bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of Mold Filling and Solidification on Gravity Casting of Al-Si Alloy (A357)
Authors: Mi Guo Fa , Zhao Heng Tao , Wang Kuang Fei , Xu Zhi An , Niu Ji Tai
Published: March 2009

The temperature at specific positions was measured by multi-channel data acquisition
system in order to understand the solidification and feeding process of the sample. The Olympus
metallurgical microscope was used to observe the macrostructure of the casting and analyze the
freezing mechanism. The mold filling and solidification processes of the Al-alloy sample were
studied by using the commercialized simulation software Z-Cast. And the simulated result was
compared with the results of practical pouring test. When preheat temperature of mold is low, the
pouring temperature should be higher in order to ensure completely filling of mold. As a result the
solidification of sample could be feeding effectively, and the shrinkage on the upper end of sample
could be eliminated. It is shown that the casting simulation software Z-CAST can be used to
simulate the filling and solidification process of gravity cast Al alloy and can provide exact flow
fields and temperature fields thus can predict cast defects and their positions.
Numerical Analysis of Electromagnetic Field of Solid Rotor Asynchronous Permanent Magnetic Coupling by Finite Element Method
Authors: Yang Chao Jun , Li Quan Wen , Ma Hong Liang , Jiang Sheng Fa
Published: March 2009

A new-type of solid rotor asynchronous magnetic coupling which works on the principle
of electromagnetic induction is researched by ourselves. This kind of asynchronous magnetic
coupling can solve the problem effectively that the permanent magnets on its inner rotor is
demagnetized if its temperature is too high, because its inner rotor need not the permanent magnets.
in order to study the transmission capability of the new-type magnetic coupling, its magnetic field
should be analyzed. Because of its magnetic field variety, it is extremely complicated and a
precision result is difficult to be got by the analytic method of the magnetic field calculation. Here
the software ANSYS FEM is used to analyze its magnetic field. And some formulas were deduced
and used to calculate its torque. The experimental and calculational results indicate that this design
is practicable.
Semi-Enclosed Cold Forging Process Analysis and Progressive Die Design of CPU Fin
Authors: Su Juan Hua , Ren Feng Zhang , Wang Lei
Published: March 2009

This paper analyzes the forming process methods of fin used in CPU chip to emit heat.
The whole process is blanking, the first forging forming, the second forging (sizing), and trimming.
The chamfer design of CPU fin blank is simulated by finite element analysis. The optimized
chamfer 1.6 mm is available. Semi-enclosed cold forging of progressive dies is put forward. The
newly designed transfer unit is applied, which unifies the merit of high efficiency of the progressive
dies and the high material-using ratio of the project die. Quick disassembly structure is designed
and pins are used as quick disassembly pins by means of ball bearing bushing. The unique
processing of the shearing scrap structure is adopted when designing the inverted trimming dies.
Compared with the traditional die, the mechanization and electrization are realized to increase the
production efficiency and get highly precise CPU fin.
Forecast of Discharge Voltage for Electromagnetic Tube Forming Based on FEM Analysis
Authors: Yu Hai Ping , Li Chun Feng , Deng Jiang Hua
Published: March 2009

Forecast of discharge parameters is one of the key problems needed to solve urgently for
applications of electromagnetic forming technology (EMF). In this work, the forecast of discharge
voltage for electromagnetic tube forming has been investigated through a combination of the
sequential coupling numerical simulation of EMF process and the design optimization of tube
deformation. The optimum design of tube deformation during EMF process is discussed. The relative
error between the experimental value and the forecast one is less than 5.9%, which indicates that the
discharge voltage forecast method is feasible. This forecast method will be a favorable way for the
optimum design of electromagnetic sheet metal forming and tube forming with die.
Investigation to the Damage Tolerance of Composite Cylinder for Vehicles by Numerical Simulation
Authors: Xu Yan Hai , Li Yong Sheng , Huang Hai Bo
Published: March 2009

As one type of the important alternative fuel containers, composite cylinders are widely
used in compressed natural gas vehicles (CNGV) all over the world. Compared to traditional metal
containers, the performance of composite cylinders is more complicate because it is difficult to
analyze the material characteristics and the influence of manufacturing process. With the aid of
numerical simulation, the damage tolerance of one type of composite cylinder was investigated in
this paper. Firstly, the usual damage modes and sizes that are generated in the serviced composite
cylinders are classified to illustrate the dangerous parts in the composite cylinders. According to the
manufacturing process of composite cylinders, the fiber material characteristics that account of the
effects of heat and resin are evaluated to conduct the numerical simulation. Under the damage
modes and sizes such as initial flaw, fiber fracture and delamination that are distributed in the
cylinder in terms of the classification, the performance of composite cylinder are carried out. With
the convenience of numerical simulation, the map of the dangerous sites under the elaborate
damage modes and sizes is given to evaluate the running condition of composite cylinders in
practice. The quantitative results are more useful to show the damage tolerance of composite
cylinder than the traditionally qualitative check way and guarantee the running of CNGV.
Numerical Simulation of Rheo-Diecasting Mould Filling Process of Semisolid Magnesium Alloys
Authors: Yan Hong , Wang Tao , Fu Ming Fu
Published: March 2009

Base on the coupled three-dimensional model of flow temperature and apparent viscosity
on semisolid materials, the mould filling processes of liquid and semisolid magnesium alloys have
been analyzed. The simulation results showed that the semisolid mould filling with the characteristic
of pseudo-plasticity and Bingham type is steady and the air entrapment is much smaller than that of
liquid die casting. Therefore, the semisolid die casting can prevent from those defects produced by
the traditional die casting, which offer a new technology for lower interior defects and better quality.
Computer Simulation of Metal Forming Processes
Authors: Solomonov K.N. , Abashkin V.P.
Published: March 2009

In the environment of visual programming DELPHI there is developed the program complex
enabling to make express-analysis of the picture of metal flow while forming of workpieces
and to offer technological receptions for elimination of non-uniformity of shaping separate parts of
workpiece, and also for decrease in the forces necessary for workpiece forming.
Investigation of Relationship between Material Flow Direction and Local Stress Field in Plastic Deformation
Authors: Zhang Ji , He Zhu Bin , Yuan Shi Jian
Published: March 2009

The maximum mean stress gradient direction in typical plane strain and axisymmetrical
plastic deformation problems was calculated by numerical method to investigate relationships
between material flow direction and related local stress field. Good agreement was found between
the movement direction in the deforming bodies and the maximum mean stress gradient direction of
the related local mean stress field. This agreement was also found in typical 3-D problems by
numerical simulation and visualization.
Numerical Simulation and Analysis of Flow Field in TIG Arc Brazed Filler Metal Droplet
Authors: Li Rui Feng , Yu Zhi Shui , Qi Kai
Published: March 2009

Arc brazing technology for joining has been recently developed. Because of its
advantages, it has been used more and more frequently in the automobile industry, and this
technology is widely used in practical joining applications. Many welding researchers have paid
more and more attentions in this field. Based on the experimental analysis of CuSi3 filler metal
spreading, wetting behavior on galvanized steel sheet and its interfacial microstructure in tungsten
inert gas (TIG) arc brazing process, the governing equations and boundary conditions of filler metal
droplets under the actions of gravitational force, surface tension and arc pressure force is conducted,
then they have been transformed into finite volume equations, The flow behavior at different arcing
time in filler metal droplet was calculated by PHOENICS code using SIMPLEST algorithm. It can
be concluded that the flow adjacent to the surface controls the final droplet profile, and the fluid
flow does great contribution to the whisker-like intermetallic compound fragmentation behavior due
to its stirring force at the interface. The simulation is useful to interpret the free surface evolving
behavior and the final profile of filler metal droplet in arc brazing, it also provide a new idea about
the interface growth behavior study and offer a practical guide in production.
The Simulation of Residual Stress for Stud Welding and Establishment of Strength Estimating Model
Authors: Zhou Guang Tao , Liu Xue Song , Liang Guo Li , Liu Pei Zhi , Yan De Jun , Fang Hong Yuan
Published: March 2009

The distribution and value of welding residual stress for 1Cr18Ni9 stainless steel stud
welding joints was systemically simulated by ANSYS FE software. The mathematical estimating
models of strength of the welded joints were established. Simulation results showed that the
welding residual stress was tensile at the edge of the stud, while it was compressive stress at the
position near axis center. The largest tensile stress did not exceed yield limit of material. The
residual stress had more influence on the strength of welded joints.
Influence of Temperature on Field-Induced Reorientation Strain in Magnetic Shape Memory Alloy
Authors: Zhu Yu Ping , Dui Guan Suo
Published: March 2009

A constitutive model for magnetic shape memory alloys is developed through a combined
consideration of micromechanical and thermodynamic theories. Of special concern is the influence of
different temperatures on field-induced reorientation strain for a NiMnGa single-crystal specimen.
The theoretical results are found to be in general agreement with experimental data. It is shown that
the method is accurate and simple.
Influence of Delamination of Epoxy/Dielectric Interfaces on Pattern Shift and Passivation Cracking under Aeronautical Conditions
Authors: He Yu Ting , Li Hong Peng , Cui Rong Hong , Fan Chao Hua
Published: March 2009

Interfacial delamination is a recognized failure mode in Integrated circuits (ICs). A major
cause for this failure is the mismatch of Thermal Expansion Coefficients, Young’s modulus, and
Poisson’s ratios of the package materials. Here, the influence of delamination between epoxy and
dielectric layers on pattern shift and passivation cracking in IC package under aeronautical
conditions, mainly temperature and load cycles, is studied by maximum plastic strain and maximum
principal stresses theory using a certain 2D FEM model with different delamination length
“L_c.right”. Delaminations are easy to introduce more dangerous impact to the package, because
the IC microstructures endure serious thermo-mechanical loading under aeronautical working
conditions. The method can be used to find the dangerous designed structure schedules and will
provide a basis for selecting passivation materials of aeronautical IC packages.
J-Integral Estimation for the 3-D Through-Thickness Centre-Cracks in Welds of Structural Steels
Authors: Lee Chin Hyung , Chang Kyong Ho
Published: March 2009

For the fracture analysis of a crack in welds, residual stress analysis and fracture mechanics
analysis must be performed sequentially. In this study, characteristics of residual stresses in welds of
structural steels (SM490, SM520, SM570) were presented by carrying out three-dimensional (3-D)
thermal elastic-plastic finite element (FE) analysis. Then, an FE analysis method which was able to
calculate domain-independent values of the J-integral for a crack in a 3-D residual stress bearing body
was developed to evaluate the J-integral for a mode-I centre-crack in welds of structural steels when
mechanical stresses were applied in conjunction with residual stresses. The results show that the
longitudinal residual stresses in welds increase with increasing yield stress of the welded steel
(SM490<SM520<SM570). For the through-thickness centre-cracks in welds of structural steels
where only residual stresses are present, the J-integral values increase with increasing yield stress of
the welded steel. This is because the longitudinal residual stresses in welds, which in this case act as
the crack driving force, increase with increasing yield stress of the welded steel. Furthermore, the
values of the J-integral for the case when mechanical stresses, applied in conjunction with residual
stresses, are larger than those for the case when only residual stresses are present. This is because
tensile stresses by mechanical loading are added to the existing residual stresses; hence the crack
driving force is larger.
High-Accuracy Optical Subassembly for High Speed Data Transmission above 10 Gb/s/ch
Authors: Hwang Sung Hwan , Lim Jung Woon , Park Hyo Hoon , Jeong Myung Yong , Rho Byung Sup
Published: March 2009

An optical subassembly which is suitable for high speed and parallel optical modules was
introduced. The optical subassembly has features of low optical coupling loss less than 1.5 dB and
wide 3-dB bandwidth more than 20 GHz in the view of the transmission line. And it was fabricated
with a vertically stacked structure cost-effectively and precisely.
Reliability Assessment of Lead Free Soldered PWBs
Authors: Cho Il Je , Chae Kyu Sang , Kim Soon Tae , Wittler Olaf , Shin Young Eui
Published: March 2009

High integration, density and complexity are essential in electronic products such as
compact and light mobile phone recently. A new type of development for component and material
is also needed. In the PCB design aspect, a technique such as pad on via, trying to keep up with the
demand for compact and slim products, is commonly used. In a response to increased pressure from
these situations, an enhanced ability on reliability of electronic products is gradually needed. The
high cost and risk, however, are higher and higher for the assurance in the reliability. We made a
procedure which can evaluate a solder joint reliability on the product development phase.
Furthermore, we've pursued a development process for preventing failure as we analyzed the failure
mode from predicting the causes of the failure more precisely. In this study, focusing on the joint
reliability of the solder interconnection between CSP and pad on via, we have passed through a test
procedure as follows. First, making samples applied with high integrated circuit (CSP: 0.65 pitch,
via hole size: 165um, solder: Sn-3.0Ag-0.5Cu). Second, operating the thermal cycling experiment (-
45°C~+125°C, 30min/cycle) to find a failure of the test specimen with an electrical method. Third,
observation the non-destructive X-ray microscopy and the metallographic cross-sectioning. Fourth,
simulation of the finite element model and deformation analysis. Fifth, completion the modeling of
the failure mode. Lastly, prediction a lifetime of the solder joint.
Efficient Diffusion Bonding between BSCCO Superconducting Multifilamentary Tapes
Authors: Zou Gui Sheng , Wang Yan Ju , Wu Ai Ping , Bai Hai Lin , Hu Nai Jun , Song Xiu Hua , Yi Han Ping
Published: March 2009

To improve the joining efficiency of Bi-Sr-Ca-Cu-O ( BSCCO) superconducting tapes, a
new diffusion bonding technology with a direct uniaxial pressing at high temperature was
developed to join 61-filament tapes. It was observed that bonding parameters such as bonding
pressure and holding time, significantly affected the critical current ratio (CCRo). A peak CCRo
value of 89 % for the lap-joined tapes was achieved at 3 MPa for 2 h when bonding temperature
was 800 °C. Compared with the conventional diffusion bonding technology, this new technology
remarkably shortened the fabrication period and improved the superconductivity of the joints. The
bonding interface and microstructures of the joints were evaluated and correlated to the CCRo. An
uniaxial pressing at high temperature was beneficial to interface bonding, and there was an optimal
pressure value for the CCRo.
Mechanical and Microstructural Properties of Friction Spot Joined 5052 and 6111 Al Alloys
Authors: Chang Woong Seong , Chun Chang Keun , Kim Heung Ju , Cho Hyeon Jin , Kim Teuk Ki
Published: March 2009

Friction spot joining was used to make lap joints on strips of 5052 and 6111 aluminum
alloys. The influence of joining parameters such as tool rotation speeds, plunge depths and dwell
times on the weld joint properties were evaluated. A wide range of joining conditions could be
applied to join Al alloys without defects in the weld except for certain welding conditions with an
insufficient heat input. The microstructures and hardness variations in the welds were discussed.
The microstructures of welds, corresponding to the pin hole, have dynamic-recrystallized grain
similar to stir zone in FSW weld. In hardness distribution, minimum hardness region was located
about 6-mm away from the weld center, corresponding to the shoulder radius of the tool. For each
weld the results from tensile-shear tests are also presented. For sound joints without defects, tensile
shear fractured load of weld joints was higher approximately 230% than acceptable criteria of
tensile shear strength of electrical resistance spot-welded joints for aluminum (MIL-W-6858D).
Modelling the Heat and Fluid Flow in the Welded Pool from High Power Arc Sources
Authors: Leoveanu Ioan Sorin , Zgura Gheorghe
Published: March 2009

The paper proposes a numerical method for analyzing the complex phenomena’s that appear in the
case of keyholes welded pool geometry. Present model consist in a succession of analyses steps,
needed to solve the interaction between the liquid/solid, liquid/protection gaze and liquid/MHD
welded arc for arc welding, or electrons, or electromagnetic waves. The liquid/solid geometry result
by dissipation of the welding power source in a matrix of many point sources. This process gives a
first approximation of temperature fields and a good approximation of the digit 3D position, and
information about the vaporization area.
Applicability Evaluation of SS (Structural Stress) Method on Actual Project
Authors: Kim Kwang Seok , Kang Joong Kyoo , Heo Joo Ho , Lee Sung Geun
Published: March 2009

The structural stress (SS) method developed by BATTELLE has been studied based on small or mid-size
scale specimens. In order to apply the new method, such as SS, on an actual project, it should have application results
on actual project. However, SS method didn’t have a lot of application data compared to class procedure using hot spot
stress (HSS). In order to find out whether the SS method, for the evaluation of fatigue life, can give reasonable results
when it is applied under the same loading suggested by classification societies, it was compared with fatigue lives
derived by class. ABS & DNV’s simplified fatigue analysis method were adopted to check the validity of SS method.
Before applying complicated loading of class, static loading case was applied, since the class method has their own
correlation factor for wave loading. And then, simplified fatigue analysis was performed with more complicated loading
cases. From the results of fatigue life calculation, it can be said that SS shows reasonable fatigue lives with respect to
HSS or notch stress based fatigue lives.
Microstructural Evolution in 304 Austenitic Stainless Steel during Friction Stir Welding
Authors: Kokawa Hiroyuki , Park Seung Hwan C. , Sato Yutaka S. , Okamoto Kazutaka , Hirano Satoshi , Inagaki Masahisa
Published: March 2009

The characteristics of microstructures in friction stir (FS) weld of 304 austenitic stainless
steel were examined. The stir zone (SZ) and thermomechanically affected zone (TMAZ) showed
dynamically recrystallized and recovered microstructures, respectively. The hardness of the SZ was
higher than that of the base material and the maximum hardness was located in the TMAZ. The
higher hardness in TMAZ was attributed to high density of dislocations and sub-boundaries.
Electron microscopic observations revealed that ferrite and sigma phases were formed in austenite
matrix in the SZ during friction stir welding (FSW).
Acoustic-Assisted, Magnetic-Field-Induced Actuation of Ni-Mn-Ga Single Crystals
Authors: Techapiesancharoenkij Ratchat , Allen Samuel M. , O'Handley Robert C.
Published: March 2009

Ni–Mn–Ga based ferromagnetic shape memory alloys (FSMAs) have emerged as a
promising class of active materials capable of producing a large (up to 10%) magnetic-field-induced
strain (MFIS). This large strain is not the familiar anisotropic magnetostriction; it results from
field-induced twin-boundary motion and has appropriately been referred to as magnetoplasticity.
FSMAs still have several characteristic shortcomings that may limit their potential applications. A
threshold field of 150 to 300 kA/m must be overcome to initiate twin-boundary motion and a larger
field is required to achieve full strain. The operating window of the stress output from FSMA
actuators is limited to the range between 1 and 1.5 MPa. Outside this operating range, the strain
output diminishes significantly. This paper addresses these performance limitations and describes
an acoustic-assist technique that has been shown to decrease the required threshold field and
increase the stress and strain output of FSMA actuation. The application of an acoustic assistance
from a 33-mode piezoelectric stack is shown to improve MFIS of Ni–Mn–Ga single crystals by
reducing the required threshold field and twinning-yield stress. Threshold field reductions of up to
80 kA/m are observed, and the twinning-yield stress can be reduced by up to 0.5 MPa. The effect of
acoustic assistance on FSMA actuation can be understood as a form of time varying stress waves
that facilitate twin-boundary motion. A stress wave analysis is shown to give a quantitative
understanding of the measured reduction in the twinning-yield stress. For FSMA cyclic actuation,
both operating stress and strain outputs of the FSMA actuation are significantly enhanced by
acoustic assistance. Without the acoustic assistance, the maximum reversible strain of the sample
used here is 3% and appears only in the limited external stress range between 0.7 and 1 MPa. With
the acoustic assistance, the maximum reversible strain increases to 4.5% and appears in a broader
range of stress output between 0.4 and 1.2 MPa. The reduction in the twinning-yield stress due to
the acoustic assistance significantly improves the FSMA cyclic actuation performance; magnetic
energy not used to drive twin-boundary motion can be utilized to work against a larger external
load.
Advantages and Limitations of HPT: A Review
Authors: Pippan Reinhard , Scheriau Stephan , Hohenwarter Anton , Hafok Martin
Published: March 2009

The improvements in the design of the HPT tools lead to a well defined torsion
deformation and permits, therefore, a comparison with other SPD-techniques. The design of the
tools, the advantages and disadvantages of HPT, as well as the limitation in the sample size are
discussed.
Influence of Post-ECAP TMT on Mechanical Properties of the Wrought Magnesium Alloy AZ80
Authors: Müller Julia , Janeček Miloš , Wagner Lothar
Published: March 2009

It is well-known that the high-cycle fatigue (HCF) performance of severe plastically
deformed wrought magnesium alloys is not as good as one might expect from the significant grain
size refinement. Although enhanced HCF strength after ECAP as compared to as-cast material was
observed its value was significantly lower than after conventional extruding. The present
investigation was undertaken to determine whether the relatively poor HCF strength of the ECAP
processed wrought magnesium alloy AZ80 is associated with the ECAP-induced unfavorable
crystallographic textures. Post-ECAP thermo-mechanical treatment (TMT) was found to result in
favorable texture modifications as well as in markedly improved HCF performance. The proposed
novel technique consists of a not yet used combination of severe plastic deformation via ECAP
followed by a 1-step swaging process. It is shown that the resulting combination of both ultrafinegrain
sized material and beneficial crystallographic texture results in superior HCF performance not
achievable by ECAP-processing alone.
Microstructure Characterization of Aluminium Syntactic Functionally Graded Composites Containing Hollow Ceramic Microspheres Manufactured by Radial Centrifugal Casting
Authors: Ferreira S.C. , Velhinho Alexandre , Rocha L.A. , Braz Fernandes Francisco Manuel
Published: March 2009

Syntactic functionally graded metal matrix composites (SFGMMC) are a class of
metallic foams in which closed porosity results from the presence of hollow ceramic microspheres
(microballoons), whose spatial distribution varies continuously between the inner and the outer
section of the part, thus resulting in a continuous variation in properties. In this work, aluminiumbased
SFGMMC rings were fabricated by radial centrifugal casting. The graded composition along
the radial direction is controlled mainly by the difference in the centrifugal forces which act on the
molten metal matrix and the ceramic particles, due to their dissimilar densities. In this case where
the density of the SiO2-Al2O3 microballoons is lower than that of molten aluminium, the particles
show a tendency to remain closer to the inner periphery of the ring. Thus the microballoon volume
fraction increases along the radial direction of the ring from the outer to the inner periphery; in
other words, the particle-rich zone is limited to an inner layer of the ring. Precursor conventional
MMCs were prepared by stir-casting from the constituent materials, by homogeneously dispersing
commercial SiO2-Al2O3 microballoons (particle size: 50 µm; particle volume fraction: 5 and 10 %)
within a molten commercial Al-7Si-0.3Mg (A356) alloy. The resulting MMCs were then re-melt
and centrifugally cast in order to produce the functionally graded composites. Particle gradients in
the centrifugally cast composites were investigated by quantitative image analysis of optical
micrographs (for the estimation of the particle volume fraction, mean particle diameter and porosity
volume fraction).
Reactive DC Magnetron Sputtering of Vanadium Oxide Thin Films
Authors: Batista C. , Mendes J. , Teixeira Vasco , Carneiro Joaquim
Published: March 2009

Vanadium oxides are a class of materials with outstanding physical and chemical
properties. They find a wide field of technological applications such as optical and electrical
switching devices, light detectors, temperature sensors, micro batteries, etc. There are several
studies regarding the production of vanadium oxide films by radio-frequency (RF) magnetron
sputtering, and with increasing interest on the thermochromic VO2 phase. However, literature with
focus on vanadium oxide films deposited by direct current (DC) magnetron sputtering is very
limited. In this work, we have successfully deposited vanadium oxide thin films by reactive DC
magnetron sputtering under several processing conditions. The effect of substrate type, temperature,
and O2/Ar flow ratio on phase formation has been studied. Structural analysis and phase
determination have been carried out by X-ray diffractometry (XRD). Some single phase samples
were also analysed with respect to surface morphology by means of scanning electron microscopy
(SEM) and atomic force microscopy (AFM). The thermochromic behaviour of single phase VO2(M)
films has been evaluated by optical spectrophotometry.
Hyperelastic Modelling of Cork-Polyurethane Gel Composites: Non-Linear FEA Implementation in 3D Foot Model
Authors: Antunes P.J. , Dias Gustavo R. , Coelho A.T. , Rebelo F. , Pereira T.
Published: March 2009

The CPGC – Cork-Polyurethane Gel Composite is a material that is mechanically
characterized by non-linear elastic behaviour at large deformations. The non-linear behaviour can be
modelled by hyperelastic constitutive models based on strain energy functions enabling a structured
phenomenological framework for CPGC material modelling. The CPGC is a promising material for
human comfort enhancement and dynamic damping/control applications. This paper presents the
experimental methodology used for the CPGC evaluation of material parameters used in the
hyperelastic models and the finite element model build-up. A 3D foot FEA model is presented in
order to evaluate the performance of the hyperelastic model in a real case situation and the
mechanical performance of shoe insoles, namely, trough the monitoring of the contact pressure
values at the insole/foot interface.
Different Ways to Regenerate an Activated Carbon: Comparison between an Activated Carbon from Cork and a Commercial Carbon
Authors: Mourão Paulo A.M. , Carrott Peter J.M. , Ribeiro Carrott Manuela M.L. , Marques Luisa
Published: March 2009

Activated carbons are materials extensively used to remove a variety of pollutants in
different media. The porous structure, the surface chemistry and the type of adsorptive determine
the potential of activated carbons as an adsorbent material. However, in a more global perspective it
is necessary to consider other factors such as the economical viability of production and reuse. This
last factor depends on the capacity of regeneration of the activated carbons after each application.
Following this guideline, the objective of this work was to evaluate the capacity of regeneration of
some specific activated carbons prepared from cork oak wastes, used in the adsorption of phenolic
compounds in the liquid phase. Simultaneously, the performance of our carbons are compared with
the behaviour of a commercial carbon (Norit SX plus). The experimental procedure consists in the
adsorption of one phenolic compound, followed by the regeneration of the adsorbent, succeeding a
series of adsorption/regeneration processes. The methods of regeneration used were simple washing
with distilled water under magnetic stirring, washing with ultrasound and thermal regeneration
under inert atmosphere. The performance of the activated carbons was strongly dependent on their
nature and the regeneration method applied.
Copper Slag Mortar Properties
Authors: Resende Célia , Cachim Paulo B. , Bastos Ana Maria
Published: March 2009

Copper slag is a copper industry waste that is essentially used as an abrasive for metals to
remove coatings or paintings, due to its hardness, sieve distribution and rough surface, mainly in the
naval industry. After the wearing process, copper slag retains most of its original properties, and
remaining an environmental problem. Chemical composition of copper slag presents a high Fe, Si
and Al oxide content what makes it a pozzolanic material. Thus, it is possible to use it as a partial
replacement for sand and after triturating it into very small particles as a replacement for cement.
After a chemical, physical, mineralogical, and environmental characterization of copper slag, its use
as a partial replacement of sand on mortars was investigated. The experimental program was
developed to evaluate the effect of several percentages of sand substitution in mortars. For mortars
25, 50 and 75 % of sand replacement by volume was studied. A standard 1/3 cement/sand ratio, by
weight, with cement type CEM 42.5 I, was used. The type of sand and the effect of washing the slag
were also investigated. Strength was measured at 7, 28, 60 and 90 days. Results obtained until now
indicate that a reduction of strength occurs when the slag content increases. Additionally, it was
observed a delay of the hardening process by the addition of the copper slag. As a conclusion, the
use of copper slag as a sand replacement seemed to be a practical option.
Comparative Study of Magnesium By-Products and Vermiculite Formulations to Obtain Fire Resistant Mortars
Authors: Formosa-Mitjans Joan , Haurie L. , Chimenos-Ribera Josep Maria , Lacasta Anna M. , Rosell Joan Ramon
Published: March 2009

There exists an increasing concern about the dangers originated in a building in case of
fire. In this work the behaviour of vermiculite as aggregate in fireproof mortars was compared with
mortars formulated with two magnesium by-products aggregates which undergo an endothermic
decomposition. Fire resistance and mechanical properties were evaluated. An optimal mixture of
both magnesium by-products as aggregates allows formulating mortars that improve fire resistance
at temperatures greater than 450 °C compared with vermiculite mortars. It would be interesting to
obtain mortars formulated with magnesium by products and vermiculite to study possible synergic
effects.
The Influence of the Milling Media Environment on the Characteristics of a W-Cu Composite Powder
Authors: Costa Franciné Alves , de Carvalho W.M. , Silva A.G.P. , Gomes Uilame Umbelino , Silva José F. , Ambrozio Filho Francisco
Published: March 2009

W-Cu composite powders were prepared by high energy milling under two milling
environments: cyclohexane and air. Composite particles are formed in both cases. The W particles
are fragmented and embedded into the Cu particles. Both, W and Cu, are heavily strained, mainly in
the first hours of milling. The composite powder has high homogeneity and is much finer than the
original Cu powder. The mean particle size of the powders milled in both conditions is very close,
but the wet milling was near 25% longer than dry milling and the size distribution is wider. This is
consequence of the higher milling intensity of dry milling.
Hydrogen Addition Effect on 3D Porous Titanium Produced by Powder Metallurgy
Authors: Braga N.A. , Ferreira N.G. , Neto Francisco Piorino , Baldan M.R. , Cairo Carlos Alberto Alves
Published: March 2009

Titanium is an attractive material for structural and biomedical applications because
of its excellent corrosion resistance, biocompatibility and high strength-to-weight ratio.
Power metallurgy was used in this work to prepare 3D porous titanium. The powders became
fragile from hydrogenation process and were able to be used to obtain compacts with
different porosities by uniaxial pressing and sintering without applied pressure. Since
hydrogen dissolves easily in titanium to form titanium hydrides which have a strong
influence on the microstructure coarsening and mechanical properties, the study of the
porous compacts hydrogenation was carried out by hydrogenation at different temperatures
(870 K up to 1070 K) in a hot filament reactor. Titanium surface morphology changes were
investigated by scanning electron microscopy. High resolution x-ray was used to characterize
the present phases. Evaluation of the porous titanium hydrides mechanical behavior was
realized by flexion assay performed at three points.
Mineral Constituents of a Clay from Campos dos Goytacazes, Brazil
Authors: Terrones L.A.H. , Rocha Ana L.A. , Vieira Carlos Maurício Fontes , Monteiro Sérgio Neves
Published: March 2009

The mineral constituents of a typical clay from Campos dos Goytacazes, Brazil, were
investigated in terms of their nature and morphology by analytical methods including transmission
electron microscopy and energy dispersive spectroscopy. The clay was found to have a large amount
of finer, < 2 μm, aluminumsilicate particles of kaolinite and, in smaller proportion, halloysite, which
is also an aluminumsilicate. At 1050oC the clay shows a consolidated structure with continuous
glassy matrix in which Ti, Fe and Si oxides as well as mullite crystals are thoroughly embedded.
Characterization of ZrO2 and Al2O3 Bioceramics Obtained by Gelcasting
Authors: dos Santos Claudinei , Prado Pedro H.B. , dos Santos Ortega Fernando
Published: March 2009

Gelcasting is a novel method of forming ceramics and has been increasingly employed
in preparing complex-shaped, near-net-shape advanced materials. In this work, alumina,
zirconia and alumina-zirconia bioceramics were shaped by gelcasting, using MAM-MBAM
monomer system, with subsequent sintering and characterization. High purity tetragonal ZrO2
(3mol%Y2O3) and .Al2O3 powders were used as starting powders. Powder mixture containing
80 wt.% of alumina and 20 wt.% of tetragonal zirconia were obtained by
milling/homogenization. In all cases, the suspension obtained had at least 55 vol.% solid
loading. Ceramic bodies were demolded, dried and characterized by green relative density. The
compacts were sintered in air at 1550 and 15750C, for 120 minutes, with controlled heating-rate
to facilitate organic compounds removal. Sintered samples were characterized by relative
density, and analyzed by X-Ray diffraction and scanning electronic microscopy. Hardness and
fracture toughness were determined using Vicker’s indentation method.
Production of Cellular Ceramics by Gel Casting Ceramic Emulsions
Authors: de Sousa Trichês Eliandra , Dellú Milton , Pandolfelli Victor Carlos , dos Santos Ortega Fernando
Published: March 2009

Cellular ceramics have been produced by several methods, giving a wide range of
macrostructures and properties. This work describes a novel route to produce cellular ceramics
based on the gel casting of emulsions consisting in an aqueous ceramic suspension containing
water-soluble organic monomers and an emulsified insoluble liquid phase. The effects of solids
loading and kerosene fraction on the rheological properties of emulsions were characterized.
Samples with different kerosene additions (20, 30, 40 and 50 %vol.) were produced and their green
and sintered densities were measured. The results have shown a good correlation between the
volumetric fraction of kerosene into the emulsion and the porosity of samples. Diametrical
compression was used to evaluate the strength of sintered samples, which varied with the porosity
between 18 and 37 MPa. The cellular structure was analyzed by SEM and revealed isolated pores
for samples with low porosity, which changed to an interconnected network of pores as the porosity
increased.
YZrO2-Ni Cermet Processing by High Energy Milling
Authors: Restivo Thomaz Augusto Guisard , de Mello-Castanho Sonia Regina Homem
Published: March 2009

A new method for SOFC fuel cell anode preparation is proposed where the main
difference lies over cermet powder processing by high energy milling. Yttria stabilized zirconia
powder and metallic nickel undergo co-milling in a vibratory device employing zirconia bead
media. Dispersed and homogeneous powders are therefore obtained. The material is pressed
uniaxialy and sintered at 1350°C for 0,5 h in air and under argon and hydrogen. In the former case,
partial nickel oxidation occurs before sintering leading to small shrinkage down to 2% and porosity
about 38%. Linear shrinkages from 5 to 7% after sintering in both inert and reduced atmospheres
were observed not demanding pore-former additives. Conventional YSZ, Ni and NiO powder
mixtures were prepared for comparison purpose. The high energy milling process is able to reduce
the starting sintering temperature by 130° C besides a higher densification compared to the simple
mixtures YSZ+Ni. The excessive sintering and particle coalescence is absent in high energy milled
material, where the metal is well dispersed and the microstructure is highly homogenous. The high
energy milling process is a promising route to prepare with excellent performance anode materials
for SOFC cells.
Evaluation of Silicon Nitride Ceramic Cutting Tools with Diamond Coatings
Authors: Lanna M.A. , Abrão A.M. , Levy Neto F. , dos Santos Claudinei , Silva Cosme Roberto Moreira
Published: March 2009

There is a substantial increase on carbon-carbon composites use for engineering applications,
considering its high temperature properties and low specific mass. However the machining costs are
relatively high, and new cutting tools, mainly ceramics, must be developed to overcome such difficulty,
aiming cost reductions. In this work, silicon nitride based ceramics has been prepared , by pressureless
sintering of silicon nitride powders and appropriate amounts of Al2O3,Ce2O3, Y2O3 and AlN. Cutting tools
were prepared from the sintered materials, with geometry according to ISO1832. Selected cutting tools were
also diamond coated by a hot filament-assisted Chemical Vapor Deposition (HFCVD) diamond coating
process. Carbon Fiber Reinforced Carbon (CFRP) composites machining was performed, to evaluate the
diamond coating influence on machining performance. After the tests, the uncoated tools presented severe
flank wear and shorter life than the diamond coated ceramic tools. This flank wear is caused by the abrasive
carbon powder generated during the facing operation. On CVD diamond coated α-SiAlON ceramic tools, no
flank wear was observed, and the cutting edge remained unmodified, even for severe test conditions, such as
high cutting length and speed. Carbon particles, originated from the machined composite, do not promotes
diamond film rupture, but instead, acts as lubricant film and reduces composite surface initial roughness.
Fatigue of Zirconia - Bioglass Dental Ceramics
Authors: Bicalho Luiz A. , Souza R.C. , dos Santos Claudinei , Barboza M.J.R. , Reis Pereira Baptista Carlos Antonio
Published: March 2009

In this work the cyclic fatigue life of 3mol.%Y2O3-stabilized zirconia polycrystalline
ceramics, doped with 5%wt 3CaO.P2O5,-SiO2-MgO, has been investigated. Samples with 5 and
10%wt were cold uniaxial pressed (80MPa) and sintered in air at 1200 and 1300oC for 120 minutes.
Sintered samples were characterized by X-Ray diffraction and Scanning Electronic Microscopy.
Hardness and fracture toughness were determined using Vicker’s indentation method, and Modulus
of Rupture was determined by four-point bending testing. Furthermore, the cyclic fatigue tests were
also realized by four-point bending tests, under frequency of 25 Hz and stress ratio, R, of 0.1, for the
best condition. In this condition, highly dense samples were obtained and presented values of
hardness, fracture toughness and bending strength of 11.3 ±0.1GPa, 6.1±0.4MPa.m1/2 and
320±55MPa, respectively. The increasing of stress level leads to decreasing of the number of cycles
and the number of run-out specimens. The stress induced tetragonal-monoclinic (t-m)-ZrO2
transformation, observed by X-Ray diffraction, contributes to the increasing of the fatigue life.
Samples 3Y-TZP presents clearly a range of loading conditions where cyclic fatigue can be
detected.
The Design and Evaluation of a Supply Chain Logistic Hub for Automobile and Parts Distribution
Authors: Trappey Charles V. , Trappey Amy J.C. , Liu C.S. , Lee W.T. , Hung Y.L.
Published: March 2009

Enterprises in Taiwan are facing global competition which requires enterprises to
implement sound business models and maintain effective operational processes. The most pressing
need is to develop global logistic processes and models that satisfy rapidly changing business and
operational objectives. This research studies how the automotive industry in Taiwan has adopted its
logistic hubs to improve international business operations and objectives. In the first phase of the
study, Taiwan automotive firms were surveyed and their current (as-is) logistic models were derived.
In the second phase, based on the industry characteristics and the company’s global strategy, the
improved (to-be) logistic processes were derived. Further, a case of Taiwan automobile
manufacturers is used to apply and demonstrate the to-be logistic models and evaluate the
performance of the proposed models. The resulting framework for a global logistic hub is designed to
improve the operations of automotive companies with respect to time and cost, as well as to ensure
information sharing among automotive supply chain partners.
New Tolerance Analysis Model for Normal Mean Shift in Manufacturing Process
Authors: Kuo Chang Hsin , Tsai Jhy Cherng
Published: March 2009

In this paper, we discuss the tolerance analysis methods for the component with a mean
shift or drift. A new tolerance analysis model that assumes the mean shift in normal distribution
rather than in uniform distribution is proposed. Simulation shows that the difference between the
uniform distribution and normal distribution is 1.7%, which can be ignored, for mean shift to one
standard deviation (σ). However, the difference becomes significant when the mean shift increases.
The difference increases to 5.2% with 1.5σ shift, to 10.9% for 2σ shift, and up to 30.4% for 3σ shift.
As normal distribution is a better model for statistical mean shift in manufacturing process, this
investigation shows that the proposed tolerance analysis model can give a better model compared to
conventional models.
Estimating Job Cycle Time in Semiconductor Manufacturing with an ANN Approach Equally Dividing and Post-Classifying Jobs
Authors: Chen Toly , Wang Yi Chi , Lin Yu Cheng , Yang Kai Hsiang
Published: March 2009

Estimating the cycle time of every job in a semiconductor manufacturing factory is a
critical task to the factory. Many recent studies have shown that pre-classifying a job before
estimating the cycle time of the job was beneficial to the forecasting accuracy. However, most
pre-classification approaches applied in this field could not absolutely classify jobs. Besides, whether
the pre-classification approach combined with the subsequent forecasting approach was suitable for
the data was questionable. For tackling these problems, an artificial neural network (ANN) approach
that equally divides and post-classifies jobs is proposed in this study in which a job is post-classified
by a BPN instead after the forecasting error is generated. In this novel way, only jobs which cycle time
forecasts are the same accurate will be clustered into the same category, and the classification
algorithm becomes tailored to the forecasting approach. For evaluating the effectiveness of the
proposed methodology and to make comparison with some existing approaches, some data were
collected from an actual semiconductor manufacturing factory. According to experimental results, the
forecasting accuracy (measured with root mean squared error (RMSE)) of the proposed methodology
was significantly better than those of the other approaches in most cases by achieving a 16%~44%
(and an average of 29%) reduction in RMSE over the comparison basis – multiple-factor linear
combination (MFLC). The effect of post-classification was also evident.
The Effect of Copper and Ceria Additions on the High Temperature Oxidation of Nickel
Authors: Jackson R.W. , Leonard J.P. , Niewolak L. , Quadakkers W.Joe , Pettit Frederick S. , Meier Gerald H.
Published: March 2009

In this study, the effects of alloying with Cu and external doping with CeO2 on the
oxidation of nickel were evaluated. The materials studied were pure Ni, Ni-5wt% Cu, and Ni with
the surface doped with CeO2 by pulsed laser deposition (PLD). The oxidation kinetics were
measured using thermogravimetric analysis (TGA). The oxidation microstructures were observed by
scanning electron microscopy (SEM) compositional analysis was performed with energy dispersive
x-ray analysis (EDS) and sputtered neutrals mass spectrometry (SNMS). Phase identification was
performed using X-ray diffraction (XRD).
The Cu additions had a negligible effect on the oxidation kinetics but Cu was found to be present in
the outer portions of the scale in significant concentrations. Doping with CeO2 resulted in a
significant decrease in the NiO growth rate. The scales on doped Ni grew primarily inward whereas
those on the undoped Ni grew primarily outward. Deposition of the CeO2 dopant onto Ni with a
thin, preformed NiO layer produced a similar reduction in the subsequent NiO growth rate. This
suggests that the poisoned interface model, proposed by Pieraggi and Rapp, does not describe the
effect of the CeO2 dopant.
Mechanisms are presented to attempt to describe the above observations.