bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Substrate Porosity on the Coating Adhesion of Iron Sintered Plated Parts with Infiltration Pretreatment
Authors: Etaat Moslem , Ghambari Mohammad , Riabi Mojtaba Naserian
Published: March 2009

Plating of the sintered components has some problems due to interconnected porosities in
those parts. In this research, iron-based sintered specimens infiltrated with copper were used. The
pretreated specimens were then plated with nickel and the adhesion of coated layer to substrate was
investigated. The results showed that the adhesion of coated layer in copper infiltrated iron sintered
components is independent of substrate initial density.
Features of Materials Engineering R&D and Education in Finland after Joining the EU
Authors: Kleemola H.
Published: March 2009

The influences of the membership of Finland in the European Union on the structures and development of the materials research and development, and education are discussed. It will be shown that during the membership the infrastructure and working culture have changed thoroughly.
MAgPP an Effective Coupling Agent in Rice Husk Flour Filled Polypropylene Composites
Authors: Czél György , Kanyok Zoltán
Published: March 2009

Different properties (tensile strength, elongation, modulus, impact strength) of rice husk (RH) reinforced polypropylene (PP) coupled by Maleic-Anhydride grafted Polypropylene (MAgPP) have been investigated. MAgPP is an effective coupling agent, not only in cellulosic-fibre filled polyolefine composites, but in rice husk flour filled polypropylene composite systems as well. It gives a utilizable construction polymer matrix composite (PMC) material even at a 40 wt.% RH filling degree. The strength and modulus increases by adding the rice husk but the elongation decreases in a non-monotonic way. Micrographs shows weak coupling in between RH and PP without MAgPP.
Analysis of Adobe-Clay as an Envorinmental-Friendly Structural Material
Authors: Csicsely Ágnes O. , Józsa Zsuzsanna , Sajtos István
Published: March 2009

The research topic is the analysis of adobe-clay as a structural material. The behaviour of adobe
brick elements of different mixtures were examined. The bricks of various ratios of clay, straw, reed and
sawdust were involved in the experiment, in which the process of drying and shrinkage was investigated.
Even though only a few data have been obtained so far, some important conclusions were drawn. The first
drying period was approximately three weeks long in the laboratory. The tests have shown that organic
components like straw, reed and sawdust slow down the drying process. In case of each mixture, a change
of weight was observed sooner than shrinkage. The aim of the research is to promote the application of
this building material.
Investigation of the Debonding Process in Wood Fiber Reinforced Polymer Composites by Acoustic Emission
Authors: Kocsis Z. , Czigány Tibor
Published: March 2009

Wood fiber reinforced polypropylene composites of different fiber contents without any
treatment were prepared, and tensile tests were carried out on injection molded specimens. With
increasing fiber content a decrease of the tensile strength was experienced. The weak adhesion at
the fiber-matrix interface and the typical composite failures can be seen on SEM pictures. During
the tests acoustic emission was monitored to get more information about the damage mechanism.
From the AE counts distribution it can be concluded that the maximum number of AE counts
decreases simultaneously with the tensile strength in case of the different composites.
Pulse Plated Amorphous Fe-P Thin Layers for High Frequency Magnetic Applications
Authors: Mikó Annamaria , Takács Márton , Lakatos-Varsányi M. , Varga L.K.
Published: March 2009

Amorphous and partly nanocrystalline amorphous iron-phosphorus (Fe-P) layers have been deposited by pulse electrochemical technique. X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) have been used to characterize the structure in the layers. Depending on the pulse parameters, the structure of Fe-P layers changed from mostly amorphous to partly nanocrystalline amorphous. The magnetic coercivity and the frequency limit of the samples are discussed in terms of the structure of the Fe-P layers. The frequency limit as determined from the permeability spectra is above 10 MHz, which makes these layers suitable for high frequency inductive element applications.
Laboratory Experiments for Studying the Surface Preparation and Annealing Processes before Continuous Hot Dip Galvanizing
Authors: Dénes Éva , Fauszt Anna , Kopasz László , Török Péter , Verő Balázs
Published: March 2009

The coated product market is a highly quality exigent market which has been developing
for decades. The technological process of galvanizing starts with a thermal cleaning in a continuous
annealing furnace. Therefore the understanding of the processes which take place before dipping
requires laboratory experiments modelling the oxidation and reduction of the base metal. Some of
the presented experiments are thermogravimetric oxidation and reduction tests, others are laboratory
trials carried out in special experimental furnace.
Relationship between the Primary Cast Structure and Distribution of Inclusions in a St52-3 Type Continuously Cast Steel Slab
Authors: Fehérvári Gábor , Verő Balázs , Kardos Ibolya , Csepeli Zsolt
Published: March 2009

The macrosegregation is one of the most recurrent phenomena in continuous steel casting
of slabs. It often impedes the further processing and has detrimental effect on the quality of rolled
strip. The macrosegregation can be explained by the interpretation of unit steps of solidification in
continuous casting slabs as well as on the basis of the interaction of the inclusions at the interface of
solid and liquid phases. Development of solid shell and interaction between growing dendrites and
MnS segregation has been presented. Only the pushing effect could be the real cause of MnS
segregation among the three possible interactive mechanisms. The sulphur print could give
misleading information on sulphur segregation.
Main Aspects at the Design and Loading Test of Large Scale Trusses to Achieve a Reasonable Structural Safety
Authors: Bagi István , Tomka Pál
Published: March 2009

The paper reviews the whole design process of large−scale trusses of overhead
lines for power transmission. It describes the modules of the system of interactive computer
programs made by the authors. According to the iterative nature of the design process special
graphic support helps the interaction of the designer. The effect of assumptions used during
the design process, imperfections due to the fabrications and erection of the structures can
only be detected by the loading tests carried out on newly designed set of towers. Some
experiences learned by these tests are also detailed in the paper.
Visualisation of the Melt Flow under Rotating Magnetic Field
Authors: Rónaföldi Arnold , Kovács Jenő , Roósz András
Published: March 2009

Experiments were performed for visual observation and investigation of liquid Gallium
flow at a temperature of 40oC in a rotating magnetic field. Two different measuring methods were
developed to determine the revolution number of rotating melt. In both cases the frequency of
magnetic induction was 50, 100 and 150 Hz and the values of magnetic induction could be changed
between 0 and 70 mT. The magnetic Taylor number changed between 0 and 3.54x107 during the
experiments.
Laser Shock Processing of the Maraging Steel Surface
Authors: Grum Janez , Zupančič Martin , Ocaña J.L.
Published: March 2009

Laser Shock Processing (LSP) is a process of laser treating of a surface with a
pulsed beam of high power density. The process enables hardening of a thin surface layer;
therefore, it is suitable for the improvement of fatigue strength of quality materials. Locally
directed mechanical waves produce a considerably increased dislocation density in the thin
surface layer, which affects the variations of microhardness and residual stresses. The
magnitude and variation of the residual compressive stresses in the surface layer are
favourable, which ensures higher fatigue strength. Laser shock processing (LSP) is more
exacting than conventional shot peening, but it shows certain advantages such as better
control of the surface state, processing of locally limited surfaces and a possibility to
produce different transitions between the processed surface and the non-processed one. LSP
has so far been tested and efficiently applied to various materials, including maraging
steels. Relevant publications often deal with LSP mechanisms and the influence of the
process on the dynamic strength of maraging steel, but less frequently the influence of
individual characteristics such as the microstructure of matrix and of precipitated phases or
residual stresses.
The present paper deals with LSP of 12% Ni maraging steel. The material chosen is
suitable for the production of complex structural parts and dies for die casting, which
require high resistance of the material to thermo-mechanical loads. By means of
measurement of the state before and after LSP, the value of the mean roughness Ra, surface
defects and the variation of residual stresses in the thin surface layer were determined. After
LSP of the surface, the influence of processing parameters such as laser-beam diameter and
pulse density per unit of area was established.
High Performance Microcoulometry
Authors: Murányi Roland , Cserfalvi Tamás
Published: March 2009

The purpose of this work is the development of microcoulometric cell for measurement
of halogenide ions in the range of ng amounts. The main task in the innovation is to fulfil the need
of sensitive halogene determination in the automated measurement of the so-called adsorbable
organically bound halogens (AOX) in waters. The very low consumption of supporting electrolyte
and the energy saving configuration is also important factors in designing of monitor operation. We
developed a micro volume tube reactor, which can work continuously with peristaltic pumps
feeding the supporting electrolyte and the sample. The tube cell allows the injection of liquid and
gas samples without changing the cell construction. A three electrode type potentiostatic
microcoulometer with a rotating Ag working electrode was built, which maintains a constant
electrode potential of the working electrode to the reference electrode by the generation of silver
ions through anodic dissolution. The halogenide ions in sample solution change the electrode
potential of the working electrode. The potentiostatic controller circuit sets a current flowing
between the Ag working (anode) and a counter electrode (cathode). This current generates silver
ions from the working electrode, these ions precipitate the halogenide ions from the cell electrolyte
and restore the potential of the working electrode. It was a further successful hydraulic development
to achieve a microvolume cell, which accepts both gas and liquid samples in the same equipment.
The developed microcoulometer system has high sensitivity and works reliable in a wide measuring
range.
Correlation of Microstructure with Hardness and Corrosion Resistance of Surface Alloyed Materials Fabricated with Fe-Based Metamorphic Powders by Accelerated Electron Beam Irradiation Method
Authors: Nam Duk Hyun , Lee Kyu Hong , Lee Sung Hak , Kim Nack , Kim Kyu Young
Published: March 2009

This study aims at correlating microstructure with hardness and corrosion resistance of
surface alloyed materials fabricated with Fe-based metamorphic powders by an accelerated electron
beam irradiation method. The surface alloyed materials contained 48 vol.% of hard Cr2B crystalline
phases in the Cr0.19Fe0.7Ni0.11 matrix, and thus its hardness was 2.5 times greater than that of the
steel substrate. The corrosion resistance of the surface alloyed materials was better than that of an
STS304 stainless steel or coatings fabricated by high-velocity oxygen fuel spraying of Fe-based
metamorphic powders because the Cr0.19Fe0.7Ni0.11 matrix of the surface alloyed layers and coating
was selectively corroded, while Cr2B borides were retained inside pits. These findings suggested
that the fabricated surface alloyed materials presented good application possibilities as excellent
wear- and corrosion-resistant materials.
Microstructure Characterization and Modeling of Splat Formation during Air Plasma Spraying for Inconel 625 Superalloy
Authors: Azarmi F. , Moradian A. , Mostaghimi J. , Coyle Tom W. , Pershin L.
Published: March 2009

There is a growing interest in use of the nickel-based alloy Inconel 625 coatings due to its
ability to improve base materials high temperature properties. Thermal spraying methods such as Air
Plasma Spraying (APS) can be considered as a convenient method to deposit this material. The
present work deals with APS deposited Inconel 625 structures consisting of huge number of
individual splats formed by impacting molten droplets on substrates during spraying process. It is
clear that the splat formation mechanism which dominates its size, cohesion, and boundaries highly
influences the microstructure of the coating. This paper presents a developed numerical technique
performed to simulate splat formation using a three dimensional model. In this method flow field is
solved by Finite Volume Method (FVM) and free surfaces are determined from Youngs’ Volume of
Fraction method (VOF). Finally, the model prediction is correlated with the actual splat geometries.
The Influence of Powder Types and Plasma Spray Conditions on Abrasive Wear of Nanostructured and Conventional Al2O3/TiO2 Coatings
Authors: Wang You , Wang D.L. , Liu G. , Tian W. , Wang C.H.
Published: March 2009

In this paper, Al2O3/TiO2 coatings via thermal spray approach using three different
feedstock powders, i.e., (a) reconstituted nanosized Al2O3/TiO2 feedstock powders, (b)
reconstituted nanosized Al2O3/TiO2/ZrO2/CeO2 feedstock powders and (c) conventional
Al2O3/TiO2 feedstock powders are described. Effects of different powder types and various
plasma spray conditions on the density, microhardness and crack resistance, especially on the
abrasive wear behavior of the coatings have been evaluated. The result showed that the coatings
sprayed using different feedstock powders exhibit different abrasive wear behavior with
changing the plasma spray conditions. The coatings sprayed using the reconstituted nanosized
Al2O3/TiO2/ZrO2/CeO2 feedstock powders showed a significantly improved wear resistance
compared to the coatings sprayed using reconstituted nanosized Al2O3/TiO2 feedstock powders
or conventional Al2O3/TiO2 feedstock powders. The wear mechanisms of the coatings were
discussed.
Lifetime of PEMFCs
Authors: Jörissen Ludwig , Lehnert Werner , Garche Juergen , Tillmetz W.
Published: March 2009

In this paper reactions having strong influence on the lifetime of PEMFCs are
described. These lifetime limiting reactions are related to the catalyst (increase of the
particle size, catalyst dissolution, oxidation of the carbon catalyst support, catalyst
deactivation by contaminants), to the membrane (degradation, loss of membrane
humidification, increase of membrane resistance), and corrosion of structural components
(e.g. metallic bipolar plates). Examples for such reactions are shown and rate determinining
parameter are discussed.
Manufacturing of Solid Oxide Fuel Cells - Bridging the Gap from Laboratory to Industry
Authors: Menzler Norbert H. , Buchkremer Hans Peter , Ernst Johannes , Kauert Ralf , Ruska Jürgen , Stöver Detlev , Stolz Stefan
Published: March 2009

Due to their direct conversion of electrochemical into electrical energy solid oxide fuel cells (SOFCs)
have great potential for a future additional energy supply. Even in the last two years numerous
developers of SOFCs, both industry and research institutions, have demonstrated long-term stable
operation of stacks of various dimensions (ranging from 1 to 125 kWel, with durations of up to 25000
hours of operation). Besides technical proof, single component availability (cells, bipolar plates,
sealing…), stable and low-aging operation, as well as cost efficient manufacturing of the components
is becoming more and more evident in preparation for a market launch.
Close cooperation between SOFC stack developers, SOFC users and manufacturers of powders, semifinished
parts or stack components is a prerequisite for success.
Within a collaboration project funded by the German Federal Ministry of Economics and Labor
(BMWA) the development of an SOFC as an auxiliary power unit (APU) is being promoted. The
industrial users are BMW for automotive applications and Liebherr for use in construction vehicles or
aircraft.
The content of this presentation will be the transfer of the manufacturing knowledge developed at
Research Center Jülich to CeramTec; including on the one hand the problems and limitations and, on
the other hand the successes and positive perceptions. In detail, the transfer of, for example tape
casting and screen printing will be addressed, powder characteristics concerning paste or slip
formulation and special tests with reference to SOFCs are presented, and single cell tests of various
cells manufactured with different powders or fabrication processes are described.
Additionally, some remarks will concern different priorities in either R&D or industry (e.g. R&D:
high power density; industry: reproducibility), process windows for manufacturing and the search for
alternative fabrication methods.
Fuell Cell and Hydrogen Vehicles - State of the Art and Challenges for Improved Materials
Authors: Treffinger Peter , Brinner Andreas , Schöll Roland , Friedrich Horst E.
Published: March 2009

Fuel cell vehicles should be further improved. Key issues are cost reduction; higher power density of
the primary energy converter, the fuel cell; wider operation ranges and improvement of operation
parameters, e.g. higher operation temperature and starting ability in freezing conditions. Using
advanced materials and construction principles is a key factor by meeting these requirements. The
paper gives a short introduction to the technology of fuel cell vehicles and the most prominent fuel
cell type for traction applications, the polymer-electrolyte-membrane fuel cell (PEFC). Progress in
material development of a core component of the PEFC, the bipolar plate is described.
In the second part of the paper some ideas are presented, in which way material research could help to
enable suitable on-board storages for hydrogen. Namely, a new approach to design compressed gas
storages and new developments in materials for solid state hydrogen storage are brought to attention.
A Mathematical Model of Ultra-Thin Catalyst Layer in PEFC
Authors: Wang Qian Pu , Eikerling Michael , Song Da Tong , Liu Zhong Sheng
Published: March 2009

A mathematical model for an ultra-thin catalyst layer in PEFCs is introduced. It utilizes
Nernst-Planck and Poisson equations. Calculated polarization curves are shown to compare
favourably with published experimental data for ultra-thin catalyst layers. Aspects of current
conversion, reactant, current distribution, and catalyst utilization are explored. The effect of
catalyst layers thickness on the Pt utilization is discussed. This study gives us a better
understanding of transport and reaction at the mesoscopic scale and it furnishes the directions for
optimization of this type of catalyst layer.
Brazing of AZ31B Magnesium Alloy Sheet
Authors: Watanabe Takehiko , Oohara K.
Published: March 2009

This study was carried out to newly develop the fluxes and filler metals for brazing
magnesium alloy AZ31B more easily at lower temperatures. Furthermore, surface preparation was
developed to improve the brazeability of magnesium alloy. The main results obtained are as follows.
We could successfully develop the fluxes that consisted of chlorides containing Ca ion and Li ion,
which made the faying surface of the magnesium alloy active at around 450°C. In addition, we
succeeded in developing the filler metals with the melting temperatures lower than 490°C which
were Mg-Sn-In system containing a small amount of Al to lower the melting temperature. Surface
preparation for magnesium alloy by immersion in aqueous solution containing halogen ion
improved remarkably the brazeability of the magnesium alloy. Using the surface preparation
together, the fluxes and filler metals could achieve the brazed joints with a high strength equivalent
to that of the base metal.
Corrosion Properties of Supersaturated Magnesium Alloy Systems
Authors: Blawert Carsten , Heitmann V. , Dietzel Wolfgang , Störmer M. , Bohne Y. , Mändl Stephan , Rauschenbach B.
Published: March 2009

The range of applications for magnesium alloys is still limited due to their relatively poor
corrosion behavior. In recent years, various new magnesium alloys were developed, some of them
with improved corrosion properties, thus opening new fields of application. However, the number of
alloying elements for the use in conventional cast processes is limited due to their interaction with
liquid magnesium, other alloying elements or large differences in the melting temperatures. The
possibilities for grain refinement by post-processing are also restricted. PVD techniques can help to
produce supersaturated precipitation free and microcrystalline magnesium layers.
Using ion beam and magnetron sputtering, binary or ternary Mg-Al, Mg-Ti and Mg-Sn alloy
systems as well as standard alloys (AM50, AZ91 and AE42) were deposited on silicon and on
magnesium substrates. The effect of the microstructure on the corrosion properties was studied by
comparing as cast material and PVD coatings using potentiodynamic polarization, linear polarization
resistance, and electrochemical impedance techniques.
The Microstructure of AZ 31 Magnesium Alloy by Forward Extrusion with Various Extrusion Parameters
Authors: Yoon Duk Jae , Na Kyoung Hoan , Cho Chong Du
Published: March 2009

Samples of AZ31 wrought magnesium alloy are hot extruded into forward direction with
various initial billet temperatures and extrusion ratios (ERs). Usually the insufficient room
temperature formability of magnesium wrought alloys makes processing steps like rolling, extrusion
etc. difficult, thus limiting their use for rolled or wrought parts. However, in this paper experiment
is preformed under the hot forward extrusion process for AZ31 wrought magnesium alloy with
different important parameters. Major process parameters such as punch speed, billet temperatures
and ERs are considered and applied to the hot extrusion process with a constant value of the die
land. The influence of different billet temperatures and ERs on the hot forward extrusion process is
investigated and analyzed in terms of the grain flow, microstructure, grain size and hardness
distribution of formed part for magnesium and Mg alloy. Maximum forming loads for various main
parameters is tackled and checked to know the optimum forming load for hot forward extrusion
process. Also finest grain sizes and an inhomogeneous microstructure of extruded parts seem to
occur near the die land of tool-set due to the anisotropic plastic behavior during the hot extrusion
process. Extrusion properties such as extrusion load, grain size, micro hardness and surface quality
are compared between the main parameters during the hot forward extrusion process. In addition it
is easily disclosed from the experiment results that the die land designed for safe tool-set plays a
key role in improving the mechanical properties of formed product during hot forward extrusion
process for AZ31 magnesium alloy.
On the Finite Element Simulation of Secondary Operations on Metallic Foams
Authors: Filice Luigino , Fratini Livan , Umbrello Domenico
Published: March 2009

Metallic foams have been recently introduced also as industrial materials due to their well
known advantages. In fact, their low mass in conjunction with the good thermal and mechanical
properties push toward an extensive diffusion in manufacturing industry.
In the study here addressed, a very accurate investigation concerning the latter two aspects has been
carried out. In fact, a secondary manufacturing process, i.e. the foam bending, has been taken into
account. Anyway, all the knowledge derived for sheet metal bending is not directly applicable to the
foams. A finite element code has been utilized for modeling the foam behavior during the bending
processes and an accurate material rheology description was utilized based on a porous material
model which includes the measured local density. The effectiveness of the utilized model has been
verified through the comparison with a set of experimental data.
inno.zellmet - A Concerted Approach towards the Application of Non-Foam Type Cellular Metals
Authors: Andersen Olaf , Hungerbach Wolfgang , Stephani Günther , Studnitzky Thomas
Published: March 2009

inno.zellmet is a large funded project which aims at the commercialisation of new,
non-foam types of cellular metals. The project focuses on porous structures made from metallic short
fibers and structures made from metallic hollow spheres, which are both chararacterised by multifunctionality
and low specific weight. Six research institutes and 17 partners from industry constitute
a local network that jointly develops solutions based on these "constructed materials". Target applications
are situated in industrial sectors such as light-weight construction, decentralised energy generation,
medical and biotechnology, as well as sound absorption and explosion protection for stationary
machinery. inno.zellmet has started in March 2005 and will run for 3 years. During this time,
it receives 3.9 Mio. EUR in funding from the German Federal Ministry of Education and Research
under the "Unternehmen Region" initiative. This paper highlights some of the results obtained so far.
Soft Magnetic Bulk Glassy Alloy Synthesized by Flux Melting and Water Quenching
Authors: Makino Akihiro , Bitoh Teruo , Inoue Akihisa , Greer Alan Lindsay
Published: March 2009

The flux treatment was applied to increase the glass-forming ability of a glassy
[(Fe0.5Co0.5)0.75B0.20Si0.05]96Nb4 alloy. The large bulk glassy specimen with diameter of 7.7 mm was
prepared by water quenching the melt immersed in the molten flux of B2O3. The diameter of the
specimens is approximately 1.5 times as large as the previous result, even though the cooling rate of
copper mold casting should be much higher than that of water quenching. The critical cooling rate
for a glassy phase is 150 - 170 K/s, which is much slower than 500 K/s without the flux treatment.
The flux treatment improves the glass-forming ability by cleaning the molten metal where
heterogeneous nucleation is difficult to take place.
Effects of Applied Bias and Dopants on the Photocatalytic Degradation of Aqueous Dye Solution by TiO2/Ti Electrode
Authors: Shen Jia Nian , Li Mou Cheng , Liu Dong , Sun Xian Rong , Gracien Ekoko Bakambo , Yao Shu Dian , Wan Bin
Published: March 2009

The photocatalytic degradation of organics in aqueous solution is an active research field.
Currently, the relatively low degradation efficiency is the key problem to be solved that caused by
the simple recombination of the photo-generated electrons and holes. The electrode was prepared by
anodic oxidation on titanium thin plate and produced multiporous nano-crystalline titanium dioxide
film with anatase structure on titanium substrate. In order to inhibit the simple recombination of the
electrons and holes, the electric potential bias was applied to the electrode to drive away the
chargers. The change of the photocurrent and the discolouration of the dye solution containing
either methylene blue or acid red G with different magnitude of the applied bias were measured. It
shows that the photocurrent increased by three orders of magnitude from μA to mA level by the
applied bias. Correspondingly, the discolouration rate of the methylene blue in dye solution was
increased greatly with the increasing applied bias up to 3.5V. The different kinds of transitional
metal ions dopants of Mn2+, Cr3+, Fe3+, and Ni2+ to the electrodes was done by anodic oxidation
method. The effects of different types of dopants on the photocatalytic activity were revealed by
measuring the degradation of an organics aqueous solution containing a dye using a combination of
ultraviolet light energy in the presence of these electrodes. The photocatalytic efficiency, which was
remarkably enhanced by the incorporation of Mn2+、 Cr3+.、 Mn2+, showed the largest enhancement.
However, Fe3+ changed only slightly, and Ni2+ showed no enhancement. These effects were related
to the difference of these transitional metal dopants electron work function values and also to the
difference of their ionic radii in respect to that of Ti4+. The configuration of the reactor for water
treatment with the rotating electrode and 365nm wavelength UV radiation was described.
Thermodynamic Analysis of Steels by Incorporating First-Principles Calculations into the CALPHAD Approach
Authors: Ohtani Hiroshi , Hanaya N. , Hasebe Mitsuhiro
Published: March 2009

A thermodynamic analysis of the Fe−M−P (M = Nb, Ti) ternary system has been
performed by combining first-principles calculations with the CALPHAD approach. Because of the
lack of experimental information available, thermodynamic properties of orthorhombic
anti-PbCl2-type FeMP were evaluated using the Full Potential Linearized Augmented Plane Wave
method, and the estimated values were introduced into a CALPHAD-type thermodynamic analysis.
Applying this procedure, the phase diagrams of the Fe−M−P ternary phase diagrams whose contents
are uncertain so far were calculated with a high degree of probability. Phase diagrams for high-purity
ferritic stainless steels obtained following the same procedure are also presented.
Role of Strain Gradient and Dynamic Transformation on the Formation of Nanocrystalline Structure Produced by Severe Plastic Deformation
Authors: Umemoto Minoru , Todaka Yoshikazu , Li Jin Guo , Tsuchiya Koichi
Published: March 2009

Formation of nanocrystalline structure by severe plastic deformation has studied
extensively. Although ultra fine grained structure (grain size larger than 100 nm) had been obtained
in many processes such as heavy cold rolling, equal channel angular pressing (ECAP) or accumulative
roll bonding (ARB), the formation of nano grained structure (< 100 nm) is limited to processes such
as ball milling, shot peening or drilling. In the present study, high pressure torsion (HPT) deformation
and drilling were carried out to understand the conditions necessary to obtain nano grained structure
in steels. The results of HPT experiments in pure Fe showed that HPT has superior ability of
strengthening and grain refinement probably due to a strain gradient but the saturation of grain
refinement occurs before reaching nano grained structure. Drilling experiments in high carbon
martensitic steel revelaed that nano grained ferrite forms at the drilled hole surface only when the
transformation from ferrite to austenite takes place during drilling. Considering various other
processes by which nano grained ferrite was produced, it is proposed that heavy strains with large
strain gradients together with dynamic transformation are necessary to reach nano grained ferrite
structure.
Controlling the Thickness Uniformity in Equal Channel Angular Rolling (ECAR)
Authors: Chung Young Hoon , Park Jong Woo , Lee Kyong Hwan
Published: March 2009

As the surface friction between feeding rolls and metal sheet generates the feeding power
of ECAR, the generated feeding power is low, and the friction between the metal sheet and ECAR die
should be minimized. However, for obtaining a large shear deformation by ECAR, the metal sheet
should be tightly contacted with the wall of ECAR die. In this condition, the thickness of the metal
sheet is continuously increased during ECAR. A new ECAR apparatus is developed for maximizing
the shear deformation and obtaining sheet thickness uniformity, and succeeding continuous ECAR
with such a limited feeding power. By controlling the outlet gap of the ECAR die with elastic unit, the
thickness of the metal sheet is kept uniform. Detailed thickness control mechanism during the new
ECAR process is analyzed. A sheet of Al 6063 alloy that is 1-pass deformed with the new ECAR
apparatus shows below ±0.037 mm of thickness variation and 0.61 of shear strain.
Creep Strength Assessment of High Chromium Ferritic Creep Resistant Steels
Authors: Kimura Kazuhiro , Sawada Kota , Toda Yoshiaki , Kushima Hideaki
Published: March 2009

Degradation mechanism and life prediction method of high chromium ferritic creep
resistant steels have been investigated. In the high stress condition, easy and rapid extension of
recovered soft region results in significant decrease in creep strength, however, ductility is high. In
the low stress condition, extension of recovered soft region is mainly controlled by diffusion and it
is slow, therefore, deformation is concentrated in the recovered soft region along grain boundaries
and ductility is extremely low. Delta-ferrite produces concentration gap due to difference in
equilibrium composition of austenite and ferrite phases at the normalizing temperature. It increases
driving force of diffusion and promotes recovery of tempered martensite adjacent to delta-ferrite.
Concentration gap may be produced also in heat affected zone (HAZ), especially in fine grain HAZ
similar to dual phase steel, and it has possibilities to promote recovery and, therefore, to decrease
creep strength. It has been confirmed the advantage of region splitting analysis of creep rupture
strength for high chromium ferritic creep resistant steels, through a residual error analysis. It is
important to avoid a generation of concentration gap in order to improve stability of microstructure
and to maintain high creep strength.
Manufacturing and Analysis of Mechanical Properties of Superalloy 718 in Hydraulic Forging
Authors: Song Young Seok , Lee M.R. , Kim Jeong Tae
Published: March 2009

Alloy 718 ingot with a diameter of 400mm was made by the vacuum melting process ;
VIM followed by VAR. Compression tests were conducted on samples collected from columnar
zone of the VIM/VAR-processed Alloy 718 ingot in wide temperature and strain rate ranges, i.e.
750~1,200OC and 10~0.001s-1 in order to understand the deformation behavior and evolution of
microstructure. Tensile tests at high temperature were also conducted on samples in temperature
ranges, i.e. 750~1,100OC. Effects of process parameters on the flow behavior as well as on the
microstructure evolution during compression tests at high temperatures are considered.
As a result of the deformation simulation, The VIM/VAR ingot was heat-treated for
homogenization, and casting structure of the ingot was broken down for uniform microstructures
and mechanical properties by controlled cogging process using a hydraulic press.
The observation of the microstructure and grain size distribution was carried out to evaluate the
effects of optimum process parameters during cogging and mechanical property tests were
performed in this study.
Properties of Boron Fiber Reinforced Aluminum Matrix Composites Fabricated by Pulsed Current Hot Pressing (PCHP)
Authors: Mizuuchi Kiyoshi , Takeuchi Takashi , Inoue Kanryu , Lee Jun Hee , Sugioka Masami , Itami Masao , Kawahara Masakazu , Yamauchi Isamu , Asanuma Hiroshi
Published: March 2009

Boron-fiber-reinforced Al-matrix composite was fabricated by a pulsed current hot
pressing (PCHP) process at a pressure of 32MPa for 600s. It was found that the boron fiber and
the Al-matrix were well bonded when the PCHP process was performed at a holding temperature of
773K. No interfacial reaction layer was observed along the interface between the boron fiber and
the matrix when PCHP was done at 773K for 600s. Tensile deformation carried out at room
temperature for the composite showed that the tensile yield stress increased with increasing volume
fraction of the boron fiber in the composite. The composite with 17.2 vol.% of boron fiber
presented a tensile yield stress of 600MPa. This value was about 90% the yield stress estimated by
a force equilibrium equation of a composite taking into account the direction of fiber axis.
Magnetic Field-Induced Martensitic Transformation of Heusler-Type Ni2MnGa System
Authors: Inoue Kazuko , Yamaguchi Yasuo , Ishii Yoshinobu , Yamauchi Hiroki , Shishido Toetsu
Published: March 2009

Magnetic field effect on a Heusler-type Ni2MnGa off-stoichiometric alloy having a martensitic
transformation temperature around room temperature which is coincident with a Curie temperature
has been investigated. The process of martensitic transformation of a single crystal was
investigated by neutron diffraction under the magnetic field up to 8 [T]. It was found that the magnetic
field, which is applied at a temperature near the transformation temperature, causes the martensitic
transformation. The process of the transformation caused by the increase in magnetic field is quite
similar to the process caused by the decrease in temperature.
Effects of Fiber-Resin Interface Property on Shape Recovery and Mechanical Properties of Denture-Base-Resin Matrix Smart Composite
Authors: Hamada Kenichi , Kawano Fumiaki , Asaoka Kenzo
Published: March 2009

NiTi shape memory alloy fiber-embedded denture-base-resin matrix smart composites
were developed as a new denture base material for a “smart denture”, whose shape could be
recovered simply by heating after fracture. Three types of fiber surface treatment were applied for
the composites and their properties were evaluated by the fiber-pull-out test and bending test, and
shape change after repair was examined. A high interface debonding strength increased the fracture
strain but did not affect bending strength, and a low interface sliding strength minimized shape
change after repair. These results indicate that the fiber-matrix interface with a strong bonding but
easy sliding after debonding could improve the preciseness of “smart repair”.
Molecular and Nanometer-Scale Self-Organized System Generated by Protein Motor Functions
Authors: Oiwa Kazuhiro , Kometani R. , Li Dong Yang , Shitaka Y. , Nakamori R. , Matsui S. , Sakakibara H.
Published: March 2009

Creatures have evolved extremely intelligent and complex adaptive systems
for conducting their movements. They are protein motors with typical sizes of a few
tens of nanometers. Protein motors include three major protein families, myosin, kinesin
and dynein, which participate in a wide range of cellular processes, using energy from
the hydrolysis of adenosinetriphosphate ATP. To harness these protein motors to power
nanometer-scale devices, we have investigated effective and non-destructive methods
for immobilizing protein motors on surfaces and to arrange the output of these motors,
e.g. force and movement, to be in a defined direction. We found NEB-22 to be useful
for retaining the abilities of protein motors to support the movement of protein filaments.
We fabricated various patterns of tracks of NEB-22 on coverslips and protein motors
were introduced and immobilized on glass surface. The trajectories of protein polymers
were confined to these tracks. Simple patterns readily biased and guide polymer
movement confining it to be unidirectional. In addition, having used dynein c purified
from Chlamydomonas flagellar axoneme, we showed that microtubules driven by
surface-bound dynein were self-organized into dynamic streams through collisions
between the microtubules and their subsequent joining.
Nitrogen Ion Beam Irradiation on Amorphous Carbon
Authors: Watanabe Yoshihisa , Aono Masami , Kitazawa Nobuaki
Published: March 2009

Both bulk and thin film amorphous carbon were irradiated using a nitrogen
ion beam and changes in surface roughness and composition after ion beam irradiation
have been studied. Amorphous carbon thin films were prepared from toluene vapor
using plasma enhanced chemical vapor deposition. Ion irradiation was performed at
room temperature using a nitrogen ion beam and the ion beam energy was varied from
0.2 to 1.5 keV under the constant ion current density. Surface morphology was
observed with atomic force microscopy (AFM). Depth profiles of nitrogen in the
irradiated specimens were analyzed by X-ray photoelectron spectroscopy (XPS). AFM
observations reveal that after the ion beam irradiation the surface of the bulk amorphous
carbon becomes rough, while the surface of the amorphous carbon films becomes
smooth. However, the notable difference in the surface roughness is hardly observed
between low- and high-energy ion irradiation. From XPS studies, it is found that the
nitrogen concentration near the surface increases after the ion irradiation for both bulk
and thin films and irradiated nitrogen ions are combined with carbon, resulting in
formation of carbon nitride layers. Depth profiles of nitrogen show that for the bulk
specimen low-energy ion irradiation is more effective for the carbon nitride formation
than high-energy ion irradiation, while for the thin films high-energy ions are implanted
more deeply than low-energy ions.
Study on the Magnetic Properties and Domain Structure of NdFeNbZrB Nanocomposite Permanent Magnets
Authors: Qin W.Y. , Chen X.Y. , Jiang Z.L. , Lin Z.D. , Chen H.M.
Published: March 2009

A new kind of nanocomposite rare-earth magnets of Nd2Fe14B/ α-Fe were prepared by
melt-spinning method. Effects of alloying element and processing parameter on the microstructure
and magnetic properties of nanocomposite materials have been investigated. Zr is effective to
enhance coercivity of alloys because of a refinement of grains, so that in alloy of Zr content with
1.0 at% (Zr1.0) has the smallest grain size of 17 nm and therefore causes the highest intrinsic
coercivity . Addition of Zr can also enhance the ability of amorphous-forming. The combination of
adding of Zr and using a smaller diameter of the nozzle in the melt-spinning method is effective for
the forming of amorphous structure.
According to the MFM study, the length of the magnetic contrast in the alloy is much larger
than the mean grain size. The large length corresponds to that of interaction domains(ID), which is
related to the exchange coupling effect.
Effect of Aging and Microstructure on Mechanical Rolling CuAlNi Shape Memory Alloy
Authors: Yang Gon Seung , Lee Jong Kook , Jang Woo Yang , Jeong Soon Jong , Inoue Kanryu
Published: March 2009

CuAlNi shape memory alloy with Cu-13.5Al-4.5Ni(wt%) composition was prepared by
cross-rolling method and the aging effect, phase transformation characteristics, microstructural
variation were investigated. Transformation temperature was greatly increased in aged specimens at
250°C. Transformation temperature was not changed after the second reversed transformation, and
Ms point was same in most specimens with third reversed transformation cycle. The variation of Ms
point was not seen with aging at 100°C, but it was decreased with aging at 250°C. Transformation
temperatures appear to be constant, to an measurable extent, in specimens prepared by both hotrolling
and cross-rolling at 900°C. Plate shaped-specimen with the thickness of about 1mm was
prepared by cross-rolling treatment at 350°C. The transformation temperatures did not change after
the second transformation-reverse transformation cycling, and specially transformation start
temperature was the same in most specimens experiencing third thermal cycle and thereafter.
Undesirable tweed-like structure was observed in 250°C-aged specimen after a cross-rolling at
350°C. On aging the specimen prepared by cross-rolling, G.P zone was formed easier than that of γ2
phase. This phase was transformed to plate-like θ phase during aging.
Texture and Orientation Relationships in Phosphorus Added TRIP Steels
Authors: Verbeken Kim , Barbé L. , De Cooman Bruno C.
Published: March 2009

Phosphorus added TRIP steels were subjected to Electron BackScattering Diffraction
(EBSD) measurements in order to study the texture of the three different phases and in order to
evaluate the orientation relations that are active during the transformation of austenite to bainite.
The retained austenite had a maximum intensity on the Brass component and the intensity gradually
decreased along the alpha and the beta fibre. The intensity of both BCC phases was comparable, but
the bainite texture displayed clear transformation products that could be related with the dominant
Brass component of the intercritical austenite. A detailed evaluation of the crystallographic
orientation relationships between about 360 retained austenite grains and their BCC neighbours was
performed. Three relationships were considered, namely Kurdjumov-Sachs, Nishiyama-Wassermann
and Pitsch. It was found that the majority of the austenite grains had at least one neighbour that could
be related with one of the three orientation relationships. The Kurdjumov-Sachs relationship appeared
to be dominant and no strong indication for variant selection could be retrieved from the studied data.
Multiscale Modelling of Plastic Deformation of Polycrystals: Implementation of Texture-Based Anisotropy in Engineering Applications (FE Codes for Forming, Prediction of Forming Limit Curves)
Authors: van Houtte Paul , Van Bael Albert , Seefeldt Marc
Published: March 2009

Finite element models for metal forming are used to design and optimise industrial forming
processes. The limit strain in sheet metal forming can be predicted for monotonic loading or strain
paths with changes. Models like these should be as accurate as possible in order to be useful, and
hence take the texture, microstructure and substructure (dislocation patterns) into account. To achieve
this, a hierarchical type of modelling is proposed in order to maintain the balance between calculation
speed (required for engineering applications) and accuracy. In that case, FE models to be used at the
engineering length scale work with an analytical constitutive model, the parameters of which are
identified using results of multilevel models (meso-scale with an homogenisation procedure). The
analytical model to be used at macro-scale will be discussed, as well as the identifications procedure.
The later make use of meso-scale models. Finally an example will be given (formability of a sheet
material).
New Analyses of Pressure Filtration Curves of Al Alloys: A Case Study
Authors: Cao Xin Jin , Jahazi Mohammad
Published: March 2009

There has been an increasing tendency to determine liquid metal quality using pressure
filtration methods such as Prefil Footprinter tests. The scientific understanding of this method,
however, is emerging only recently with the introduction of derivative methods. Based on the
investigation of flow behavior over the pressure filtration test, classic filtration theory has been
successfully applied to understand the filtrate weight versus filtration time curve. The “clean” and
“effective” resistance of filter medium, overall filtration resistance, cake resistance, pressure loss
and distribution can be quantitatively calculated now. In the present work, a typical weight versus
time curve from the Prefil Footprinter test of a cast Al-Si alloy is analyzed and discussed in details.
The method developed in the work can provide new insights into the filtration behavior.
Hydrogen Measurements in SiNx: H/Si Thin Films by ERDA
Authors: Ionescu Mihail , Richards Bryce , McIntosh Keith , Siegele R. , Stelcer E. , Cohen D.D. , Chandra Tara
Published: March 2009

Thin SiN film deposited on Si by plasma enhanced chemical vapour deposition
(PECVD) is used for surface passivation of Si. During the PECVD process Hydrogen is
incorporated into the SiN film, and the passivation properties of the resulting SiNx:H layers
play an important role in enhancing the energy conversion efficiency of solar cells. It is
believed that the Hydrogen present in SiNx:H is responsible for this enhancement, and
therefore its concentration in the passivating layer is an important parameter. The Hydrogen
composition and its depth profile in thin SiNx:H films of 20nm to 200nm was measured by
elastic recoil detection analysis (ERDA), using a 1.7MeV He+ ion beam of (1x2)mm2,
generated by a high stability 2MV Tandetron ion beam accelerator. Simultaneously,
Rutherford backscattering (RBS) spectra were recorded for each sample. The results show
that the Hydrogen concentration in the SiNx:H layers is dependent of the deposition
conditions. Also, Hydrogen was found to be homogenously distributed across the SiNx:H
layer thickness, and the SiNx:H/Si interfaces were well defined.