuzzy Integral and Support Vector Machine Algorithm in Machinery Diagnosis
Authors: Hao Wangs Shen , Zhu Xun Sheng , Zhao Jian Cai , Tian Biao Jun
Published: March 2009

In the field of fault diagnosis for rotating machines, the conventional methods or the
neural network based methods are mainly single symptom domain based methods, and the
diagnosis accuracy of which is not always satisfactory. To improve the diagnosis accuracy a method
that combines the multi-class support vector machines (MSVMs) outputs with the degree of
importance of individual MSVMs based on fuzzy integral is presented. This provides a sound basis
for integrating the results from MSVMs to get more accurate classification. The experimental
results with the recognition problem of a blower machine show the performance of fault diagnosis
can be improved.
Effect of Rounded Cutting Edge Radius on Residual Stress within Machined Sublayer
Authors: Deng Wen Jun , Tang Yong , Xia Wei , Wan Zhen Ping
Published: March 2009

A coupled thermal-mechanical model of plane-strain orthogonal metal cutting with
continuous chip formation is developed to investigate the residual stresses in the finished workpiece.
Deformation of the workpiece material is treated as elastic-viscoplastic with isotropic strain
hardening, and the numerical solution accounts for coupling between plastic deformation and the
temperature field, including treatment of temperature-dependent material properties. Automatic
continuous remeshing and adaptive meshing technique are employed to achieve chip separation at
the tool tip region and a satisfactory solution. The finite element model is well validated by
comparing values of the predicted cutting forces and residual stresses with experimental results.
Based on the established finite element model, the effect of rounded cutting edge radius on residual
stress distribution is analyzed. The results show that altered cutting edge radius clearly produced
significant changes in residual stresses. The maximum tensile residual stress and its penetration
depth decrease as the cutting edge radius increases.
Reconfiguration Methods for Exception Handling in Reconfigurable Manufacturing Systems
Authors: Jiang Xiao Peng , Wang Run Xiao , Li Tao , Luo Zhi Qing , Wang Dong Bo
Published: March 2009

Reconfigurable manufacturing systems (RMS) offer capabilities for quick adjustment of
production capacity and functionality in response to sudden changes in market conditions. Both at
the system and at the cell level exception events occur dynamically and unpredictably during the
production process. These exceptions interrupt the production process by causing errors in the
schedule plan. Error/ exception handling is the policy how to deal with errors caused by the
occurrence of out-of-ordinary events. Author explores the new strategies to handling error events
and proposes an intelligent control structure for real-time error handling, and illustrates the
reconfiguration ability is the new crucial technological factor enabling new strategies to handle
out-of-ordinary events of the production process.
A Study of a Digital Manufacturing Procedure for Freeform Optics
Authors: To Suet , Wang Er Qi , Lee Wing Bun , Cheung Chi Fai
Published: March 2009

An investigation into a Digital Manufacturing and Testing Procedure (DMTP) for freeform
optics is presented in this paper. The paper studies the characteristics of the DMTP which are of
special use in ultra-precision machining (UPM) of freeform optics, i.e. the construction of a model of
DMTP, the construction of a digital prototype of an optical system, a Digital Testing (DT) system for
image quality, digital testing and simulation of the optical image quality.
General Subdivision Inferred from Catmull-Clark Subdivision Algorithm
Authors: Wang Yang , Ji Shi Jun , Yang Li Jun
Published: March 2009

Subdivision algorithms have emerged recently as a powerful and useful technique in
modeling free-form surfaces. Subdivision algorithms exited at present however, being their
disadvantages, can’t meet the demand of wide application in modeling surfaces and don’t still
belong to a general theory. In this paper, a general subdivision algorithm is presented which is a
general conclusion inferred from classical Catmull-Clark subdivision algorithm and can produce
existing subdivision algorithm by selecting reasonable vertical weights and horizontal weights. The
subdivision algorithm is an ideal resolution for keeping shape feature such as crease, corner and dart
contrast to all existing subdivision algorithms, it also have the advantage of flexible weights
selection, easily control of shape and high compute speed. Therefore, the algorithms are extensively
applicable for shape modeling in computer aided geometric design, industrial prototype design and
reverse engineering.
Representation of Developable Surfaces and Achievement of the Algorithm
Authors: Zhou Min , Ye Zheng Lin , Peng Guo Hua , Yang Yun Qing , Zheng Hong Chan
Published: March 2009

In order to overcome the difficulties in representation of developable surfaces utilizing traditional approaches, and resolve the problems in adjusting and controlling the position and shape of developable surfaces that often faced in Engineering. In this paper, we propose a directly explicit and efficient method of computer-aided design for developable surfaces based on triangle-B spline. The shapes of developable surfaces can be adjusted using a control parameter. Meanwhile, we show that the techniques for the geometric design of developable surfaces in this paper have all the characteristics of existing approaches for curves design. The algorithms are explained in detail, and demonstrated with the examples in the paper.
Study on the Dynamic Active Confocal Probe Based on Time Difference for Surface Measurement
Authors: Zhang Hong Wei , Zhang Guo Xiong , Fan Yu Ming , Qin Jia , Li Zhi , Gao Xiang
Published: March 2009

With the development of modern industry, the consciousness of quality monitoring
increases rapidly. The requirements to the dimensional control and profile monitoring of the
products including the mechanical, optical and electric ones become higher and higher. New,
non-contact and convenient instruments are needed to enable people to evaluate their products. A
new type of dynamic active confocal probe is developed in this paper. The key point of this new
method is that the displacement measurement of the vibrating lens located on the tuning fork is
converted to time difference measurement, which is much simpler and assures higher accuracy in
measurement. System structure and improvement, electric circuit and signal processing system are
discussed. Experimental studies of the probe performance and analyses of the experimental results
are presented.
Contact Analysis and Optimization of Elastic Orientating Component by Finite Element Method
Authors: Liu Da Li , Ma Feng Lei , Wang Guo Pu
Published: March 2009

In this paper, the strength and deformation of an elastic orientating component (sleeve)
were analyzed by Finite Element Method (FEM). The highest stress of the part and the relationship
between the dimension and deformation were found. The position under the critical situation was
obtained. The optimal dimension of the sleeve was given.
Manufacturing-Oriented Multi-State Model for Aircraft Sheet Metal Parts
Authors: Wang Jun Biao , Liu Chuang , Han Xiao Ning , Feng Bing
Published: March 2009

In order to define the intermediate workpiece information for the digital manufacturing of
aircraft sheet metal parts, the Manufacturing-Oriented Multi-State Model for Sheet Metal Part
(MOSS) is further studied. The model structure is constructed by the hierarchy of State, Feature,
Element and Data (SFED). The hierarchy represents its content and relationship among its
components in detail. The model application scheme shows that state information can be integrated
with the systems of process planning and tool design, and the model provides a foundation for
digital and intelligent manufacturing of aircraft sheet metal parts.
Numerical Simulation of Temperature Field and Grain Structure in the Solidification of K4169 Superalloy Shell Casting
Authors: Chen Jian Lin , Zhao Zhi Long , Yan Guang Ming , Liu Lin
Published: March 2009

The associated modeling method of complex foundry system was investigated under
software environment of PRO/E and ANSYS. The 3D-structure of K4169 superalloy shell castings
constructed by applying PRO/E was guided into ANSYS to reconstruct the whole foundry system.
The variation of temperature field with solidifying time was calculated by ANSYS to check each
key node in casting structures. According to the temperature changing curves of key nodes, the
grain structural feature values were obtained by using consecutive nucleation model. Based on the
2D cellular automaton method, the evolution of grain structure in some sections of casting was
visually simulated. The results of simulation are good accordance with the measured grain feature
values.
Investigations on Edge Chipping in Rotary Ultrasonic Machining Using Finite Element Analysis
Authors: Chen Yu , Pei Zhi Jian , Treadwell Clyde
Published: March 2009

This paper reports two investigations on the edge chipping in rotary ultrasonic machining
using finite element analysis (FEA). The first FEA investigation establishes a relationship between
edge chipping thickness and cutting force. The second FEA investigation is to understand the effects
of three parameters (cutting depth, support length, and pre-tightening load) on edge chipping
thickness. The investigation results showed that the edge chipping thickness could be reduced by
increasing support length and decreasing cutting force.
Mechanical Event Simulation of Drop Testing for Toy Product
Authors: Yam Anthony Yee Kai , Yung Kai Leung , Lam Chi Wo
Published: March 2009

Toys that are free from drop failures normally take a long time to develop. It is often time
and cost consuming after the production tooling is built to detect drop test failure. This paper
introduces a new drop testing analysis method for Toys. The method uses a simple approach with a
local analysis that based on the linear and non linear finite element analysis. Modeling and transient
drop analysis of a pre-school toy is used as a case study to demonstrate the method. The impact
analysis of the product hitting the solid concrete floor after a free fall is presented. The analysis
focuses on the deformation of the housing for a product with electronic circuit and mechanical
mechanism inside. Experimental data has been obtained for drop simulation of the housing and its
correlation with the plastic material properties. The stress and strain of the housing during drop
impact tests are noted. The effects of the material properties to the housing deflection under
drop/impact shock have been investigated. Numerical results are compared with experimental results
to validate the method.
Synthesis and Properties of Open-Celled Metal Foams
Authors: Quadbeck Peter , Stephani Günther , Kümmel Kerstin , Adler Joerg , Standke Gisela
Published: March 2009

Open-celled metal foams were synthesized using a replication technique. Therefore a
reticulated polyurethane template was coated by a slurry and removed thermally, followed by a
sintering step. Since the process is feasible for a multiplicity of metals the experiments were
performed on the example of stainless steel 316L. Highly porous components were obtained
showing adjustable densities between 0.3 and 2.0 g/cm³. The cell structure is exceedingly
homogeneous and the cell sizes may be chosen in the range of 10 – 80 ppi. In order to characterise
the properties, compression tests and acoustical tests were carried out. A significant influence of the
density and the cell size on the acoustical and mechanical properties was noticed.
Particle Size and Shape Analysis the Key to Success in Metal Powder Production
Authors: Pankewitz Axel , Behrens Christian , Kesten Ulrich , Park Yong Jae
Published: March 2009

The particle size distribution is one of the important parameters for characterisation of
quality of metal powders. Specific material properties such as ability to flow, reactivity as well as
compressibility and its hardening potentials – hence the most important characteristics of sintered
metals - are determined by the size distribution. The correct particle size distribution is the key to
best product quality in atomisation processes of aluminium, milling of pure metals and other
processes.
Phase Orientation of a TiC-TiB2-SiC Ternary Eutectic Composite Prepared by An FZ Method
Authors: Tu Rong , Li Wenjun , Goto Takashi
Published: March 2009

The TiC-TiB2-SiC system was a ternary eutectic, whose eutectic composition was 34TiC-22TiB2-44SiC (mol%). A TiC-TiB2-SiC ternary eutectic composite were synthesized via the floating zone method using TiC, TiB2 and SiC powders as starting materials. The TiC-TiB2-SiC eutectic composite showed a lamellar texture. TiC(022), TiB2(010) and SiC(111) of the eutectic composite were perpendicular to the growth direction. The TiC-TiB2-SiC ternary eutectic composite had a specific relationship among the crystal planes: TiC[011]//TiB2[010]//SiC[112], TiC(200)// TiB2(001)//SiC( 402 ) and TiC(111)//TiB2(101)//SiC( 220 ).
Preparation of Silicon Nitride-Silicon Carbide Composites from Abrasive SiC Powders
Authors: Kasuriya Supawan , Thavorniti Parjaree
Published: March 2009

Silicon nitride - silicon carbide composite was developed by using an abrasive SiC powders as a raw material. The composites were prepared by mixing abrasive SiC powder with silicon, pressing and sintering at 1400°C under nitrogen atmosphere in atmosphere controlled vacuum furnace. The proportion of silicon in the initial mixtures varied from 20 to 50 wt%. After sintering, crystalline phases and microstructure were characterized. All composites consisted of α- Si3N4 and β-Si3N4 as the bonding phases in SiC matrix. Their physical and mechanical properties were also determined. It was found that the density of the obtained composites increased with an increase in the Si3N4 content formed in the reaction.
A Study of Reduced and Carburized Reactions in Dry-Milled WO3+Co3O4+C Mixed Powders with Different Carbon Content
Authors: Im Hoo Soon , Hur Jah Mahn , Lee Wan Jae
Published: March 2009

The dry-milling technique was used for mixing and crushing oxides and graphite powder
to get homogeneous mixed powders. The weight ratio of ball-to-powder was 30:1 and argon gas
was filled in jar. The carbon content was more 10~ 20wt% than the stoichiometric amount. The drymilling
was carried for 20 hours. After milling, the mixed powders were reduced and carburized at
900~980°C for 3 hours flowing Ar gas in tube furnace. The dry-milled powders showed wide
diffraction patterns of X-ray. The reactions of reduction and carburization were completed in 3
hours at 980°C. After the reactions, the mean size of WC particles was about 200 nm. The content
of free carbon in WC/Co mixed powders decreased as the reaction temperature increased.
Effects of Inhibitors on the Synthesization of WC/Co Composite Powders by Mechanochemical Method
Authors: Im Hoo Soon , Hur Jah Mahn , Lee Wan Jae
Published: March 2009

Nano-sized WC particles in WC/Co composite powders were synthesized by
mechanochemical method. The raw powders(WO3, Co3O4, VC, Cr3C2 and graphite) were mixed by
planetary milling with ethyl alcohol for 30 hours. The compositions were WC-10 and -20 wt% Co
after reduction and carburization. The powders of VC and Cr3C2 were added as the inhibitors to
inhibit the formation of nano-sized WC particles. The direct reduction and carburization of the
oxides with carbon were carried at 900°C for 1 to 3 hours under flowing Ar gas. The resultant
powders were compacted and sintered at 1300~1360°C for 0.5 hour. The degree of the direct
reduction and carburization of the mixed powders increased with the reaction time. The mean size
of WC particles in WC/Co composite powders was about 16 nm, and the mean size of WC/Co
composite powders was about 240 nm. In WC-10 and -20 wt% Co, the sintered compacts shrank by
16% and 24%, respectively. The mean sizes of WC in WC/Co composite powders were about 50
and 30 nm.
Hybrid Composite Nano-Sized WC-Co Cemented Carbide
Authors: Park Sun Yong , Lee Wan Jae
Published: March 2009

To improve the mechanical properties of WC-Co cemented carbides, a dual composite was studied. The compositions of granule and matrix were nano-sized WC-6 wt% Co(granule) and normal sized WC-20 wt% Co(matrix), respectively. The granules were made by spray-drying method and sintered at 1380°C for 10 minutes in vacuum. After sieving, the granules were grouped to 50, 100 and 150 ㎛ and mixed with WC and Co powders as the volume fractions of granule to matrix were 50 to 50, 40 to 60 and 30 to 70. These compacts were sintered at 1380°C for 10 minutes in vacuum. The microstructure, transverse rupture strength and wear resistance were investigated. The relative densities of the dual composites were about 98% after sintering. The mean size of the WC grains in the dual composite was about 300~400 nm. As the volume fraction of the matrix in the dual composite increased, the transverse rupture strength increased and hardness decreased. The wear resistance of the dual composite increased with decreasing matrix volume fraction and increasing granule size.
Influence of Cobalt Content on the Fatigue Strength of WC-Co Hardmetals
Authors: Nakajima Takeshi , Hosokawa Hiroyuki , Shimojima Koji
Published: March 2009

The behavior of hardmetals under cyclic loads is investigated. Unnotched specimens were employed to obtain practical information regarding fatigue in hardmetals. All the tested hardmetals exhibit an increase in the number of cycles until failure with a decrease in the maximum stress, i.e., the hardmetals exhibit a high fatigue sensitivity. The fatigue strength increases with the cobalt content. Although distinct fatigue limits, as observed in metals, cannot be observed, the calculated fatigue limit stress at 107 cycles is found to be approximately 70% of the flexural strength, and the stress value exhibits a linear relationship with the flexural stress.
Synthesis and Characterization of Branched Sulfonated Poly(ether Sulfone-Ketone) Copolymer and Organic-Inorganic Nano Composite Membranes
Authors: Lee Dong Hoon , Park Hye Suk , Seo Dong Wan , Hong Tae Whan , Ur Soon Chul , Kim Whan Gi
Published: March 2009

Branched sulfonated poly(ether sulfone-ketone) copolymer was prepared with bisphenol A, 4,4-difluorobenzophenone, sulfonated chlorophenyl sulfone (40mole% of bisphenol A) and THPE (1,1,1-tris-p-hydroxyphenylethane) as a branching agent. THPE was used 0.4 mol% of bisphenol A to synthesize branched copolymers. Organic-inorganic nano composite membranes were prepared with copolymer and a series of SiO2 nanoparticles (20 nm, 4, 7 and 10 wt%). The composite membranes were cast from dimethylsulfoxide solutions. The films were converted from the salt to acid forms with dilute hydrochloric acid. The membranes were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. Branched copolymer and nano composite membranes exhibited proton conductivities from 1.12x10-3 to 6.04x10-3 S/cm2, water uptake from 52.9 to 62.4%, IEC from 0.81 to 1.21 meq/g and methanol diffusion coefficients from 1.2x10-7 to 1.5x10-7 cm2/S.
Synthesis of WC-10wt.%Co Nanocrystalline Powders with Grain Growth Inhibitor by MTP
Authors: Park Dong Kyu , Jung Kwang Chul , Kim Jin Chun , Bae Sung Yeal , Ahn In Sup
Published: March 2009

To improve the fracture strength and wear resistance of WC-Co cemented carbide,
various technologies have been developed related producing the nano crystalline. There have
been extensive studied conducted to retard grain growth during liquid phase sintering. However,
when this inhibitor is added by simple mixing, a micro-pores forms during sintering In this study,
WC-Co nanocrystalline powders with grain growth inhibitor in the site were prepared by MTP
(Mechano-Thermic carburizing Process) to minimize this formation of micro pores and to retard
grain growth effectively during sintering. In addition, then the phase and grain size of WC-Co
nanocrystalline powders were evaluated according to the condition of MTP.
Influences of Doping Methods on Microstructure and Fracture Toughness of Mo-La Alloys
Authors: Wang Lin , Sun Yuan Jun , Luo Jian Hai , Zhu Yon Gan , Niu Ping Wen
Published: March 2009

Lanthanum oxide was introduced to molybdenum powder by liquid-liquid doping and
liquid-solid doping respectively. Mo alloys were prepared by powder metallurgy technology. The
size distribution and feature of dopant particles and the fractographs of Mo alloys were investigated
by TEM and SEM respectively. The results indicated that liquid-liquid doping method is favorable
for refining and dispersing La2O3 particles uniformly in matrix. Fracture toughness of Mo alloys
prepared by liquid-liquid doping showed better results than that of liquid-solid doping. Furthermore,
the influences of the size distribution of La2O3 on properties of Mo alloys was discussed by
dislocation pile-up theory.
Determination of Non-Stoichiometry of Tubular Titanium Carbide Formed by Self-Propagating High Temperature Synthesis
Authors: Choi Y. , Cho Nam Ihn
Published: March 2009

Titinium carbide (TiCx) was produced by self-propagating high temperature synthesis
(SHS) method. The morphology and non-stoichiometric number of the SHS product were observed
by scanning electron microscopy and neutron diffractometry, respectively. Tubular titanium carbide
with hole inside was formed with different non-stoichiometric number (x), which value increased
with combustion temperature.