bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of the Alloying Element Distribution in Al-Alloys by High Magnetic Fields
Authors: Wang Qiang , Pang Xue Jun , Wang Chun Jiang , Liu Tie , Li Dong Gang , He Ji Cheng
Published: March 2009

The distribution and solidified structure of alloying elements are important for the
quality and the properties of alloys. In the present study, the solidification behavior of
aluminum-rich alloys is studied under various high magnetic field conditions, and the
influences of uniform and gradient magnetic fields with different intensity and direction on the
distribution and the morphology of solute elements of Al-Cu and Al-Mg alloys are investigated.
It is found that because of the differences of the electromagnetic force (Lorentz and
magnetization forces) acting on Cu element and Mg element with different physical properties
in the matrix, the regularities of distribution for Cu element and Mg element are opposite just in
the intracrystalline and intergranular under high uniform magnetic field condition, and not only
the content but the distributions of Cu and Mg elements are obviously different under high
gradient magnetic field conditions as well. It can be concluded that high magnetic field has
different effect on the solute distribution in alloys with different physical properties such as
density, susceptibility, conductivity, etc. And the experimental results indicate that it is possible
to control the terminal solubility and morphology of the solute elements in alloys by high
magnetic fields.
The Effect of Plastic Deformation on the Formation of Different Morphologies of Ferrite upon Cooling
Authors: van Leeuwen Y. , Sietsma Jilt
Published: March 2009

This paper addresses the physical mechanisms of the transformation of deformed
austenite into allotriomorphic ferrite and Widmanstätten ferrite. The possible implementation of
deformation in currently available transformation models for allotriomorphic ferrite and
Widmanstätten ferrite is discussed based on a series of deformation dilatometry experiments. It is
concluded that a small amount of deformation already gives significantly faster transformation
kinetics and a significant decrease in fraction Widmanstätten ferrite, and that the key to
understanding the effect of deformation on transformation lies in the nucleation of allotriomorphic
and Widmanstätten ferrite. For Widmanstätten ferrite also the growth needs further study.
Modeling the Effect of Austenite Grain Size Distribution on Austenite Decomposition Kinetics
Authors: Samoilov Andrej , Titovets Yuri , Zolotorevsky Nikolay Y. , Hribernig Gottfried , Pichler Andreas
Published: March 2009

The model of the γ→α transformation calculated with the CATRAN program is
described. The expected effect of former austenite grain size on the transformation kinetics as well
as the final microstructure is analyzed and compared with experimental data. The effect of austenite
grain size distribution spread on the transformation kinetics is also considered and must be included
as the additional input parameter in the computer model of austenite decomposition. In particular,
probable variations of grain size non-uniformity should be taken into account when comparing
transformation kinetics observed in the dilatometer experiment and under industrial conditions.
Effect of Hot Deformation and Cooling Rate on Phase Transformations in Low Carbon HN5MVNb Bainitic Steel
Authors: Lis Andrzej Kazimierz , Lis Jadwiga
Published: March 2009

Deformations at temperatures 900 °C, 860 °C, 810 °C and 780 °C in the consecutive
amounts 24%, 20%, 19% and 18.5% were applied to low carbon HN5MVNb bainitic steel using hot
compression testing in dilatometer Bähr 805 followed by continuous cooling. The results show
clearly that the kinetics of the austenite decomposition were depended on local equilibrium
conditions between recovery, recrystallization and phase transformation processes for a given
cooling rate. Bainite transformation was accelerated when sample was cooled after deformation at
cooling rate 60 °C/s. At lower cooling rates than 5 °C/s down to 0.5 °C/s, bainite transformation was
postpone when comparing its kinetics with those for non deformed steel. The bainitic
transformation cannot be fitted to a single transformation mechanism owing to the formation of
carbides. Different behavior was observed for austenite to ferrite transformation. Usually it was
accelerated with consecutive deformations of the steel for all cooling rates used in experiments.
Stress- and Strain Induced Phase Transformations in Pearlitic Steels
Authors: Ivanisenko Julia , Łojkowski Witold , Fecht Hans Jorg
Published: March 2009

An overview of the mechanically driven phase transformations taking place in
nanocrystalline pearlitic steels in conditions of the severe plastic deformation (SPD), i.e. combination
of high pressure and strong shear strains will be given. Conditions of the discussed experiments (room
temperature and moderate strain rates) exclude any thermal origin of the observed transformations.
One of them is strain induced cementite decomposition, which is a well-documented phenomenon
taking place at cold plastic deformation of pearlitic steels. We explain this process taking into account
friction forces at the interface between the hard cementite and ferrite. Under the high pressures and
stresses higher than the ferrite matrix yield stress, the later one behaves like a viscoelastic fluid. The
friction at the precipitate/matrix interface leads to two effects. One is to induce high strains on the
precipitates. This leads to shift of thermodynamic equilibrium towards dissolution of the cementite.
The second is wear of the cementite phase due to friction at the ferrite/cementite interface and
mechanically induced drag of carbon atoms by the ferrite. This had been recently confirmed in 3D AP
experiments, which demonstrated that the process of cementite decomposition starts with depleting of
carbides with carbon and formation of non-stoichiometric cementite. The existing theories of atom
drag by moving dislocations (ballistic models) can be regarded as one of the many possible
mechanism of wear discussed by the wear theory. In that respect the process can be called athermal, as
temperature indirectly influences wear processes but is not their main cause. We observed also
another strain driven transformation in nanocrystalline pearlitic steel during room temperature high
pressure torsion. This is a stress induced α→γ transformation, which has never been observed at
conventional deformation of coarse grained iron and carbon steels. This was concluded to have
occurred due to a reverse martensitic transformation.
Transformation and Precipitation Behavior in the New Conceptual TMCP Process Utilizing Heat Treatment On-Line Process
Authors: Shinmiya T. , Ishikawa Nobuyuki , Endo S. , Okatsu M. , Nakamichi Haruo
Published: March 2009

New conceptual TMCP process for manufacturing high strength steel plates, which is
applied an on-line heat treatment immediately after accelerated cooling (ACC), was developed.
Transformation and precipitation behavior in the new TMCP process was investigated and
compared with those in conventional ACC process and quenching and tempering process (Q+T).
In the ACC process and Q+T process, microstructures were consisted of bainitic ferrite and
second phase, such as cementite or martensite-austenite constituent (MA). And fine carbides, which
were formed randomly, were observed in Q+T steel. On the other hand, in the new TMCP process
polygonal ferrite was observed in addition to bainitic ferrite and cementite, and two kinds of
precipitation forms, random precipitation and row precipitation, were observed. It was found that
ferrite transformation is promoted during heating after accelerated cooling, which brings row
precipitation of fine carbides.
Furthermore, Control of the formation of MA this new TMCP process. In the conventional
ACC process, MA constituents are formed from carbon enriched untransformed austenite during air
cooling after ACC, and formation of MA is hard to prevent for higher strength steels. On the other
hand, carbon enrichment to untransformed austenite can be prevented by carbide formation during
on-line heat treatment after ACC. It was demonstrated that homogeneous microstructure with very
low amount of MA constituents was achieved by the new TMCP process. And, absence of brittle
phase brought excellent resistance to hydrogen induced cracking in NACE sour environment.
In this paper, details of the metallurgical and mechanical feature of this new TMCP steel were
discussed, and application to sour resistant linepipe steel was introduced.
Thermomechanical Treatments of Ultrahigh Carbon Steels and Optimal Microstructures to Improve Toughness
Authors: Carsí Manuel , Fernández-Vicente A. , Sherby Oleg D. , Peñalba Félix , Ruano Oscar
Published: March 2009

Thermomechanical processing allows the attainment of spheroidized microstructures that
show improved mechanical properties. In this work, a thermomechanical processing route
consisting of two steps was developed for two ultrahigh carbon steels (UHCS) containing 1.3 and
1.5%C. This route develops structures of fine spheroidized cementite particles in a fine-grained
ferrite matrix. Spheroidized microstructures are formed by eutectoid carbide particles in the UHCS-
1.3C and by proeutectoid and eutectoid carbide particles in the UHCS-1.5C. In the latter steel, the
proeutectoid carbide particle size is larger than the eutectoid carbide particle size. The carbide size
distribution remains basically constant with austenitizing temperature for both steels. Plane-strain
fracture toughness of spheroidized UHCS-1.3C is higher than for UHCS-1.5C, about 80 vs 40 MPa
m1/2. These values do not vary significantly with austenitizing temperature which is attributed to
the constancy of the mean proeutectoid and eutectoid carbide size.
Development of Anti-Coarsening Steel for Carburizing
Authors: Kubota M. , Ochi T.
Published: March 2009

There is a glaring need for omitting intermediate heat treatments in the manufacturing
processes of carburized parts and increasing the carburizing temperature aimed at cost reduction. It
is necessary to develop techniques to inhibit grain-coarsening since some austenite grains tend to
grow abnormally during carburizing and coarse grains have negative effects on the properties of
parts. Therefore, we developed new techniques to inhibit grain-coarsening by refining precipitates’
size and increasing their volume fraction based on the abnormal grain growth theory by Gladman.
In this study, AlN and Nb(CN) were chosen as the precipitate particles for the pinning of austenite
grain growth. And we investigated grain-coarsening behavior in several manufacturing processes of
parts. As a result, we developed anti-coarsening steels for various manufacturing processes of
carburized parts.
Electron Beam Freeform Fabrication on Stainless Steel
Authors: Wanjara Priti , Brochu Mathieu , Jahazi Mohammad
Published: March 2009

The use of electron beam technology for freeforming 321 SS was investigated using 347
SS solid wire and BNi-2 brazing paste as filler materials. The electron beam freeforming (EBFF)
studies involved examining the effect of processing parameters on the characteristics of the line
build-ups. Specifically, the effective growth rate and the dimensional features (height-to-width
ratio) of the build-ups were found to be dependent on the beam energy and the filler material
conditions (e.g. wire feed rate and the number of re-melting passes). The EBFF work indicated that
build-ups with either filler material could be deposited on 321 SS using an optimized processing
window that resulted in properties comparable to technical data available for 347 SS and BNi-2.
Decomposition of Austenite in Fe-25Cr-1N Alloy Produced by Solution Nitriding
Authors: Tsuchiyama Toshihiro , Hirakawa N. , Nakada Nobuo , Takaki Setsuo
Published: March 2009

The nickel-free austenitic stainless steel produced by solution nitriding (Fe-25%Cr-1%N
alloy) was subjected to isothermal heat treatment, and then the microstructure formed through the
decomposition of austenite was investigated in terms of the morphology of eutectoid structure and
the size of eutectoid block. On the isothermal heat treatment at 873K~1223K for the
solution-nitrided steel, the austenite decomposed to eutectoid structure composed of ferrite and
Cr2N nitride. This transformation could be completely finished after long time heat treatment in the
above temperature range. The nose temperature of T.T.T. curve was around 1173K, and the time to
start the eutectoid transformation was only 100~200s. The eutectoid structure was formed mainly
along austenite grain boundaries and then grew into the untransformed austenite region. Finally, the
austenite was completely decomposed into ferrite and Cr2N nitride. As a result of OIM observation
for the specimen after isothermal heat treatment, the eutectoid structure was found to be divided
into small-sized ferrite blocks, in which lamellar Cr2N plates were finely distributed. The block size
and the mean ferrite path of eutectoid structure were decreased with lowering the heat treatment
temperature. In the 873K heat-treated material, these values were estimated at 20 microns and 0.1
microns, respectively.
Processing and Property of Net-Shaped Fe-Based Nanoparticulate Material
Authors: Lee Jai Sung , Cha B.H. , Kang H.G. , Kang Yun Sung
Published: March 2009

This paper overviews our recent investigations on the processing of net-shaped Fe-based
nanoparticulate materials and their related material properties such as mechanical and corrosion
properties. The key-process for fabricating fully densified net-shaped nanopowder by pressureless
sintering is an optimal control of agglomerate size of nanopowder. Enhanced mechanical property
of powder injection molded Fe-Ni nanopowder could be explained by grain refinement and
uniformity of microstructure.
Structural Change during Cold Rolling of Electrodeposited Copper
Authors: Huang X. , Lu Q.H. , Sui M.L. , Li D.X. , Hansen Niels
Published: March 2009

Copper sheet samples composed of nanometer scale lamellar twins was produced by
electrodeposition. The coherent lamellar twin boundaries were within 20˚ of being parallel to the
sheet plane in more than 60% of the grains. The electrodeposited sample was cold rolled to 30 and
85% reductions in thickness and the structural evolution during cold rolling was examined by
transmission electron microscopy (TEM) and high resolution TEM (HRTEM). Extensive activity of
partial dislocations along twin boundaries and of perfect dislocations within twins (in particular in
coarse twins >100nm) were identified. Moreover, it was found that shear banding occurred, which
locally destroyed the lamellar twin structure. A dislocation structure developed within the shear
bands, and such a structure evolved with strain and gradually replaced the lamellar twin structure.
After 85% deformation, a large volume fraction of the lamellar twin structure was replaced by a
lamellar dislocation structure characteristic of high strain rolling where the lamellar dislocation
boundaries are almost parallel to the rolling plane. It was also found that the structural scales are
coarser in the lamellar dislocation structure than in the initial lamellar twin structure.
Degradation Studies of Some Polymeric Biomaterials: Polypropylene (PP) and Polyvinylidene Difluoride (PVDF)
Authors: Silva Rui A. , Silva P.A. , Carvalho M.E.
Published: March 2009

Degradation studies of PP and PVDF monofilaments were carried out using a special chamber for
several periods of time. One set of the samples was exposed to a 0.9 % NaCl solution and to
ultraviolet radiation at 830 C and the other set involved the exposition in air under the same
conditions of irradiation and temperature.
Scanning Electron Microscopy (SEM) analysis showed direct evidence of PP degradation.
Meanwhile, the PVDF monofilaments showed no apparent evidence of degradation under the same
conditions. Differential Thermal Analysis (DTA) curves, FTIR spectra and Oxidation Induction
Time experiments confirmed the results of SEM Analysis.
Investigation of the Hydroxyapatite Crystallites in Bone at the Interface with Implant by Neutron Diffraction
Authors: Benmarouane Abdelilah , Hansen T. , Millet Pierre , Lodini Alain
Published: March 2009

The basic principles behind human tissue response to artificial surface implantation may be
developed under its biological aspect, it is necessary for a medical use to study the mechanical
limits of every biomaterials to predict the tissue and the body's response according to the
composition, the structure and the design of a biomedical material. To promote a stable and
functional direct connection between bone and implant, titanium implants can be coated with
materials based on calcium phosphate ceramics such as hydroxyapatite (HAp)(Ca10(P04)6(OH)2).
The preferred orientation of HAp crystallites at the interface bone-implant in sheep tibia bones has
been measured with the neutron 2-axis diffractometer D20 at the Institut Max von Laue-Paul
Langevin (ILL), extracted 60 days after implantation. The implant has two faces, one coated and one
non-coated with plasma-sprayed HAp (80 .m). We probed the samples with a spatial resolution of
0.5 mm started from the interface in order to inspect the reorganisation of the HAp crystallite’s
distribution after implantation.
Common Features on Damage Mechanisms Identified on Various Metal and Ceramic on Polyethylene Articulating Surfaces of Total Hip Prostheses
Authors: Najjar Denis , Hennebelle Francois , Iost Alain , Migaud H.
Published: March 2009

This paper presents a methodology for assessing the in-vivo degradation mechanisms of
articular components of total hip replacement (THR) prostheses of Charnley type. The experimental
procedure revealed that common features can be observed even if the clinical cases under
investigation were quite different with regard to the demographic data. It particularly emphasises
the detrimental effects of foreign bodies on the damage of the articulating surfaces. These foreign
bodies can migrate into the joint space before embedding definitely into the Ultra High Molecular
Weight Polyethylene (UHMWPE) acetabular cup surface where they further participate to a third
body wear mechanism accelerated by a progressive increase of the femoral head roughness.
Our experimental results underline, from a practical point of view, the need for careful
manufacturing and clinical handling of porous surfaces, advocate for a systematic assessment of
retrieved components, particularly when changed because of unexplained wear, and make
questionable the clinical use of multifilament trochanteric cables.
Multi-Scale Numerical-Experimental Analysis of Failure in Solder Alloys
Authors: Geers M.G.D. , Ubachs R.L.J.M. , Erinc M. , Matin M.A.
Published: March 2009

The past years have triggered considerable scientific efforts towards the predictive analysis
of the reliability of solder connections in micro-electronics. Undoubtedly, the replacement of the
classical Sn-Pb solder alloy by a lead-free alternative constitutes the main motivation for this. This
paper concentrates on the theoretical, computational and experimental multi-scale analysis of the
microstructure evolution and degradation of the conventional solder material Sn-Pb and its most
promising lead-free alternative, a Sn-Ag-Cu (SAC) alloy. Special attention is given to the thermal
anisotropy of bulk SAC and the interfacial fatigue failure of SAC interconnects.
Different Processing Methods to Obtain Porous Structure in Shape Memory Polymers
Authors: Farè Silvia , de Nardo Luigi , Cicco S. De , Jovenitti M. , Tanzi Maria Cristina
Published: March 2009

In the last few years, clinical procedures undergone huge modifications. Among them,
mini-invasive surgery has modified the clinical practice and the quality of life of patients. Shape
Memory Polymers (SMPs), a class of stimuli-responsive materials, can be considered ideal
candidates for the design of devices for mini-invasive surgical procedures. Such a device can be
inserted in a packed in, temporary shape and later can expand at body temperature. A bone defect
could be filled by a SMP porous structure, that improves the tissue integration and healing.
In this work, two different processing techniques to obtain porous shape memory polymer scaffolds
from Calo MER™ and MM-4520, two SMPs, are presented. Porous structures were obtained by
micro-extrusion with different chemical foaming agents or with sodium chloride, or by solvent
casting/particulate leaching. The morphology, the thermo-mechanical and the shape recovery
properties of the SMP porous samples were investigated. Tridimensional porous structures showed
a well interconnected morphology, with a pore size in the range aimed for bone interaction
applications. The shape memory properties were not significantly affected by the transformation
processes: a good ability of recovering the original shape was verified. Therefore, the porous
structures, obtained from these SMP materials, appear adequate for an use as bone filler.
Influence of Applied Tensile and Bending Strains on Local and Overall Critical Current of Multifilamentary Bi2223-Composite Superconductor
Authors: Ochiai Shojiro , Doko D. , Okuda Hiroshi , Oh Sang Soo , Ha Dong Woo , Tanaka Masashi , Hojo M. , Osamura Kozo , Miura M.
Published: March 2009

Influence of applied tensile and bending strains on the local and overall transport critical
current Ic and n-value at 77 K of multifilamentary Bi2223-composite superconductor was studied,
where the n-value refers to the sharpness of the transition from super- to normal conducting state.
Under both tensile and bending strains, the damage such as transverse and longitudinal cracking of
the Bi2223 filaments and interfacial debonding between the filament and silver progressed. The
extent of damage and accordingly the critical current was different among the local portions. The
relation of the local current and n-value to overall ones was analyzed with a voltage summation
model, with which the experimental result was described well. Further analysis revealed that the
distribution of local critical current could be described by the Weibull distribution function and
n-value could be expressed as a function of critical current. Based on these results, a Monte Carlo
simulation was carried out to predict the overall critical current from the distribution of local critical
current, with which the experimental results could be described.
Mechanical Properties of Composite Materials Consisting of M3/2 High Speed Steel Reinforced with Niobium Carbides
Authors: Jiménez José A. , Frommeyer Georg , López Marta , Candela N. , Ruano Oscar
Published: March 2009

Fully dense composite materials of M3/2 high speed steel reinforced with 5, 10 and
15vol. % of high purity niobium carbide were developed using powder metallurgy processing. This
work describes and discusses the mechanical behavior of the various composite systems.
Mechanical properties were characterized by Rockwell hardness, compression and three point
bending tests. It was found that the addition of ceramic particles causes a very small increase in the
hardness and 0.2% yield strength, but a decrease in the transverse rupture strength is observed. In
order to eliminate the influence of martensite on the mechanical properties, measurements were also
conducted after tempering. After this treatment, the reinforced materials showed a moderate yield
stress increase at room temperature respect to the unreinforced M3/2. However, the bend strength
values were not affected significantly by this treatment. At high temperatures, the addition of
reinforcement particles causes a slight increase in the strength. Strain rate-change tests in
compression were performed at strain rates ranging from 3 x 10-6 to 2 x 10-3 s-1 in the temperature
range from 650 to 750°C. The deformation behaviour was characterized by a stress exponent
ranging from 5 to 7 and an activation energy for plastic deformation similar to that found in high
alloyed ferritic steels.
Processing Ti-Al-Nb Composite Sheet Materials Using Cold Roll Bonding and Reaction Annealing
Authors: Acoff Viola L. , Zhang Ren Gang
Published: March 2009

Multi-layered composite sheet materials with nominal composition of Ti-46Al-9Nb
(at.%) were successfully processed from Ti, Al and Nb elemental foils using the cold roll bonding
technique. To promote the formation of intermetallic compounds in these composites, annealing at
600°C was employed for specimens subjected to various amounts of reduction. The microstructures
and phases that formed after cold rolling, the first annealing stage, and the second annealing stage
were characterized using scanning electron microscopy (SEM) equipped with an energy dispersive
x-ray spectrometer (EDS), transmission electron microscopy (TEM), and x-ray diffraction (XRD).
Good bonding was achieved for all rolled samples with a threshold reduction in thickness of about
35% in the first rolling pass. No new phases were formed in the cold rolling stage. Annealing stage
did promote the formation of the TiAl3 and NbAl3 phases at the interfaces.
Evaluation of Wear Behavior of Feldspar Particles Reinforced Copper Alloy Composite Materials
Authors: Satish B.M. , Girish B.M.
Published: March 2009

The wear behavior of unreinforced as well as feldspar particles reinforced copper alloy
(phosphor-bronze) composites was studied as a function of sliding speed and applied loads under
unlubricated conditions. The content of feldspar particles in the composites was varied from 1-
5% by weight in steps of 2%. A pin-on-disc wear tester was used to evaluate the wear rate.
Loads of 20-160 N in steps of 20 N and speeds of 1.25, 1.56, and 1.87 m/s were employed. The
results indicated that the wear rate of both the composites and the alloy increased with increase
in load and sliding speed. However, the composites exhibited lower wear rate than the alloy. It
was found that above a critical applied load, there exists a transition from mild to severe wear
both in the unreinforced alloy and in the composites. But the transition loads for the composites
were much higher than that of the alloy. The transition loads increase with the increase in weight
% of feldspar particles, but decreases with the increase in sliding speeds.
Combustion Synthesis of TiB2 Particle Dispersed Metal Matrix Composites
Authors: Matsuura Kiyotaka , Obara Yuki
Published: March 2009

FeAl-TiB2 composites have been combustion synthesized from mixtures of
Fe, Al, Ti and B powders. When the powder mixture was heated in vacuum to
approximately 900 K, an abrupt increase in temperature was observed, indicating that
the combustion synthesis reactions occurred in the powder mixture. X-ray diffraction
analyses revealed that the combustion-synthesized sample consisted of only FeAl and
TiB2. Metallographic investigations using a scanning electron microscope revealed that
fine TiB2 particles were dispersed in FeAl matrix phase. As the volume fraction of the
TiB2 particles increased from 0.3 to 0.8 by controlling the powder mixture composition,
the average TiB2 particle size increased to 1 to 7 μm and the average Vickers hardness
of the composites increased from 800 to 1600. This method has been applied to the
fabrication of some other ceramic particle dispersed metal matrix composites such as
Fe-TiC and FeAl-TiC systems.
Synthesis of Carbon Nanotube-Reinforced Al Matrix Composites
Authors: Ahn Jung Ho , Wang Yan Li , Kim Yong Jin , Kim Sung Jin , Chung Hyung Sik
Published: March 2009

We have synthesized multi-wall carbon nanotube (MWCNT)-reinforced Al matrix
composites. The Al/MWCNT composite powders were prepared by ball milling using pristine Al or
ball-milled Al powders as starting materials. The composite powders were consolidated by a
conventional cold-compaction, followed by sintering. Uniform dispersion of individual MWCNTs
within the matrix was in particular a critical factor for obtaining high density and high quality
Al/MWCNT composites. Compared to pristine Al powders as starting materials, the Al powders
previously attrition-ball-milled with carbon-based PCA (process control agent) in an ammonia
atmosphere resulted in a better distribution of carbon nanotubes within the Al matrix and a higher
density after sintering.
Estimation of Critical Composition for the Transition from Brittle to Ductile in W-Cu Composites
Authors: Hiraoka Yutaka , Hanado H. , Inoue Takeshi , Akiyoshi N. , Yoo M.K.
Published: March 2009

A series of industry-scale and laboratory-scale W-Cu composites containing copper of
19-51 vol% were prepared by infiltrating a tungsten skeleton with liquid copper. These composites
were subjected to a three-point bend test at temperatures between 77 and 363 K, and yield and
maximum strengths were evaluated as a function of both the temperature and the composition.
Fracture surface was observed using SEM and its fracture mode was examined. Results are
summarized as follows. (1) Critical Cu content for the transition from a brittle to a ductile
deformation behavior at room temperature was about 20 vol%. (2) Critical Cu content for the
transition from a bcc-type to a fcc-type deformation behavior was 38-45 vol%.
Effects of Spatial Distribution of Defects on Bending Deformation and Critical Current in Bi2223/Ag Superconducting Composite Tapes
Authors: Hojo M. , Nakamura M. , Tanaka Masashi , Adachi T. , Sugano M. , Ochiai Shojiro , Osamura Kozo
Published: March 2009

The strain dependence of the critical current, Ic, of Bi2223/Ag/Ag-alloy composite
superconducting tapes has been studied both experimentally and analytically under bending
deformation for two types of tape used in the VAMAS bending round-robin program (classified as
VAM1 and 3). Our former analysis showed that the experimentally obtained Ic values were between
the calculated ones based on a damage-free initial state and a case where delamination occupied the
full width of the tape mid-plane. The experimentally obtained Ic values were explained by the
delamination occupying partial width of the tape mid-plane. However, the microscopic observation
indicated that the delamination location in the thickness direction was not limited to the mid-plane.
In the present study, the analysis was modified to incorporate the movement of the delamination
location in the thickness direction. The calculated Ic values with delamination increased when the
delamination location moved to compressive side of the tape, and decreased when that moved to
tensile side of the tape. Finally, the experimental Ic values can be understood by the distribution of
delamination in both width and thickness direction.
Embossing on Epoxy Thermoset Polymer Using SiO2 Coated Nickel Template
Authors: Byeon Kyeong Jae , Hong Sung Hoon , Yang Ki Yeon , Kim Deok Kee , Lee Heon
Published: March 2009

Embossing or imprint lithography is the key-technology for the mass production of nanosized
structures with low cost. Currently Si or quartz template which is produced by e-beam or
DUV lithography and reactive ion etching, is used. However they are very expensive and easily
damaged due to their brittleness. On the other hand, Ni template has high mechanical durability and
can be fabricated with low cost by electroplating. However, one of the key obstacles of Ni template
is poor antistiction property, when it is used with sticky thermoset polymer. Due to its poor
antistiction property, detachment of Ni template from epoxy substrate is one of the key obstacles. In
this experiment, quartz template with 150nm to 1μm sized surface protrusion was fabricated and
used to emboss the PMMA coated Si wafer. Then the imprinted PMMA layer was coated with
metal seed layer and electroplating of Ni was followed to fabricate Ni template with 150nm to 1μm
sized patterns. In order to form antistiction layer on Ni template, SAM antistiction layer was formed
on SiO2 coated Ni template. As a result, nano patterns could be successfully transferred to sticky
thermoset polymer using Ni template without any degradation of antistiction property.
Nanoporous Titania by Embossing with PMMA Nanopoles Made from Nanoporous Alumina Template
Authors: Her Hyun Jung , Kim Jung Min , Lim Yun Soo , Kim Jae Wan , Choi Y.J. , Kang C.J. , Kim Yong Sang
Published: March 2009

We produced highly uniform nanoporous thin films of the dense array of titania (TiO2)
pores of 70~80 nm in diameter with nanoimprinting method. Titania in HCl and 2-propanol solution
was coated on an indium tin oxide (ITO) surface and embossed with an array of PMMA nanopoles
which was produced using a nanoporous alumina (Al2O3) template. Two-step anodization was
introduced to produce highly uniform and dense nanopores on the aluminum surface. The polymethyl
methacrylate (PMMA) was poured onto and infiltrated into the nanoporous alumina surface which
was heated at 150 oC. The alumina nanopores and aluminum plate were removed by wet-etching
leaving an array of PMMA nanopoles. These highly uniform nanostructured titania films will be very
useful for photovoltaic and photocatalytic applications where nanostructuring of surface with
controlled dimensions are essential.
Application of Platinum and Titanium Materials as an Electrode for Hygiene Purpose
Authors: Oh B.S. , Park S.Y. , Jung Y.J. , Baek K.W. , Hwang T.M. , Cho Kyoo Sung , Kang J.W.
Published: March 2009

The aim of this study was to investigate the application of electrochemical technology in
relation to the electrolysis of water in specific fields, including mouthrinses for the control of
periodontal disease and the cleaning of contact lenses. A platinum (Pt) coated titanium (Ti) electrode
cell (Pt/Ti cell, Dolki Korea Ltd.) was used for electrochemical experiments. Using the disinfection or
oxidation potential of the Pt/Ti cell, sterilized water was prepared for clinical testing. An
experimental group used mouthrinses with the sterilized water, where as the control group did not. In
the experimental group, the gingival and plaque indices, the probing pocket depth and clinical
attachment level all showed statistically significant decreases, but in the control group showed
significant increases (P<0.05). The electrochemical sterilization of water using the Pt/Ti cell was also
applied for the cleaning of contaminated contact lenses. SEM (Scanning Electron Microscope) data
demonstrated that a foreign body adhered to the contract lens could be removed during the electrolysis
of water containing the contaminated contact lens.
Effect of Annealing Treatment on Solid State Recycled Magnesium Alloy AZ91D
Authors: Lin Ying Nan , Wang Jian Yih , Lee Shyong
Published: March 2009

A practical and important idea regarding solid state recycling of magnesium alloys is explored.
Chips of AZ91D have been put in hot air environment for accelerated oxidation to simulate the
to-be-recycled state of Mg alloy scraps. These chips materials received extrusion process and
subsequent annealing treatment. Tensile tests showed that the extruded plate had higher strength than
that of ordinary die cast counterpart. Micro-structure investigation indicated it was probably due to
finer grains of the Mg matrix as a result of extrusion. Further annealing did not seem to alter this fine
structure, yet it could diminish some un-favored form of Mg17Al12 compound. Thus, post-annealed
solid state recycled AZ91D showed impressive strengths and elongations.
Effect of Product Quality on Life Cycle Assessment in Aluminum Die Casting Process
Authors: Kim Shae K.
Published: March 2009

Driven largely by the never ending quest for weight reduction to decrease fuel consumption
and emission, the automotive industry is predicting significant growth in the use of aluminum alloys.
Generally, cold chamber type die casting process is utilized for aluminum alloys. In order to comply
with the growing demand for life cycle environmental effect, life cycle assessment (LCA) was carried
out for producing A356 aluminum alloy by cold chamber type die casting process, based on what has
been experienced as needed for LCA study. The main emphasis of this study is to evlauate the effect
of trial of improving die casting process and product quality on the environmental value obtained by
LCA. Also the results will be compared by the trial of life cycle improvement. In LCA, the process
evaluated was based on yields of finished parts relative to the metal input. This is important both in
environmental point of view and in commercial point of view, because the environmental data are
sensitive to the design of the cast part and the efficiency of the die casting operation.
Recycling of Waste Rock as a Filler to Prevent Ground Subsidence
Authors: Lee Woo Keun , Ban Hyo Jin , Im I Rang
Published: March 2009

In this study, we investigate to use waste rock as a filler for filling the cavity of
abandoned mines. We discuss that waste rock can be used as a filler in the side of environmental
and structural stability. Waste rocks from four mines, such as Samgi, second Yeonwha, Dongwon
and Dogye, are used. Leaching tests are conducted to check the environmental stability by four
methods of Soil Leaching Test, MALT, TCLP and KSLT. According to the results, Cu, Cd, Cr and
As were not detected and other metals leached below 0.5 ppm. Compressive strength of waste rock
and crushed waste rock are measured to evaluate the structural stability. Mixtures of crushed waste
rock are used to evaluate the possibility of enhancing compressive strength. Mixture 1 is composed
of 11.1% of above 13.2mm, 22.2% of 9.5-13.2mm, 33.3% of 6.7-9.5mm, 22.2% of 3.5-6.7mm and
11.1% of 2.0-3.5mm. And mixture 2 is composed of 50% of above 13.2mm and 50% of
9.5-13.2mm. Compressive of the latter was more than that of the former. Waste rock can be
probably used as a filler, considering the compressive strength of commercialized filler, or 40
Kg/cm2.
Thermal Properties and Microstructure of Zirconia/Monazite-Type LaPO4 Composites for Powder Preparation Methods
Authors: Kim Seung Ho , Sekino Tohru , Kusunose Takafumi , Hirvonen Ari T.
Published: March 2009

Thermal conductivity and microstructure of 3YSZ/monazite-type LaPO4 composites were investigated. Powders were prepared by two kinds of preparation methods such as conventional ball-milled and chemical precipitation of LaPO4 on the zirconia powder surface. Thermal conductivity of 3YSZ/monazite-type LaPO4 composites was lower than that of 3YSZ. That of 3YSZ/monazite-type LaPO4 composites was influenced on the powder preparation methods and as a function of measured temperature. Microstructure of 3YSZ/monazite-type LaPO4 composites was not much affected by the amount of dispersed LaPO4 particles. 3YSZ/monazite-type LaPO4 composites were observed to pores after thermal etched. The pore of synthesized specimens was observed remarkably in compared with conventional ball-milled specimens.
Influence of the Nickel on the Corrosion Behavior of Al-Mg-Sc-Zr Alloy
Authors: Zhao W.T. , Yan De Sheng , Rong Li Jian
Published: March 2009

The corrosion behavior of cold worked Al-Mg-Sc-Zr-Ni alloys prepared by vacuum
induction melting in acidic chloride solution was studied. The morphological characteristics of the
corroded specimens were examined by OM(optical microscopy), SEMand EDX techniques. The
results indicated that the intergranular and exfoliation corrosion susceptibility dramatically depended
on the Ni content. The Al-Mg-Sc-Zr alloy with 0 and 0.5 wt.% Ni were lightly susceptible to
intergranular corrosion as the precipitation of Mg2Al3 phases presented at grain boundaries and the
Al3Ni particles were finely dispersive. The intergranular corrosion was enhanced by the Al3Ni
particles enrichment and became pitting corrosion with increasing Ni to 1.0 wt.%. Finally, the
exfoliation corrosion happened to the alloy with 2.0wt.% Ni. This trend correlated well with the
electrochemical property and distribution of Al3Ni phases. The corrosion potential of Al3Ni
intermetallic phase is nobler than the β phase and the matrix, which result in an appearance of
galvanic coupling. In addition, the increase of Al3Ni particles enlarged the attack area and the
inhomogeneous segments of Al3Ni and Al3Mg2 phases accelerated the localized corrosion.
Development of New Generation Turbine Disk Superalloys in the HTM21 Project
Authors: Gu Yue Feng , Cui C. , Ping D. , Harada Hiroshi , Sato Akihiro , Fujioka J.
Published: March 2009

A new kind of cast & wrought (C&W) Ni-Co base superalloys named as “TMW alloys”
was developed recently for compressor and turbine disk of gas turbine engines in the High
Temperature Materials 21 Project at the National Institute for Materials Science (NIMS) in Japan.
These Ni-Co base superalloys combine the characters of two kinds of γ- γ’ two-phase alloys (Ni-base
and Co-base superalloys) and can be fabricated by cheap cast and wrought processing route. The
results showed that some of these TMW alloys have superior tensile strength at temperatures up to
750 °C and higher creep resistances up to 725 °C than commercial UDIMET 720 LI alloy.
Effect of Heat Treatment on Microstructure and Mechanical Properties for a Ni3Al Base Single Crystal Alloy DDIC6
Authors: Kong Zhi Gang , Ji Lei , Li Shu Suo , Han Ya Fang , Xu Hui Bin
Published: March 2009

The effect of heat treatment on microstructures and stress rupture property of a Ni3Al base
single crystal alloy DDIC6 was studied in the present investigate. The single crystal specimens were
produced by screw selection crystal method. The heat treatment for the alloy was
1300°C/10h+1120°C/4h+870°C/32h and 1300°C/10h+870°C/32h.The microstructures were
examined by SEM, TEM and X-ray EDS techniques. The stress rupture tests were carried out in air by
constant load creep machines under 1100°C/130MPa with the specimens size of φ5×25 mm. The
experimental results showed that the as-cast large size γ′ phases entirely dissolved after 1300°C/10h,
and secondary fine γ′ phases precipitated by following aging at 1120°C and 870°C for certain periods
of time. The stress rupture life under 1100°C/130MPa increased from 20~30hrs for as-cast condition
to 60~100hrs for heat treatment condition. The improvement of the creep resistance of the alloy may
attribute to the decrement of the elements segregation at dendrite and interdendritic areas, and the
proper size and distribution of γ′ phases.
Microstructural Characterization and Properties of SiC/Al Composites for Electronic Packaging Fabricated by Pressureless Infiltration
Authors: Cui Yan
Published: March 2009

High volume fraction (63vol.%) SiCp/Al composite for electronic packaging fabricated by
pressureless infiltration was characterized by microscopy, physical and mechanical tests. Microscopy
observations and XRD analysis indicated that the composite appeared to be free of porosity and
macroscopically homogeneous, SiC-Al interface was atomic bonding interface with low thermal
resistivity and electrical resistivity, no interfacial reaction products was detected. Examination of the
fracture surfaces of the composites revealed that the cracks passed through the SiC particles and Al
matrix, no debonding of SiC-Al interface was observed. The fracture mode indicated that the bonding
between SiC-Al was sufficient strong. The properties of the composite were noted for its ultrahigh
thermal conductivity of 235W/m·K and specific modulus (79.9×105m), low coefficient of thermal
expansion (7.2×10-6/K) and density of 2.99g/cm3. The advantages of the composite over traditional
materials used as the electronic packages for aerospace applications were analyzed.
Fluorinated Acrylic Films: Effect of F Content on Aging and Corrosion Testing
Authors: Zheng Tian Liang , Wang Xuan , Li Ying Bo , Chen Bing Qing
Published: March 2009

Four fluorinated polyacrylate dispersions, which based on chlorotrifluoroethylene (CTFE),
acrylic acid (AA), vinyl acetate (VAc) and ethenyltriethoxysilane (ETOS) as monomers, are
synthesized by free radical polymerization. The influence of xenon lamp and UV-light aging on the
film with the fluorine content is discussed. The effect of salt-spray corrosion before and after
UV-light aging with F wt% of film is also studied. The results show that low surface energy of high
fluorine content film can retard salt-spray corrosion compared with no or low fluorine content films.
Study on the Microstructure and Mechanical Property of High Strength Mg-Nd-Zn-Zr Alloy
Authors: Ding Wen Jiang , Fu Peng Huai , Peng Li Ming , Jiang Hai Yan , Zeng Xiao Qin
Published: March 2009

The microstructure and mechanical properties of Mg-3wt％Nd-0.2wt％Zn-0.4wt％Zr
alloy in as-cast, solution-treated and solution-treated + peak-aged were investigated. The alloy had a
cast structure with large intergranular Mg12Nd phase between the α-Mg matrix. After solution-treated,
the intergranular Mg12Nd phase disappeared and lots of small Zr-containing particles distributed
inside the grains. Small plate-like phases precipitated inside the grains strengthened the alloy to a high
level after peak-aged at 200°C for 16 hours: the ultimate strength of the alloy up to 305 MPa, with
considerable elongation rate 11%, and yield strength 140 MPa. The peak-aged samples also had good
creep resistance, with strain rate less than 0.2% after 120 hours creep test under the condition of 110
MPa at 200°C. The minimum creep rate was about 4.64×10-9. The alloy had different fracture pattern
in different states: as-cast state, intergranular fracture was the key pattern to failure; after
solution-treated, the fracture pattern turned to cleavage transgranular fracture; after peak-aged, the
alloy had a mixed fracture pattern of transgranular and intergranular, in which transgranular was the
main style.
Effect of Mg Content in Matrix on Infiltration Height in Producing MgO/Al Composite by Vacuum Infiltration Method
Authors: Calin Recep , Citak Ramazan
Published: March 2009

Vacuum infiltration is one of the composite production method. Reinforcement volume
ratio, vacuum value, molten matrix composition and temperature, infiltration atmosphere and time are
important parameters in infiltration of molten metal into preformed reinforcement. In this study, MgO
powder and Al were used as reinforcement and matrix respectively. Mixture of MgO and Al powders
with –105 μm particle size were filled in quartz tubes freely to form 30 % reinforcement volume ratio.
Liquid pure Al with varying Mg contents were vacuum infiltrated into the MgO powder under 550
mmHg vacuum at two different temperatures in normal atmosphere for 3 min. After vacuuming,
infiltration height and density of produced composite have been determined. Fracture behavior of
composites has also been determined by three point fracture test. Microstructure of composites and
fracture surface were investigated by SEM analysis. It has been found that fracture strength of
composites decreased although infiltration height and density increased with increasing Mg content of
liquid Al. It has been also determined that molten metal temperature facilitates infiltration.
Zr-Containing Precipitates in Mg-3wt%Nd-0.2wt%Zn-0.4wt%Zr Alloy during Solution Treatment at 540°C
Authors: Fu Peng Huai , Peng Li Ming , Jiang Hai Yan , Zhai Chun Quan , Gao X. , Nie Jian Feng
Published: March 2009

The microstructure of Mg-3wt%Nd-0.2wt%Zn-0.4wt%Zr (NZ30K) alloy after solution
treatment was investigated and several kinds of interesting phases containing zirconium were found
in this study. NZ30K was gravity cast using permanent die casting. After high tempering solution
treatment at 540°C, cluster particles were observed inside the grains under optical microscopy. The
detailed investigations were carried out on transmission electron microscopy (TEM). Four kinds of
precipitates were visible inside grains with different shapes: block-like, globular, short rod-like, long
rod-like. The block-like particle was identified as ZrH2 phase and the globular one was Zn2Zr3 phase.
The other two were still Zr-containing phases, which could not be identified to any of existed
compounds containing Zr. The formation of Zn-Zr compounds would probably be due to relative
high ratio of Zr to Zn in the center of grains. ZrH2 would be the results of reaction of zirconium with
H element during solution treatment, which probably came into the alloy during melting.