bluuebunny/crossref_metadata_2025 huggingface dataset:
In Situ Investigation of Orientation Changes during Heating of Extruded AZ31
Authors: Yi Sang Bong , Brokmeier Heinz Günter , Homeyer Jens
Published: March 2009

The orientation changes during heating of extruded AZ31 were investigated using synchrotron Xrays
by in-situ experiments. The as-extruded sample shows a strong <10.0>-fiber texture which is
generally observed after round extrusion. The initial <10.0>-fiber texture, in which the <10.0>
direction of the hexagonal crystallites is parallel to extrusion direction, starts to change to <11.0>-
fiber component at 300 °C. The orientation change rate shows an exponential relation to the heating
temperature and the soaking time. The microstructure observations, prior and post heat treatment,
indicate that the texture changes occur mainly during grain growth.
Use of Taguchi Method to Study a Robust Design for H-Sectioned Porous Beams during Rolling
Authors: Chen Dyi Cheng , Chen Cheng Fu
Published: March 2009

Commercial DEFORMTM three-dimensional finite element (FE) code is employed to
examine the plastic deformation behavior of porous beams at the roll gap during the H-sectioned
rolling process. The simulations assume that the rolls are fully rigid and that the change in
temperature induced in the beams during rolling can be ignored. The simulations systematically
examine the respective effects of the arc radius of the H-section flange region of the upper and
lower rolls, the friction factor between the beam and the rolls, the density of the porous beams and
the radii of the upper and lower rolls on the filling ratio at the roll gap, the thickness reduction of
the rolled beam in the flange region, and the effective stress and strain distribution induced in the
rolled product. The Taguchi method is then employed to optimize the processing parameters for the
H-sectioned rolling of porous beams. Overall, the simulation results confirm the effectiveness of the
Taguchi design methodology as a means of optimizing the H-sectioned rolling process conditions.
The Effect of Transformation Plasticity on Prediction of Tooth Distortion of Heat-Treated Helical Gear
Authors: Sugianto A. , Narazaki Michiharu , Kogawara M. , Kim S.Y. , Kubota S.
Published: March 2009

The displacement profile in a shank and dedendum-addendum circle of helical gear made
of through-hardened S45C carbon steel and carburized-hardened SCr420H low alloy steel by gas
carburizing was measured and predicted using a finite element method of DEFORM-HT. Both gears
were quenched into same oil quenchant. Heat Transfer Coefficient (HTC) was taken by measuring
thermal history inside of firstly silver probe and secondly stainless steel SUS304 gear blank. Uniform
HTC of silver probe was calculated by lumped heat capacity method, whereas zone-based HTC of
SUS304 gear blank was calculated by iterative modification method. Transformation plasticity was
included and excluded to predict the tendency of distortion. Simulation results were analyzed and
compared to the experimental results to validate the influence of transformation plasticity on the
prediction of distortion during the martensitic and bainitic/pearlitic transformation. However, more
accurate distortion profiles require detailed HTC by taking thermal history on the surface of the tooth.
Surface Energy of In-Doped ZnO Studied by PAW+U Method
Authors: Gu You Son , Qi Jun Jie , Zhang Yue
Published: March 2009

Surface energies of indium doped ZnO were calculated to explain the polarized growth of ZnO
nanodisks due to indium doping. Calculation results show that the surface energy of ZnO (0001) surface is
much larger than that of ZnO (10 1 0) surface, leading to a preferred growth direction of [0001] for pure ZnO.
At a doping rate of 1/8, the surface energies of indium doped ZnO are greatly reduced, but the surface energy
of (0001) surface is still larger than that of (10 1 0) surface. At a doping rate of 1/4, the surface energies are
decreased further, and the surface energy of (0001) surface is lower than that of (10 1 0) surface. Hence,
growth of ZnO along [10 1 0] direction is made possible by heavy indium doping.
The Motion of Dislocation in Iron Pinning by Carbon Interstitials
Authors: Shu Xiao Lin , Wang Chong Yu
Published: March 2009

The dislocation 1/2[111](1-10) in iron is constructed. The motion behaviors of dislocation
1/2[111](1-10) in iron, as well as the dislocation with the Carbon located in dislocation core, are
simulated by the molecular dynamics method with a modified analytic embedded atomic method
(MAEAM). The carbon atoms are easy captured by the dislocation core and they can block the
dislocation moving. After the carbon atoms are separated from the dislocation, the moving velocities
of the dislocation are similar as the case of single dislocation.
Parameter Identification of Thermal Visco-Plastic Model Considering Dynamic Recrystallization
Authors: Jin Quan Lin , Zhang Yan Shu
Published: March 2009

A hybrid global optimization method combining the Real-coded genetic algorithm and
some classical local optimization methods is constructed and applied to develop a special program for
parameter identification. Finally, the parameter identification for both 26Cr2Ni4MoV steel and
AZ31D magnesium alloy is carried out by using the program. A comparison of deformation test and
numerical simulation shows that the parameter identification and the obtained two sets of material
parameters are all available.
Study on the Simulation of Grinding Based on Virtual Reality Technology
Authors: Yu Tian Biao , Yang Jian Yu , Gong Ya Dong , Xu F. , Liang F. , Wang Wan Shan
Published: March 2009

For properly choosing grinding parameters, predicting probable faults and processing
quality, simulation of grinding based on virtual reality technology was study. Physiognomy forming
mechanism of grinding wheel was analyzed and a 3D virtual grinding wheel models was built. Effects
to grinding wheel physiognomy by grain size and organization number were analyzed and grain
distribution was visually represented. Effect to processing quality by grinding wheel granularity,
dressing parameters, grinding wheel speed, feed speed and grinding depth was simulated. And
experiments were carried out for comparative analyzing. Experiments result proved the reliability and
practicality of the virtual grinding wheel model.
Stacking Fault Energy of Cu-Ga Alloys from First Principles
Authors: Fujita S. , Uesugi Tokuteru , Takigawa Yorinobu , Higashi Kenji
Published: March 2009

The segregation energy of solute Ga in the staking fault in Cu-Ga alloy was calculated
from the first principles. Then, we presented numerical results of the stacking fault energy for
Cu-Ga alloy using the value of the segregation energy as a input parameter to a expression in the
equilibrium state. The numerical results of the stacking fault energy were in good agreement with
the experimental values.
The Effect of Solidification Models on the Prediction Results of the Temperature Change of the Aluminum Cylinder Head Estimated by FDM Solidification Analysis
Authors: Onda Hiroshi , Sakurai Kazunari , Masuta Tatsuya , Oikawa Katsunari , Anzai Koichi , Kasprzak Wojciech , Sokolowski Jerry
Published: March 2009

This paper presents the prediction results of the temperature change during the
solidification process of the cylinder head made of the AC2A aluminum alloy. Prediction results
have been obtained by using the FDM solidification analysis based on two different solidification
models were investigated. Here, the solidification model means functional relationship between the
Temperature and the Fraction Solid. The first model is a simple Linear function and the second
model is estimated from DSC measurement. The comparison between the simulated and measured
temperatures of the aluminum cylinder head revealed that the selection of solidification models
significantly reflects the prediction results. The DSC model gives higher prediction accuracy of the
temperature change than the Linear model. The solidification models estimated by using Thermo-
Calc and UMSA [3] were also investigated.
First Principles Study of Point Defects in Uranium Dioxide
Authors: Chen Ying , Iwasawa Misako , Kaneta Yasunori , Ohnuma Toshiharu , Geng Hua Yun , Kinoshita Motoyasu
Published: March 2009

To clarify the origin of a characteristic fine grain structure formed under the high burn-up of the
nuclear fuel, the comprehensive first-principles calculations for UO2 containing various types of point defect
have been performed by the PAW-GGA+U with lattice relaxation for supercells containing 1, 2 and 8 unit
cells of UO2. The electronic structure, the atomic displacement and the defect formation energies of defective
systems are obtained, and the effects of supercell size on these properties are discussed. Based on this
relatively high precise self-consistent formation energies dataset, thermodynamic properties of various types
of point defects in UO2 are further investigated in the framework of the point defects model.
Modeling of Contact Pressure in Sheet Metal Forming
Authors: Pereira Michael P. , Yan Wen Yi , Rolfe Bernard F.
Published: March 2009

For a given sheet metal forming process, an accurate determination of the contact
pressure distribution experienced is an essential step towards the estimation of tool life. This
investigation utilizes finite element (FE) analysis to determine the evolution and distribution of
contact pressure over the die radius, throughout the duration of a channel forming process. It was
found that a typical two-peak steady-state contact pressure response exists for the majority of the
process. However, this was preceded by a transient response, which produced extremely large and
localized contact pressures. Notably, it was found that the peak transient contact pressure was more
than double the steady-state peak. These contact pressure results may have a significant influence
on the tool wear response and therefore impact current wear testing and prediction techniques.
Hence, an investigation into the validity of the predicted contact pressure was conducted.
Heat and Mass Transfer in the Process of EB Penetration
Authors: Ho Je Ee , Ho Ching Yen
Published: March 2009

The incident energy flux impinged on the free surface of liquid layer was considered to be
balanced with the latent heat in evaporation and the heat in directional conduction but neglecting
convective heat transfer due to a small Peclet number at the cavity base. The quasi-steady state
model was developed in this study to analyze the effect of the energy density during the penetration
process and an exponential expression for penetration velocity as a function of liquid-thickness and
temperature was also derived. The penetration velocity versus energy density calculated by the
present model showed good agreements with the experimental data for drilling copper, which the
relative errors between the calculated and the experimental data are less than 15%. By the setup of
non-uniform grids distribution in numerical method, this work had successfully predicted the
variation of the penetration velocity with energy density distribution. The effects of the energy
density on flow rate, thickness of liquid layer, base temperature of fusion zone had also been
discussed in this study.
Stress Distribution in Be Compact Tension Specimen
Authors: Li Rui Wen , Dong Ping
Published: March 2009

Beryllium (Be) is susceptible to introduce stress because it is a brittle metal with a high
elastic modular. The compact tension (CT) specimens of beryllium were designed to determinate
stress and fracture behaviors. Stress distribution near notch in CT beryllium was measured by the
combination of an X-ray stress analysis and a custom-designed load device. The results show that
local stresses near notch tip are much higher than those on other area. Thus, stress concentration lead
the CT specimens fracture along the notch direction. Residual stresses due to machining are remained.
A finite element ( FE ) calculation on the same loaded geometry was made, and the result is agreement
with the measured stress distribution near notch.
"In Situ-Tracking” Observation of Stainless Steel Microstructural Development during Elevated Service Using EBSD and SEM
Authors: Huang Ya Ming , Fu Qiang , Pan Chun Xu
Published: March 2009

Electron backscatter diffraction (EBSD) has been developed as a novel technique for
characterizing crystallographic textures in recent years. The present paper proposes an
“in-situ-tracking” approach using SEM and EBSD to examining the microstructural development and
grain boundary variation of stainless steel during elevated 1200 °C service. The results revealed that in
addition to the coarsened grains the fraction of low angle grain boundaries (LABG) became increased
and flattened obviously during service. Comparing to the regular high temperature service (below 900
°C), the present “recovery and recrystallization” process was accelerated due to dislocation fastened
movement and intensive interaction. However, the grain growth mechanism still meet the
well-accepted dislocation model of subgrain combination.
Site-by-Site Electronic Structure Analysis of Al-Containing Complex Compounds Using Channeling EELS and First Principles Calculations
Authors: Tatsumi Kazuyoshi , Yamamoto Yu , Muto Shunsuke
Published: March 2009

Al K ELNES of oxide ceramics, which show reverse spinel and garnet structures
containing two types of Al sites, are investigated site-selectively using TEM-EELS under electron
channeling conditions. We applied a self-modeling curve resolution (SMCR) technique to separate a
set of experimental spectra into individual spectra of individual atomic sites. The refined spectra after
SMCR were in consistent with the theoretical spectra obtained by the first principles electronic
structure calculations. The spectral difference of the six-coordinated aluminum between the two
materials was discussed in terms of the cationic coordination.
A Study on the Microstructure of Ultra Low Carbon Bainitic Steels by RPC Technique
Authors: Wang Zhi Fen , Pu Shao Kang , Guan Y. , Li Ping He , Wu Li Xin , Chen Qing Feng
Published: March 2009

The effect of tempering process on the microstructure of ultra low carbon bainitic (ULCB)
steel produced by relaxation precipitation controlled phase transformation (RPC) has been
investigated by transmission electron microscopy (TEM) and electron backscattered diffraction
(EBSD). The results showed that the final microstructure mainly contained lath-like bainitic ferrite,
granular bainite and martensite-austenite (MA) constituent in ULCB steels. On tempering at 650°C a
slight increase was detected in the effective grain size as the strain-induced precipitates pinned up the
dislocation walls and subgrains. After tempering at 700°C, bainitic ferrite laths started to coarsen and
polygonal ferrite occurred. The effective grain size of ULCB steels in as-rolled condition was 1.5 μm
at the tolerance of 10o~15o measured by EBSD technique.
In Situ Analysis of Phase and Magnetic Transformation Process in Fe-Pt Nanoparticles
Authors: Nakanishi Masatoshi , Sasaki Katsuhiro , Saka Hiroyasu , Kuroda Kotaro
Published: March 2009

The process of phase transformation in individual Fe-Pt and Fe-Pt-Cu nanoparticles
synthesized by the reverse micelle method with chemical homogeneity and mono-dispersion has
been investigated by in-situ high-resolution electron microscopy (HREM) observation and in-situ
nano-beam diffraction (NBD). The Fe-Pt particles, initially polycrystalline with the chemically
disordered fcc (A1) phase, were reconstructed into A1 single crystals between 550 and 650°C,
followed by a phase transformation from A1 to the chemically ordered fct (L10) phase between 650
and 680°C. The coalescence began almost concurrently with the phase transformation. They
were transformed into round-shaped single-crystalline particles between 680 and 720°C. Similar
processes were also observed in the Fe-Pt-Cu nanoparticles. The temperatures at which these
processes occurred were substantially lower than those required for the Fe-Pt nanoparticles. We
investigated the magnetic-field distribution of a submicron-size island comprising isolated L10
Fe-Pt nanoparticles magnetized along one direction by using in-situ electron holography at elevated
temperatures. Although the magnetization decreased between 212 and 412°C to 25% of the
strength at 25°C, it recovered 67% of the initial strength during cooling. However, when an island
was heated to 512°C, the magnetization diminished and did not recover during cooling. The Curie
temperature (Tc) was determined to be 350°C and was in good agreement with the Tc determined
by bulk measurements, which was approximately 100°C lower than the Tc for bulk Fe55Pt45.
Thermal Degradation and Kinetic Characterizations of Jatropha Waste under Isothermal and Dynamic Experiments
Authors: Sricharoenchaikul Viboon , Atong Duangduen
Published: March 2009

Thermal decomposition characteristic of waste material from oil extraction of Jatropha
(physic nut), including shell and kernel, was investigated using thermogravimetric analysis (TGA)
and pyrolysis experiments. Effects of heating rate (5-90°C/min), reaction temperature (500-900°C)
and hold time at final temperature (3-15 min) on the feature of thermogram, kinetic parameters as
well as product distribution were evaluated. Thermal conversion of this residue composed of
cellulose, hemicellulose, and lignin degradation steps with maximum weight losses around 250 to
450°C. The order of reaction increased with temperature from 0.28 at 250°C to 0.81 at 450°C. The
activation energies ranging from 105-184 kJ/mol depend on the stage of devolatilization. The
amount of gas product increased with temperature with the expense of reducing char and liquid
from secondary heterogeneous cracking reactions. More than 14% of hydrogen in residue was
converted to H2 during pyrolysis at 900°C. Major hydrocarbon gases are those of C4+ species with
measurable amount of CH4 and C2 derivatives. Increase in reaction temperature can lead to a
noticeable increase of hydrogen and hydrocarbon gas yields. Addition of catalyst and steam would
promote the formation of fuel gas from this waste material.
High Cycle Fatigue Behavior of Thermally Oxidized Ti6Al4V Alloy
Authors: Cingi Mehmet , Meydanoglu Onur , Guleryuz Hasan , Baydogan Murat , Çimenoğlu H. , Kayali S.
Published: March 2009

In this study, the effect of thermal oxidation on the high cycle rotating bending fatigue
behavior of Ti6Al4V alloy was investigated. Oxidation, which was performed at 600°C for 60 h in
air, considerably improved the surface hardness and particularly the yield strength of the alloy
without scarifying the tensile ductility. Unfortunately, the rotating bending fatigue strength at 5x106
cycles decreased from about 610 MPa to about 400 MPa upon oxidation. Thus, thermal oxidation
leaded a reduction in the fatigue strength of around 34%, while improving the surface hardness
(HV0.1) and yield strength 85 % and 36 %, respectively.
Determination of Material Constants for Crack Size-Dependence Crack Growth Model
Authors: Tiong U.H. , Jones Rhys , Molent Lorrie
Published: March 2009

A crack size-dependence crack growth model was used to characterise the fatigue crack
growth in AL 7075-T6 and AL 2024-T351 alloys. It is shown that the crack growth parameters %K
and a can be used to linearise the crack growth in regions I (elastic) and II (plastic) by plotting
fatigue data linear-linear da/dN×√a versus %K3, where cubic stress dependency is assumed. A
theoretical attempt was made to relate this crack size-dependence fatigue crack growth parameters
to the strain-life relationship constants. A reasonably good agreement was achieved when
comparing between the theoretical predicted and experimental determined material constants.
Acoustic Emission as Analyzing Tool for Wear Mechanisms of Composite Materials
Authors: Quintelier Jan , Degrieck Joris , Samyn Pieter , De Waele Wim , Kalogiannakis Georgios , Van Hemelrijck Danny
Published: March 2009

This article summarizes the efforts done for using acoustic emission as wear mechanisms
monitoring technique for wear testing in a pin-on-disc setup. The basic characteristics of the
mechanisms were previously determined via controlled tensile testing (fiber breakage, debonding
…). The knowledge of these basic characteristics then resulted in an easier classification of wear
mechanisms related to wear testing of pultruded glass fiber reinforced polyester.
Fatigue and Damage Testing Rubber with Steel Cord Materials Combined
Authors: Kopecky Miroslav
Published: March 2009

The contents of the paper point out the necessity of combining the theoretical and
experimental approaches in the investigation of tyre load in vehicles.
The models are planar and they model the cross-section of the tyre enabling the consideration of
the bottom load and the internal pressure in the tyre, as well as the influence of the lateral force.
The paper presents the findings, the formulations necessary for solving the task obtained in the
experimental model tests and serving as a basis for comparison with the results obtained from
purely theoretical approaches, e.g. by the method of finite elements, with identical load conditions.
The steel cords reinforcing motor vehicle tyres are unevenly loaded in time as the tyre is in
operation and in contact with the road surface.
The conditions for conducting and evaluating experimental tests that would model the considered
loading of the steel-cord-reinforced tyre have been defined.
To be able to conduct these experimental tests, it was necessary to design simple test equipment for
cyclic loading of the test specimens.
Thermoelastic Analysis of Crack Propagation in AA6082 Friction Stir Welded Joints
Authors: Di Sante Raffaella , Cavaliere Pasquale , Rossi Gian Luca , Squillace Antonio
Published: March 2009

Thermolastic Stress Analysis (TSA) has been recently developed as a direct investigating
method for the study of the stress field around the crack tip of a cyclically loaded structure. The
advantage of using measurement techniques based on the thermoelastic effect lays in the fact that
stress intensity factors may be determined based on the effective stress distribution around the crack
tip rather than calculated from the crack length and amplitude of cyclic loads. This paper reports
results related to fatigue tests on Friction Stir Welded alluminium alloys sheets. Fatigue crack
propagation experiments were performed by employing single-edge notched specimens, in tensiontension
condition with R=0.1, up to failure. The application of TSA allowed the monitoring of crack
formation and growth in real time, providing the actual stress distribution around the crack tip for
the different technological parameters used in the welding process. Stress intensity factors were
determined based on the TSA data and compared to those calculated using an ABAQUS FE model.
Laser Rapid Forming of Ti-Ni Functionally Graded Alloy
Authors: Xu Xiao Jing , Lin Xin , Chen Jing , He Fei , Huang Wei Dong
Published: March 2009

Ti-Ni based functionally graded alloy is a kind of the promising material, which has
potential to be used in aero engines. Using laser rapid forming, a Ti-Ni graded alloy with a continuous
compositional gradient from pure Ti to Ti-50wt.%Ni were fabricated. On comparison with the graded
alloy, a series of homogenous deposits with the typical composition between pure Ti to Ti-50wt.%Ni
were also laser rapid formed. The phase evolution along the compositional gradient direction in the
graded alloy is: α+β→β+Ti2Ni →(TiNi +Ti2Ni)+ TiNi; and the phase evolution in the corresponding
compositional homogeneous deposit is: α+β→ β+(β+Ti2Ni)→ β+Ti2Ni+(β+Ti2Ni)→
(TiNi+Ti2Ni)+TiNi. The phase transformation and microstructural evolution along the compositional
gradient were analyzed by using the microstructure selection map.
Precipitation in Aged N-Containing Austenitic Stainless Steels
Authors: Saucedo-Muñoz M.L. , Victoria-Hernández V.M.
Published: March 2009

Three types of austenitic stainless steels JK2, JJ1 and JN1 were isothermally aged at
temperatures from 873 to 1173 K for 10 to 1000 minutes in order to study the microstructural
evolution. In general, the kinetics of precipitation for JN1 steel was faster than that of JJ1 steel,
because of its higher interstitial solute content. The TTP diagrams showed that the intergranular
precipitation of M23C6 and M2N preceded to the intragranular precipitation of M2N and M2N and η
phase in JN1 and JJ1 steels, respectively.
Design of Structure, Composition and Heat Treatment Process for High Strength Steel
Authors: Hsu T.Y. , Xu Zu Yao
Published: March 2009

For steel with combination of high strength (~2000MPa) and toughness, along with low
cost, the designed structure should be low-temperature tempered, fine lath martensite with high
density of dislocation, coated by film of austenite with considerable thickness and distributed with
fine ε (η) or (and) complex carbide. Correspondently, the steel should contain less than 0.5 (wt%) of
carbon, certain amount of alloying elements for lowering Ms, such as Ni, Mo and (or) Mn, carbide
forming element, e.g. Nb, as well as Si or (and) Al, the element depressing the formation of
cementite, the brittle phase in high strength steel. The heat treatment process is suggested as:
austenitizing at a temperature slightly above Ac3, followed by quenching at Ms-Mf, partitioning either
at quenching temperature or at slightly above Ms for a few minutes, cooling down to room
temperature and tempering at low temperature about half an hour.
Interfacial Structural Modification of Martensitic Transformations
Authors: Meng Q.P. , Chen N.
Published: March 2009

The free energy function of martensitic transformation is established using Landau
polynomial. According to the free energy function, the interfacial structural modification of
austenite-martensite with the chemical driving force of martensitic transformation and elastic
constants of materials is discussed. Some characteristics of martensitic transformation, such as the
difference between thermoelastic and nonthermoelastic martensitic transformation, martensitic
growth, are explained.
Microalloying Effects of Ca, Ag, Ni and Zn on Mechanical Properties in an Mg-3mass%Y Alloy
Authors: Suzuki Mayumi , Tsuchida Kayo , Maruyama Kouichi
Published: March 2009

Microstructures and Vickers hardness have been investigated in hot-rolled Mg-3mass%Y based
solid solution alloys containing microalloying elements (Ca, Ag, and Ni). Transmission electron micorscope
(TEM) observations have revealed that the stacking faults on the (0001) magnesium matrix planes have been
observed in Mg-Y-Zn based alloys and the stacking fault (SF) density depends on other additional
microalloying elements. In single addition of Zn to the Mg-Y alloy, SF density increases with increasing Zn
content and was saturated over 0.5 mass% addition. On the other hand, in simultaneous addition of Zn and Ca,
SF density increases with increasing Ca content significantly. Many precipitates were observed in Ni and Ag
added Mg-3Y-0.5Zn alloys and their SF densities were lower than Mg-3Y-0.5Zn. Vickers hardness increased
by the simultaneous microalloying of Zn and Ca, while Ag showed a negative effect for hardness in
Mg-3Y-0.5Zn (in mass%) ternary alloy. The dense SF density could act as obstacles to the dislocation motion
so that SF density has positive relationship in the Vickers hardness.
Textures in AZ31 Magnesium Alloy Induced by Repeated Cross Wavy Rolling
Authors: Yamamoto Atsushi , Tsukahara Yuichiro , Fukumoto Shinji
Published: March 2009

A new technique has been developed, which enables one to randomize the basal plane
texture formed in wrought magnesium alloys, AZ31B. Rolls with about 60 mm in diameter having
wavy surface of 8 mm in wave length and 3 mm in peak to valley depth were used. The peak lines
were perpendicular to the roll axis. The alloy sheet specimen of 50 x 50 mm with 2.5 mm in
thickness was heated at temperatures ranging from 623 to 723 K, and then immediately wavy-roll
formed. The specimen was re-heated at the same temperature, and then wavy-roll formed with
rotating at 90 degree. Such a process was repeated at eight times, then finally flat-rolled with a
slight reduction. Electron backscattered diffraction analyses showed that the basal plane texture
was predominantly formed in the start material, while after the cross wavy roll-forming,
accumulation of basal plane tended to be diffusely distributed.
Influence of Repeated Quenching After Carburizing on Prior Austenite Grain Size
Authors: Fujimatsu Takeshi , Nishikawa Motohiro , Hashimoto Kazuya , Yamamoto Atsushi
Published: March 2009

High strengths and impact values are required for carburizing steels used for automotive
drive train parts. It is well known that the finer-grain microstructures are favorable for these
properties. In this study, with a view to effective refining of grain size with controlling the alloying
elements, influence of Mn and Cr content on prior austenite grain size after carburizing and
repeated quenching was investigated on Ti-modified carburizing steels with ferrite and pearlite
microstructure. It was found that the increase in Mn and Cr contents in steels were effective for the
grain refining. These effects were attributed to fine ferrite and pearlite microstructure caused by the
lowered Ar3 point due to higher Mn content, and retarding the grain growth of austenite by the fine
dispersion of carbides in the carburized layer of specimen due to higher Cr content.
Hydrogen Diffusivity and Permeability In Pd50-xTi50(Cr, Fe)x Alloys
Authors: Yoshinari Osamu , Itoh Daisuke
Published: March 2009

Hydrogen diffusivity (D) and permeability (q) in Pd50-xTi50(Cr, Fe)x alloys were
measured at temperature range between 570 and 770 K. During a heating measurement of
Pd47Ti50Cr3 alloy, both D and q abruptly increased by factors of 5 and 2, respectively, at 712 K,
with a phase transformation from B19 to B2 structures. However, q was far smaller than those in
pure bcc metals (eg. V, Nb and Ta), where the hydrogen atoms occupy the tetrahedral interstitial
sites. A first-principles calculation revealed that hydrogen atoms occupy the octahedral interstitial
sites in Pd50Ti50 with B2 structure. It is concluded that the small hydrogen diffusivity in B2
Pd50-xTi50(Cr, Fe)x alloys is due to the long distance hydrogen jump and the resultant high activation
energy for the diffusion.
Two-Phase Microstructures Formed by Phase-Separations of Ordered Precipitates in Fe-Si-V Alloys
Authors: Doi Minoru , Moritani Tomokazu , Kozakai Takao
Published: March 2009

Phase-separation of D03 precipitates in A2 matrix of Fe-Si-V alloys was investigated with
TEM. When Fe-14.5at%Si-12.9at%V alloy is aged at 873 K, the phase-separation of cuboidal D03
precipitates occurs and A2 particles newly appear in each D03 cuboid. The A2 particles grow to
become plates, then the A2 plates elongate along {100} to reach the A2 matrix, and finally the split of
D03 cuboid is realized to form smaller cuboids. When Fe-15.5at%Si-5.0at%V alloy is aged at 873 K,
the phase-separation of rod-shaped D03 precipitates occurs and A2 particles newly appear in each D03
rod. The A2 particles elongate along the long axis of D03 rod to reach the A2 matrix, and the split of
D03 rod is realized to form thinner rods. The split in each alloy brings the refinement of two-phase
microstructure, which is a result of not only the elastic energies but also the chemical free energy.
Improvement of Surface Roughness on ABS 400 Polymer Using Design of Experiments (DOE)
Authors: Horvath Daniel , Noorani Rafiq , Mendelson Mel
Published: March 2009

The objective of this research was to find the best combination of factor levels that minimized the
surface roughness of prototyped samples from Fused Deposition Modeling (FDM). Two sets of
experiments were conducted for that purpose; a two-level three-factor full factorial experiment and
a three-level two-factor full factorial experiment. The parameters chosen for this research were
model temperature, layer thickness and part fill style. The results obtained from both experiments
were compared and analyzed in order to determine the best combination of factors that minimized
the surface roughness of the specimens. The significant factors, their interactions and the optimum
setting are presented in this paper
Structural and Electrical Properties of ZnO Films on Freestanding Thick Diamond Films
Authors: Sun Jian , Bai Yi Zhen , Sun Jing C. , Yang Tian P. , Du Guo T. , Jiang Xin
Published: March 2009

In this paper, ZnO films are deposited on Freestanding Thick Diamond (FTDF) by
plasma-assisted Metal Organic Chemical Vapour Deposition (MOCVD). Diethyl zinc, O2, and N2O
are applied as precursors and different substrate temperatures are used to achieve high quality ZnO
films. The influence of substrate temperature on the properties of ZnO films is systematically
investigated by X-ray diffraction, Hall measurements, and electron probe microanalysis.
Experimental results demonstrate that ZnO films deposited at 600°C and 73Pa displays fine electrical
quality and Zn/O atomic ratio plays an important role in the electrical property of ZnO films.
HRTEM Observation of Rod-Shape Precipitates in Al-Mg-Si-Ag Alloy Aged at 523 K
Authors: Nakamura Junya , Matsuda Kenji , Nakamura Yoshio , Sato Tatsuo , Ikeno Susumu
Published: March 2009

The purpose of this study is to identify the crystal structure of metastable phase in Ag
added Al-Mg-Si alloy to compare the formation of β’-phases in Al-Mg-Si alloys without Ag, using
images of high resolution transmission electron microscope (HRTEM), selected area electron
diffraction (SAED) patterns and an energy dispersive X-ray spectroscopy (EDS). The result of
SAED patterns and HRTEM images have been simulated and compared with images then SAED
patterns obtained from actual precipitates. SAED patterns and HRTEM images obtained from
metastable phase in the Ag added Al-Mg-Si alloy showed similar to those of β’-phase in Al-Mg-Si
alloy without Ag and the lattice spacings changed because of the effect of Ag.
Study of Metal Coating on Lead-Free High Refractive Index Glass Prepared from Local Sand
Authors: Dararutana Pisutti , Sirikulrat Narin
Published: March 2009

Lead-containing glasses coated with lead metal have been used for decoration in Thailand
for a long time, were a high refractive index glass. Due to harmful effects of lead, time degradation
of glass and because of many kinds of local raw materials for glass production especially sand,
colorless lead-free high refractive index glasses were prepared by using local raw materials. In this
work, the various kinds of metals; silver and aluminum, were coated on the surface of the prepared
glasses using both chemical and physical methods. The joining interfacial layer between the glass
body and the coated layer was studied using a scanning electron microscope and the hardness of the
coated glasses was measured by a microhardness tester to compare with those of lead coating. It
was found that the structures between the joining interfacial layers were similar. The values of the
Knoop hardness were approximately 520±20 kg/mm2. This glass can be used to replace the lead
glass for restoration glass or decoration onto the surface of the new wood or the metal carving
products.
Characterization of Coating Morphology and Heat-Resistance in Plasma Electrolytic Oxidation of Magnesium Alloy
Authors: Wang Li Shi , Pan Chun Xu , Cai Qi Zhou , Wei Bo Kang
Published: March 2009

This paper reports the heat-resistance of plasma electrolytic oxidation (PEO) coatings
formed on AZ91D alloy in phosphate electrolytes (P-film) and silicate electrolytes (Si-film). The
results showed that the P-film was mainly composed of MgAl2O4, MgO and the Si-film was
composed of Mg2SiO4, MgO. Thermoanalysis results verified that all these phases contained in the
two type coatings had excellent thermal stability below 800oC. Meanwhile, the total area of heat
erosion formed on the surface of samples tended to be increased with the exposure time prolonged in
high temperature (410 oC and air atmosphere).
Effects of Laser Processing Parameters on Grain Boundary Character Distribution and Corrosion Resistance of Austenite Stainless Steel
Authors: Yang Sen , Kokawa Hiroyuki , Wang Zhan Jie
Published: March 2009

In order to modify grain boundary character distribution (GBCD) and to improve
intergranualr corrosion (IGC) resistance of 304 stainless steel, laser surface remelting experiments
were conducted on 304 stainless steel using a 2kW CW Nd: YAG laser, and the effects of laser
processing parameters on GBCD and corrosion resistance were investigated in detail under the
optimal annealing condition (1220K 28h). The experimental results showed that combination of laser
surface remelting and the following annealing treatment could change the GBCD remarkably and
improve the IGC resistance of 304 stainless steel. However, there are no obvious effects of laser
processing parameters on the final depth of the processed zone, although the depth of the molten pool
increases with the increase of the laser output power or the decrease of the scanning velocity, and the
subsequent GBCD and corrosion resistance.
Deformation Induced Ferrite Transformation in Microalloyed Steels: Theory and Application
Authors: Weng Yu Qing , Sun Xin Jun , Dong Han
Published: March 2009

Deformation Induced Ferrite Transformation (DIFT), i.e. transformation occurs
during deformation applied in the temperatures above Ar3, has received wider
attention since it has been proved to be a very effective way to produce ultrafine
grained ferrite in low carbon steels. Although numerous works have been done on this
topic in the past decade, the systematic works on DIFT in microalloyed steel,
especially on the role of microalloying elements are still lacking compared with those
in plain carbon steel. In this paper, the common features of DIFT will reviewed firstly,
then an attempt will be made to elucidate the role of microalloying elements (niobium
and vanadium) in DIFT, and the application of DIFT technology in microalloyed
steels will be presented finally.
Effects of Homogenization Treatment on Mechanical Properties of Hot-Rolled AZ31 Magnesium Alloy
Authors: Huang Xin Sheng , Suzuki Kazutaka , Watazu Akira , Shigematsu Ichinori , Saito Naobumi
Published: March 2009

The mechanical properties of the AZ31B alloy sheets processed by differential speed
rolling (DSR) from the cast ingots homogenized at two different conditions were investigated. There
still existed the uneven distribution of Al and Zn in the ingot homogenized at 673 K for 6 h, while it
was homogeneous for the ingot homogenized at 723 K for 24 h. Compare with the sheet rolled from
the ingot homogenized at 673 K for 6 h, the sheet rolled from the ingot homogenized at 723 K for 24
h exhibited a lower proof stress, a larger elongation, and a lager strain hardening exponent. The
improvement in the ductility can be attributed to the elimination of the microsegregation of Al and Zn
in the matrix.
3D Image-Based Modeling of Ductile Fracture in an Aluminum Alloy Using Synchrotron X-Ray CT Images
Authors: Qian L. , Toda Hiroyuki , Uesugi Kentaro , Kobayashi Masakazu , Kobayashi Toshiro
Published: March 2009

Traditional computational models always assume idealized crack geometry. However,
actual crack geometry is very complex in real materials and thus, those simulations do not
realistically represent the actual loading conditions of a real crack. In this paper, three-dimensional
(3D) image-based simulation was performed to investigate the fracture behavior of an aluminum
alloy, and the model takes into account the real crack geometry based on the 3D images of the crack.
Accordingly, many essential features of fracture can be identified and interpreted, and some new
insight into fracture behavior in real materials can be offered.
HREM and HAADF Studies of Precipitates in the Mg-Y-Nd Alloy System
Authors: Sun Wei , Sun Li , Liu Lin Lin , Zhang Ze
Published: March 2009

By means of high resolution transmission electron microscopy (HREM) and high-angle
annular dark-field image technique (HAADF), morphological, structural and compositional
characteristics of the precipitates in the Mg-4Y-3Nd alloy aged at 200°C for different periods of time
have been studied. On the basis of HREM observations, an atomic structural model for the
β’-precipitate with an orthorhombic unit cell has been proposed. The characteristic distribution of the
precipitates which are rich in rare-earth elements (Y, Nd) has been clearly revealed by the HAADF
imaging technique.
Phase Transformation Rule, Microstructure and Properties of JG590 High Strength Steel
Authors: Feng Yong , Sun Wei Hua
Published: March 2009

The phase transformation rule, microstructures and properties of JG590 high strength steel
produced in Jinan Iron and Steel Co. ltd. have been investigated in this paper. When the chemical
composition of steel are given, the cooling rates after finished rolling affect on the properties of steel
greatly. The yield strength and tensile strength increasing, the elongation and reduction of area
decreasing as increasing of cooling rates after rolling. The main cause is due to appearance and
increasing of Bainite and Martensite other than Ferrite and Pearlite in room temperature. The finished
rolling temperature have distinct effects upon the mechanical properties of steel plates. Finished
rolling at different temperature with the 0.5°C/s cooling rate, the tensile strength vary in 599-698MPa,
the yield strength changed from 412 MPa to 536MPa. The elongation is between 30.4-40.5%. But
when finished rolling at different temperature with the 2.0°C/s cooling rate, the tensile strength vary
in 747-784MPa, the yield strength changed from 441 MPa to 601MPa. The strength index can both
meet the requirements of employ. But the elongation is only 18.7-24.5%. This is related with
production of lots of Bainite microstructure more than 2°C/s cooling rate. In the procedure of
manufacture of JG590 high steel, the quickly cooling rate should be avoided to keep suitable
microstructure and good elongation and toughness.
Influences of Hydrogenation on Microstructure and Microhardness of Ti6Al4V Alloy
Authors: Zhao J.W. , Ding Hua , Zhao Wen Juan , Tian X.F. , Xiao H.W. , Hou Hong Liang
Published: March 2009

The microstructures of Ti6Al4V alloy after hydrogenation have been investigated and
analysed by optical microscopy (OM), X-ray diffraction (XRD) and transmission electron microscopy
(TEM), and the influence of hydrogenation on the hardness of α and β phases has been analysed by
microhardness testing. The microstructure observation revealed that δ hydride (fcc structure)
precipitated in the specimens with 0.278 wt.% and 0.514 wt.% hydrogen, and a lot of dislocations and
twins have been found simultaneously. The diffraction peaks moved to the lower angles because of
the lattice expansion of β phase with the solution of hydrogen atoms. The result of microhardness
testing shows that the hardness of α and β phases increases synchronously with increasing of
hydrogen and the increment of β is larger than that of α. It is considered that the formation of δ
hydrides, lattice defects and alloying element diffusion are the major factors leading to the
microhardness change.
Phase Analysis for Mg-Zn-Y Magnesium Alloys by Using Extraction Technology
Authors: Liu Chuan Pu , Pan Fu Sheng , Wang Wei Qing
Published: March 2009

The structure, morphology and size distribution of phases in the Mg-Zn-Y magnesium
alloys have very important effects on their mechanical properties. In this paper, the compound
powders of Mg-Zn-Y phases were obtained from as cast and as aged Mg-6.0Zn-1.2Y and
Mg-6.0Zn-0.6Zr-1.0Y magnesium alloys respectively by using of electrolysis extraction technology.
Then several tests, such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy
dispersion X-ray detector (EDX), were performed to investigate the structure and morphology of
these compound powders. The results proved that picric acid - acetic acid - ethanol electrolyte was
useful than DDTC-CAS-carbinol electrolyte in the electron extraction for Mg-Zn-Y magnesium
alloys. The XRD results showed that the Mg3Y2Zn3, Mg10Y2Zn, Mg3YZn6, Mg-Y-Zn quasicrystal
phases were obtained from Mg-6.0Zn-1.2Y magnesium alloy, and Mg3Y2Zn3, Mg10Y2Zn, ZrO2
phases were obtained from Mg-6.0Zn-0.6Zr-1.0Y magnesium alloy. The analyses of morphology and
size distribution of these phases were put forth in this paper.
Effect of Initial Microstructure under Different Solidification Conditions on Hot Working Behavior of AZ31 Alloy
Authors: Shang L. , Yue Stephen , Essadiqi Elhachmi , Javaid A. , Carter Jon T. , Verma Ravi
Published: March 2009

In order to investigate the effect of the as-cast microstructure on the hot working behavior
of an AZ31 magnesium alloy, specimens were cast in copper moulds with and without water cooling.
A series of compression tests were performed at a temperature of 350 °C, a strain rate of 0.01 s-1, and
at strains up to 1.0. It was found that as-cast microstructure is very sensitive to the solidification
conditions, which leads to a significant difference in flow behavior and dynamic recrystallization
(DRX) characteristics. It appears that more uniform and refined as-cast grain size promotes dynamic
recrystallization and reduces the flow stress. It is also possible that second phases (>1+m in size)
contribute to DRX by acting as nuclei.
Effect of TiH2 on the Microstructures and Refining Performance of Al-Ti-C Master Alloy
Authors: Zhuang Hong Yu , Pan Xue Min
Published: March 2009

Al-Ti-C master alloy with or without the TiH2 was prepared by Self-propagating
High-temperature Synthesis (SHS) induced by laser. The phases, composition, microstructure
morphologies of master alloy and its thermal reaction process were investigated by XRD, EPMA,
DTA and SEM. The results show that adding TiH2 has obvious effect in promoting the synthesizing
reaction of Al-Ti-C master alloys. Active Ti atoms and catalyzing H atoms released by TiH2 thermal
decomposition cause critical reacting temperature of the SHS decreasing. The addition of TiH2 affects
the morphologies and distribution of TiAl3 and TiC particles (size of TiC was smaller than 1μm in
diameter), and restrains the congregating tendency of TiC particles. The refining test on aluminum
indicates that master alloys with TiH2 possesses more excellent grain refining perfprmance than
without, because of the composition and morphology of the master alloy is cut out for refining
processing.
Effect of Initial Grain Size on the Dynamic Recrystallization Behaviours of Austenite
Authors: Dehghan-Manshadi A. , Hodgson Peter
Published: March 2009

The effect of initial grain size on the recrystallization behaviour of a type 304 austenitic
stainless steel was investigated using hot torsion. Refinement of the initial grain size to 8 μm had a
considerable effect on the flow curve shapes, peak and critical strains and also on DRX kinetics,
compared with an initial grain size of 35 μm. Microstructural investigations using EBSD suggest a
transition from conventional (discontinuous) to continuous dynamic recrystallization with
decreasing initial grain size. Also, there was a moderate effect of initial grain size on the DRX grain
size.
Investigation of Streaking Defects on Aluminium Extrusions
Authors: Zhu H. , Cáceres Carlos H. , Zhang Xin Quan , Couper Malcolm J. , Dahle Arne K.
Published: March 2009

The presence of surface defects, such as streaking, is one of the most serious quality
issues for 6000-series aluminium extrusions. The formation of a streaking defect near a web
intersection of a hollow profile was investigated in detail. The streak was apparent on the extrusion
in both the as-extruded and the as-anodised conditions. Microstructural examinations indicate that
the streaked region contains different surface imperfections compared to the normal region and
smaller grains and stronger texture than the normal region. The effects of die design and
microstructural variables on the formation of streaks on aluminium extrusions are discussed.