bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the In Situ SEM Tension Observation of E-A356 Alloys
Authors: Li Ji Wen , Xie Jing Pei , Wang Wen Yan , Wei Shi Zhong
Published: March 2009

The fracture mechanisms of E-A356 alloys (T5 treatment) have been investigated by
means of in situ SEM under nonaxial tension loading. It is found that the crack initiated at the casting
defects, such as at the gas or the shrinkage pores, because of the debonding of the silicon particles
from the Al matrix. The crack propagation was mainly in the Al matrix and along the matrix/particle
interface secondarily. The crack growth could be influenced by the eutectic silicon particles, when it
encountered the Si particles, the growth direction would be changed and turned toward the weaker
areas. The fracture resistance or the mechanical properties of the E-A356 alloys will be improved by
means of reducing, eliminating gas or shrinkage pores and increasing the interface bound strength of
the eutectic silicon particles with the Al matrix.
Experimental Study of Stress Induced Martensite Transformation under Plane State of Stress
Authors: Cortés-Pérez J. , Souza Jiménez A. , Lara Rodríguez G.A. , Ferrer A. L.A. , Flores Zúñiga H.
Published: March 2009

An experimental study of stress induced martansite transformation by electrical strain gauges is
present. The studies were performance on polycrystalline Cu-Al-Be Shape Memory Alloys. Beams
and a bar in cantilever flexion hold to punctual load were instrumented with electrical strain gauges
in several points where the state of stress is: a) simple tension, b) simple shear and b) tension-shear.
Employing the trasforational load values in each plot was calculated critical principal stresses.
Employing the results obtained, 1 2 σ −σ plots were constructed and a comparison with the yield
Von-Mises criteria, Patoor model and Buchheit model for the critical stress were do.
Hydroxyapatite Formation on Calcium Phosphate Coated Titanium
Authors: Sato Mitsutaka , Tu Rong , Goto Takashi , Ueda Kyosuke , Narushima Takayuki
Published: March 2009

Calcium phosphate films were prepared by MOCVD using Ca(dpm)2 and (C6H5O)3PO
precursors. The phases, composition and morphology of films changed depending on the molar ratio
of Ca to P precursors (RCa/P), total pressure (Ptot) and substrate temperature (Tsub). α-tricalcimu
phosphate (α-TCP, α-Ca3(PO4)2) films in a single phase were obtained at Tsub = 1073 K, 0.1 < RCa/P <
0.4 and Tsub = 973 K, RCa/P < 0.4. Hydroxyapatite (HAp, Ca10(PO4)6(OH)2) films in a single phase
were obtained at Tsub = 1073 K, 0.8 < RCa/P < 1.0 and Tsub = 973 K, 0.5 < RCa/P < 0.6. Ca-P-O films had
a dense and smooth surface. HAp formed within 1 day on the α-TCP film and wholly covered the
specimens within 2 weeks in a Hanks’ solution. The surface of CVD-HAp film was covered by
precipitated HAp within 6 hours.
Surface Modification of Titanium with Hydrothermal Treatment
Authors: Obata Akiko , Kasuga Toshihiro
Published: March 2009

Hydrothermal treatment was performed on a titanium plate for its surface modification to
enhance its bioactivity. The titanium plate was autoclaved in deionized water (DW) or 0.05 mol/l
NaOH solution at 120, 200 and 240 °C for 24 hr. The titanium surfaces autoclaved in DW were
homogeneously coated with nano-sized particles and polygonal deposits with the sizes of several
hundreds nanometers. The deposits were regarded as anatase according to the results of laser
Raman spectroscopy (LRS). In the case of autoclaving in 0.05 mol/l NaOH solution, leaf-like,
needle-like and pyramid deposits were observed on titanium surfaces and regarded to consist of
anatase or brookite by LRS analysis. The formation of the deposits significantly depended on the
autoclaving temperature. The deposits adhered on the titanium surface though a tape-test; the
adhesion of the particle was found to be excellent.
Catalytic Combustion Synthesis of Carbon Nanofibers
Authors: Zhu Guang , Zou Xiao Ping , Cheng Jin , Li Fei , Zhang Hong Dan , Ren Peng Fei , Wang Mao Fa
Published: March 2009

The catalytic combustion technique was used to synthesize carbon nanotubes and carbon
nanofibers. In this paper, we report that carbon nanofibers were synthesized by ethanol catalytic
combustion technique. The as-grown products were characterized by means of scanning electron
microscopy, transmission electron microscopy, Raman spectroscopy. The results showed that the
products have a mass of carbon nanofibers. However, morphology and microstructure of carbon
nanofibers are affected by synthesis conditions, such as stability of flames and sampling time,
sampling temperature etc. Different Influence factors were depicted in detail. Ethanol catalytic
combustion technique offer a simple method to synthesize carbon nanotubes and carbon nanofibers, it
also has some advantages, such as flexible synthesis conditions, simple setup, and
environment-friendly.
Martensitic Transformation of TiAu Shape Memory Alloys
Authors: Hosoda Hideki , Tachi Ryosuke , Inamura Tomonari , Wakashima Kenji , Miyazaki Shuichi
Published: March 2009

Martensitic transformation temperatures were measured and transformation strains were
evaluated in a promising high temperature shape memory alloy TiAu with a compositional range from
46 to 53mol%Au. It was found by differential scanning calorimetry that martensitic transformation
start temperature (Ms) is kept almost constant value of 880K in the Au-rich side of the stoichiometric
composition. On the other hand, Ms decreases monotonically with decreasing Au content in the
Au-poor side. X-ray diffraction analysis revealed that apparent phase of all the alloys at room
temperature is B19 martensite phase. Under an assumption that the atomic volume is constant during
martensitic transformation, the lattice parameters of B2 parent phase and maximum transformation
strain were calculated. It was found that the maximum transformation strain depends on chemical
composition and that it reaches 10.75% for Ti-53mol%Au alloy. The value is comparable to that of
Ti-Ni.
Enhancing the Bonding Strength of Plasma-Sprayed HA Coating on Pure Ti
Authors: Yang Sen , Man Hau Chung
Published: March 2009

A layer of bioceramic HA was coated on laser gas nitrided and grit-blasted pure Ti
substrates using plasma-spraying technique, respectively. X-ray diffraction analysis showed that the
microstructures of the coating were mainly composed of HA, amorphous calcium phosphate and
some minute phases of tricalcium phosphate, tetracalcium phosphate and calcium oxide. The
experimental results showed that the 3-D TiN dendritic scaffold structure produced on the surface of
pure Ti using laser gas nitriding technique in advance could anchor the HA coating and improved the
interfacial adherence significantly as compared with those on the grit blasted surfaces.
Characteristics of Hydrogen Storage by Sn/MgH2 Nanocomposite Obtained by Mechanical Milling of MgH2 with Sn
Authors: Imamura Hayao , Yoshihara Kazuki , Yoo Mika , Kitazawa Ichiro , Sakata Yoshihisa , Ooshima Shinji , Kataoka Takeshi
Published: March 2009

The hydrogen desorption of Sn/MgH2 nanocomposite which is formed by ball milling of MgH2
and tin compounds (Sn, Sn(C4H9)4 or SnCl2), has been studied. The hydrogen desorption
properties (desorption temperature and enthalpy of dehydriding) were significantly improved as a
result of a Sn/MgH2 nanocomposite formation. TDS (thermal desorption spectrometry), TG
(thermogravimetry) and DSC (differential scanning calorimeter) measurements exhibited the
existence of at least two types of hydrogen species in the Sn/MgH2 nanocomposite resulting from
ball milling of MgH2 with Sn; the one was hydrogen in the newly formed Sn/MgH2 nanocomposite
and the other hydrogen derived from MgH2 remaining in Sn/MgH2.
Mechanical and Thermal Properties of Micro-Closed Cellular Materials Containing Different Materials from that of Cell Walls
Authors: Kishimoto Satoshi , Hasegawa Yoshio , Kodama Hiroto
Published: March 2009

A method to fabricate the metallic closed cellular material has been developed. Powder
particles of polymer or ceramics coated with a metal layer using electro-less plating were pressed
into pellets and sintered at high temperatures by heating and spark plasma sintering (SPS) method.
A metallic closed cellular material containing different materials from that of cell walls was then
fabricated.
The mechanical and Thermal properties of this material were measured. The results of the
compressive tests show that this material has the different stress-strain curves among the specimens
that have different thickness of the cell walls and the sintering temperatures of the specimens affect
the compressive strength of each specimen. Also, it seems that the results of the compressive tests
show that this material has high-energy absorption and Young’s modulus of this material depends
on the thickness of the cell walls. Also thermal properties of this material were measured.
Physicochemical Properties of Carbons Prepared from Physic Nut Waste by Phosphoric Acid and Potassium Hydroxide Activations
Authors: Pechyen Chiravoot , Aht-Ong Duangdao , Atong Duangduen , Sricharoenchaikul Viboon
Published: March 2009

Char derived from pyrolysis of physic nut waste at 400-800°C was used for the
preparation of activated carbon by chemical impregnation of phosphoric acid and potassium
hydroxide. The original char exhibited the BET surface area in the range of 120-250 m2·g-1. The
surface area increased to 480 and 532 m2·g-1 when activated with H3PO4 and KOH, respectively.
Equilibrium adsorption data was found to be best represented by the Langmuir isotherm with
maximum monolayer adsorption capacity of 560.13 mg·g-1 at 30°C. The adsorption capacity of the
physic nut residue activated carbon was comparable to commercial activated carbon.
Characterization of High Strength Alloy Formed by Ion Irradiation of Metallic Glasses
Authors: Carter Jesse , Fu En Gang , McDeavitt S.M. , Zhang Xing Hang , Xie Guo Qiang , Shao Lin
Published: March 2009

We have explored irradiation effects on metallic glasses by using 140 keV He ions. The
mechanical properties of nanostructured metallic glass are studied by using microindentation. The
study shows the feasibility of developing a high strength alloy by ion irradiation of metallic glasses.
Corrosion Behavior of CLAM in Liquid LiPb Alloy at 480°C
Authors: Zhang M.L. , Huang Qun Ying , Wu Y.C. , Zhu Z. , Gao S. , Song Y. , Li C.
Published: March 2009

China Low Activation Martensitic steel (CLAM), which is one of the RAFMs (Reduced
Activation Ferritic/Martensitic steels) and under development in ASIPP, is considered as the
primary candidate structural material and LiPb eutectic as both tritium breeder and coolant of the
blankets in FDS series fusion reactors. The corrosion behavior of CLAM steel exposed to the liquid
breeder LiPb is of significance. Corrosion tests of CLAM in flowing LiPb at 480°C were performed
up to about 2000 hrs to analyze the corrosion mechanism of CLAM exposed to liquid LiPb. The
specimens were observed and analyzed by Scanning Electron Microscopy (SEM) and Energy
Dispersive X-ray Spectroscopy (EDX) after 500hrs, 1000hrs and 2000hrs corrosion experiment
respectively. The corrosion is of non-uniform and the weight loss was about 0.23 mg/cm2 after 2000
hrs’ exposure, which is smaller for CLAM compared to those of other RAFMs.
Experiment and FEM Simulation on Residual Stress of Cold Expansion Hole
Authors: Shao Xiao Jun , Liu Jun , Liu Yong Shou , Yue Zhu Feng
Published: March 2009

A 2D cylindrical plate model has been established to study the distribution of residual
stress of cold expansion hole under different interference values. In addition, the effects of material
models on residual stress fields are considered also. Experiments are carried out to measure the
residual stress of cold expansion hole and verify simulation results. FEM results show, with
interference values increasing, the higher residual radial and circumferential stresses are obtained. At
same interference value, the residual stress of Hardening Material( HM ) model is much larger than
that of Elastic Perfectly Plastic Material( EPPM ) model.
Phase Field Modeling of Recrystallization Grain Growth during Re-Aging Process in Cu-Ni-Si Alloy
Authors: Long Yong Qiang , Liu Ping , Zhang Wei Min
Published: March 2009

The micro structural evolution and the mechanism of recrystallization grain growth were
studied during re-aging process in Cu-Ni-Si alloy containing finely pre-aging δ-Ni2Si precipitates
using computer simulations based on a diffuse-interface phase-field kinetic model. In this model, the
temporal evolution of the spatially dependent field variables is determined by numerically solving the
time-dependent Ginzburg-Landau (TDGL) equations for the structural variables. The simulation
results quantify the effects of the precipitation on recrystallization. It is shown that the finely
dispersed pre-aging δ-Ni2Si precipitates exert a strong pinning effect on the recrystallization grain
boundaries. The recrystallization grain growth for r = 3 fa = 0.015 can be described as R =1.04∗t 0.33
at the beginning, followed by a gradual transition to growth stagnation. The final grain size follows a
Zener type relation
lim 0.49 1.41
a
R r
f
=  
 
for 0.01 ≤ fa ≤ 0.21 and r = 2.5 or 3.
An Anisotropic Model for the Plastic Response of Powder Compacts
Authors: Ruziwa Walter R. , Cocks Alan
Published: March 2009

In this paper we present an anisotropic compaction model based on a generic
modeling framework. The model is a generalization of Hill’s anisotropic model to
compressible materials and reduces to a Cam-clay type model in the isotropic limit. The
model has been calibrated using experimental data for a commercial steel powder
obtained from a computer controlled triaxial cell in which the yield surface was probed
following loading along different paths in stress and strain space. Closed-form
analytical expressions are presented for the yield surface as a function of the inelastic
strain. The model has been implemented in the general purpose finite element code
ABAQUS. Simulations are presented which explore the effect of a detailed structure of
the constitutive law on the compaction response.
Development of New Types of Magnesium Alloys Containing Sr or RE Elements
Authors: Pan Fu Sheng , Yang Ming Bo , Ma Yan Long
Published: March 2009

The latest research results on new types of magnesium alloys containing strontium or rare
earth elements are reviewed. Special attentions are paid to the alloying design, microstructure and
properties controlling, the influence of minor addition of Sr and RE on the microstructure and
properties of existing magnesium alloys. Some new types of magnesium alloys containing Sr or RE
are introduced and discussed.
Numerical Simulation and Optimisation of Sheet Metal Forming for Auto-Body Panel Using AutoForm Software
Authors: Wang Xuan Zhi , Masood Syed H. , Dingle M.
Published: March 2009

This paper focuses on a rapid simulation methodology for sheet metal forming, using
AutoForm™ software, for an auto-body panel. An engine hood is selected as a sample part.
Simulation of the whole process cycle, including drawing, cutting and flanging is presented generally.
According to the required outer surface forming quality, the dominant parameter is determined firstly
from various parameters using AutoForm™ sigma module. The optimisation of the dominant
parameters is then performed to obtain the best result. This methodology can decrease the
optimisation time and predict the most crucial parameter in the forming process for design engineers,
which can dramatically reduce the lead time of automobile industries.
The Study of Undercooling of Homogeneous Nucleation for Metallic Melting
Authors: Huang Cheng , Song Bo , Zhao Pei
Published: March 2009

In this paper, the thermodynamic and kinetic requirements of heterogeneous and
homogeneous nucleation of metallic melting were suggested. Based on the kinetic requirements of
nucleation, the mathematic model of wetting angle of heterogeneous nucleation was developed,
Based on the wetting angel model, it was predicted that the maximum undercooling of homogeneous
nucleation for melts is two thirds of melting temperature. With the wetting angel model, the wetting
angles of different catalysts in liquid iron were calculated, and calculation results are in agreement
with that of other researchers.
Extraction of Elastic Modulus and Hardness of the Soft Metallic Films on Hard Substrates by Nanoindentation
Authors: Zhou X.Y. , Wang Hai Rong , Jiang Zhuang De , Yu Rui Xia
Published: March 2009

A simple method to extract the intrinsic mechanical properties of the soft metallic thin
films on hard substrates by nanoindenation is presented. Utilizing the geometry relationship of
residual impressions obtained by the SEM image and the cross-sectional profile, the pile up error in
elastic modulus determination of soft thin films by the Oliver and Pharr analysis is first corrected.
Knowledge of the ‘true’ elastic modulus, the ‘true’ hardness of thin film is then extracted from the
measured contact stiffness data for an elastically homogeneous film-substrate system. The present
method is applied for a 504 nm Au thin film sputter deposited on the glass substrate and the results
show that the ‘true’ elastic modulus and hardness of Au film are 80 GPa and 1.3 GPa, which are in
agreement well with the literatures.
Determining the Surface Properties and Inherent Properties of Solid Materials Using Material-Independent Indentation Technique
Authors: Bao Yi Wang , Sun Li
Published: March 2009

A simple and material-independent indentation technique is presented to determine the
hardness and elastic modulus of solid materials. This method requires only three experimentally
measured quantities to determining the material properties, i.e., the peak load, corresponding
displacements and the depth of residual indent, without curve fitting process and regression analysis.
The results obtained from this simple technique were consistent with those obtained by using the
conventional method. Furthermore, energy dissipation and the ability of elastic recovery of the
ceramic materials were evaluated from the measured indentation data.
Reciprocating Friction and Wear Behavior of WC-Co Based Cemented Carbides Manufactured by Electro-Discharge Machining
Authors: Bonny Koenraad , de Baets Patrick , Van der Biest Omer , Vleugels Jef , Lauwers Bert
Published: March 2009

Tungsten carbide based hardmetals with cobalt binder phase are widely used in
engineering industries for their excellent mechanical properties and outstanding wear performance.
Reciprocative sliding wear behaviour of a number of WC-Co based hardmetal grades was
investigated using a small-scale pin-on-plate tribometer. Test samples were manufactured by
electro-discharge machining (EDM) with various surface finishing regimes. SEM topographies and
cross-section views of the cemented carbides were obtained both before and after dry friction tests,
revealing distinctive wear mechanisms. The generated wear loss was quantified topographically
using surface scanning equipment. Wear debris particles were collected and examined by EDX and
TEM analysis. Based on experimental results, the execution of consecutive gradually finer EDM
cutting steps was found to considerably enhance wear performance. Furthermore, a significant
influence of contact load, sliding movement duration, application of lubricant and wear debris
formation on wear rate and friction was established.
Effect of Structure and Morphology on Photo-Oxidation Degradation of Polyethylene
Authors: Yang Rui , Liu Ying , Yu Jian
Published: March 2009

Photo-oxidation of polyethylene (PE) has been studied thoroughly these years owing to its
high output and various applications, which makes knowledge about its degradation of vital practical
importance. Polyethylene products often suffer from service environment factors including ultraviolet,
heat or chemicals, which may deteriorate their mechanical properties. The degradation behavior
varies with the chain structure and morphology of polyethylene, e.g., branches, linear segments length
and crystallization. Natural degradation of three kinds of polyethylene (HDPE, LDPE and LLDPE)
has been examined in samples using different annealing conditions in this work. The extent of
degradation, described as carbonyl index, was evaluated by Fourier transform infrared spectroscopy
(FTIR). Crystallinity measurements were made using differential scanning calorimetry(DSC). The
investigation indicates that the branch structure plays a dominant role in the photo-oxidation of
polyethylene. Annealing will change the crystallinity of polyethylene before aging, but do not show
obvious dependence on the oxidation.
Variation of Hardness with Microstructure Evolutions in Metastable β Titanium Alloy TIMETAL®LCB
Authors: Sakamoto Tatsuaki , Nakai Kiyomichi , Maeda Munehiro , Kobayashi Sengo
Published: March 2009

Microstructure evolutions and hardness variation during aging in metastable β titanium
alloy TIMETAL®LCB have been examined. In as-quenched specimen after solution treatment,
athermal ω phase formed. Isothermal ω phase formed during aging at 623 K, and α phase formed after
precipitation of isothermal ω phase during aging at 673 and 773 K. Alpha phase nucleated at
isothermal ω phase, and had the orientation relationship with β and ω, (111)β//(0001)ω//(1120 )α and
[10 1 ]β//[1120 ]ω//[0001]α . During aging at 873 K, α phase formed without isothermal ω phase.
Hardness increased with increasing aging time and decreasing aging temperature, partly because
number density of isothermal ω or α precipitates increased with increasing aging time and decreasing
aging temperature.
Stoichiometric Study of Iron Sulfide Prepared by Mechanochemical Reaction
Authors: Lin Chung Kwei , Yi Chen Chin , Lee Pee Yew , Chan Chih Chieh
Published: March 2009

In the present study, pure elemental powders of Fe and S were mixed to give the desired
compositions of Fe50S50. A SPEX 8000D high-energy ball mill was used to synthesize iron sulfide
powders under an Ar-filled atmosphere. The prepared powders were examined by conventional
X-ray diffractometry and synchrotron X-ray absorption spectroscopy. The experimental results
revealed that mechanochemical reactions occurred during the ball milling process for all the
compositions. The Fe50S50 phase was obtained after ball milling for 20 h. Extended X-ray
absorption fine structure (EXAFS) results revealed that the nearest neighbor bond lengths of the
radial distribution function (RDF) for iron decreased when iron sulfides formed. X-ray absorption
near edge structure (XANES) of S K-edges distinguished better the structural evolution of these iron
sulfides.
Effect of Isothermal Aging on the Growth and Morphology of the Intermetallic Compounds Formed at the Solder/Cu Interface of the Lead - Free Solder Joint
Authors: Fu Yun , Zhang Qi , Sun Feng , Bai Hao Yu
Published: March 2009

The growth and morphology of the intermetallic compounds (IMC) formed at the
interface between the solder ( Sn–3.5Ag–0.5Cu ) and the Cu substrate of the lead - free solder joint
have been investigated by means of isothermal aging at 125°C. The scalloped Cu6Sn5 intermetallic
compound layer was formed at the interface between the solder and Cu substrate upon reflow. The
thickness of Cu6Sn5 layer increased with aging time. Cu3Sn appeared between Cu6Sn5 layer and Cu
substrate when isothermally aged for 100 hours. Compare to Cu6Sn5 , the thickness of Cu3Sn was
rather low, and nearly did not increase with aging time.
In this paper, the comparison was made among the Sn-Pb and the Sn-Ag-Cu(SAC) solders which
were pre-treated differently before soldering.
Corrosion Behavior of Pure Titanium Produced by MIM Process under SSRT Condition
Authors: Sunada Satoshi , Kawagishi Masaru , Majima Kazuhiko
Published: March 2009

Metal injection molding (MIM) process has the advantage of better formability of three
dimensional complex shape products with high density and high performance properties
compared to the ingot metallurgy (I/M) process. Two kinds of pure titanium specimens, i.e., the first
one is prepared by the I/M process and the second one is prepared by MIM process are used in this
experiment, and their corrosion behavior under stress has been investigated in several aqueous
solutions by Slow Strain Rate Tensile (SSRT) test. Both I/M and MIM specimens showed good
corrosion resistance in the aqueous solution composed of 2.5 kmol/m3 H2SO4 and 0.2 kmol/m3
NaCl as well as saline solution. This aqueous solution is noted one in which Type 304 stainless steel
showed SCC. In the aqueous solution composed of CH3OH and 0.1 kmol/m3 HCl containing
8.6kg/m3 H2O, the elongation of MIM specimen was slightly higher than that of I/M specimen
though both specimens indicated the remarkable decrease in elongation.
Electrochemical Dissolution Characteristics of Magnesium Alloy Produced by Roll Compaction Process
Authors: Sunada Satoshi , Kawamura Takahito , Kondoh Katsuyoshi , Notoya Hisakimi , Majima Kazuhiko
Published: March 2009

The extruded AZ31B Mg alloy specimens using powders fabricated by roll compaction
processing (RCP) was prepared, and their corrosion behavior has been investigated through the
polarization test, electrochemical impedance spectroscopy test, immersion test and SEM
observation in comparison to that of the conventional AZ31B Mg alloy, hereafter shortened as I/M
specimen. The extruded AZ31B Mg alloys using RCP powder showed little change in Ecorr
irrespective of number of pass cycles. Both anodic and cathodic current density suppression of the
RCP specimens became larger with an increase in number of pass cycles. It was also confirmed that
the corrosion characteristics of the RCP specimens depended strongly on their structural
morphology and that the corrosion resistance of the RCP specimens subjected to 50 pass cycles was
nearly same as that of the I/M specimen.
Preparation and Characterisation of TiO2 Thick Films by Gel Oxidation
Authors: Abdullah H.Z. , Sorrell Charles C.
Published: March 2009

Titanium foils were subjected to soaking in NaOH aqueous solutions in the concentration
range 0.1 M to 10.0 M, followed by oxidation in the range 400°C to 800°C. The samples were
characterised by glancing angle X-ray diffraction and Raman microspectroscopy.
The results showed that the corrosion by NaOH solution resulted in:
• Partial dissolution of the anatase passive oxidation layer
• Partial dissolution of the underlying titanium foil
• Formation of a TiO2-rich sodium titanate hydrogel (Na2O·mTiO2·nH2O)
The subsequent oxidation of the hydrogel on the titanium substrate resulted in:
• Recrystallisation of sodium titanate (Na2O·5TiO2)
• Recrystallisation of the rutile polymorph of TiO2
The concentration of the NaOH solution was important in that it affected the dissolution or retention
of the anatase passive oxidation layer, where lower concentrations (0.5 M and 1.0 M NaOH)
resulted in a lower degree of dissolution in comparison to where higher concentrations (5.0 M and
10.0 M NaOH) were used.
Cyclic Deformation of Al-Mg Single Crystals with a Single Slip Orientation
Authors: Fujii Toshiyuki , Uju Shizuma , Watanabe Chihiro , Onaka Susumu , Kato Masaharu
Published: March 2009

Fully reversed tension-compression fatigue tests were performed on solid-solutioned
Al-0.7mass%Mg single crystals with a single slip orientation under constant plastic-strain
amplitudes. Dislocation microstructures were quantitatively examined by transmission electron
microscopy. The cyclic stress–strain curve (CSSC) exhibited three distinct regions with a short
plateau region in the intermediate plastic-strain amplitude range, and the plateau stress was 26MPa.
Characteristic microstructures were developed corresponding to the three regions in the CSSC.
Vein structure was observed at the low strain-amplitude region. In the plateau regime, the
persistent slip bands (PSBs) were observed. Labyrinth structure was also observed at the higher
strain-amplitude region. The plateau stress, the cyclic flow stress of PSBs, can be explained by
considering not only the Orowan bowing stress and the dipole passing stress of screw dislocations
but also solid-solution hardening by Mg atoms.
Investigation of Deformation Gradients in Surface Zone of Mechanically Surface Treated CuZn30
Authors: Yi Sang Bong , Ludian Tomasz , Wagner Lothar
Published: March 2009

The deformation degrees in near-surface zones and related microstructural changes in CuZn30 were
determined after shot peening and ball-burnishing. The induced depths of plastic deformation
increase with Almen intensity and rolling pressure in shot peening and ball-burnishing, respectively.
As the ball size in burnishing increases, the depth of plastic deformation also increases. The local
degrees of cold work within the affected depths were estimated by comparing micro-hardness
values, penetration depths of induced slip bands as well as X-ray diffraction peak widths with those
measured in blanks cold rolled to fixed degrees of plastic strain. The results clearly indicate that
very high local deformation degrees above 80% are typically induced by mechanical surface
treatments in areas very close to the surface with this deformation degree gradually decreasing with
increasing distance to the surface. Depending on the intensity of ball-burnishing, deformation
degrees still of the order of 10% were observed in regions having distances to the surface of as large
as 1000 (m.
Analysis of Creep Deformation Process of Heat Resistant Steels Using Positron Annihilation Lifetime
Authors: Igarashi Masaaki , Moriguchi Koji , Muneki Seiichi , Abe Fujio , Shirai Yasuharu
Published: March 2009

Creep deformation mechanism of the steels with a different matrix, α (ferrite), α’
(martensite) and γ (austenite), and precipitates such as MX and M23C6 has been analyzed using
positron annihilation lifetime measurement. The positron annihilation lifetime has been found to be a
very useful tool for evaluating the characteristic creep damage of the steels with different
microstructure and the corresponding microstructural evolution during creep deformation. The creep
deformation process of the α steel is heterogeneous, while the α’+M23C6 steel exhibits gradual
changes in the creep rate in both transient and acceleration creep regions with the largest off-set
strain, implying the homogeneous creep deformation. The α’+M23C6+ MX steel is in between the α
and α’+M23C6 steels. The homogeneous creep deformation takes place in the γ steel.
Three-Dimensional Finite Element Modelling of Laser Shock Peening Process
Authors: Yang Chun Hui , Hodgson Peter , Liu Qian Chu , Ye Lin
Published: March 2009

Laser shock peening (LSP) is an innovative surface treatment technique for metal alloys,
with the great improvement of their fatigue, corrosion and wear resistance performance. Finite
element method has been widely applied to simulate the LSP to provide the theoretically predictive
assessment and optimally parametric design. In the current work, 3-D numerical modelling
approaches, combining the explicit dynamic analysis, static equilibrium analysis algorithms and
different plasticity models for the high strain rate exceeding 106s-1, are further developed. To verify
the proposed methods, 3-D static and dynamic FEA of AA7075-T7351 rods subject to two-sided
laser shock peening are performed using the FEA package–ABAQUS. The dynamic and residual
stress fields, shock wave propagation and surface deformation of the treated metal from different
material modelling approaches have a good agreement.
A Theoretical Model for Digestive Ripening
Authors: Lee Dong Kwon , Park Sung Il , Lee Jong K. , Hwang Nong Moon
Published: March 2009

Recently, gram quantities of monodisperse gold or silver nanoparticles were reported to be
produced through a digestive ripening process, in which colloidal particles of size 2 to 40 nm are
transformed to nearly monodisperse particles of 4 ~ 5 nm diameter. Digestive ripening, an example
for an inverse Ostwald ripening process, is a puzzling phenomenon since it appears to go against the
usual capillary effect, i.e., reduction of interfacial free energy. A theoretical model is presented, which
accounts for the monodisperse state of such nanoparticles by considering the effect of charges on the
particles and thus electrostatic energy during particle size evolution.
Phase-Field Simulation of γ"(D022) Precipitation in Ni Base Superalloys
Authors: Koyama Toshiyuki , Onodera Hidehiro
Published: March 2009

Although the γ"(D022) phase has been known as a strengthen phase for the turbine disk of
wrought Ni-base superalloys, the computer simulation of the γ"(D022) precipitation is hardly
performed. In this study, it is demonstrated that the phase-field modeling of the complex
microstructure developments including γ"(D022) precipitation in Ni-V-X (X=Co,Nb,Fe) alloys. The
simulation results obtained are as follows: (1) The complex morphologies of the γ(A1)+γ"(D022)
two-phase microstructure, such as the maze-microstructure, the chessboard-microstructure, and the
chessboard-like microstructure, in Ni-V-X (X=Co,Nb,Fe) alloys are simulated reasonably by using
phase-field method. (2) The morphology of the microstructure is mainly controlled by the elastic
strain energy induced from the lattice mismatch. In particular, the tetragonal distortion is a key
parameter to control and understand the complex microstructure changes.
Metastable Precipitates and their Misfit Strains in a Cu-0.9wt%Be Single Crystal
Authors: Monzen Ryoichi , Sakai Toshiro , Watanabe Chihiro
Published: March 2009

The precipitation processes from G.P. zones to γ’ in a Cu−0.9wt%Be alloy single crystal
containing only the G.P. zones parallel to the matrix (001)α plane are investigated by high-resolution
electron microscopy. The precipitate phases follow a G.P. zone → γ” → γI + γ’ sequence. The G.P. zone
to γI phase transformation occurs successively via γ” during aging, while the γ’ phase heterogeneously
precipitates on the γI phase. From length-change measurements during aging, the misfit strains of γ’
precipitates in directions perpendicular and parallel to [001]α are estimated as ε11 =ε22 = −0.03 and
ε33 = −0.09, respectively. The observation that the estimated absolute value of ε33 is much smaller than
that of ε33 = −0.25 calculated using lattice parameters of the γ’ phase and Cu matrix is understood in
terms of the relaxation of ε33 by interfacial misfit dislocations.
TEM Observations of Precipitation of Coherent L12 and D022 Ordered Phases in Ni-V-Ge Alloys
Authors: Inuzuka Yusuke , Ito Shogo , Kozakai Takao , Doi Minoru
Published: March 2009

Phase separations of A1 (γ) supersaturated solid solution into γ, cubic-L12 (γ') and
tetragonal-D022 (γ") phases were investigated in Ni-V-Ge alloys by means of transmission electron
microscopy (TEM). When Ni-15.8at%V-9.0at%Ge alloy is aged at 1073 K, at the early stage of
ageing γ" phases are observed in the γ matrix as triangle- or diamond-shaped precipitates. With
further ageing, colonies of lamellar structure consisting of two variants of γ" phase are dispersedly
formed in the γ matrix and then γ" plates grow along the <110> direction. When
Ni-14.5at%V-8.8.at%Ge alloy is isothermally annealed at 1023 K, first spherical γ' particles
precipitate homogeneously in the γ matrix, followed by the formation of lamellar structure of γ"
phases. In the course of further ageing, the lamellar structure develops, and only γ' particles around
the lamellar structure grow and others gradually fade out.
Sensitivity to Fatigue Cracks Initiation of Symmetrical <110>Tilt Grain Boundaries in Pure Copper Bicrystals in 1M NaNO2 Solution
Authors: Miyamoto Hiroyuki , Kuroda K. , Mimaki Takura
Published: March 2009

Sensitivity to corrosion fatigue (CF) crack initiation has been investigated in a series of pure copper bicrystals with a symmetrical <110>-tilt grain boundary. Tests were performed by axial tension-compression tests in 1M NaNO2 solutions. The small-angle tilt bicrystals fractured in both intergranular and transgranular manners accompanied by a large amount of plastic strain to fracture while the large-angle bicrystals fractured in almost intergranular manner with a smaller plastic strain. Susceptibility to CF cracks increases with increasing misorientation. It seems that effect of grain boundaries structures, i.e., Σ-values is small in this experiment. Stress concentration generated by the pile-up of trapped dislocations at the grain boundary could account for the high susceptibility of the intergranular cracks in large-angle grain boundaries
TEM Characterization of 2º Tilt Grain Boundary in Alumina
Authors: Tochigi E. , Shibata Naoya , Nakamura Atsutomo , Yamamoto Takahisa , Ikuhara Yuichi
Published: March 2009

Dislocation structure of {1120}/<1100> 2º tilt grain boundary in alumina was observed by
transmission electron microscopy (TEM). The grain boundary consisted of periodical array of basal
dislocations, which were dissociated into pairs of 1/3<1010> and 1/3<0110> partials with {1120}
stacking-fault in between. The relationship between the separation distance of partials and the
stacking-fault was modeled by considering the force balances of periodical dislocations. The
estimated stacking-fault energy for 2o tilt grain boundary was consistent with the previous reports.
First-Principle Study of Sulfur Adsorption on Ir(100) Surface
Authors: Ma S.H. , Zu Xiao Tao
Published: March 2009

The atomic sulfur adsorption on the metastable, unreconstructed Ir(100) surface is studied
from density functional theory calculations with two exchange correlation functionals. The fourfold
hollow site is energetically preferred for both the p(2×2) and c(2×2) structures. Based on the most
favored adsorption georemetries, vibrational frequency and work function are also calculated.
Moreover, a detailed comparison is presented between two functional performances.
Dislocation Structure Analysis of Low Angle Tilt Grain Boundaries in Alumina by Elastic Theory
Authors: Nakamura Atsutomo , Tochigi E. , Shibata Naoya , Yamamoto Takahisa , Ikuhara Yuichi
Published: March 2009

Structure and configuration of boundary dislocations on the low angle tilt grain boundaries
in alumina were considered based on the ideas that the boundary is composed of regularly arrayed
edge dislocations and that the dislocations could dissociate into partial dislocations as well as glide
dislocations in bulk. Moreover, the structure of the dissociated boundary dislocations were evaluated
by the calculations based on an elastic theory. The calculations indicated that the largeness of the
stacking fault region between partial dislocations formed by the dissociation will decrease with
increasing tilt angles. It can be said that the idea and calculations used here will be powerful in
considering the dislocation structure of low angle tilt grain boundaries that are not or are difficult to be
identified.
Investigation on Fatigue Crack Growth Behaviour in S45C Steel by Water Cavitation Peening with Aeration
Authors: Han B. , Ju Dong Ying , Nemoto Tetsuya
Published: March 2009

Water cavitation peening (WCP) with aeration is a recent promising method in the
surface enhancement technique, which can induce compressive residual stress in the near surface of
mechanical components by the bubble collapse on the surface of components in the similar way as
conventional shot peening. In this paper, the effect of WCP on fatigue crack growth behavior was
investigated in single-edge-notched flat tensile specimens of S45C steel. The notched specimens
were treated by WCP, and the compressive residual stress distributions in the near surface layer
were measured by X-ray diffraction method. The tension-tension (R = Smin/Smax = 0.1, f = 10 Hz)
fatigue tests were conducted. A Shimadzu servo-hydraulic fatigue test machine with in-situ
observation by JSM-5410LV scanning microscope was used for all testing. Compared with those
without WCP treatment, WCP can induce the residual compressive stress in the near surface layer,
and delay the fatigue crack initiation, and decrease the rate of fatigue crack growth.
Effect of Processing Route on Microstructure and Texture Development in ECAP of Al-Ti Alloy
Authors: Watanabe Yoshimi , Sequeira P.D. , Sitdikov Oleg , Sato Hisashi , Zhang Zuo Gui , Kim Ick Soo
Published: March 2009

Microstructure and texture evolution during equal channel angular pressing (ECAP) of
Al-5 mass%Ti alloy are investigated for up to 8 passes via routes A and BC. Platelet-shaped Al3Ti
particles in the Al-5mass%Ti alloy are cracked severely with repetitive ECAP passes, and the mean
size of the Al3Ti particles is decreased with increasing the number of ECAP passes.
Microstructural observation showed that an Al–Ti supersaturated solid solution is formed during the
ECAP process. It is also found that the Al-Ti alloy after ECAP by route A and route Bc methods
have very different microstructures. Namely, after ECAP by route Bc, the fine Al3Ti particles are
homogeneously dispersed in Al matrix, while the microstructure has highly anisotropic distribution
after ECAP by route A.
Changes in the Mechanical Properties and Microstructure of AZ91 Cast Mg Alloy Caused by Heat Treatment
Authors: Fujii Kaname , Kawabata Tokimasa , Matsuda Kenji , Ikeno Susumu
Published: March 2009

Changes in the mechanical properties on AZ91 Mg alloy cast into sand mold caused
by heat-treatment and its microstructure were investigated by the tensile test and observation
using optical and scanning electron microscopes, and chemical composition analysis. Tensile
test results show that the specimens aged at 441K have larger elongation than those of aged at
489K, although they had same proof stress. The fracture surface observation reveal the cleavage
fracture of aged specimen caused by the nodular structure as well as the formation of micro void
around the coarse spheroidal Al-Mn-(Fe) phase.
Microstructure Sensitive Design and Quantitative Prediction of Effective Conductivity in Fuel Cell Design
Authors: Garemstani Hamid , Li Dong Sheng , Khaleel Moe A.
Published: March 2009

Statistical continuum approach is used to predict effective conductivity of anisotropic
random porous heterogeneous media using two-point correlation functions. Probability functions
play a critical role in describing the statistical distribution of different constituents in a
heterogeneous media. In this study a 3-dimensional two-point correlation function is utilized to
characterize the anisotropic porous media of a Cathode materials to incorporate all the details of the
microstructure. These correlation functions are then linked to the effective properties using
homogenization relations. An anisotropioc Green’s function solution is used to solve the set of
field equations. Examples in this study demonstrated how the model captured the anisotropy in
effective conductivity of the random heterogeneous media. Predicted results showed the influence
of microstructure on the effective conductivity tensor.
Microstructure and Deformation Behavior of Lamellar Ti-Rich TiAl Crystal with Lotus-Type Aligned Pores
Authors: Nakano Takayoshi , Tachibana Takahiro , Hagihara Koji , Umakoshi Yukichi , Ide Takuya , Tane Masakazu , Nakajima Hideo
Published: March 2009

A porous Ti-48.0at.%Al (Ti-rich TiAl) crystal, in which lotus-type long cylindrical pores
were aligned and (γ/α2) two-phase lamellar structure was simultaneously developed, was fabricated
by floating zone method under the pressure of hydrogen and helium mixed gas. Plastic deformation
behavior and microstructure of the Ti-rich TiAl crystal with lotus-type aligned pores were
investigated by focusing on the elongated pore direction. The as-grown and annealed crystals show a
well-developed lamellar structure and no texture accompanied by 52% porosity and a mean pore
diameter of 380 μm. Yield stress strongly depends on the loading direction against the elongated
pore. When loading directions are parallel and perpendicular to the pore direction, yield stresses obey
K=1 and 2.5, respectively, in equation of σ=σ0(1-p)K, where σ is the yield stress with pores, σ0 is the
yield stress without pores and p is porosity. This reflects macroscopically homogeneous and locally
heterogeneous plastic deformation between pores, respectively.
Microstructures Evolution of a Ni-Base Superalloy after Long-Term Aging at 750°C
Authors: Cui Tong , Wang Ji Jie , Chen Li Qing , Zhao Guang Pu , Yang Hong Cai
Published: March 2009

The microstructures evolution of a new type Ni-base superalloy has been investigated
after long-term aging at 750°C for 2000h. The results indicate that TCP, a harmful phase greatly
affects the mechanical properties of the alloy, is un-precipitated in the aging process. γ´ phase is
precipitated in two kinds of sizes during long-term aging. The shape of larger one is transit from
spherical to cubic with prolonging of aging time. The M23C6 carbide formed mainly by Cr, and other
elements such as Al, Ti, Co and Mo is also precipitated in both γ matrix and grain boundaries, and
the quantities of the carbide increase gradually with the increasing of aging time.
Effect of Third Elements on Pseudoelastic Behavior in Fe3Al Single Crystals
Authors: Yasuda Hiroyuki Y. , Kase T. , Minamiguchi S. , Yokoyama A. , Umakoshi Yukichi , Bronsveld P.M. , de Hosson Jeff T.M.
Published: March 2009

The pseudoelastic behavior of Fe3Al single crystals doped with an extra element (e.g. Ti, V,
Cr, Mn, Co, Ni, Si, Ga, Ge) was investigated. In binary Fe-23.0at.%Al crystals with the D03 structure,
1/4[111] superpartial dislocations moved independently dragging the nearest-neighbor anti-phase
boundaries (NNAPB) during loading. During unloading, the NNAPB pulled back the superpartials
decreasing its energy resulting in a giant pseudoelasticity of which the recoverable strain is about 5 %.
Addition of a third element significantly affected the pseudoelastic behavior of Fe3Al single crystals.
Mn- or Ga-doped crystal demonstrated a giant pseudoelasticity. In particular, Ga-doping was found to
be effective in the enhancement of the pseudoelasticity. On the other hand, the amount of strain
recovery decreased upon doping of the other elements. The frictional stress of the superpartials, the
back stress of the NNAPB and ordered domain structure in the crystals changed upon doping, which
was closely related to the pseudoelastic behavior.
Influence of Electrical Parameter on the Size of Superalloy Powders Prepared by Spark Plasma Discharge Process
Authors: Yu Jun , Ge Chang Chun , Ni Guo Hua , Meng Lu Lu , Shen Wei Ping , Meng Yue Dong
Published: March 2009

Superalloy powders, which have a small particle size and spherical shape, were prepared by
a spark plasma discharge process. The electrical parameter, spark voltage, current and pulse duration
have very important effects on the size distribution of produced superalloy powders. When current or
pulse duration changed the mean size significantly changed.