bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Magnetic Separation in Heavy Metals of Municipal Solid Waste Incineration Bottom Ash
Authors: Han Gi Chun , Um Nam Il , You Kwang Suk , Cho Hee Chan , Ahn Ji Whan
Published: March 2009

Bottom ash contains many ferrous materials (e.g. ferrous metals, Fe3O4, Fe2O3, FeS). In
addition, ferrous metals include the heavy metals, as Ni and Cr have a chemical attraction to iron,
with Cu used to coat with Ni and Cr metals for polishing or to prevent corrosion. For ferrous metals,
the formation of a Fe3O4-Fe2O3 double layer (similar to pure Fe) was found during air-annealing in
an incinerator (1000C). A strong thermal shock, such as that which takes place during
water-cooling of bottom ash, leads to the breakdown of this oxidation layer, facilitating the
degradation of ferrous metals and the formation of corrosion products. Therefore, Fe-ion (heavy
metal) oxides can be formed on ferrous metals, and magnetic separation can separate it from bottom
ash. Thus, in this study the objection is to investigate the separation ratio of heavy metals by
magnetic separation along with the mineralogical formation of Fe-ion (a heavy metal).
Properties of Waste Derived Mullite
Authors: Sanewirush U.Sangwanna , Buaheepkaew M. , Kosasang O. , Saewong P.
Published: March 2009

Waste sediment (WS) from three different aluminum factories and rice husk ash (RHA)
from power plants are used as precursors. Each WS is calcined to remove structural water then
mixed and wet milled with RHA by 70 wt% until a homogeneous slip is obtained. The samples are
formed by means of slip casting in plaster molds and fired at 1400 °C for 2 hours. The fired samples
normally contain ~94 wt% mullite, 6 wt% residual silica and small amount of oxides of alkali and
alkaline earth elements. It is found that their density and flexural strength are affected by alkali and
alkaline earth contents and generally range from 1.53 to 2.38 g/cm3 and 18.11 to 76.37 MPa,
respectively. While thermal expansion coefficient varies from 5.78 x 10-6 to 8.16 x 10-6 /°C and
thermal shock resistance (T) from =200 to 300 °C.
Quality Characteristics of MSWI Ash Melted Slag by Crystallization
Authors: Shin Hyun Chul , Kim Beom Suk , So Hyung Suk , Yoo Yeong Seok , Kim Jong Bo
Published: March 2009

This study was conducted to investigate on crystallization condition and its effect on
quality of melted slag that was made from incineration ash of domestic waste. By increasing
operating temperature, good crystallization was developed and 900~1,000°C was proved optimal.
Longer detention time made better crystallization development, and critical detention time was 3 hour.
But too a long detention time caused residual stress by mutual interference of long crystals. Cooling
rate might affect the quality of crystallization, but below 5°C/min had no difference. For quality and
economics, minimum operating conditions could be comparatively low temperature of 800°C and
detention time of 1~3 hour from which high Vickers hardness of about 660~720 kgf/mm2 was
achieved. It was compared well with crystallized commercial glass which is about 630 kgf/mm2. Thus,
optimum crystallization conditions was suggested to be : temperature 900~1000°C, detention time 3
hours, and cooling rate 5°C /min. Also, observation of microstructure of crystallized slag by SEM
identified reinforcement of matrix by particles and crack deflection that could render the crystallized
slag an improved mechanical strength.
Structural and Electrical Properties of Lead Zirconate Titanate Thick Films Fabricated by Screen-Printing Method
Authors: Lee Sung Gap , Park Sang Man
Published: March 2009

Ferroelectric Pb(Zr0.6Ti0.4)O3 (PZT(60/40)) powder was prepared by a sol-gel method and
PZT thick films were fabricated by the screen-printing method on the alumina substrates. The Pt
bottom electrodes were screen-printed on the alumina substrate. The PZT(60/40) thick films were
annealed at 1050°C for 10min in PbO atmosphere. Pb(Zr0.4Ti0.6)O3 (PZT(40/60)) precursor solution,
which prepared by sol-gel method, was spin-coated on the PZT thick films to obtain a densification.
These PZT multilayered thick films were annealed at 650°C for 2 h in PbO atmosphere. The upper
electrodes were fabricated by screen printing the Ag paste and then firing at 590°C for 10min. Its
structural and electrical properties of the PZT thick films with the treatment of PZT(40/60) precursor
solution coating were investigated. The coating and drying procedure was repeated 4 times. And then
the PZT(40/60) precursor solution was spin-coated on the multilayered thick films. A concentration
of a coating solution was 1.5 mol/L and the number of coating was repeated from 0~15. The porosity
of the thick films was decreased with increasing the number of coatings. All PZT multilayered thick
films showed the XRD patterns of typical peroveskite polycrystalline structure. The relative dielectric
constant of the PZT-15 (15: number of solution coatings) thick film were 370. And the PZT-15 thick
film shows the remanent polarization of 23.5 μC/cm2 and coercive field of 18.0 kV/cm, respectively.
Apatite Formation on Surface of Plasma-Sprayed TiO2 Coating by Sulfuric Acid Treatment
Authors: Zhao Xiao Bing , Liu Xuan Yong , Xie You Tao , Chen Zhi Gang , Ding Chuan Xian
Published: March 2009

TiO2 coatings on titanium alloy substrates were prepared by atmospheric plasma spraying
using commercial nano-powders and followed by H2SO4 treatment. The bioactivity of coatings was
evaluated by the simulated body fluid soaking test. Scanning electron microscopy and
energy-dispersive X-ray spectrometry were used to characterize the surface morphologies and phase
composition of the coating before and after soaking in simulated body fluid. The results obtained
indicate that H2SO4-treated TiO2 coating can induce a bone-like apatite formation on its surface,
however, no apatite appears on the surface of as-sprayed TiO2 coatings. The acid concentration and
treated time affected the bioactivities of TiO2 coatings.
Application of Cr-X-N Thin Film to Improve the Tribological Properties of Environment Friendly Hydraulic Components
Authors: Lee Sang Yul , Kim Jung Teack , Lee Bo Young , Hong Yeh Sun , Kim Eun Young , Kim Moung Keun
Published: March 2009

In this study, CrZrN film was deposited on AISI 4130 cylinder barrel and valve plate using
a unbalanced magnetron sputtering. The tribological properties between a coated steel cylinder barrel
and coated steel valve plate were evaluated by a custom-built disk-to-disk tribometer and the results
were compared with those between a coated steel cylinder barrel and a conventional bronze valve
plate. The lowest friction coefficients were observed between a coated steel cylinder barrel and coated
steel valve plate and they were approximately one half of those between a coated steel cylinder barrel
and conventional bronze valve plate in the range of testing up to 1600rpm. Coated valve plate and
bronze valve plate showed a steady state of friction coefficient at approximately 0.03 and 0.06,
respectively after about 1000 rpm, but steel valve plate without coating showed a continuous
decrease in friction coefficient, which suggested that active wear is continuously occurring. By
applying CrZrN coating on the commercial cylinder barrel and steel valve plate, much improved
tribological results could be obtained, by a factor of approximately 2 in terms of friction coefficient
than those from bronze valve plate. Under a tap water environment CrZrN coating appeared to
perform better than CrSiN coating. Although further work to reduce the friction coefficient below
0.13 in the steady state after initial drop is still needed, possibilities of applying CrZrN coating to
realize a water hydraulic pump were demonstrated through the present work.
Characterization of Nano-Rod ZnWO4 Prepared by Surfactant-Assisting Solvothermal Reaction
Authors: Thongtem Titipun , Katunyoo Suttasinee , Thongtem Somchai
Published: March 2009

Nano-rod ZnWO4 was solvothermally prepared by the reaction of Zn(CH3COO)2.2H2O
with Na2(WO4).2H2O in water at 150-200 oC using the pH of 5.0, 7.0, 9.0 and 12.0 for 24, 48 and
72 h. N-cetyl pyridinium chloride was used as a surfactant. By using XRD, SAED, EDX and TEM,
nano-rod ZnWO4 containing Zn, W and O was detected. The pH values can play a role in the length
of the nano-rods and their crystallinities. FTIR revealed the presence of Zn-O-W, W-O and Zn-O
stretching vibrations of the products. Their photoluminescent (PL) spectra are similar and the
wavelengths at the highest intensities were detected over the range of 445-450 nm.
Decomposition Characteristic of Carbon Tetrafluoride Using 2.45GHz Microwave at Various Gases
Authors: Choi Sun Yong , Taguchi Yuko , Minami Wataru , Kim Lae Hyun , Kim Hee Joon
Published: March 2009

The decomposition characteristics of CF4 with Argon or oxygen in 2.45GHz microwave
has been investigated by using a Langmuir probe with variation of the microwave power and chamber
pressure. For CF4/Ar and CF4/O2/Ar discharges, the ion density and the electron density decrease with
increasing microwave power. The electron temperature was decreased by reducing the mean free path
of electrons with increasing microwave power. Also with increasing pressure, the electron
temperature increase, and ion and electron density decrease by increase of inelastic collision
frequency and of collision with the walls in the chamber. The electron temperature is 13.6 ~ 5.9 [eV],
the electron density is 4.4×1010 ~ 2.2×1010 [cm-3] and ion density is 5.2×1011 ~ 4×1010 [cm-3].
According as add oxygen, ion and electron density increased relatively comparing to CF4/Ar
discharge. The electron temperature is 8.5 ~ 6.2 [eV], the electron and ion density is 5.1×1010 ~
2.1×1010 [cm-3] and 3.7×1011 ~ 7.3×1010 [cm-3], respectively.
Fabrication and Thermoelectric Properties of p-Type Si0.8Ge0.2 Alloy Doped with Boron
Authors: Hwang Sung Doo , Min Wang Kee , Park Ik Min , Park Young Do , Kim Young Seok , Park Yong Ho
Published: March 2009

P-type thermoelectric material Si0.8Ge0.2 was fabricated by mechanical alloying(MA) and
Hot-Press Process(HP) The effect of Boron(0.25~2wt%) addition on the thermoelectric properties of
p-type Si0.8Ge0.2 alloy was reported. Experiments showed that the electrical conductivity decreased
with Boron content at temperature ranging from 500K to 1250K. The carrier concentration measured
by the Hall effect measurement also decreased as a function of doping level. With increasing
temperature, the Seebeck coefficient and the power factor increased with boron content. Based on
measured results, the Figure of Merit (Z) value of 0.5 wt% Si0.8Ge0.2 alloy increased with the small
addition of Boron, and reached maximum rapidly; the Z value was 0.9×10-3/K, the highest value
among the prepared alloys.
Microstructural and Mechanical Properties of Polymer-Based Scaffolds Reinforced by Hydroxyapatite
Authors: Jin Hyeong Ho , Lee Won Ki , Park Hong Chae , Yoon Seog Young
Published: March 2009

Various polymer-based scaffolds reinforced by the hydroxyapatite (HAp) for bone tissue
engineering were successfully synthesized by in-situ co-precipitation method. The influence of HAp
in composite scaffolds on the pore morphology, microstructure, and mechanical properties was
investigated. The polymer-based scaffolds appeared to be macroporous and an interconnected open
pore microstructure with pore size around 200 μm. The pore structure of the composite scaffolds
was not much changed by the presence of HAp but the pore size of the composite scaffolds
decreased with adding the HAp. The compressive modulus and yield strength of the polymer-based
scaffolds improved by the presence of HAp.
Parameters Affecting the Structure and Yield of Carbon Nanotubes in CVD Method
Authors: Zheng Guo Bin , Sano Hideaki , Uchiyama Yasuo
Published: March 2009

Carbon nanotubes and nanofibers were synthesized at 400-800°C by a typical CVD
method using SiO2, Al2O3, or MgO supported Ni or Co catalyst, and acetylene as feedstock. The
effects of temperature, substrates and catalyst on the yield and structure of carbon nanotubes and
nanofibers were investigated in detail. The experimental results showed that Ni based catalysts
tended to form carbon nanofibers with “herringbone” structure, though for Ni/Al2O3 catalyst, the
products at 800°C changed to a structure like carbon nanotube. Co based catalysts tended to form
carbon nanotubes.
Preparation of Nano-Size PbTiO3 Particles and its Characteristics on the Adsorption of Organic Acids
Authors: Song Kun Ho , Kim Byoung Moon , Kim Jeong Eun , Lee Kwang Rae
Published: March 2009

The nano-size PbTiO3 particles were prepared by sol-gel method and the effects of processing
variables such as concentration of sol solution, catalyst, concentration of catalyst, calcination
temperature and calcination process on particle size of PbTiO3 were analyzed. The condition for
preparation of sol solution from the precursor is very critical to the size of PbTiO3 particle. At
certain experimental conditions, the particles of 129nm, 213nm and 343nm were obtained.
However, the particle size of commercialized PbTiO3 powder was 5㎛(5,000nm). The prepared
nano-size PbTiO3 powder adsorbed more acetic acid and formic acid than the commercialized
one; 1.5 times for acetic acid and 1.2 times for formic acid. Formic acid was preferentially
adsorbed than acetic acid.
Properties of Sol-Gel Coating Film from Colloidal Silica-Silane Sol
Authors: Na Moon Kyong , Ahn Myeong Sang , Park Hoy Yul
Published: March 2009

Two kinds of colloidal silica(CS)/silane sol solutions were prepared. Two sol solutions are
involved with the kinds of silane such as methyltrimethoxysilane(MTMS) and -Glycidoxypropyl
trimethoxysilane(ETMS) using LS CS. MTMS was added to two sol solutions. Whether ETMS was
added or not, two kinds of sol solutions were synthesized. Using two kinds of sol solutions, sol-gel
coating films were formed on glass substrates via dip-coating process. Here, seasoning effect of for
enhancing properties of sol-gel coating layer on glass was investigated while such sol-gel solutions
were left for 7days. Also, their properties such as surface free energy, roughness, thermal property,
potential hardness and elastic portion were characterized in order to understand the effect of addition
of ETMS. In this case of LS/MTMS sol, the coating film had low surface free energy and more
enhanced flat surface than that of the case of LS/MTMS/ETMS sol. ETMS forms hydrophilic
hydroxyl group in sol solution, then surface free energy of LS/MTMS/ETMS coating film increased.
In the beginning of reaction sol solution seemed to be unstable, but 4days later their coating film
properties such as surface free energy and roughness enhanced. The elastic portion of coating films
obtained from LS/MTMS/ETMS sol increased with addition of ETMS, but thermal stability
decreased.
The Behavior of Automobile Shredder Residue Chips in a Precalciner for Cement Manufacturing Process
Authors: Oh Sea Cheon , Jin Cheol Min , Hong John Hee , Kwon Woo Teck , Kim Soo Ryong
Published: March 2009

This paper presents a numerical simulation of Automobile Shredder Residue (ASR) chips
motion and combustion in a cement works precalciner. The work was done using the commercial
computational fluid dynamic (CFD) code FLUENT. The aim of this work is to develop an
understanding of the processes within the percalciner to aid in the prediction of ASR chip
aerodynamic and combustion behaviors for its use as an alternative fuel. The effects of the mutual
interactions between ASR chips were simulated by discrete phase modeling approach, while ASR
combustion was simulated by the finite rate devolatilization models. A useful approach to simulate
the characteristics of turbulent gas-particle flow, heat transfer and ASR combustion process in a
precalciner has been demonstrated.
Two Types of Phase Separation and Crystal Nucleation-Growth Mechanisms for Machinable Glass Ceramic
Authors: Ma Xin Pei , Li Guang Xin , Yang Jian Feng , Jin Zhi Hao
Published: March 2009

Machinable mica glass ceramics with more ZnO and B2O3 showed the phase separation
by spinodal decomposition. the size of two phases formed by phase separation is in micron meter
order. The nucleation and growth of crystal is performed through the diffusion of atoms. Another
kind of materials with no ZnO and B2O3 addition behaves different mechanism of phase separation
in terms of nucleation and growth. Many fine particles are obtained after the phase separation , the
size of which is less than 100nm in diameter. Subsequently nucleation and growth in the
crystallization is accomplished by aggregation and unification of the granular phase precipitation.
The mechanism of the aggregation and unification nucleation-growth is different from one
controlled by atom diffusion in nature. The different mechanisms in crystal nucleation and growth,
caused by the composition changing.
Effect of Yb Additions on Microstructures and Properties of High Strength Al-Zn-Mg-Cu-Zr Alloys
Authors: Chen K.H. , Fang H.C. , Zhang Z. , Huang L.P.
Published: March 2009

The effect of 0.30 Yb (mass fraction,%) additions on the microstructure and properties of
high strength Al-Zn-Mg-Cu-Zr aluminum alloys has been investigated by TEM, optical microscopy,
hardness and electric conductivity measurement, tensile test, stress corrosion cracking test. The
results show that the ytterbium additions to high strength Al-Zn-Mg-Cu-Zr aluminum alloys
significantly inhibited recrystallization during solution treatment. The tensile and yield strengths,
elongation, hardness, electric conductivity and stress corrosion cracking resistance of the
Yb-containing alloys are improved compared to the alloys without Yb additions. By Yb additions, the
critical stress intensity (KISCC) is enhanced from 7 MPa·m1/2 up to 14.5 MPa·m1/2 with the
improvement of the strength and ductility. The mechanism for the property improvement from Yb
additions has been discussed.
Magnetically Aligned Al3Ni Phase in Al-Ni Alloys Solidified with a High Magnetic Field
Authors: Wang Hui , Wang Qiu Liang , Ren Zhong Ming , Yan Lu Guang
Published: March 2009

When Al-Ni alloys solidified from melted zone and semi-solid zone, respectively, with a
magnetic field up to 12.0T (Tesla) applied, the paramagnetic Al3Ni crystals in the precipitated Al3Ni
phase were aligned with their c-axes parallel to the field and a unique laminated textured
microstructure of the precipitated phase perpendicular to the field was formed. There were critical
values of magnetic intensity Bcrit and heating temperature Tcrit at or above which the textured
microstructure could be formed. The behavior of magnetic orientation of the precipitated phase was
investigated experimentally. The results were discussed in terms of magnetic rotation of crystals with
magnetic anisotropy, crystal growth, mechanical and magnetic interactions among the magnetized
Al3Ni grains in a high magnetic field.
Dynamic Recrystallization of 3104 Aluminum Alloy during Isothermal Compression Deformation at Elevated Temperatures
Authors: Huang Guang Jie , Liu Qing , Wang Ling Yun , Yin Xiao Hui
Published: March 2009

The dynamic recrystallization characteristic of 3104 alloy has been investigated by
isothermal compression deformation at temperatures from 573K to 773K under constant strain rates
ranges from 10-3s-1 to 1s-1. It was shown that the form of flow stress curves were very sensitive to
temperature and strain rate. At high temperatures and low strain rates, dynamic recrystallization of
3104 alloy deformation occured. The critical value for dynamic recrystallization start was determined
from an inflection point that was observed in the plot of work hardening rate vs. flow stress and
verified metallograhically based on quenching samples interrupted during deformation. In the
experimental domain studied, the ratio of the critical strain for the initiation of dynamic
recrystallization to that of the peak strain falled in the range 0.4-0.6. Furthermore, the dependence of
εc on Zener-Hollomon parameter( Z) has been developed.
Flow Field and Gas-Bubble Size Analysis in Water Model for the Process of Aluminum Melt Degassing by Particle Image Velocimetry
Authors: Wu Rui Zhi , Shu Da , Wang Jun , Sun Bao De , Zhang Mi Lin
Published: March 2009

The flow field and gas-bubble size during the process of aluminum melt degassing were
investigated in water model. A Φ400mm×400mm transparent water model and an impellor degassing
device were used in this study. The instantaneous velocity fields of water and bubbles under the
mixture of rotary injector were measured with PIV velocity field measurement technique. Then the
pictures of bubbles gained from PIV were analyzed with software to get the bubble size distribution.
The results showed that bubble flow field and bubble size were influenced by rotary speed of rotor and
gas flow-rate. With the increase of rotary speed of rotor, the horizontal velocity components of
bubbles became larger, the stagnant time of bubbles in water increaseed correspondingly and bubble
size became smaller. With the increase of gas flow-rate, the longitudinal velocity components of
bubbles became larger, the stagnant time of bubbles in water decreased correspondingly, and the
bubble size became larger also.
Corrosion Behavior of Metallic Materials in Ethanol-Gasoline Alternative Fuels
Authors: Nie Xueyuan , Li X. , Northwood Derek O.
Published: March 2009

Corrosion performances of several metallic materials (Al6061 and Al319 alloys, 304
stainless steel and grey cast iron) in the ethanol-gasoline alternative fuels were investigated. Cyclic
potentiodynamic polarization tests were used to study their corrosion behavior. Anodizing and
plasma electrolytic oxidation (PEO) techniques were used to produce oxide coatings on the Al6061
and Al319 alloys, and the corrosion properties of these coatings in the alternative fuel environments
were also evaluated. The results showed that, the 304 stainless steel, Al6061 and the coating materials
are compatible with the alternative fuels. The oxide coatings on both Al alloys provided effective
corrosion protection in the alternative fuel environments.
Atomic Partitioning of Platinum and Ruthenium in Advanced Single Crystal Ni-Based Superalloys
Authors: Tin S. , Zhang L. , Ofori A.P. , Miller Michael K.
Published: March 2009

The elemental partitioning characteristics of advanced single crystal Ni-base superalloys containing additions of both Pt and Ru have been investigated using atom probe tomography. Detailed microanalysis revealed Ru additions partitioned preferentially to the disordered matrix, whereas Pt additions tended to partition to the ordered intermetallic γ′ precipitates. The partitioning characteristics of three nominally similar alloys with systematic variations in the levels of Cr, Ru and Pt were investigated. For this particular set of experimental alloys, minor changes in the partitioning characteristics of the constituent elements could be attributed to additions of Cr and Ru. The preferential site occupancy of Pt within the L12 lattice was also statistically quantified with ALCHEMI (atomic site location by channelling enhanced microanalysis). In contrast to the atomic partitioning characteristics of Ru, Pt exhibited a tendency to occupy the Ni sublattice sites in the γ′ structure.
Precipitate Free Zones along Recrystallization Grain Boundaries during Creep in a Directionally Solidified Superalloy
Authors: Wang Li , Xie Guang , Zhang Jian , Lou Lang Hong
Published: March 2009

Microstructural evolution of an experimental directionally solidified superalloy with local
recrystallization during creep was studied. Precipitate free zones (PFZs) were formed along the
recrystallization grain boundaries that are perpendicular to the applied stress. The formation
mechanisms of PFZs and creep cracks associated with PFZs were discussed based on the
experimental observation.
Effect of Temperature on Formation of Borides in TLP Joint of a Kind of Nickel-Base Single Crystal Superalloy
Authors: Liu J.D. , Jin Tao , Zhao N.R. , Wang Z.H. , Sun Xiao Feng , Guan Heng Rong , Hu Zhuang Qi
Published: March 2009

a kind of as-cast nickel-base single crystal superalloy was TLP bonded using Ni-Cr-B
amorphous foil at different temperatures. Special attention is paid to the formation of boride in
diffusion zone of TLP joints at different conditions. The chemical composition and microstructure of
borides were investigated by scanning electron microscopy (SEM) and transmission electron
microscopy (TEM). At different bonding temperature, M3B2 precipitates appear distinct
morphologies. At 1200°C, both blocky and plate-like borides formed owing to the diffusion of boron
atoms into base metal and precipitation during the cooling process. At 1230°C or above, due to the
diffusion of boron atoms the constitutional liquation of original γ/γ′ eutectics in the base metal occurs
and borides formed when the system was cooled to room temperature. The analysis of TEM results
reveals that M3B2 has a tetragonal structure and is rich in Mo, W, and Cr elements.
Stress Rupture Properties of the Second Generation Single Crystal Superalloy DD6 after High Temperature Exposure
Authors: Jin Hai Peng , Li Jia Rong , Liu Shi Zhong
Published: March 2009

The effects of high temperature exposure simulating service conditions on stress rupture
properties were studied for the second generation single crystal superalloy DD6. The specimens with
[001] orientation were exposed in air at temperatures of 980°C and 1070°C for 100h to 1000h. They
were then tested using conventional mechanical tests at 1070°C/140MPa to determine the effects of
exposure on stress rupture properties. The analysis indicated that stress rupture life decreased with
increasing exposure time. At the temperature of 980°C, the stress rupture life is more than 180h after
exposure for 1000h. When the test temperature increased to 1070°C, the stress rupture life exceeds
100h after 800h exposure. The morphology of γ prime phase after exposure was observed by using
scanning electron microscopy (SEM). Morphologies evaluations have shown that alloy DD6 exhibits
excellent microstructure stability after exposure. TCP (Topologically Closed Packed) phases have not
been observed. It has been also found that the morphology and size of γ prime affected stress rupture
life of the alloy. The decrement in stress rupture life with increasing exposure is a result of γ prime
rafting.
INCONEL Alloy 783: An Oxidation Resistant, Low Expansion Superalloy for Gas and Steam Turbine Applications
Authors: Mannan S.K. , Patel Shalesh J.
Published: March 2009

Recently developed alloy 783 (nominal composition of Ni-34Co-26Fe-5.4Al-3Nb-3Cr, UNS R30783) is precipitation strengthened by Ni3Al-type gamma prime and NiAl-type beta phases. The alloy is being used for seals/casings in aircraft gas turbines and for bolting in steam turbines due to its low co-efficient of thermal expansion, high strength, and good oxidation resistance. It has also been specified for other aircraft gas turbine components such as rings for casings and shrouds. This paper presents the alloy’s basic characteristics, applications, and hot and cold workability.
Ultrasonic Treatment of Magnesium Alloy Melts and its Effects on Solidification Microstructures
Authors: Zhang Zi Qiang , Le Qi Chi , Cui Jian Zhong
Published: March 2009

The effects of high intensity ultrasonic melt treatment on the microstructure of magnesium
alloys were investigated in this paper. Magnesium melts were treated with power ultrasonic wave and
then cooled to a predetermined temperature. With the increase in ultrasonic power, the structure
exhibited refined and spheroidzed crystal grains. After further increasing the ultrasonic power, the
grains tended to somewhat coarsened. And increasing the ultrasonic processing time led to a grain
refinement of magnesium alloy.
Investigation on Dynamic Recrystallization Behavior in Hot Deformed Superalloy Inconel 718
Authors: Wang Y. , Shao Wen Zhu , Zhen Liang , Lin L. , Cui Y.X.
Published: March 2009

The nucleation and development of dynamic recrystallization (DRX) in hot deformed
superalloy Inconel 718 during uniaxial compression were investigated by optical microscopy and
electron back-scattered diffraction (EBSD) technique. The results showed that the discontinuous
dynamic recrystallization was the predominant DRX mechanism in this alloy. The variations of
partial crystallographic orientations led to the individual nucleation inside the deformed grains, which
implied the occurrence of local continuous dynamic recrystallization. The progressive subgrain
rotation can be confirmed neither near the prior high angle grain boundaries nor within the original
grains. It was found that, as the strain increased, the initial twin boundaries were gradually
transformed to ordinary mobile high angle boundaries. Meanwhile, the new twin boundaries were
formed inside the recrystallized grain necklaces. It was suggested that the characteristics of the twin
boundaries evolution with increasing strain were associated with the transformation of initial twin
boundaries as well as the generation of new ones, which resulted in the development of DRX.
Femtosecond Laser Ablation of a Single Crystal Superalloy CMSX-4 in Different Environments
Authors: Wen Quan , Feng Qiang , Cheng Guang Hua , Zhao Wei , Sun Zu Qing
Published: March 2009

The femtosecond laser ablation has been investigated on second generation single crystal
superalloy CMSX-4 using a commercial titanium:sapphire laser system (λ = 780nm, τ = 120 fs).
The ablation thresholds of bulk alloy CMSX-4 have been determined as a function of the pulse
number (1, 10, 100, 1000) in air, argon gas and vacuum. The results indicate that the multiple-pulse
threshold of this material decreased with increasing the pulse number in all the cases. For the same
pulse number, the threshold changed in the descending order: air, vacuum and argon gas. The
incubation coefficient in air has been determined: ξ = 0.86 ± 0.03. The preliminary results showed
the better quality of femtosecond laser machining of CMSX-4 in vacuum and argon gas than in air.
Hydrogen's Absorption/Desorption Behavior in Gaseous-Phase Charged Duplex-Annealed Ti-6Al-4V Alloy
Authors: Tal-Gutelmacher E. , Eliezer Dan , Boellinghaus Thomas
Published: March 2009

Ti-6Al-4V alloy has proven to be technically superior and cost-effective materials for a
wide variety of aerospace, industrial, marine and commercial applications. The mechanical properties
of Ti-6Al-4V are very sensitive to the microstructure obtained after the thermo-mechanical treatment.
The duplex structures provide good tensile ductility, fatigue strength, resistance to microcrack growth
and crack initiation, and are often used in demanding fatigue critical tasks. However, although
Ti-6A-4V is considered to be reasonably resistance to chemical attack, severe problems can arise
when it comes in contact with hydrogen-containing environments due to its susceptibility to hydrogen
embrittlement. The objective of this paper is to investigate the absorption and desorption behavior of
external hydrogen on a duplex-annealed Ti-6Al-4V alloy. While investigating the desorption profile,
we seek to better understand the thermodynamics and the kinetic nature of the interaction between
traps and hydrogen atoms, with specific emphasis on the investigation of the impact of these
interactions on the microstructure of the studied aerospace applicative titanium alloy. In order to
achieve these goals, thermal desorption spectroscopy (TDS) was applied and the data obtained from
this analysis was supported by a variety of other experimental techniques, such as LECO hydrogen
determinator, XRD and microstructure investigations by means of optic and electronic microscopy.
Hydrogen was found to influence significantly the microstructure of the alloy. The process of
hydrogen evolution was found to be a very complex process, being affected mainly by the phase
transformations that may occur during the thermal analysis.
Microstructural and Mechanical Characterization of TiAl/Ti6242 Diffusion Bonds
Authors: Zheng Xiu Hua , Dogan Bilal , Bohm Karl Heinz
Published: March 2009

Ti-6242 alloys have been widely used in aero-engine applications due to high temperature
strength and creep resistance. The γ-TiAl based intermetallics are considered as candidate materials to
replace the current materials weed at high temperatures. The present paper reports on the
microstructural and mechanical characterization of γ-TiA/Ti6242 diffusion bonds. The emphasis is
put on the better understanding of microstructural development during diffusion process and
mechanical properties of diffusion bonds. The process variables of temperature, pressure and time
were optimized to produce joints with sound microstructure and bond quality for mechanical
characterization. The micro and standard tensile tests were applied to determine bonding strength of
joints. Metallographic and fractographic examinations on diffusion joints and tested specimens were
carried out using SEM coupled with EDX. The concentration profiles of elements from EDX analysis
combined with SEM/BSE investigation demonstrated that the strong inter-diffusion of main elements
Al and Ti across the bonding interface occurred during DB process leading to the formation of a
noticeable diffusion zone consisting of fine* α2/α grains. The micro tensile tests showed that the
preference of fracture on base materials far from the bonding line, but a more marked tendency to
brittle failure along bonding interface shown by the standard tensile test results, indicating a
significant sample size effect on mechanical property measurements.
Hydrogen Behavior in GTA Welded Ti-6Al-4V and Beta-21S Aerospace Applicative Titanium Alloys
Authors: Tal-Gutelmacher E. , Eliezer Dan , Boellinghaus Thomas
Published: March 2009

Ti-6Al-4V and β-21S (Ti-15Mo-3Al-3Nb-0.3Si, wt%) titanium alloys were exposed to a
hydrogen-containing environment, introduced by Gas-Tungsten Arc welding via a mixed Ar + 5% H2
shielding gas. The different characteristics of hydrogen absortion/desorption behavior and trapping in
the welded Ti-6Al-4V and β-21S alloys were studied by means of thermal desorption spectroscopy
(TDS). Thermal spectra analysis is supported by data from a variety of other experimental techniques,
e.g., Leco hydrogen determinator and microstructure investigations. In the specimens welded in
hydrogen-containing environment, no cracking was observed. However, the complex process of
hydrogen desorption was found to be significantly affected by the microstructure developed in the
alloys after welding. The unique microstructural morphology, the presence of potential irreversible
trapping sites and phase transitions (oxide dissociation) were considered to be the potential
parameters affecting the hydrogen desorption behavior from the alloys.
Effect of Mo on the Oxidation Behavior of NiTiAl Alloy
Authors: Xu Jian , Zhao Xin Qing , Gong Sheng Kai
Published: March 2009

The effect of Mo on the oxidation behavior of TiNiAl at 1073K has been investigated. It is
found that 1at.% Mo addition can increase the diffusion of Al in the alloys and promote the formation
of dense and continuous Al-rich oxide layer. Therefore the oxygen diffusion can be effectively
impeded and the oxidation behavior of TiNiAl is improved. The observation of the cross-sectional
oxidation layer showed that beneath the top oxide scale a Mo-rich oxide layer formed. Because the
oxide of Mo is volatile at high temperature, voids formed in the oxide scales during the oxidation
process. 3at.% Mo addition could cause cracks between the oxide scale and the substrate, resulting in
poor adhesion of the oxide scale to the substrate.
Effects of Cr and Al on High Temperature Oxidation Resistance of Nb-Si System Intermetallics
Authors: Qu Shi Yu , Han Ya Fang , Song Jin Xia , Kang Yong Wang
Published: March 2009

The effects of Cr and Al on high temperature oxidation resistance of Nb-Si system
intermetallics have been investigated by scanning electron microscopy (SEM), X-ray diffraction
(XRD) and weight gain method. The results showed that the high temperature oxidation resistance
can be substantially improved by proper Cr or Al addition. The further analysis revealed that Cr
promotes the formation of CrNbO4 in scale and improve the adherence between the oxide scale and
the substrate. It also found that Al improves the surface morphology of oxide scale and changes
oxidation products by promoting the AlNbO4 formation.
Fabrication of AlN-SiC-TiB2 Ceramics by Self-Propagating High Temperature Synthesis and Hot Isostatic Pressing
Authors: Zhou Li Juan , Zheng Yong Ting , Du Shan Yi , Li Hong Bo
Published: March 2009

The fabrication of AlN-SiC-TiB2 ceramics with powder mixtures of Al, 6H-SiC and TiB2
was investigated by self-propagating high temperature synthesis (SHS) and hot isostatic pressing
(HIP). The powder mixtures were shaped by isostatic cool pressing method and the combustion
reaction was carried at the pressure of 100-200 MPa N2 by an ignitor. The compositions and
morphologies of the combustion product were studied by XRD and SEM. The determined bending
strength and the fracture toughness of the ceramics were 350 MPa and 3.5 MPa⋅m1/2 respectively.
Effect of Needling Parameters on Mechanical Properties of C/C Composites Reinforced by Carbon Cloth
Authors: Zhang Xiao Hu , Li He Jun , Hao Zhi Biao , Cui Hong
Published: March 2009

The influence of needling parameters on mechanical properties of carbon-carbon
(C-C)composites reinforced by needled carbon cloth was studied in the present investigation. The
results showed that needling density (ND)and needle-punching depth (PD) both had a larger effect on
interlaminar shear strength (ILSS) than on compression strength and flexible strength of Needling
C-C(NC-C). The mechanical properties of NC-C increased with increasing punching density in the
range of 20-45 punch/cm2 and also with increasing punching depth range from10 to16mm. The NC-C
with the highest ND value of 55punch/cm2 had highest ILSS value of 27 MPa.The optimized ND and
PD parameters was 30 punch/cm2 and 12mm respectively, which resulted in a high value of tensile
strength(119MPa), bending strength (220MPa) and compression strength (235 MPa) in the X-Y
direction .
Preparation of AlN-BN Composite by Composite Powders
Authors: Zhang Ju Xian , Liang Long , Feng Jin Jun
Published: March 2009

AlN-BN composite Powders with the microstructure of micrometer-sized AlN particles
coated with BN particles were prepared via a chemical reaction, which used a mixture of boric acid
(H3BO3) and urea (CO(NH2)2) as reactants coated on the surface of the AlN particles to react in
nitrogen ambient. The XRD and TEM studies showed that the coating layer (BN) was composed
mostly of amorphous BN particles at the reaction temperature of 850oC ~1100oC. When the
composite powders formed into pellets using cold isostatic-pressing, then, sintered at pressureless
sintering, the relative density of the composites that contained 15wt% BN reached above 98%, and
there was homogeneous microstructure.
Microstructure and Mechanical Properties of Mg-Gd-Sm-Zr Alloy
Authors: Zhao Yang , Wang Qu Dong , Gu Jin Hai , Gao Yan , Tong Yan
Published: March 2009

Microstructure and mechanical properties of three kinds of Mg-Gd-Sm-Zr alloys have
been analyzed in this paper. Results exhibit that the microstructure of as-cast Mg-Gd-Sm-Zr alloy
contains α-Mg and eutectic compounds which are mainly comprised of most Mg5Gd-base phases and
a few Mg41Sm5-base phases by EDX and XRD analysis. Ultimate tensile strength and yield strength
of the alloys can be significantly improved after T6 treatment. Mechanical properties of studied
alloys in T6 condition are better than that of WE54-T6 alloy.
Optimization of Radar Absorbing Structure Using the Genetic Algorithm
Authors: Jiang Shicai , Xing Li Ying , Li Bin Tai , Chen Xiang Bao
Published: March 2009

In this study, multi-objective optimization of radar absorbing structure with circuit analog
structure using the genetic algorithm was investigated, at the basis of the study on the influence of the
size of the circuit analog, the electromagnetic parameter and the thickness of the medium ply on the
properties of the microwave-absorbing composite. Based on the concept of Pareto optimality,
Sharing and Niche technology was applied in the algorithm(NSGA), and the calculating results
converged at the Pareto front dividedly. The study have been showed that the calculating values fit
well with that of the experiment, which indicate that this algorithm is proper and has extensive
adaptability. The results also showed that introducing circuit analog structure(CAS)into the radar
absorbing structure composite design can improve its wave-absorbing properties. So, the radar
absorbing structure composite with CAS is a promising radar absorbing structure composite form.
Modification of Diallyl Isophthalate with Dimethacrylate Liquid Crystalline
Authors: Zuo Rui Lin , Liang Guo Zheng , Chang Peng Shan
Published: March 2009

Two kinds of DMLC which have same mesomorphic unit but different spacer chain were
used to toughen brittle DAIP. In order to get the best toughening effect, influences of curing procedure,
especial the curing temperature on the formation of mesomorphic structure and miscibility between
DAIP and DMLC were studied. The results showed that when DMLC was used to toughen brittle
resins, the initiation curing temperature of the modified system was desired to be higher than it’s Ti
and lower than DMLC’s Ti. When cured as the above procedure, the modified DAIPs showed
macroscopic disordered but microscopic ordered structures. At the same time, most of modified
DAIP systems showed great improvement of impact strength, as well as bend strength, modulus and
heat resistance. The results also showed that when the DMLC with spacer chain was used, the
modified DAIPs will have better toughness than DAIPs modified with no spacer DMLC. Fracture
surfaces of the modified DAIPs were studied with SEM further. The results revealed that it was the
ductile and strong DMLC mesomorphic domains to modify the toughness of brittle DAIP matrixes.
Microstructures and Toughening Mechanisms of Y2O3 Doped Al2O3/ZrO2 Eutectic Composite Ceramics Prepared by SHS Melt-Growth Process
Authors: Zhang Long , Zhao Zhong Min , Song Yi Gang , Wang Wei Guo
Published: March 2009

By introducing ZrO2(4Y) powder of suitable content into the thermit and based on
oxidation-reduction reaction of the thermit and liquid-liquid phase separation of ceramics/metal
under gravity, Al2O3/ZrO2(4Y) composite ceramics have been prepared through melt-growth with
eutectic reaction under high degree of undercooling from SHS process. It has been found that the
ceramics were composed of major rod-shaped sapphires with 8.0~12.0 aspect ratios and minor
plate-like α-Al2O3 grains, and within the sapphires t-ZrO2 nano-micron fibers were embedded.
Flexural strength and fracture toughness were measured to be 1256MPa and 13.2MPa·m1/2. It was
obtained that a number of low energy interfaces (the interface distance on nano-micron scale) between
two Al2O3/ZrO2 (4Y) phases and the strong compressive residual stress in the sapphires made the
sapphires reinforced, forcing the crack to propagate along the rod-shaped sapphires; meanwhile,
crack-bridging and pull-out of the sapphires, crack - bridging and frictionally interlocked effects of
plate-like α-Al2O3 grains in the wake of crack tip also rendered the crack stabilization to arise.
Mechanical Properties and Creep Behavior of Mg-Gd-Y-Zr Alloys
Authors: Gao Yan , Wang Qu Dong , Gu Jin Hai , Zhao Yang , Tong Yan
Published: March 2009

The microstructure, mechanical properties and creep behavior of Mg-Gd-Y-Zr alloys at
different temperatures and stresses have been investigated. Results show that the tensile properties
and creep resistance at T6 condition is much higher than that at as-cast condition. The creep
resistance of Mg-Gd-Y-Zr alloy at 250°C/80MPa is markedly better than that at 300°C/50MPa,
indicating that temperature makes more effects on the creep resistance than the stress.
Study on the Vibration of a Sandwich Beam with Smart Composites—MRF
Authors: Hu Bai Xiang , Zheng Guo Liang , Xia Pin Qi
Published: March 2009

Smart composite material-MRF’s rheological properties such as viscosity and shear modulus can vary when subjected to different magnetic fields. This paper established the vibration model of the smart composite beam featuring MRF. The vibration analysis was finished under different magnetic field strengths using the method of complex stiffness. The experiment was performed to validate the theoretical predicted vibration responses. From both studies, the natural frequencies and loss factors of the MRF beam were shifted to a higher lever when the applied magnetic field increases. From the findings of the analysis, it is observed that MRF presents vibration control capabilities.
Visible-Blind Metal-Semiconductor-Metal Structured Deep-Ultraviolet Photodetectors Using Single-Crystalline Diamond Thin Film
Authors: Liao Mei Yong , Koide Yasuo
Published: March 2009

Metal-semiconductor-metal (MSM) planar photodiodes and photoconductors were
fabricated on unintentionally doped homoepitaxial diamond thin films deposited on Ib and IIa-type
diamond substrated. The MSM photoconductor on the epilayer grown on the Ib-type substrate
exhibits the highest discrimination ratio up to 108 between 210 nm and visible light and a
photocurrent gain around 33 at 220 nm. The persistent photoconductivity is rather week for such kind
of photoconductor.
Magnetron Sputtering High Temperature Mo-Al2O3 Cermet Solar Selective Coatings
Authors: Du Xin Kang , Wang Cong , Wang Tian Min , Chen Bu Liang , Zhou Long , Ru Ning
Published: March 2009

Based on double cermet layer structure, Mo-Al2O3 cermet solar selective coating was
prepared on stainless steel substrate. A solar absorptance of 0.92 and normal emittance of 0.19 at
room temperature have been achieved. Vacuum annealing treatment was done and its influences on
the solar selective performance was discussed. Absorptance changed between 0.90 and 0.92 under the
selected annealing temperature range of 350-800°C, and emittance varied from 0.19 to 0.23 when
heated at 650°C. The microstructures before and after annealing process at different temperatures
were investigated.
Neutron Diffraction Studies of the Zr/Nb Effects on the Nb3Sn Phase Formation of Monofilament Wires
Authors: Soubeyroux Jean Louis , Zhang C.W. , Sulpice Andre , Zhou Lian , Tang X.D. , Tournier Robert F.
Published: March 2009

The layer growth of the A15 (Nb3Sn) superconducting phase produced by the internal tin
method on model monofilament wires was studied by neutron diffraction and electron microscopy
techniques. Different ratios of the inner part of the wire (Sn/Cu) and the effect of the addition of 1% of
zirconium to niobium were studied. The high temperature heat treatment plays a key role on the A15
formation and on the cost of the final wires produced. Different temperatures in the range 650-725°C
and different annealing times in the range 8-200 hrs have led to the preparation of 72 different
samples. The neutron diffraction study has evidenced the different phases formed during the heating
treatment and the electron microscopy study has evidenced a power law for the growth rate of the A15
phase. In both studies the addition of zirconium in niobium is very effective on the growth rate of the
A15 phase.
Change of Inclusion and Mechanical Properties of Magnesium Alloy during Vacuum Melting
Authors: Zhang Jin Ling , Wang She Bin , Li Ming Zhao , Liu Xu Guang , Xu Bing She
Published: March 2009

Rare earth was added in foundry magnesium alloy in vacuum melting. Analysis and
measurement showed that the quantity of inclusions was decreased and the mechanical properties
were improved. The size of crystal grain was decreased by 59%, the yield strength was increased by
38% and elongation percentage was increased more than 7 times. On the basis of this experiment, the
approaches of improving the mechanical properties of magnesium alloy were brought up.