bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of the Metal Head on the HTC Evolution in the Sand Casting of A357
Authors: Meneghini Andrea , Tomesani Luca
Published: March 2009

The influence of the effective metal head height on the HTC (Heat transfer coefficients)
in sand casting of A357 aluminum alloy is analyzed here. Different metal heads were used for the
same casting process, evaluating the heat transfer at the metal-chill interface. Thermal analysis and
inverse modeling techniques were used, based on the temperature measurements at selected
locations in the casting and the chill. The experiments were specifically developed for replicating
typical sand casting manufacturing conditions. Aluminum was used as the chill material. Evolutions
of HTC and heat flow are reported as a function of time, casting temperature, chill temperature and
variation in temperature between casting and chill.
New Quaternary Type of Al-Sr-Ti-B Master Alloy for Grain Refining and Modifying of Al-Si
Authors: Moldovan Petru , Popescu Gabriela , Popescu C.A. , Apostolescu Ioana , Buzaianu Aurelian
Published: March 2009

The paper’s aim is to present the processing of a new master alloy similar to
STROBLOY. This alloy represents a combination of two master alloys, already known in
aluminum industry (AlTiB and AlSr). The benefits of this new alloy are the cut of Ti, B and Sr
consumption, as well as a grain refining/modification ecological technology for Al-Si and Al-Mg-Si
alloys. So, this alloy was obtained from binary AlB8, AlSr10 and AlTi10 master alloys melted in an
electric resistance furnace and argon atmosphere. Samples were cast in an iron mould. As
STROBLOY, this new quaternary alloy contains fast dissolving SrAl4 particles important in
modification stage, and nucleating particles such as TiB2 and (Al, Ti)B2 essential for grain refining
of aluminum alloys.
Undesirable Graphite Morphologies Incidence in Inoculated Grey Irons
Authors: Stan Stelian , Riposan Iulian , Chisamera Mihai , Barstow Michael
Published: March 2009

Successful inoculation is not guaranteed and effects may even be deleterious. The main
risks are the appearance of types B and D graphite, associated with ferrite and/or carbides due to
lack of control of undercooling during eutectic solidification. Alternatively coarse type C graphite
in hypo to eutectic grey irons may result from inadequate or excessive inoculation. Sulphur and
aluminium content in a molten iron are considered to be the main factors to control the degree of
eutectic undercooling, graphite morphology and inoculation efficiency. Thermal conditions, such as
superheating, inoculation and pouring temperature play an important role in controlling these
effects. Cooling rates due to different mould materials and casting thickness were also considered.
In order to resolve individual problems, different inoculant systems have to be considered, such as
Sr-FeSi, Ca-FeSi, Ti,Ca-FeSi, Zr,Ca-FeSi, Ba,Ca-FeSi, RE-FeSi (Ca). The present paper made a
synthesis of other published papers by the authors, but also added many original un-published
results.
Investigation of Weldability of P/M Bronze Materials by Tig Welding Technique
Authors: Kurt Adem , Ates Hakan
Published: March 2009

In this study, weldability of bronze parts produced by powder metallurgy has been
investigated by using TIG welding technique. Bronze powders were pressed into 55x44x5 mm size
specimens under pressure of 350 MPa. Then these specimens were sintered at 650, 750 and 870 °C
for 45 minute under argon atmosphere. Finally, the parts were welded by TIG welding method.
Hardness values of the welded joints were measured and microstructural features were investigated.
Severe Plastic Deformation Technologies for Ultra Fine Grained Alloys
Authors: Canta Traian , Frunză Dan
Published: March 2009

Some of new severe plastic deformation processes as equal channel angular extrusion,
and strip shearing are presented as very efficient techniques for grain refinement. Channel
geometry, contact friction, strain rate and multi-pass processing versus microstructure and
mechanical properties are shown.
Recovery of Copper Powder from Polluting Industrial Waste through Lively Bioleaching
Authors: Ivănuş R.
Published: March 2009

An experiment of lively biohydrometallurgical leaching of worn-out hydrogenation catalysts in an aerobic batch system with Thiobacillus ferrooxidans is carried out for process parameters optimization. The maximum bioleaching of worn-out catalysts is noticed at 74.85% (w/w) and 71.50% (w/w) for 25 kg Cu/m3 and 30 kg Cu/m3 initial concentration of 200 to 240 μm waste mesh size in 192 h with pH 2.5 and temperature 35°C, respectively. The optimum shaking speed is noticed as 60 rpm. All results are noted after subtraction of leaching in control conditions. Seven days age-old and 20% (v/v) innoculum culture is used in the present study. The dissolved copper was precipitated by the precipitation using metallic iron splinter. The copper powder obtained was characterized by chemical and physical methods.
Development of Aluminium Alloys and Metal Matrix Composites by Powder Metallurgy
Authors: Ruiz-Navas E.M. , Delgado M.L. , Torralba José M.
Published: March 2009

Consolidation of aluminium alloys by sintering present a main problem: the oxide layer
that cover aluminium particles. Some alternatives are studied in this work as solution to the oxide
layer problem during the sintering of series 2xxx aluminium alloys. One of these solutions is related
to the addition of tin traces, and the other is the addition of a second alloy. Moreover, aluminium
metal matrix composites are characterized by excellent properties as combination of properties
which comes from the matrix and from the reinforcement. In the first part of this work is analyzed
the influence of trace additions, and the last part of this study is focused to the analysis of one
aluminium matrix composite as the influence of several quantities of reinforcement.
The Effect of Ferro-Molybdenum Addition on the Microstructure and Mechanical Properties of Sintered Steel
Authors: Yilmaz R. , Gökçe A. , Kapdibaş Hakan
Published: March 2009

In this study, various ratios of ferro-molybdenum were added into low alloy distaloy steel
powder and then the compacts were fabricated by powder metallurgy process. The effect of ferromolybdenum
addition on the properties of these sintered materials such as density, microhardness
and impact toughness were investigated. The results obtained from experimental works showed that
ferro-molybdenum addition to the starting powder resulted in an increment in density and
microhardness values. On the other hand, ferro-molybdenum addition has influence on impact
toughness values of the sintered low alloy steel.
Mechanical and Technological Properties of Sintered Cu90Ni10 Compacts
Authors: Sorcoi L. Adriana
Published: March 2009

This paper presents Cu90Ni10 alloy properties. These alloys were produced in three
distinct modes: alloyed powders (P), powder made from elemental powders of copper and nickel
(A); powders from the Cu80Ni20 alloy and an alloying element (D). The influence of time,
composition and properties of the powder mixture upon the final properties of the sintered alloys
was studied. A comparative study of the sintered compacts obtained by varying the parameters of
procedure, compacting pressure and sintering time was performed. The work aimed to research the
influence of the parameters above mentioned: density, compressibility, structure of compacts, etc.
The sintering capacity was also assessed through the resistence to fracture and hardness of samples,
also versus the parameters above mentioned.
Effect of Carbon Content and Post-Sintering Cooling Rate on Mechanical Properties of Fe-Ni-Cu-Mo-C High Density Sintered Steel
Authors: Ivănuş R. , Brânduşan Liviu
Published: March 2009

Powders-based on the Fe-Cu-Ni-Mo system are well known in the P/M industry for
combining good compressibility and dimensional stability with a potential for high strength. The
typical heterogeneous microstructure of these materials has proven to provide favourable
mechanical properties. However, in applications where strength and hardness become critical
variables, faster cooling rates after sintering are required to meet application requirements. Test
specimens containing various graphite contents to achieve 0.20, 0.35 and 0.55% combined carbon
were pressed to 7.0 and 7.2 g/cm3, sintered in a furnace at 1150°C and cooled directly from
sintering temperature with either normal or rapid cooling. Test results are discussed in terms of
tensile properties, apparent hardness and microstructure. The formation of bainite and martensite by
raising carbon content and cooling rate increased tensile strength and apparent hardness, while a
higher green density maintained satisfactory ductility. It was possible to achieve ultimate tensile and
yield strengths as 920 and 660 MPa respectively with apparent hardness 30 HRC.
The Elaboration of Composite Materials from the Cu-Al2O3 System Using CuO and Al2O3 Powders
Authors: Salomie Dana , Pavel Codruta , Mureşan Radu
Published: March 2009

The main objective of this study is to find out a simple method to ensure a good dispersion of Al2O3 in the Cu matrix. The method should avoid the segregation effect due to the high difference of the densities of Cu (8.93 g/cm3) and Al2O3 (3.96 g/cm3). In the process of obtaining of the Cu-Al2O3 composite we have considered starting with a material whose density is closer to the density of Al2O3. We have chosen CuO whose density is about 6 g/cm3 so the composite material was obtained starting with copper oxide and alumina powder. We have studied the influence of Al2O3 content and of the compacting pressure upon material’s compactness and hardness. The dispersion finer is highlighted by the microstructure of the surfaces.
The Separation of Spherical Shape Powder Particles from the Non-Spherical Ones
Authors: Spârchez Zeno
Published: March 2009

The conditions needed for an efficient separation together with the most important factors
influencing the accuracy of the separation are emphasized. Some relationships that allow the
evaluation of the covering degree of the separation surface and the volume of the charge with single
dimension particles corresponding to a unit separation surface are presented. The efficiency of
spherical shape particles separation and the productivity of the separation process have been
analysed. Some technical and practical considerations on the separation process are given.
Optimizing Electrochemical Buffing Control Parameters for Surface Finishing of Ultrahigh Purity Components
Authors: Tsui H.P. , Yan Biing Hwa , Wu K.L. , Wu W.C.
Published: March 2009

Electrochemical buffing technology (ECB) applies electrochemical and mechanical finishing characteristics in the surface finishing process. ECB can buff ultrahigh purity components to make them shine, without leaving residual stress, micro-cracks, and etc. The control parameters of the ECB process include current density, the rate of revolution of the buffing head, the buffing pressure on the surface, the concentration of electrolyte, the buffing time and others. Improper control parameter setting in the process will result in unsatisfactory surface quality. It is necessary to determine optimal control parameters of an ECB process with robust performance that can insure surface quality and process reliability. In this study, parametric analyses were conducted on electrochemical buffing technology.An ECB system with a CNC machine was established. The buffing head was clamped on the tool holder of the CNC machine. It was used on a flat surface for automatic surface buffing. Taguchi′s parameter design approach is employed to evaluate signal-to-noise ratios (SN) given from various levels of these factors. Then, the optimized control parameters will be recognized thus can get the optimal surface buffing, reducing with the lowest variability. The contribution of every factor to the sum of square is calculated. An experiment is performed using the optimal control parameters to confirm the results of the previous experiment. The results reveal that the ECB process yields the desired mirror-like surface.
Studies on Disfigurement-Fee Technology of Drilling Carbon Fiber Reinforced Plastics
Authors: Wang Yong Qi , Bao Yong Jie , Gao Hang
Published: March 2009

Based on the analysis of various disfigurements of carbon fiber reinforced plastics
formed in drilling process, the formation model of disfigurement is built up, and analysis results
shows that the main reason of disfigurement is the exceeding cutting force. By focusing on these
problems, new-type drill—super-hard electroplated abrasive drill is developed, and some
experiments were carried out. Compared with the traditional sintered-carbide drill in drilling, the
super-hard electroplated abrasive drill has lower drilling force, better drilling quality, higher
machining efficiency, and longer life-span. A conclusion that super-hard electroplated drill is more
suitable for drilling CFRP is gained.
Study on Effect of Composite Particles in Polishing Process and Its Mechanism
Authors: Xu Xue Feng , Ma B.X. , Chen Feng , Peng Wei
Published: March 2009

In this paper, mixed slurries containing silica abrasives and polystyrene (PS) polymer
particles in deionized water at pH 10.5 have been evaluated for silicon wafer polishing. By applying
the theory of electric double layer model, the effect of the particle interactions in mixed slurry is
investigated. Zeta potential measurements and TEM images have been used to show the formation
of composite particles. The polishing mechanism with composite particles slurries is discussed.
Polishing experiments with the mixed slurries formed by coating smaller (~30nm) abrasives onto
softer and larger (~2000nm) polymer particles have shown the superior characteristic with higher
removal rate and high surface quality.
Computer Emulation to the Tool Head of the Ultrasonic Vibration Machine for Honing
Authors: Zhu X.J. , Gao Yan Xia , Lu Zhi Meng
Published: March 2009

In the design of ultrasonic honing equipment, it is hard to accurately get the natural vibration frequency of the ultrasonic vibration with the regular computing technology, which takes great inconvenience during designing of the device and puts it into production. This paper studies the ultrasonic vibration honing vertical equipment of φ150mm that is designed by the North University of China and carried on the natural vibration frequency analysis and corresponded numerical simulation, which got excellent achievement. In the paper the mathematical model is set up, which uses the MARC software to accomplish the numerical simulation and corresponds the vibration modal of the tool head of the devise, this paper also carries on the dynamic response analysis and solves the related difficult problem successfully. In the end, the proof test is done to support the theory.
Effects of the Wear Characteristics of Brazed Diamond Grits on Grinding Forces
Authors: Zhan You Ji , Li Yuan , Huang Hui , Xu Xi Peng
Published: March 2009

Grinding forces, protrusion and wear of diamond grit have been studied in grinding granite
with a single-layer brazed diamond wheel. The experiment results indicate that the primary wear
progression of diamond grits in the whole grinding process follows the mode of whole,
micro-fractured, macro-fractured and pull-out when grinding granite with the brazed diamond wheel.
The proportions of the whole, fractured, pull-out, break flat and the mean height protrusion of grains
are more closely related to grinding forces. The grinding forces decreased with the increasing
proportions of whole and break flat grains, and the tangential and normal force components increased
with the gradual wear of the brazed diamond wheel during a long-time grinding process.
A Method for Grinding Mode Identification in Grinding of Silicon Wafers
Authors: Huo Feng Wei , Jin Zhu Ji , Kang Ren Ke , Guo Dong Ming
Published: March 2009

A new non-destructive method was developed to identify the grinding mode of silicon
wafers, which is based on the information of subsurface cracks extracted from the surface
topography of the ground silicon wafers measured with a 3D surface profiler. We examined
extensive measurement data of the surface topography of silicon wafers processed by single grain
grinding or real grinding operation, and our results show that the information about median cracks
could be captured if the lateral sampling interval of the 3D surface profiler is small enough, even if
the grain depth of cut is below 20nm. If the maximum valley of the measured surface topography is
approximately equal to the grain depth of cut, surface formation will be under ductile mode,
whereas, if the maximum valley is several times larger than the grain depth of cut, surface
formation will be under brittle mode. According to this criterion, silicon wafers ground by ductile
mode or brittle mode could be identified rapidly and conveniently. Experimental validation shows
that this method is accurate.
Fuzzy Control in Profile Envelope Process of Form Cutter for Involute Gear and its Movement Control
Authors: Kang Jing , Guan L.N.
Published: March 2009

In profile envelope process of form cutter for involute gear, the grinding depth is variable which causes grinding force to change on a large scale and the profile error of envelope to increase. To improve form cutter accuracy, a closed-loop control system was designed to accomplish control of envelope process. For complicated dynamic process, fuzzy controller is used to adjust parameters online. By measuring grinding force, characteristic information of grinding process is acquired. Regulation factor of feed rate is determined by grinding force ratio, force deviation and its change rate used as evaluation indexes. Thus, fuzzy control of constant force grinding process is accomplished. Simulation and cutter grinding test indicates that the system has high precision and stability, and reduces cutter error effectively.
Study on the Magnetic Saturation Flux Density Measurement of Fluid Magnetic Abrasives
Authors: Sun Huan Wu , Yang Shi Chun
Published: March 2009

The fluid magnetic abrasives (FMA) are a new type of precision finishing abrasives, which can be used to finish the parts with intricate or complex shape to a quite low surface roughness value. As a key parameter, the magnetic saturation flux density has a great impact on the design of finishing devices and the control of finishing process. In order to measure the magnetic flux density and determine the magnetization curve of FMA, a new apparatus has been developed. The measuring mechanism and the experimental apparatus are presented. The experimental results are discussed as well in this paper.
Effective Deburring of the Burr at Intersecting Hole by Permanent Magnet Inductor
Authors: Jo S.R. , Ko S.L. , Baron Yuri M.
Published: March 2009

The sharp burrs produced by plastic deformation during machining of the precision
components deteriorates the precision and performance of a machine. Thus, effective removal of the
burrs may improve productivity and performance of the machinery. This study was conducted based
on the experiment to remove fine burrs produced during machining process using the magnetic
abrasive finishing method. The magnetic abrasive finishing using the abrasive feature of an abrasive
and the magnetic nature of iron is an abrasive method to brush the burrs with iron powder that has a
cohesive power due to the line of induction. The purpose of this study is to remove the burrs at
intersecting holes which are difficult to access with tools, using the magnetic abrasive finishing
method. Special tool is designed for deburring micro burr at intersecting holes. To find the proper
deburring condition, gap distance, rotational speed of inductor, components of powder and effect of
coolant are analyzed.
Surface Microscopic Characteristics Analysis on Electrochemical Mechanical Finishing of Stainless Steel in NaNO3 Electrolyte
Authors: Li Zhi Yong , Niu Zong Wei , Ji H.
Published: March 2009

The mechanism of electrochemical mechanical finishing (ECMF) process was
investigated. The ECMF experimental system and control unit were developed and some vital
procedure parameters such as operating voltage, electrolyte component and concentration,
machining temperature, electrode gap and current density were also evaluated and optimized, then
the optimal procedure parameter match was obtained. Furthermore, the important surface roughness
characteristics before and after ECMF process such as height and spacing characteristics of surface
roughness, surface waviness characteristics, surface microscopic appearance and light reflection
characteristics were compared. The experiment and measurement results indicate that ECMF
process can distinctly improve surface quality, eliminate the surface scratch marks and defects and
reduce surface roughness.
Power Spectral Density Analysis Finished Surface by Abrasive Jet with Grinding Wheel as Restraint
Authors: Li Chang He , Xiu Shi Chao , Hou Ya Li , Cai Guang Qi
Published: March 2009

The abrasive jet finishing process with wheel as restraint is a kind of compound
precision finishing process that combined grinding with abrasive jet precision machining, in which
inject slurry of abrasive and liquid solvent to grinding zone between grinding wheel and work
surface under no depth of cut feed condition when workpiece grinding were accomplished. The
abrasive particles are driven and energized by the rotating grinding wheel and liquid hydrodynamic
pressure and increased slurry speed between grinding wheel and work surface to achieve micro
removal machining. The micro removal machining with grinding wheel as restraint, not only to
attain higher surface form accuracy but also to can efficiently acquire defect-free finishing surface
with Ra0.15~1.6$m and finally achieve high efficiency, high precision and low roughness values,
furthermore, integrating grinding process and abrasive jet finishing into one features. In the paper,
surface topography finished by abrasive jet with grinding wheel as restraint was analyzed and
evaluated with power spectral density function. Experiments were performed with plane grinder
M7120 and workpiece material 45 steel. The machined surface morphology was studied using
Scanning Electron Microscope (SEM) and the microscope and microcosmic geometry parameters
were measured with TALYSURF5 instrument. The experimental results show that microcosmic
geometry parameter values were diminished comparing with ground surface. Furthermore, the mean
ripple peak distancing was decreased and, ripple and peak density were increased. The results
indicate that surface qualities by machined with abrasive jet precision finishing were improved
obviously.
The Valley between the Engineering and Technology
Authors: Takazawa K.
Published: March 2009

This document describes the philosophy on how to produce things. First of all, a sprout
of technology in the East and the importance of skill that the technology was born are described.
How to fill in the valley between the engineering and technology has been my subject throughout
my life. To display original creativity is very important.
White Layer and Surface Roughness in High Speed Milling of P20 Steel
Authors: Pang Jun Zhong , Wang Min Jie , Duan Chun Zheng
Published: March 2009

Using solid carbide straight end mills with TiAlN coating, A P20 steel at 41HRC is
machined in the cutting speed range of 301 to 754m/min. The workpiece subsurface are examined
using scanning electron microscope (SEM) and surface roughness tester. The results show that the
white layer is produced in all of the cutting conditions tested, and the white layer thickness and
surface roughness are dependent on the cutting conditions. The result obtained by analysis of
variance analysis shows that feed rate and cutting speed are the most significant effects on the white
layer thickness and surface roughness. Furthermore, the mathematical models for the white layer
thickness and the surface roughness in high speed side milling of hardened P20 steel are proposed,
respectively.
Research on Technology and Application of Pulse Electrochemical Finishing
Authors: Zhai X.B. , Wang H. , Xu Wen Ji , Li H.Y. , Zhou Jin Jin
Published: March 2009

Top-quality surfaces are obtained by means of pulse electrochemical finishing (PECF) in
neutral electrolyte. The machining principles and advantages of PECF are analyzed. Moreover, the
technique are applied to some typical cases such as sheeny lettering, fine and deep holes and
complex shaped surface finishing, gear surface finishing that all of them are more difficult to be
machined by the traditional finishing technologies. The results show mirror-like surfaces could be
gained by PECF and the surface roughness values could be reduced from more than Ra 0.8 μm to
less than Ra 0.08 μm within 1~2 seconds. It’s hoped that PECF will play an important role in
finishing key parts in the modern manufacturing industries.
The Injection Molding Simulation of Lever Cam Ass’y Using High-Functional Polymer
Authors: Hahn Chang Su , Noh Sang Ho , Kim Dong Ok , Ryu Yong Mun , Han Beom Suck
Published: March 2009

Recently the application of lever cam ass’y made of the high-functional polymer is
increasing internationally to improve the productivity and weight reduction. But the application of
injection molding of lever cam ass’y in our country is not reported yet because of the lack of the
optimal selection technique of proper material and the optimal design of injection parameter. In
order to solve the problem, the injection molding simulation is used. The modification of gate
position and rib thickness was done and the parameters like injection time, injection temperature,
packing pressure and cooling time were changed. As a result, the comparison between models was
done and the optimal shape of lever cam ass’y was developed.
The Effect of the Heat Flux and Temperature on Thermal Strain of Aluminum Alloy Casting Mold
Authors: Yoon Hee Sung , Kim Young Sun , Oh Yool Kwon
Published: March 2009

In this study, numerical analysis applying the finite element method (FEM) was used to
investigate the effect of heat flux and temperature on thermal strain of aluminum alloy casting mold.
For numerical analysis, analysis model was considered the effect of shrinkage, rapid temperature
variation on the casting mold and was applied the temperature calibration to reduce the deformation
and stress by temperature difference of inside and outside the mold during the cooling process. In
detail, temperature, deformation and stress distributions occurred inside of casting mold predicted by
numerical method and then investigated the correlations between the heat flux and temperature
variation during the cooling process. As a result, aluminum alloy casting mold is occurred
deformation and stress because of rapid temperature difference in the initial of cooling, but it can be
reduced the thermal strain through the heat flux control and temperature calibration. Accordingly, the
technique of this numerical study will be helped to make the effective and the good quality of casting
mold products.
High Temperature Corrosion Behaviors of Carbon Steels by A Pressurized Water
Authors: Lee Sang Ll , Lee Moon Hee , Lee Jin Kyung , Lee Joon Hyun , Kong Yu Sik
Published: March 2009

The long-term corrosion resistances for the carbon steels have been investigated under high
temperature pressurized water atmosphere, in the conjunction with the analysis of nondestructive
properties by the ultrasonic wave. The corrosion test for carbon steels was carried out at the
temperature of 200 °C under a water pressure of 10 MPa. The corrosion test cycles for carbon steels
were changed up to 65 weeks. The mechanical properties of carbon steel suffered from the corrosion
cycle were investigated by a tensile test, attaching an acoustic emission sensor on the test sample. The
tensile strength of carbon steels greatly decreased beyond the corrosion cycle of 35 weeks,
accompanying the increase of weight loss by the creation of corrosion damages. The attenuation
coefficient of carbon steels by the ultrasonic wave increased with the increase of corrosion cycles.
Electric Field-Induced Structural Modulation of Epitaxial PbZrTiO3 Ferroelectric Thin Films as Studied Using X-Ray Microdiffraction
Authors: Bark Chung W. , Ryu Sang Woo , Koo Yang Mo , Jang Hyun M.
Published: March 2009

This time, we would like to report our recent study on Pb(ZrTi)O3(PZT)-based
ferroelectrics, currently one of interesting topics in condensed matter science. In this study, a new
method, called synchrotron X-ray microdiffraction (XRMD) in situ, was introduced to examine the
electric field-induced structural modulation of the epitaxially grown tetragonal PZT thin film. To
evaluate the d-spacing (d001) from the measured intensity contour in the two theta-chi space, the peak
position in each diffraction profile was determined by applying the two-dimensional Lorentzian
fitting. By tracing the change of d-spacing as a function of the applied electric field and by examining
the Landau free energy function for P4mm symmetry, we were able to estimate the two important
parameters that characterize the field-induced structural modulation. Further theoretical analysis
shows that the compressive epitaxial in-plane stress dominantly contributes to the elongation of the
c-axis lattice constant in the c-axis oriented epitaxial PZT film.
Application of a Temperature-Compensating FBG Sensor to Strain Measurement
Authors: Jung Dal Woo , Kwon Il Bum , Choi Nak Sam
Published: March 2009

A temperature-compensating fiber Bragg grating(FBG) sensor having two different FBGs in one fiber line
was applied to the real time measurement of mechanical normal strain in structures. Measurement of mechanical strains
of the aluminum beam surface by the double FBG sensor was performed under various thermal conditions, which was
compared with results of electrical resistance strain gage. The FBG sensor fabricated in this study could detect
accurately values of mechanical strains without containing any thermal strain component.
Precipitation Behavior of MN(M=V,Nb) Phase in the 7Cr-1.5Mo Ferritic Heat Resistant Steels
Authors: Bae Deuck Seung , Jung Woo Sang
Published: March 2009

The relationship between precipitation behavior of MX(M=V, Nb) nitrides and
mechanical property during aging in 7Cr-1.5Mo ferritic heat resistant steels were investigated in
this study. Artificial aging was carried out at 700°C for different time from 100 to 10000 hours to
simulate the environment of fossil power plant. The Ostwald ripening equation is related to the
containing elements can explain the accelerated coarsening of MX in the model alloys. The Ostwald
ripening equation was modified by introducing the effective diffusion coefficient as a sum of the
lattice diffusion coefficient and dislocation diffusion coefficient, based on an assumption that V, Nb
and Ti might diffuse not only by the lattice diffusion mechanism but also by the dislocation
diffusion mechanism.
Nanostructural Characterization of Hydrothermally Stable γ-Alumina-Based Composite Materials by Transmission Electron Microscopy
Authors: Fujisaki Shinji , Zahir Md. Hasan , Ikuhara Yumi H. , Iwamoto Yuji , Kuroda Kotaro
Published: March 2009

La2O3 and/or Ga2O3 doped, and the double dopant γ-Al2O3 composite powder samples
were prepared by the sol-gel method. Nanostructural characterizations of the powder samples were
performed by high resolution transmission electron microscopy (HRTEM) in order to clarify the role
of the metal oxide dopants for the improved hydrothermal stability of the La2O3-doped Ga2O3-Al2O3
composite material. The results of HRTEM study and selected area electron diffraction (SAED)
analysis revealed the formation of the uniform solid solution of Ga2O3-Al2O3. In addition, the results
of X-ray elemental mapping analysis revealed the existence of well-dispersed La2O3 on the grain
surface of Ga2O3-Al2O3 solid solution. These structural features could act an important role for the
improved hydrothermal stability of the La2O3-doped Ga2O3-Al2O3 composite material.
A Study of Mechanical Behavior of Au Films by Visual Image Tracing System
Authors: Lee Sang Joo , Hyun Seung Min , Han Seung Woo , Lee Hak Joo , Kim Jang Hyun , Kim Young Il
Published: March 2009

Mechanical behavior of small size materials has been explored due to many industry
applications such as MEMs and semiconductors. The accurate measurements for mechanical
properties of thin films are very challenge due to several technical difficulties. The proposed solution
is the Visual Image Tracing (VIT) strain measurement system coupled with a micro tensile testing
unit, which consists of a piezoelectric actuator, load cell, microscope and CCD cameras. This system
has shown advantages of real time strain monitoring during the test and ability to measure the
Young’s modulus, yiled strength and Poisson’s ratio of the material. Free standing Au films 0.5, 1 and
2 μm thick with average grain sizes of 104, 148 and 219 nm prepared by sputtering were studied using
VIT system. The yield stresses of the films are dependent on film thickness and grain size.
Effect of Processing Conditions of Dolomite on the Antiviral Activity
Authors: Motoike K. , Hirano S. , Yamana H. , Onda Tetsuhiko , Maeda T. , Hayakawa Motozo
Published: March 2009

The effect of the processing conditions of dolomite powders on the antiviral activity was
studied against H5N3 avian influenza virus. When dolomite was fired in the ambient atmosphere, it
decomposed into MgO and CaO by two stages at different temperatures, namely into MgO+CaCO3
at ca.1010 K and MgO+CaO at ca. 1070 K. Strong antiviral activity was observed after the
complete decomposition into CaO and MgO. However, when the firing temperature exceeded
1673 K, the antiviral activity was degraded. It was also found that the degraded antiviral activity
was recovered by sever ball mill grinding.
Hydrazine-Dependency of Low-Alloy Steel Flow-Accelerated Corrosion in a Deoxygenated Solution at 250°C
Authors: Sung Ki Woung , Seo Hyun Il , Kim Uh Chul , Maeng Wan Young
Published: March 2009

In the nuclear power plants (NPPs), wall thinning of the piping materials is generally caused by a
flow-accelerated corrosion (FAC) and leads to a rupture with no warning unless it is detected and
repaired in a timely manner. To reduce the FAC, it is better to use low-alloy steels, such as 1Cr-½Mo
and 2¼Cr-1Mo, having higher FAC-resistance than carbon steel. Meanwhile, in the secondary water
chemistry at the NPPs in Korea, hydrazine concentration is maintained within the range of 100~150
ppb. For applying these low-alloys to a piping material, we investigated the influence of hydrazine
concentration on their FAC. An experiment was carried out at pH25°C of 9 controlled with ammonia in
a deoxygenated aqueous solution containing 0~250 ppb-hydrazine by using a FAC test loop at 250°C
for 300 hours. Experimental weight loss showed a hydrazine concentration dependency of the FAC in
this concentration range, giving minimum at 150 ppb.
Carbon Nanostructures by Using FeCl3 as Catalyst Precursor
Authors: Zhang Hong Dan , Zou Xiao Ping , Cheng Jin , Li Fei , Ren Peng Fei
Published: March 2009

Carbon nanotubes and carbon nanowires were synthesized by ethanol catalytic combustion
(ECC) technique, using FeCl3 solution as a catalyst precursor. Applying the 0.01 mol/l, 0.1 mol/l and
1 mol/l FeCl3 as catalyst precursor solution to the copper plate, carbon nanotubes and carbon
nanowires were synthesized. The effect of concentration on growth and structural changes of the
as-grown nanomaterials are illustrated and discussed. This technique has advantages of low cost,
large scale production and flexible reaction conditions, etc. This technique can be used to synthesize
carbon nanotubes and nanowires on metal substrate directly. This technique also has potential
applications for fabricating nano-electrical devices.
Microstructure-Based Computational Simulation and Experimental Measurement of Stresses in Spheroidized Steels
Authors: Che Lei , Gotoh Masahide , Horimoto Yoshiaki , Hirose Yukio
Published: March 2009

Carbon steel is the most popular engineering material, usually consisted of ferrite and
cementite phases. Internal stress state of the steel under thermal or mechanical loading is strongly
affected by the amount and morphology in the cementite phase. With this aim, a computational model
which applies the finite element method at the microscale was used in present study. Effects of
volume fraction and particle size of the spheriodal cementite on the internal stress states in carbon
steels under the mechanical and thermal loadings are investigated. To verify the reliability of the
computational simulations, the residual stresses in the constituent phases are measured by means of
X-ray stress diffraction technique. The computational simulations fit well with the experimental data,
and the microstructure-based model is validated.
Assessment of Behaviour Characteristics for Geobag Wall System Using Recycled Waste Concrete
Authors: Kim Jin Man , Lee Dae Young , Oh Se Yong
Published: March 2009

Field instrumentation for a recycled waste concrete geobag wall was performed to
investigate the performance of the geobag wall, and uniaxial compression tests for a recycled waste
concrete geobag were executed in the laboratory. The strength of a recycled waste concrete geobag,
the lateral earth pressure of a geobag wall, the horizontal deflection of a geobag wall, and the
deformation of the backfill in a geobag wall are evaluated in this study. Based on the results of
analysis bylaboratory tests and measurements, the recycled waste concrete geobag wall displacement
was within the recommended allowable range for mechanically stabilized earth walls. Furthermore,
the recycled waste concrete in geobag wall provided stability, construction ease, and good
performance.
AE Evaluation of Relationship between AE Signals and Fracture Mechanisms for the Weldment of Pressure Vessel Steel
Authors: Na Eui Gyun , Koh Seung Kee , Lee Dong Whan
Published: March 2009

The purpose of this study is to find out the AE characteristics and fracture mechanisms
through AE signal analysis for the weldment, PWHT specimen and basemetal of the pressure vessel
steel. Charpy sized specimens were taken from the multi-passed weld block. Specimens were given
to four point bend and AE tests. Lots of AE signals were emitted from the weldment compared with
the basemetal and PWHT specimen. Besides, amplitude for the weldment was the largest, followed
by PWHT specimen and basemetal and more AE counts for the weldment were emitted in the
process of deformation. Lots of microcracks around the notch for the weldment were formed so that
more AE signals were produced. In addition, second phase particle such as MgO for the basemetal
acts as AE source. However, in case of weldment, debonding mechanisms between matrix and hard
oxides which are formed during welding in air attributed to the emission of AE signals and softened
particles for the PWHT specimen cause to produce the low level AE signals.
Measurement of Residual Stress in Thin-Sized Steel Wires by Using Focused Ion Beam and Digital Image Correlation Method
Authors: Yang Yo Sep , Bae Jong Gu , Park Chan Gyung
Published: March 2009

The residual stress in axial direction of the steel wires has been measured by using a
method based on the combination of the focused ion beam (FIB) milling and digital image
correlation (DIC) program. The residual stress is calculated from the measured displacement field
before and after the introduction of a slot along the steel wires. The displacement is obtained by the
digital correlation analysis of high-resolution scanning electron micrographs, while the slot is
introduced by FIB milling with low energy beam. The experimental procedures are described and
the feasibilities are demonstrated in steel wires fabricated with different conditions.
Terrace Formation of SrTiO3 (111) Substrates for Epitaxial Thin Film Growth with Various Etching Conditions
Authors: Suh Ju Hyung , Lee Yong Seok , Park Chan Gyung
Published: March 2009

The optimized terrace formation of SrTiO3 (111) substrates was investigated in various
etching conditions. HCl-HNO3 solution was unstable for etching the SrTiO3 (111) substrates with
different surface states. It was found that etching in buffered HF (BOE) solution for 2min provides a
stable etching condition for SrTiO3 (111) substrates with various surface states and etching process is
an important factor for the formation of step-terrace structures. The surface degradation of SrTiO3
(111) in normal atmosphere was also observed and it is considered that the humidity is a important
factor for the surface degradation.
Distribution Characteristics of Stress Corrosion Cracks in a Retired Steam Generator
Authors: Hwang Seong Sik , Jung Man Kyo , Kim Hong Pyo , Kim Joung Soo
Published: March 2009

Steam generators(SG) of the Korean nuclear power plants were replaced with a new one
after a 20 year operation. A metallographic examination of the defected tubes is needed for setting
up a guide line for a safe operation of the other SG. A destructive analysis of 50 tubes was
addressed, and a relationship between the SCC defect location and defect depth was
obtained. Tubes extracted from the retired SG were transferred to a hot laboratory. Detailed
nondestructive analysis examinations were taken, then the tubes were destructively examined.
Types and sizes of the defects were characterized. A location and depth of the SCC were evaluated
in terms of the location and height of the sludge. Most axial cracks were in the sludge pile, whereas
the circumferential ones were around the top of the tube sheet(TTS) or below the TTS. Cracks were
found with various lengths in a specific zone. Average defect depth of the axial cracks was deeper
than that of the circumferential ones.
A New Method for Nondestructive Evaluation of Mechanical Properties Using Instrumented Indentation Technique
Authors: Lee Kyung Woo , Kim Kug Hwan , Kim Kwang Ho , Kwon Dong Il
Published: March 2009

The development of the instrumented indentation test (IIT), which gives accurate
measurements of the continuous variation in indentation load as a function of depth, has paved the
way to assessing tensile properties and residual stress in addition to hardness by analyzing the
indentation load-depth curve. In this study, analytic models and procedures are presented for
evaluating tensile flow properties and residual stress states using IIT. Tensile properties were
obtained by defining representative stress and strain beneath the spherical indenter. The evaluation
of residual stress is based on the concepts that the deviatoric stress part of the residual stress affects
the indentation load-depth curve, and that analyzing the difference between the residual stressinduced
indentation curve and the residual stress-free curve permits evaluation of the quantitative
residual stress in a target region.
Experimental Study of Interference Factors and Finite Element Simulation on Oil-Gas Pipeline Magnetic Flux Leakage Density
Authors: Qi Jiang
Published: March 2009

Some methods of enhancing oil-gas pipeline magnetic flux leakage (MFL) detection
technique are introduced in the paper. Some man-made defects or imperfections on the pipe surface
are detected via the axial magnetization inspection vehicle along the pipeline. The magnetic dipole
model of corrosion defect is stated and the important interference factors on magnetic flux leakage are
analyzed. Finite element method is used to analyze and simulate normal defects on pipe surface,
which can attribute to get natural defect MFL signal. The influence of benign pipeline artifacts
(valves, welds, tees, flanges, etc.), pipe material and pipe wall, vehicle velocity, defect dimensions
and interaction among defects, and so on are studied in detail. The magnetic flux leakage contour
images or indication extraction maps are given and presented. These interference factors are
compensated and solved. These approaches and results applied in the paper are contributed to the
feature extraction and indication of pipeline abnormality. The results suggest that these approaches
and conclusions are significantly effective for the pipeline magnetic flux leakage inspection.
Thermophysical Behavior of Micro Void in μ-Via of Microelectronic Substrate during Reliability Test
Authors: Lee Hyo Soo , Lee Hai Joong , Lim Sung Chul , Kwon Hyouk Chon
Published: March 2009

The μ-via in microelectronic substrate should have multiple purposes, one of them is to
allow to the path of signal or current from electronic devices. The micro void can be easily formed
in μ-via because μ-vias are filled with a screen printing process and the size of via is small. The
residual void has been known as crack initiation of copper layer during a reliability test. The solder
resist filling process and the behavior of a residual void in μ-vias were investigated. The void
extraction process was very effective comparing with the conventional process to remove a residual
void. As extracted with 1.5 atm for more than 30 sec, the residual void in μ-BVH was perfectly
eliminated.
Damage Index Comparison for a Composite Stiffened Panel Using Lamb Wave
Authors: Park Chan Yik
Published: March 2009

Various damage index (DI) algorithms of detecting changes such as a loosen bolt and a
delamination development in a composite structure were examined using ultrasonic Lamb waves
generated by embedded piezoelectric active sensors. The DI is a single value that is a function of
response signal’s attenuation due to any damage or changes in a structure. Various DI algorithms
such as active damage interrogation (ADI), time domain root men square (RMS), short time Fourier
Transform (STFT) and time reversal (TR) were discussed. For experimental validation, a composite
stiffened panel was used, and loosen bolt damage and low-velocity- impact damage were tested. In
order to pitch and catch Lamb waves, surface mounted PZTs (lead zirconate titanate) were used.
According to the DI algorithms, appropriate ultrasonic guided Lamb waves were selected for
actuators. Each set of DI algorithm and drive signal showed different characteristics to detect the
damage.
HRTEM Observation of α-Phase in Cu-Zn Alloy Annealed at Lower Temperature
Authors: Kato Koji , Hamatani Daisuke , Matsuda Kenji , Kawabata Tokimasa , Uetani Yasuhiro , Ikeno Susumu
Published: March 2009

It is known that the phase-decomposition process of 60/40 Cu-Zn alloy is so-called the
bainitic transformation, and decomposition of α-phase from the β’-phase is as follow: β’ → α9R →
αfcc. In this work,decomposition of α-phase from the β’ single phase of Cu-40.26at.%Zn alloy has
been investigated by high-resolution transmission electron microscopy (HRTEM) to understand the
phase transformation of this alloy. Especially, striations in the α-phase has been focused on the
special feature for the change of the structure and hardening of this alloy during annealing. The result
of a comparison between this alloy and the Si added alloy is also reported.
Relationship between Tensile Deformation and Crystallographic Orientation of Grains in Al-Mg-Si Alloys with Cu
Authors: Tsukiyama Junji , Matsuda Kenji , Uetani Yasuhiro , Ikeno Susumu
Published: March 2009

It is very popular to improve mechanical properties of Al-Mg-Si alloys by adding other
element. For example, it is well known that addition of transition metals is useful because the
refinement of grain size can be achieved, and with the addition of Cu to Al-Mg-Si alloy can
increase the strength and hardness of the materials. Also, there are a few reports about the addition
of Ag, which is particularly good for elongation. However, even now it has not been clarified yet
why Cu and Ag are useful in improving alloys elongation. In this work, we have investigated the
tensile behavior of excess Si-type Al-Mg-Si alloys, which contain Cu. The tensile test and hardness
measurement were carried out. Scanning electron microscope (SEM) was used to investigate the
fracture surfaces and individual crystallographic orientation. After small additional deformation, the
crack was observed by the interface between higher Schmid Factor (S.F.) and lower S.F. grains. It
was thought that this crack influenced fracture from fracture surface.