bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of the Bulk Amorphous Ni-W Alloy by an Electroforming Process
Authors: Wakayama Shin , Kimoto Yoshihisa , Takigawa Yorinobu , Uesugi Tokuteru , Higashi Kenji
Published: March 2009

A 2mm-thick bulk amorphous Ni-W alloy is formed by applying a new electroforming
process and its states are investigated by the XRD analyses and the EDS measurement. The
homogeneities of the electroformed alloys are evaluated by the linear analyses on the cross sections
of the sample. The fluctuation of the millimeter-scale W-concentration of the bulk amorphous alloy
obtained in the present work is reduced to almost the same as that of the bulk nanocrystalline alloy
reported in the previous work. Compared to the thin-film specimen produced by the conventional
electroplating processes, the gradient of W-concentration of the bulk amorphous specimen can be
reduced to two-fifth in the micrometer-scale profiles. Therefore new electroforming process can be
successfully applied to the fabrication of the bulk amorphous Ni-W alloy.
Development of Amorphous and TiAl-Nb2Al Intermetallic Nanocomposite Powders by Mechanical Alloying
Authors: Kumaran S. , Chantaiah B. , Rao T. Srinivasa
Published: March 2009

Present investigation was focused on to synthesize TiAl-Nb2Al nanocomposite powders by
high energy ball milling from a mixture of prealloyed TiAl, niobium, aluminium and SiC powders.
Systems chosen with different Nb and Al concentrations were processed at optimized ball milling
parameters. The synthesized powders were characterized with the help of X-ray diffraction (XRD),
electron microscopy, differential thermal analysis (DTA) to understand the milling behaviour of
TiAl / TiAl-Nb-Al-SiC systems. High energy ball milling of prealloyed TiAl powder resulted
nanocrystalline structure at early time intervals (10hrs) and sustained up to 50hrs. TiAl-Nb-Al-SiC
systems exhibited amorphous structure in lower Nb content and formation of Nb2Al nanocrystalline
compound with increasing Nb and Al additions. Stability of TiAl covalent bonded intermetallic
compound was weakened by dissolution of Nb in the matrix and resulted amorphous structure. The
final product contained nanocrystalline TiAl, amorphous structure and TiAl-Nb2Al intermetallic
nanocomposite powders with varying Nb and Al concentrations.
Phase Constitution and Heat Treatment Behavior of Zr-Nb Alloys
Authors: Ikeda Masahiko , Miyazaki Tsuyoshi , Doi Satoshi , Ogawa Michiharu
Published: March 2009

Phase constitution in the solution-treated and quenched state and the heat treatment
behavior were investigated by electrical resistivity, hardness, and elastic modulus measurements,
X-ray diffraction, and optical microscopy. Hexagonal martensite and the β phase were
identified in the Zr-5mass%Nb alloy. β and ω phases were identified in the Zr-10 and
15mass%Nb alloys, and only the β phase was identified in the Ti-20Nb alloy. Resistivity at RT,
Vickers hardness and elastic modulus increased up to 10Nb and then decreased dramatically at
15Nb. Above 15Nb, these values slightly decreased. The elastic moduli for 15Nb and 20Nb
were 59.5 and 55.5 GPa, respectively. On isochronal heat treatment, the isothermal ω phase
precipitated between 473 and 623 K and then the α phase precipitated in the 10Nb, 15Nb and
20Nb alloys.
Change in Material and Structural Parameters of Bone Mechanical Function during Long-Bone Regeneration
Authors: Ishimoto Takuya , Nakano Takayoshi , Umakoshi Yukichi , Yamamoto Masaya , Tabata Yasuhiko
Published: March 2009

Bone mechanical function is given as a result of the material and structural parameters of
bone tissue. We previously reported that the material parameter of regenerated bone can be evaluated
dominantly using two indices of the density and the preferred orientation degree of biological apatite
(BAp). In addition, bone morphology remarkably changes during bone regeneration, which may lead
to a dynamic change in the mechanical function of whole bone. In this study, therefore, material and
structural parameters of regenerated bone are analyzed separately. A 5-mm-long defect was
introduced in rabbit ulna and spontaneously regenerated, and then a three-point bending test was
conducted at the regenerated portion. The important parameter which dominantly controls the whole
bone mechanical function shifts from a structural to material parameter during bone regeneration.
Moreover, it was statistically demonstrated that the increase in the material parameter is strongly
determined by recovery of the orientation degree of the BAp c-axis.
pH-Sensitivity of N-Carboxyethyl Chitosan Hydrogel and Drug Controlled Release In Vitro
Authors: Li Zuo Wei , Zhang Li Yan , Zeng Qing Xiao
Published: March 2009

N-carboxyethyl chitosan (ACS) was formed by a Micheal reaction. Through the analysis
of IR and 1H-NMR spectra, the Micheal reaction was carried out between - NH2 of chitosan and - C
= C - of acrylic acid. ACS hydrogel (ACSG) was prepared by cross-linking with glutaraldehyde.
ACSG show pH-sensitive swelling behavior, and the smallest swelling rate (SR) of ACSG is in pH5.0
buffer solution.With dosage of glutaraldehyde increasing, the SR of ACSG decreased. With grafting
degree (GD) increasing, the SR of ACSG increased first and decreased afterward. Using bovine
serum albumin (BSA) as a model medicine, the releasing behaviors of ACSG were investigated in
vitro. In simulated gastric and intestinal fluid, the ACSG loading BSA (GD=20.45%) has better
releasing behaviors.
Effect of Rotation Speed on Transformation Behavior in Ti-48at%Ni Shape Memory Alloy Melt-Spun Ribbon
Authors: Xing Hong Yan , Kim Hee Young , Miyazaki Shuichi
Published: March 2009

Effects of rotation speed on the microstructure and transformation behavior were investigated for Ti-48at%Ni melt-spun ribbons. The Ti-48at%Ni shape memory alloy ribbons were fabricated by the melt-spinning method with various rotation speeds ranging from 2500rpm to 7500rpm. The melt-spun ribbons were completely crystallized to TiNi B2 phase during solidification at lower rotation speeds less than 4000rpm. Amorphous and B2 phase coexisted in the melt-spun ribbons fabricated at higher rotation speeds of 5000rpm and 7500rpm. The martensitic transformation behavior was investigated both in the as-spun and heat-treated ribbons. The transformation temperature increased with decreasing cooling rate and increasing heat-treatment temperature.
Corrosion Behavior of Zirconium Based Alloys in Simulated Body Fluids
Authors: Tsutsumi Yusuke , Takano Yousuke , Doi Hisashi , Noda Kazuhiko , Hanawa Takao
Published: March 2009

The corrosion behavior of Zr-Ti and Zr-Hf alloys with various concentrations in properly
deaerated Hanks’ solution were investigated by electrochemical techniques. The effects of the
thermal treatment with the purpose of homogenization of chemical composition on the pitting
potentials of the Zr-Ti alloys were also examined. The results indicated that sufficient addition of Ti
to Zr improved its corrosion resistance, especially in terms of the pitting potential and the passive
current density. On the other hand, addition of Hf totally lowered the corrosion resistance of the alloy.
The thermal treatment improved the pitting corrosion property of Zr-Ti alloys, and Zr alloys with
over 5mol% Ti showed much higher pitting potentials than that of pure Zr. The treatment also
improved the reproducibility of the measurement and narrowed the data scattering. This phenomenon
was discussed with the model of rapidly-cooled metallographic structure.
Effect of Nitrogen on Microstructure of Porous CoCrMo Alloy Compacts for Biomedical Applications
Authors: Nomura Naoyuki , Abe Mariko , Lee Sang Hak , Chiba Akihiko
Published: March 2009

Porous Co-29Cr-6Mo alloy compacts were fabricated and their microstructures were
examined. The Co-29Cr-6Mo alloy powders were atomized by using Plasma Rotating Electrode
Process (PREP) in an Ar atmosphere. These powders were hot-pressed at 1223 K in Ar or nitrogen
and annealed at 1473 K in vacuum or nitrogen. X-ray analysis revealed that the γ phase (f.c.c.) mostly
exists in the compact hot-pressed in nitrogen although the ε phase (h.c.p.) is dominant in the compact
hot-pressed in Ar. In addition, precipitates are observed at the interdendritic region in the compact
hot-pressed in nitrogen. These results suggest that the Co-29Cr-6Mo alloy powders react with
nitrogen to stabilize the γ phase. Accordingly, the constituent phase in the Co-29Cr-6Mo alloy is
strongly affected by the atmosphere during hot-pressing.
Decomposition of a Biocompatible Zr-Ta-Nb Alloy
Authors: Sun Wei
Published: March 2009

A Zr-Ta-Nb alloy made of biocompatible alloy elements only and consisted of single
β-phase with bcc structure was prepared by conventional solidification. Electron diffraction,
transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM) were
used to examine microstructural evolutions of the β-Zr-Ta-Nb alloy subjected to different heat
treatments. The results show that the metastable β-phase in the as-solidified Zr-Ta-Nb alloy turned to
decompose when annealed at 400°C and this led to the formation of a highly strained structure
containing nanosized precipitates and local disordered regions. Striking phase separation including
the formation of the equilibrium α-phase was found to occur at 600°C. By means of nanosized
electron-probe analysis of energy dispersive X-ray spectroscopy, the compositions for the nanosized
phases formed due to different heat treatments were analysis.
Hydrogen Quasi-Chemically Trapped between Defective Graphene Layers in Nanostructured Graphite
Authors: Miyabe Yumiko , Yoshida Tomoko , Muto Shunsuke , Kiyobayashi Tetsu
Published: March 2009

Direct evidences of hydrogen loosely trapped between graphene layers in nanostructured
graphite prepared by mechanical milling in a hydrogen atmosphere are presented, based on a
combinational study of FT-IR, electron diffraction (ED) and electron energy-loss spectroscopy
(EELS). The FT-IR spectrum of nanostructured graphite exhibited a new broad absorption band at
very low frequencies around 660 cm-1, which almost disappeared by annealing up to 800 K. ED and
plasmon peaks in EELS detected the unusual shrinkage and subsequent expansion of the fragmented
graphene interlayer distance by hydrogen incorporation and desorption with annealing, well
correlated with the change in intensity of the 660 cm-1 IR band. All the present results support our
previous studies [S. Muto et al., Jpn. J. Appl. Phys. 44, 2061 (2005); T. Kimura et al, J. Alloys and
Compounds 413, 150 (2006).].
Phase Transition of Mg/Pd Laminate Composites during Hydrogenation/Dehydrogenation
Authors: Takeichi Nobuhiko , Tanaka Hideaki , Tanaka Koji , Kuriyama Nobuhiro , Ueda Tamotsu T. , Tsukahara Makoto , Miyamura Hiroshi , Kikuchi Shiomi
Published: March 2009

Mg-based laminate composites prepared by a repetitive-rolling method have a large
hydrogen capacity as well as good kinetics and reversibility for hydrogen reaction. Mg/Pd laminate
composite (Mg/Pd=6) can absorb a large amount of hydrogen up to 1.47 H/M (4 mass%), and desorb
hydrogen reversibly at 573K. In this study, we investigated the mechanism of phase transition of the
Mg/Pd laminate composites during hydrogenation/dehydrogenation by means of in-situ XRD
measurements. In Mg/Pd laminate composite (Mg/Pd=6), the XRD profile of as-rolled sample indicated
the existence of Mg and Pd within the detection ability of our XRD equipment. Mg6Pd intermetallic
compound are formed during initial activation process. The Mg6Pd intermetallic compound can store
hydrogen reversibly through the disproportionation and recombination processes.
The Alloy Design of Metallic Interconnector of Solid Oxide Electrolyte Fuel Cell (SOFC)
Authors: Chen Ian Bo , Lian Shuang Shii , Li Chia Ying , Shong Wei Ja , Lee Ruey Yi
Published: March 2009

This study is intended to reduce the difference of thermal expansion coefficient between
metallic interconnector and solid electrolyte of SOFC (Solid Oxide Fuel Cell) without sacrificing of
electrical conductivity.
Fe-Cr alloys have been chosen as candidate materials due to its merit of low cost and high
temperature oxidation resistance. Different amount of alloys element and compositions have been
varied to optimize the properties by method of alloys design with aid of thermodynamics software
Thermal-Cal. Phase diagrams of multi-components alloys have been drawn to predict the possible
stable phases formed in the investigated metals. An arc melter and plasma melting furnace were
used to melt the investigated alloys. The measurements of thermal expansion coefficients and
electrical conductivities are carried out with TMA and ASR resistance instrument. The results
indicate that the Fe-10Cr alloy exhibits the smallest thermal expansion coefficient among the alloys,
while Fe-16Cr has a lowest electrical resistance .
Modeling of Mechanical Behavior of Porous Sintered Timing Wheel in Contact with Chain Wheels
Authors: Alizadeh M. , Khorsand H. , Shokuhfar Ali
Published: March 2009

The mechanical properties of sintered timing wheel in contact with chain wheels were analysed using Finite Element Methods
(FEM), in which the timing wheel is modelled as a metal powder. The mechanical properties of sintered timing wheel were
investigated as a function of sintered density.
Tensile strength and Young’s modulus increased with a decrease in porosity. Current methods of calculating gear contact stresses
use Hertz’s equations, which were originally derived for contact between sintered timing wheel and chain wheels. The results of the
2D dimensional FEM analyses from ANSYS are presented.
The relationship between relative density of P/M steels and mechanical behavior is also obtained from FEM and compared with the
experimental data. Good agreement between the experimental and FEM results is observed, which demonstrates that FEM can
capture the major features of the P/M steels behaviour during loading. This indicates that the FEM model is accurate.
Whisker Initiation Behavior from Electrodeposited Sn/Cu Coating on Cu Leadframe
Authors: Kato Takahiko , Akahoshi Haruo , Terasaki Takeshi , Iwasaki Tomio , Nakamura Masato , Hashimoto Tomoaki , Nishimura Asao
Published: March 2009

Tin/copper (Sn/Cu) coatings on Cu leadframes (CUFE), in which Fe atoms are doped as a minor
element, showed whisker initiation at room temperature over a long period of 47 months. By means
of the planar slice method and electron back scattering pattern (EBSP) measurement, the whisker
roots were consistently found to be located at the intersections of grain boundaries in the coating.
Whisker roots were also located above the peaks and ridge lines of intermetallic compound (IMC)
Cu6Sn5, which was formed with a pyramid-shaped configuration between the Sn/Cu coating and Cu
leadframe. Using finite element analysis (FEA), we calculated stress distribution in the coating. The
results indicated that compressive stress normal to the grain boundary was induced with a gradient
toward the surface in the coating. Therefore, the compressive stress gradient induced by the
pyramid-shaped IMC is thought to be the root cause of whisker initiation in Sn/Cu coatings on Cu
leadframes.
When the Cu leadframe with a minor doped element of Cr atoms (CUCR) was used as the
substrate with the same Sn/Cu coating, no whisker initiation was observed even after a longer storage
time of 65 months. Through field-emission scanning transmission electron microscopy (FE-STEM)
and field-emission transmission electron microscopy (FE-TEM) microstructural observations of
vertical sections of each sample, the shape of the IMCs formed between the coating and the leadframe
in the Sn/Cu-CUFE sample was found to be different from that in the Sn/Cu-CUCR sample. The
difference in whisker initiation tendency can therefore be explained by the difference in compressive
stress depending on the shape of the Cu-Sn IMCs, because stress distribution in the coating of the
Sn/Cu-CUCR sample calculated using FEA revealed a smaller stress gradient than that in the
Sn/Cu-CUFE sample.
Degradation Mechanisms of Pressure Vessel Internal Steel (18Cr-10Ni-Ti) Irradiated with Heavy Ions
Authors: Voyevodin V. , Borodin O. , Bryk V. , Kalchenko A. , Parkhomenko A. , Tolstolutskaya G.
Published: March 2009

Mechanisms of degradation of physical-mechanical properties of PVI steels during
irradiation are studied. Microstructure evidence of influence of irradiation temperature, dose and
dose rate on processes of low-temperature swelling and embritllement of pressure vessel internal
materials, 18Cr-10Ni-Ti steel, of reactor WWER 1000 are presented. Micro mechanisms of plastic
deformation and steel failure in wide range of temperatures and irradiation doses are described.
Analysis of influence of subsequent and simultaneous irradiation with beams of gas and heavy ions
is carried out for investigation of influence of gaseous impurities that form through transmutation
nuclear reactions on defected structure evolution under irradiation.
Microstructural Refinement and Mechanical Property Improvements of Ti-5Al-1Sn-1V-1Zr-0.76Mo Alloy by Equal Channel Angular Extrusion Processing
Authors: Protasov Vadim , Colombo Gian , Sastry Shankar M.L. , Imam M. Ashraf
Published: March 2009

Severe plastic deformation (SPD) by equal channel angular extrusion (ECAE) was investigated as a
way to produce ultra fine grain (UFG) microstructure in Ti-5Al-1Sn-1V-1Zr-0.76Mo. DEFORM
3D Finite Element Model (FEM) was used to predict loads and strain distribution associated with
ECAE which were validated experimentally The effects of resulting ultra fine grain microstructure
on room temperature mechanical properties and high temperature super plasticity were
investigated. ECAE processing: resulted in the conversion of coarse Widmanstatten structure to
fine equiaxed microstructure with an average grain size of 4 μm. The alloy with fine grained
equiaxed microstructure has 20- 25% higher yield strength, 15% higher ultimate tensile strength,
and 50-100% higher % elongation to fracture and % reduction in area compared to the as received
alloy containing coarse Widmanstatten microstructure. The ECAE processed alloy exhibits
attractive superplastic formability charactersistics at 900-950oC with m value >0.4, flow stresses <
20 MPa, and superplastic elongations > 200%
In Situ TEM Observation of Precipitation of Zirconium Hydrides in Zircaloy-4 under Hydrogen Ion Implantation
Authors: Shinohara Yasunari , Abe Hiroaki , Kido Toshiya , Iwai Takeo , Sekimura Naoto
Published: March 2009

The formation of hydrides in zirconium alloy has been one of the essential matters of
discussion to maintain mechanical strength of nuclear fuel cladding tubes. In this work, we examined
the precipitation process of zirconium hydride by transmission electron microscopy under hydrogen
ion irradiation. Zircaloy-4, which has been used extensively as nuclear fuel cladding, was irradiated
with hydrogen ion at room temperature to achieve enough hydrogen concentration for precipitation.
The growth of hydrides accompanied with dislocations around hydrides was observed under hydrogen
implantation. The observed hydride was the γ-hydride phase with fct structure and the orientation
relationship was <110>γ ||<1120>α as reported previously. As the hydride grew, the dislocations were
generated gradually. This process can be explained using a ratchet mechanism suggested by Carpenter.
The growth rate became lower according to the approach of other hydrides. This behavior is
considered to be influenced by the strain field caused by other hydrides.
New Expression of the Chemical Bond in Perovskite-Type Oxides
Authors: Shinzato Y. , Saito Yuki , Yukawa Hiroshi , Morinaga Masahiko , Baba Takeshi , Nakai Hiromi
Published: March 2009

A new expression for the chemical bond in perovskite-type oxides is proposed based on the
atomization energy concept. The atomization energies, Eo for oxygen atom and EM for metal
atom in each oxide are evaluated theoretically using the energy density analysis of the total energy,
and the 9EO vs. 9EM diagram called atomization energy diagram, is constructed. Every oxide can
be located on the atomization energy diagram, although there are significant differences in the
nature of the chemical bond among the oxides.
Numerical Simulation of Compacting Process of Green Sand Molding Based on Sand Filling
Authors: Li Wen Zhen , Wu Jun Jiao
Published: March 2009

The mathematical models of compacting process in green sand molding were built up
based on the experiment results of molding sand property testing, in which the nonlinearity
problems involved in the molding sand material, the pattern geometry and the contact between sand
and flask were considered. These models were then used to numerically simulate the compacting
process of green sand and predict the hardness distribution of green sand mold. The effect of sand
filling on the initial sand density distribution was taken into account, which was obtained through
the two phase flow simulation of sand filling. The predicted results were compared with the
measured ones and good agreement was obtained.
Thermodynamic Analysis of the Fe-Mn-P Ternary Phase Diagram by Combining the First-Principles and CALPHAD Methods
Authors: Tokunaga T. , Hanaya N. , Ohtani Hiroshi , Hasebe Mitsuhiro
Published: March 2009

A thermodynamic analysis of the Fe-Mn-P ternary system has been carried out using the
CALPHAD method. Among the three binary systems relevant to this ternary phase diagram, the
thermodynamic parameters of the Mn-P binary system were evaluated in this study. The enthalpy of
formation of the binary phosphides obtained from our first-principles calculations was utilized in the
present analysis to compensate for the lack of available experimental data. The thermodynamic
descriptions of the Fe-Mn and Fe-P binary systems were taken from previous studies. The phase
equilibria in the Fe-Mn-P ternary system were analysed based on the experimental data on the phase
boundaries. The calculated phase diagrams are in agreement with the experimental results.
3-D FE Simulation and Analysis on Radial-Axial Large Ring Rolling
Authors: Pan Li Bo , Hua Lin , Lan Jian
Published: March 2009

An effective method was proposed to simulate and control the motion track of guide
roller during radial-axial ring rolling in FE simulation. The 3-D finite element model was
constructed according to the principle and feature of rolling technology. The rolling process was
simulated and analyzed by using dynamic explicit finite element technology. The different rolling
processes with different technology parameter were simulated. The width spreads and rolling forces
under different parameters are compared and analyzed. The results indicated that high quality ring
product could be obtained when rational parameters in radial and axial were assigned.
Point Defects in L10 Phase FePt Alloy: A First Principle Study
Authors: Sui Yang , Chen Zi Yu , Shu Xiao Lin , Wang Tian Min
Published: March 2009

L10 phase FePt alloy is regarded as one of the most promising materials for ultra high
density magnetic recording media. However, structural point defects, which would reduce the media's
signal to noise ratio, are inevitable in non-stoichiometric L10 FePt alloy. Hence, possible types of
point defect (vacancy and anti-site defect) in non-stoichiometric ordered FePt alloy were fully studied
using density functional theory. Investigation over vacancy shows the formation energy of Fe and Pt
vacancy is respectively 2.58eV and 3.20eV. Geometry relaxation implies Fe vacancy has a stronger
deformation force upon the original lattice. Meanwhile, anti-site defect study shows that the
formation energy of Fe anti-site (Fe occupation in Pt sublattice) and Pt anti-site (Pt occupation in Fe
sublattice) is respectively 1.05eV and 0.66eV. Therefore, for Fe-rich and Pt-rich alloy, the preferred
structural point defects are both anti-site substitution rather than vacancy due to the much lower
formation energy.
Phase Field Calculations with CVM Free Energy within Square Approximation
Authors: Mohri Tetsuo , Fujihashi Nao , Chen Ying
Published: March 2009

Phase Field Method is combined with the Cluster Variation Method within the square
approximation, and the multiscale ordering behavior from atomistic to microstructural evolution
process of ordered domains in the two dimensional square lattice is investigated. The transition
temperature is determined at 1:1 stoichiometric composition and it is confirmed that the transition is
of the second order. The growth process of the ordered domains is visualized and it is revealed that the
sharp decrease of the free energy takes place during the process.
Physical Modeling on Recrystallization of Austenite in Steels in Thermo-Mechanical Processing
Authors: Wang X.T. , Yu Z.L. , Siwecki Tadeusz , Engberg Göran , Sun Zu Qing
Published: March 2009

A physical model for austenite recrystallization of steel concerning TMCP is developed.
Dislocation density plays a key role as recrystallization driving force. The dislocation density change
is a result of competition between dislocation generation and dynamic recovery. Recrystallization is
described as a nucleation-growth process. An abnormal subgrain growth mechanism is introduced for
nucleation. A few subgrains fulfilling abnormal growth conditions will stand out and become nuclei
of recrystallization. The recrystallized grain grows to the deformed materials driven by the stored
energy. Oswald ripening occurs for grains surrounded by recrystallized grains. The models were
verified by laboratory simulation results for selected austenite stainless steels. It showed good
agreement between predicted and experimental results.
Nonlinear Steady Temperature Fields in Non—Homogeneous Materials
Authors: Dai Yao , Sun Qi , Tan Wei , Sun Chang Qing
Published: March 2009

Functionally gradient material (FGM) developed for heat-shielding structure is often used
in the very high temperature environment. Therefore, the material property parameters are not only
functions of spatial coordinates but also ones of temperature. The former leads to partial differential
equations with variable coefficients, the latter to nonlinear governing equations. It is usually very
difficult to obtain the analytical solution to such thermal conduction problems of FGMs. If the finite
element method is adopted, it is very inconvenient because material parameter values must be
imputed for each element. Hence, a semi-analytic numerical method, i.e., method of lines (MOLs)
is introduced. The thermal conductivity functions do not need to be discretized and remain
original form in ordinary differential equations. As a numerical example, the nonlinear steady
temperature fields are computed for a rectangular non-homogeneous region with the first, the
second and the third kinds of boundary conditions, where three kinds of functions, i.e. power,
exponential and logarithmic ones are adopted for the thermal conductivity. Results display the
important influence of non-linearity on temperature fields. Moreover, the results given here provide
the better basis for thermal stress analysis of non-homogenous and non-linear materials.
Development and Application of the Finite Element Analysis Program of the Stress-Based Forming Limit Criterion for Sheet Metal Forming
Authors: Chen Ming He , Li J.H. , Gao Lin , Zuo Dun Wen , Wang Min
Published: March 2009

In order to solve the problem existed in the numerical simulation of sheet metal forming for
its use the strain-based forming limit diagram as criterion, which has the flaw of dependence on the
strain paths, this paper develops the finite element analysis program based on the stress forming limit
criterion applicable to the blank plastic forming technique, which follows the stress-strain
transformation relationship when the sheet metal is undergoing plastic deformation, chooses Hill’s
quadratic normal anisotropic criterion as computational model and selects the commercial finite
element code Dynaform as its development environment. Also it be analyzed the finite element
numerical simulation results of two deep drawing parts by the developed program module and
realizes the prediction of sheet metal forming limit adopting the FLSD as criterion. The stress-based
forming limit criterion for the developed program provides a new means to analyze the forming limit
for the multistage sheet metal forming.
Hydrogen Evolution Behavior in an Al-Mg-Si Alloy Affected by Hydrogen Embrittlement
Authors: Horikawa Keitaro , Kobayashi Hidetoshi
Published: March 2009

Hydrogen evolution behavior of an Al-Mg-Si alloy affected by hydrogen
embrittlement was investigated using a tensile testing machine equipped with quadruple
mass spectrometer in an ultrahigh vacuum chamber. Plate type test pieces were
solutionized at 540°C for 1h, quenched in water and then aged at 175°C for 8h or 240h.
Some of the aged test pieces were pre-deformed in air with a relative humidity of 90%
at a slow strain rate of 8.3x10-7s-1 to introduce hydrogen from the testing atmosphere.
As a result of the tensile test with mass spectrometry, it was shown that hydrogen was
highly evolved at the moment of fracture. The area fraction of intergranular fracture
decreased when the aging condition was changed from peak-aged to over-aged, which
was in agreement with the decrease in the amount of hydrogen evolved at the moment
of fracture.
Effect of Mg Content on the Precipitation in Al-Mg-Ge Alloys
Authors: Matsuda Kenji , Munekata Teruyoshi , Ikeno Susumu
Published: March 2009

Rod-shaped precipitates in Al -1.1 mass% Mg2Ge (balanced) and Al -1.0 mass% Mg2Ge –
0.5 mass% Mg (excess Mg) alloys aged at 523 K were observed by high-resolution transmission
electron microscope (HRTEM) to understand their crystal lattices and chemical compositions.
Rod-shaped precipitates were parallel to <100> directions of the matrix. There were 2 groups for
rod-shaped precipitates in the base alloy, namely, small cross sections about 10 nm and large ones
over 20nm in diameter. Small precipitates showed a hexagonal network of bright dots in their
HRTEM images, and its crystal lattice was estimated as a hexagonal having a= 0.72 and c= 0.405 nm
based on analysis of HRTEM images and selected area electron diffraction (SAED) patterns. This
lattice parameter was slight larger than that of the β’-phase in Al-Mg-Si alloy.
Tensile Properties and Deformation-Fracture Behavior of Ti-6Al-4V Alloy at Cryogenic Temperature
Authors: Dong Shang Li , Xin Y.C. , Lu G. , Yang D.Z. , He S.Y. , Han En-Hou
Published: March 2009

Tensile properties and deformation-fracture behavior at temperatures ranging from 123K
to 293K of a Ti-6Al-4V alloy sheet with a thickness of 1.5mm has been studied, and the effects of
testing temperature, specimen orientation and heat-treatment were investigated. An increase in
strength and a decrease in fracture strain were found with decreasing tension temperature, and the
anisotropy in tensile properties was observed at room and cryogenic temperatures both in the annealed
and solution treated and aged (STA) specimens. TEM examinations indicated that plastic deformation
occurred within both α and β phases in the STA specimens testing at either room or cryogenic
temperature. The dominant deformation mechanism varied from dislocation slip at room temperature
to twinning at 123K. SEM observations showed that the amount of dimples and tearing grains on
fractured surfaces of the specimens decreased as testing temperature was decreased.
Electron Holography on Charging Effect in Non-Conductive Materials
Authors: Kim Ki Hyun , Kim Joong Jung , Xia Wei Xing , Akase Zentaro , Shindo Daisuke
Published: March 2009

The charging effects on non-conductive materials due to electrons irradiation were
investigated by electron holography. The phenomena that the charging effects were more enhanced
with an increase in the incident electron density were visualized through the direct observations in
the electric potential distribution around the specimens. In addition, through the comparison
between the electron holography results and the simulations, we were able to obtain the quantitative
results indicating the amount of charges accumulated during electron irradiation.
Study on Al Alloy Surfaces Treated by Ion Beams
Authors: Li Yu Lan , Peng Xiao Dong , Xie Wei Dong
Published: March 2009

Plasma-enhanced ion beams are used for the surface modification of 2024 Al and 7075 Al
alloy samples. The morphology of the treated surface of the samples is examined. The corrosion
resistance and bending fatigue properties were measured on the treated and untreated samples. The
effects of ion beam parameters are discussed. It is indicated that during the ion bombardment, craters
are formed and surface melting is produced on the treated surfaces. The effects of ion beam
bombardment are limited to the surface layer of samples. With the ion beam energies used in this
study, improved corrosion resistance was obtained from the treated surfaces of the samples.
Investigation of Phase Composition in Dense and Porous Gelcast Alumina Sintered under Argon Atmosphere
Authors: Menchavez Ruben L. , Fuji Masayoshi , Yamakawa Tomohiro , Endo Takeshi , Takahashi Minoru
Published: March 2009

This study investigates the phase compositions in gelcast dense alumina and porous
alumina that were sintered in an inert atmosphere. Both materials were gelcasted using identical slurry
composition except for adding surfactant to slurry intended for porous shaping. The resulting
gelcasted samples were dried and then sintered in argon gas at 1700oC. The X-ray photoelectron
analysis was used for identifying the phase compositions in sintered samples, which was supported
with TG/DTA and electrical measurements. Results showed that, in addition to alumina and carbon
phases, the dense sample yielded Al4C3 and Al, while porous sample yielded aluminum oxycarbides.
The formation of these phases reduced the carbon content through different chemical reactions to a
limited extent because they formed a protective layer on alumina grains, which prevented the direct
contact between alumina and carbon. Subsequent measured electrical resistivities of dense and porous
alumina were, respectively, 0.20 and 0.32 ,-cm, indicating that the carbon networks are preserved in
both materials.
A Characteristic of Spherical Indentation Curve and its Application in Measuring Material Properties
Authors: Yan Wen Yi , Sun Qing Ping , Hodgson Peter
Published: March 2009

The spherical indentation obeys Hertz contact theory when the applied load is within the
elastic limit. Once the applied load is over the elastic limit, the indentation curve starts to deviate
from the original purely elastic indentation curve. This deviation point, which indicates the start of
the nonlinear deformation, is an important characteristic of a spherical indentation curve. The
indentation force corresponding to the deviation point is related to a basic material constant, which
is the yield stress for an elastic-plastic material or the transformation stress for a shape memory
alloy. This relationship can be applied to measure the yield stress or the transformation stress from a
simple spherical indentation curve. Detailed discussion on the relationship and the method is
presented in this short paper.
Preparation and Characterisation of TiO2 Thick Films Fabricated by Electrophoretic Deposition
Authors: Abdullah H.Z. , Sorrell Charles C.
Published: March 2009

Rutile nano-powders were suspended in a solution of acetylacetone and iodine. The
suspensions were electrophoretically deposited on titanium foil at a voltage range of 5-30 V over
times of 5-120 s. The dried tapes then were sintered at 800°C for 2 h in flowing argon. Both the
green and fired tapes were examined by field emission scanning electron microscopy, optical
microscopy, X-ray diffraction, and Raman microspectroscopy.
The thickness of the films depended on the voltage and the time of deposition. The sintered
microstructures depended significantly on the thickness of the film, which was a function the
proximity to the Ti/TiO2 interface. The interface is critical to the microstructure because it acts as
the source of defect formation, which enhances sintering, grain growth, and grain facetting.
Fast and Non Destructive Technique to Characterize Thin Film Porosity: Example on Cubic Mesoporous TiO2 Thins Films
Authors: Moreau Antonin , Defranoux Christophe , Piel J.P. , Bourgeois A. , Martin M.O.
Published: March 2009

Spectroscopic ellipsometry is the technique of choice to characterize thickness and refractive indices of
transparent and semi-transparent thin layers with thickness ranging from few Angstroms to few micrometers. However,
in case of porous thin film, traditional EMA (Effective Medium Approximation) fails to provide qualitative information
on porosity. However, Spectroscopic Ellipsometry can benefit elaborated hardware and software set-up involving the
adsorption/desorption of an adsorbate in the porous thin film, we call it, Ellipsometry Porosimetry Atmospheric (EPA)
and the adsorbate is water. The change in refractive index induced by the introduction of water is measured and thanks
to Lorentz Lorenz effective medium model, the volume of water adsorbed by the material is calculated. EPA becomes an
effective method for characterization of porosity volume, pore size distribution (PSD), average pore size, cumulative
surface area and Young’s modulus of porous films. EPA is also suitable to evaluate the sealing of a porous layer. An
example of study is carried on for TiO2 mesoporous prepared by Evaporation Induced Self-Assembly with various
calcinations treatment. Plots results are characteristic of mesoporous medium with well defined pore dimensions. Upon
calcinations, EP-A allows to follow a significant pores enlargement from 3 to 10 nm. In this paper, the instrument as
well as TiO2 porous thin film study will be presented.
Heating Effects in WC-Co Cemented Carbides as a Result of Reciprocative Dry Sliding Friction
Authors: Bonny Koenraad , de Baets Patrick , Van der Biest Omer , Vleugels Jef , Lauwers Bert
Published: March 2009

WC-Co based cemented carbides are widely used in technical applications, in which they
are exposed to complex thermo-mechanical loadings. Previous research work has demonstrated that
these materials exhibit a lifetime-limiting fatigue sensitivity at room temperature. This investigation
is focused on the influence of heating as a result of friction of pin-on-plate tribocouples. WC-Co
samples have been manufactured and surface finished by wire-EDM and grinding. Reciprocative
dry friction experiments are performed under various loading conditions and sliding velocities.
Correlations are established between the bulk temperature rise of the test samples and the imposed
test conditions, material properties, surface conditions and coefficient of friction. Topographies and
cross-section views of the tested samples were examined by SEM, revealing temperature dependent
wear mechanisms, including binder phase modification.
Recycling of Mg-Al-Ca Based Alloy by Vacuum Distillation
Authors: Inoue Makoto , Shima Nasashi , Tsukeda Tadayoshi
Published: March 2009

In this study, it examined recycling of a Mg-Al-Ca based alloy by vacuum distillation.
The vacuum distillation used a vacuum distillation apparatus and it evacuated a vacuum and
heated the Mg-Al-Ca based alloy to less than 1Pa at 600°C. Condenser temperature changed it
into 280-420°C and performed it. It melted and cast the magnesium condensate which I collected
by the vacuum distillation and investigated corrosion resistance and mechanical properties. The
condensation ratio increased so that condenser temperature was low. The quantity of zinc decreased
so that condenser temperature was high. The quantity of calcium increased slightly so that
condenser temperature was high. Most of the other elements did not mix it. The corrosion resistance
of castings was good. The elongation of castings became bigger than commercial pure magnesium.
An Investigation on Failure Analysis of Titanium Gas Turbine Compressor Blades
Authors: Sepehri Amin H. , Kermanpur Ahmad , Ziaei-Rad Saeed , Farhangi Hassan , Mosaddeghfar M.
Published: March 2009

Several premature failures were occurred in the high-pressure section of an industrial gas
turbine compressor due to the fracture of Titanium blade roots. In this work, the failure process of
the compressor blades was investigated based on the experimental characterisation.
Macro/microfractographic studies were carried out on the fracture surfaces. Optical and scanning
electron microscopy of the blade airfoil and root were performed. Mechanical properties of the
blade alloy were also evaluated and compared with the standard specifications.
The experimental results showed no metallurgical and mechanical defects for the blade materials.
Microstructures of the blade root and airfoil as well as the hardness and tensile properties were all
comparable with those reported in the standard specification AMS 4928Q. Fractography
experiments showed clearly multiple crack initiation sites and fatigue beach marks. Debris particles
were observed on the fracture surface of samples and in the mouth of initiated cracks. The blade
surface in contact to the disc in the dovetail region showed a higher surface roughness than the
other surfaces. Based on the results obtained, the fretting fatigue mechanism was proposed for the
premature failures. It was concluded that the stress concentration has been caused by either
unsuitable curvature ratio of the disk dovetail, incorrect design of the blade or insufficient distance
between the blade root and the disk in dovetail region.
The Influencing Factors and Assessment Rule of Fatigue Life of Shaft Based on Product Lifecycle Management
Authors: Li You Tang , Ma Ping , Zhao Jun Tian
Published: March 2009

Product lifecycle management is one of the main developmental aspects of advanced
manufacturing technology. Anti-fatigue design is the key content in product lifecycle management.
For designing the fatigue life of shaft exactly and determining the assessment method, the influencing
factors must be realized roundly. The mechanical model of shaft is set up at first, and then the main
factors that affect the fatigue life of shaft is discussed, the interrelations of the main factors and the
framework are founded. The assessment equation of fatigue life for shaft is put forward and the
influencing coefficient of multi-axial stress to fatigue life is analyzed. The results of this paper will
establish the base of anti-fatigue and assessment life of shaft.
Growth of Individual Austenite Grains Measured with 3DXRD Microscopy
Authors: Savran V.I. , Offerman S. Erik , van Dijk Niels H. , Lauridsen Erik M. , Margulies L. , Sietsma Jilt
Published: March 2009

Studying austenitisation in steel, so far, was either limited to observations at the surface
of the material or to the determination of the average grain growth behavior in the bulk. The
development of the three-dimensional X-ray diffraction (3DXRD) microscope at beam line ID11 of
the European Synchrotron Radiation Facility in Grenoble, France, made it possible to study the
transformation kinetics in-situ and at the level of individual grains in the bulk of the material.
Unique in-situ observations of austenite growth kinetics during continuous heating experiments
were made for two commercial low-alloy steels (C22 and C35). The observed growth behavior of
individual austenite grains gives a valuable contribution to understanding the phase transformations
on heating, i.e. austenite formation from ferrite and pearlite.
A Study of the Microstructural Evolution and Strengthening Effects of Non-Spherical Precipitates in an Al-Cu-Based Alloy
Authors: da Costa Teixeira Julien , Bourgeois Laure , Hutchinson Christopher R.
Published: March 2009

The microstructural evolution and associated strengthening during isothermal ageing of an
Al-3Cu-0.05Sn reinforced by non-spherical θ' (Al2Cu) precipitates is studied. Emphasis is placed on
the plate shape of the θ'. It is found that the microstructure parameters governing the magnitude of
the precipitation strengthening effect are completely different from the classical case of spherical
precipitates. New possibilities for microstructure design are discussed.
Specimen-Size Dependence of the Martensitic Transformation Temperature of Yttria Doped Zirconia
Authors: Tamaki Masanori , Onda Tetsuhiko , Hayakawa Motozo
Published: March 2009

Small spherical specimens of ZrO2-1.5mol%Y2O3 with diameters ranging from 150 to
900μm were prepared and the burst temperature was measured on an individual specimen under
optical microscope with cooling stage. The range of scatter of the burst temperature increased with
decreasing specimen’s size. While the upper limit of the scatter remained nearly the same, the lower
limit of the scatter markedly decreased with decreasing specimen’s size. The distribution of
potential embryos was deduced by fitting the simulated distribution of burst temperatures to the
observed result by adjusting the assumed distribution of potential embryos used for the simulation.
Effect of Magnetic Field on Isothermal Martensitic Transformation in SUS304L Stainless Steel
Authors: Lee Jae Hwa , Fukuda Takashi , Kakeshita Tomoyuki
Published: March 2009

We have found that solution-treated or sensitized SUS304L stainless steel transforms
isothermally from the γ (fcc)-phase to the α' (bcc) martensite via the ε' (hcp) martensite, that is, the
amount of the α'-phase increases with increasing holding time. By applying magnetic field, the α'
martensite can be induced in the ε'-plate when the steel has a sufficiently large ε' plate formed
beforehand by isothermal holding. However, the α' martensite cannot be induced by magnetic field in
the ε'-plate formed beforehand by a deformation-induced transformation.
Femtosecond Laser Synthesis of Polymorphic Diamond from Highly Oriented Pyrolytic Graphite
Authors: Sano Tomokazu , Takahashi Kengo , Hirose Akio , Sakata Osamu , Okoshi Masayuki , Inoue Narumi , Kobayashi Kojiro F.
Published: March 2009

We synthesized polymorphic diamond directly from highly oriented pyrolytic graphite
(HOPG) using femtosecond laser driven shock wave without catalyst. A femtosecond laser pulse
(wavelength: 800 nm, pulse width: 120 fs, intensity: 2×1015 W/cm2) was irradiated onto the HOPG
surface in air. Crystalline structures of HOPG after the laser irradiation were analyzed using the
synchrotron X-ray at the BL13XU in the SPring-8. We found that the hexagonal diamond exists in the
HOPG which was irradiated by the femtosecond laser normal to the basal plane.
Improvement of Strength and Ductility by Controlling PFZ with Microalloying Elements in Al-Zn-Mg Alloys
Authors: Ogura Tomo , Shoichi Hirosawa , Sato Tatsuo
Published: March 2009

The effectiveness of microalloying addition and two-step aging on the mechanical
properties of the Al-Zn-Mg alloy has been investigated using TEM, tensile test and nanoindentation.
By decreasing width of PFZ and size of grain boundary precipitates through the addition of (Ag+Sn)
or two-step aging process, tensile properties of Al-Zn-Mg alloys are markedly improved. The
elongation was quantitatively related to the three microstructural factors; i.e. the width of PFZ, size of
grain boundary precipitates and the level of proof stress, to predict ductility of the alloys with known
microstructural factors. The fracture mode change is reasonably in terms of the hardness difference
between grain interiors and PFZ region by a noindentation technique.
Development of Nanocrystalline Copper-Refractory Metal Alloys
Authors: Rigsbee J.M.
Published: March 2009

Precipitation-strengthened Cu-based alloys have limited use as structural materials at
high temperatures due to precipitate coarsening and strength loss. We have recently shown that Curefractory
metal alloys produced by various physical vapor deposition methods have stable,
nanocrystalline microstructures and maintain their strength properties even when annealed at
temperatures as high as 900 C for up to 100 hours. This paper presents discussions of how these
alloys are processed and the resulting microstructures. X-ray and electron microscopy results will
be presented to document the phase transformations that occur in these alloys and result in such
exceptionally stable microstructures.