bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanochemical Synthesis of Zinc Ferrite, ZnFe2O4
Authors: Sawada Yutaka , Iizumi Kiyokata , Kuramochi Tomokazu , Wang Mei Han , Sun Li Xian , Okada Shigeru , Kudou Kunio , Shishido Toetsu , Matsushita Junichi
Published: March 2009

Mechanochemical synthesis of zinc ferrite, ZnFe2O4, was attempted from a powder
mixture of iron (III) oxide, alpha-Fe2O3 and zinc (II) oxide, ZnO. Nanocrystalline zinc ferrite,
ZnFe2O4 powders were successfully synthesized only by milling for 30 hours. The X-ray
diffraction spectrum of the as-milled powders (without heating) showed twelve ZnFe2O4 peaks and
four weak peaks of coexisting unreacted Fe2O3. The crystallite size of the mechanochemicallysynthesized
ZnFe2O4 was 26.3 nm. Evidence of the ZnFe2O4 formation was absent for the powders
milled for 10 and 20 hours; milling lowered the crystallinity of the starting materials. Heating after
milling enhanced the formation of ZnFe2O4, the crystal growth of ZnFe2O4 and the unreacted
starting materials. The unreacted starting materials decreased their amounts by heating at higher
temperatures.
Microstructure and Bonding Strength of Tungsten Coating Deposited on Copper by Plasma Spraying
Authors: Song Shu Xiang , Zhou Zhang Jian , Du Juan , Zhong Zhi Hong , Ge Chang Chun
Published: March 2009

Tungsten coatings with different interlayers onto the oxygen-free copper substrates were
fabricated by atmosphere plasma spraying. The effects of different interlayers of NiCrAl, NiAl and
W/Cu on bonding strength were studied. SEM, EDS and XRD were used to investigate the
photographs and compositions of these coatings. The tungsten coatings with different initial particle
sizes resulted in different microstructures. Oxidation was not detected in the tungsten coating, but in
the interlayer, it was found by both XRD and EDS. The tungsten coating deposited directly onto the
copper substrate presented higher bonding strength than those with different interlayers.
Fabrication of Deep-Sub-Millimeter-Thick Compacts Using Spark Plasma Sintering
Authors: Tanaka T. , Ohashi T. , Oshiro Kazunori , Fujimori Hirotaka , Kurisu H. , Matsuura M. , Yamamoto Setsuo
Published: March 2009

Nd-Fe-B type powder was sintered using spark plasma sintering method. Fabricated compact sintered at the temperature of 700 °C, is found to be a composite magnet with Nd-Fe-Co-B and α-Fe. The compact sintered at 700 °C shows slightly low coercivity and large remanent magnetization comparing to the compact sintered at 600 °C due to the formation of α-Fe phase, resulting in the large maximum energy product. Maximum energy product tends to decrease with decreasing thickness of sintered compacts below 0.5 mm in thickness.
Investigation of Sintering Behaviors of Steatite Parts Produced by Powder Injection Molding
Authors: Uslan Ibrahim , Berber Mahmut , Karatas Çetin , Saritaş Suleyman
Published: March 2009

In this study, the properties of sintered parts produced by Powder Injection Molding
(PIM) from the feedstocks of steatite powders with water based binders were investigated. The
steatite powder solid loading was 58 vol. %. The properties investigated were density, % size
change, tensile and bending strengths. Sintering in a high temperature furnace at different
temperatures, heating rates and sintering times have been carried out. Densities of sintered parts
have been measured by using Archimedes’ principle. Maximum attained relative density was 96 %
at 1275 °C sintering temperature, 5 °C/min heating rate and 3 hours sintering time. At this sintering
condition, linear shrinkage was 17.6 %, tensile strength was 16.7 MPa and bending strength was
130.6 MPa.
Synthesis and Densification of Nanostructured Al2O3-(Zro2+3%Mol Y2O3) Bioceramics by High-Frequency Induction Heat Sintering
Authors: Kim Sug Won , Khalil Khalil Abdel-Razek
Published: March 2009

Nanostructured Alumina – 20 vol% 3YSZ composites powder were synthesized by wetmilling technique. The starting materials were a mixture of Alumina micro-powder and 3YSZ nano-powders. Nano-crystalline grains were obtained after 24 h milling time. The nano-structured powder compacts were then processed to full density at different temperatures by high-frequency induction heat sintering (HFIHS). Effects of temperature on the mechanical and microstructure properties have been studied. Al2O3-3YSZ composites with higher mechanical properties and small grain size were successfully developed at relatively low temperatures through this technique. The samples were densified by heating to a sintering temperature in the range of 1100 to 1400 °C, and then fast cooled to 500 °C within short time. A relative density of up to 99% theoretical density of the composites was achieved after sintering at 1370 °C.
True Sedimentation and Particle Packing Rearrangement during Liquid Phase Sintering
Authors: Lee Jong K. , Xu Lei , Lu Shu Zu
Published: March 2009

When an alloy such as Ni-W is liquid phase sintered, heavy solid W particles
sedimentate to the bottom of the container, provided that their volume fraction is less than a critical
value. The sintering process evolves typically in two stages, diffusion-driven macrosegregation
sedimentation followed by true sedimentation. During sedimentation, the overall solid volume
fraction decreases concurrently with elimination of liquid concentration gradient. However, in the
second stage of true sedimentation, the average solid volume fraction in the mushy zone increases
with time, and oddly, no concentration gradient is necessary in the liquid zone. In this work, we
propose that the true sedimentation results from particle rearrangement for higher packing
efficiency.
In-Situ TEM Observation on Phase Formation of TiO2 Nanoparticle Synthesized by Flame Method
Authors: Park Hoon , Jie H.S. , Kim Kyou Hyun , Ahn Jae Pyong , Park Jong Ku
Published: March 2009

TiO2 nanoparticle was synthesized by the flame method using a metal organic precursor
of titanium tetraisopropoxide (TTIP, Ti(OC3H7)4), which was controlled by varying the ratio and
flow rate of gas mixtures consisting of oxygen (oxidizer), methane (fuel) and nitrogen (carrier gas).
The morphology and the size distribution of nanoparticles were observed with TEM and FESEM,
and the phase evolution was analyzed by XRD measurement using a monochromator. The
crystalline phases of TiO2 nanoparticle depended strongly on the temperature distribution in the
flame, whereas the morphology was not sensitive. During the flame synthesis of TiO2 nanoparticle,
anatase TiO2 nanoparticle was predominantly synthesized at the high flame temperature and rapid
flame cooling condition. The low flame temperature and long flame length enabled to form almost
rutile TiO2 nanoparticle (>95%). The anatase nanoparticle was formed by a homogeneous
nucleation and has finally kept the anatase phase without the phase transformation any more in the
flame. However, the rutile TiO2 nanoparticle was not formed directly and homogeneously in flame,
and was manufactured by the phase transformation such as amorphousanataserutile. It was
proved that the rutile phase was nucleated heterogeneously from the amorphous or anatase particles.
Effect of Carbon-Nanotube Addition on Thermal Stability of Ti-Based Metallic Glass Composites
Authors: Hsu Chih Feng , Lee Pee Yew
Published: March 2009

The preparation of Ti50Cu28Ni15Sn7 metallic glass composite powders was accomplished by the mechanical alloying of a pure Ti, Cu, Ni, Sn and carbon nanotube (CNT) powder mixture after 8 h milling. In the ball-milled composites, the initial CNT particles were dissolved in the Ti-based alloy glassy matrix. The thermal stability of the amorphous matrix is affected by the presence of the CNT particles. Changes in Tg and Tx suggest deviations in the chemical composition of the glassy matrix due to a partial dissolution of the CNT species in the amorphous phase. The bulk metallic glass composite was successfully prepared by vacuum hot pressing the as-milled CNT/ Ti50Cu28Ni15Sn7 metallic glass composite powders. A significant hardness increase with the CNT additions was observed for the consolidated composite compacts.
Microstructure and Properties of Plasma Spray Coatings Prepared from Ti-Zr-Ni Quasicrystalline Powders
Authors: Seok Hyun Kwang , Kim Yu Chan , Prima Frédéric , Fleury Eric
Published: March 2009

This works deals with the deposition of Ti-Zr-Ni icosahedral quasicrystalline powders by
low vacuum plasma spray technique and the performances of the resulting coating layers. The
microstructure of the coatings, as analyzed by X-ray diffraction and TEM techniques, consisted of
nanometer-sized W-Ti50Zr35Ni15 1/1 cubic approximant and TiZrNi Laves phases as well as a low
volume fraction of submicrometer-sized ZrO2 phase. The absence of the icosahedral phase in the
coating layers was explained by the loss of Ti during plasma spraying. The shift in the composition
and the presence of the ZrO2 phase within the coating layers are believed to be responsible for the
reduced microhardness and corrosion performances evaluated by electrochemical tests in a Hanks’
Balance Salt Solution at 37oC.
Fabrication of CNT-Reinforced HAp Composites by Spark Plasma Sintering
Authors: Sarkar Swapan Kumar , Youn Min Ho , Oh Ik Hyun , Lee Byong Taek
Published: March 2009

Carbon nanotube (CNT) reinforced hydroxyapatite (HAp) composites were fabricated by
using the spark plasma sintering process with surfactant modified CNT and HAp nano powder.
Without the dependency on sintering temperature, the main crystal phase existed with the HAp
phase although a few contents of β-TCP (Tri calcium phosphate) phase were detected. The
maximum fracture toughness, (1.27 MPa.m1/2) was obtained in the sample sintered at 1100 oC and
on the fracture surface a typical intergranular fracture mode, as well as the pull-out pmhenomenon
of CNT, was observed.
Low-Cycle Fatigue Performances of P/M Ti-Fe-Mo-Al-Nd Alloy
Authors: Liu Hai Yan , Tang Hui Ping , Li Cheng , Huang Yuan Ping , Huang Boyun , Liu Yong
Published: March 2009

The low-cycle fatigue performance and fracture of the P/M Ti-Fe-Mo-Al-Nd Alloys after sintering and forging have been studied, and the linear regression equation of low-cycle fatigue lifetime was obtained. The fatigue performances were investigated [Comment: Not quite sure what is mean by ‘objected’ here.] under two different conditions. The fatigue fracture surface was analyzed by SEM. The low-cycle fatigue behavior of the P/M titanium alloy are discussed.
Dispersibility of Carbon Nanotubes
Authors: Gábor T. , Aranyi D. , Papp Katalin , Kármán F.H. , Kálmán Erika
Published: March 2009

Availability of a stable carbon nanotube suspension is a prerequisite for
production of polymer composites with carbon nanotube as additives. In this work
nanotube suspensions, which have been prepared from various nanotubes in different
dispersion agents, were compared. Dispersibility of the samples was investigated by
scanning electon microscopy and atomic force microscopy. Solution of a non-ionic
surfactant was also used successfully as a new dispersion agent. Geometrical parameters
of the carbon nanotubes were determined by using atomic force microscopy. Correlation
was found between the dispersibility and the parameters of the nanotubes and relative
permittivity of the different solvents.
Study on the Production of Metal Matrix Composite Layer by Laser Melt Injection Technology
Authors: Janó Viktória
Published: March 2009

In-situ synthesized Al2O3 reinforced metal-ceramic composite coating was fabricated on lowalloyed carbon steel surface by laser cladding. Injection of the ceramic powder into the melted surface can be difficult due to the effect of surface tension and to the lower density of the Al2O3 particles, compared to that of the steel matrix. These difficulties can be avoided by the in-situ synthesis of Al2O3 particles in the liquid steel matrix. In this paper, the results of experiments performed by laser beam will be introduced, together with the interpretation of these results. Experiments proved that the Al2O3 ceramic phase can be created in-situ in the steel matrix.
Evolution of Special Grain Boundaries in Austenitic Steels
Authors: Gaál Z. , Szabó Péter János
Published: March 2009

Three different types of austenitic stainless steel (SUS 304, SUS 304L and SUS 316)
samples were cold formed in order to investigate the effect of cold forming on the grain boundary
structure of the material. SUS 304L and SUS 316 samples were cold rolled, SUS 304 samples were
tensile loaded in different manner at room temperature. Electron back scatter diffraction
measurements have been carried out in order to obtain information about the boundaries of the
treated specimen. The measurements showed that the frequency of the special Σ3n type CSLboundaries
was significantly decreased by increasing the deformation of the samples.
Thermal Schock Fatigue Process Induced Magnetic Anisotropy
Authors: Mészáros István , Ginsztler János
Published: March 2009

In this work the magnetic anisotropy of the 15Mo3 type steel was investigated which was induced
by deterioration process caused by thermal shock fatigue. The applied thermal shock fatigue
investigation can model the material degradation due to long term service in high temperature
environment. The 15Mo3 steel is widely used as reheating pipeline base material of power plant
boilers. Magnetisation curves were measured to characterise the induced magnetic anisotropy due to
thermal shock fatigue process. A parallel motion vibrating sample magnetometer (PMVSM) which
was designed at the Department of Materials Science and Engineering of BUTE was used for the
magnetic measurements.
Welding Investigations of Modern High Strength Dual Phase and TRIP-Steel for Automotive Industry Application
Authors: Orosz Cs. , Palotás Béla , Dobránszky János
Published: March 2009

Year by year the user and process site of steelmarket keep growing and lay claim to the steelmakers. The researchers, developers and technologists use every effort to try to produce steels with compound properties. From claim of users –especially the Automotive Industry – developed the DP- (Dual Phase) and TRIP - steels (TRansformation Induced Placticity). In the Automotive Industry draft mostly the claim of loose of weight and increase the safety reserve.Welding of these Advanced High Strenght Steels (AHSS does have but very few publications and studies approach the subject). This study is about problems of weldability of Dual Phase and TRIP – steels. Welding difficulties were associated with hard and brittle spot weld nuggets and fusion weld heat affected zones being caused by nitrid. Our aim is to develop a welding procedure giving good quality of spot weld, thus the problem of hardened and brittle spot welds would cease to exist.
Development of Scrap Evaluation Algorithm to Optimize the Converter Charge Composition
Authors: Taszner Z. , Ender Alfred , Grega Oszkár
Published: March 2009

Analysing the function of steel scrap and understanding its influence on development, are
the main problems which interests the steel producers of the world. To create such an essay, the
analysis of the actual developments of the quantities, the qualities and compositions of the used
scrap types should be continuously monitored in the world’s steel industry. Series of local
experiments and evaluating statistics focusing on process optimization by scrap have been done at
ThyssenKrupp Steel. This includes the current study based on the records of scrap charges. In the
following paper the development of an indirect scrap evaluation algorithm will be discussed,
compared with results of the common ways.
Relationship between Bending Modulus and Test Sizes of Laminated Glass/Polyester Composites
Authors: Simon Z.L. , Vas László Mihály
Published: March 2009

The effect of span-to-thickness ratio (L/h) on the bending modulus was investigated in
warp, 45°, 67.5° and weft directions in woven glass fiber reinforced polyester laminates. Using
classical beam theory the results of the bending tests carried out for L/h = 5,..,50 were extended to
the total range of definition (0≤L/h<∞) by applying rational fractional and exponential fractional
functions. The extensions take the asymptotic behavior of the bending test for L/h = 0 and L/h = ∞
in account while providing the best fitting to the measured data. It has been shown that the
exponential fractional estimations give better results regarding the form of functions that is
independent from the directions.
High Temperature Oxidation Resistance of Two Ni(Co)CrAlYSi(Hf) Overlay Coatings
Authors: Huang Zhao Hui , Tan Yong Ning , Zhao Xi Hong , Li Jian Ping , Zhang Qiang
Published: March 2009

Two MCrAlY overlay coatings (NiCrAlYSi and NiCoCrAlYHf) were deposited on a DS superalloy of Ni-Al-Cr-Co-W-Mo-Ta-Hf system by vacuum arc deposition method. The two coatings show a good protection for the DS superalloy during the isothermal oxidation test at 1150 for 100 h. A continuous alumina-based scale was formed at the surfaces of the coated specimens after oxidation. Y2O3, NiO and SiO2 are also detectable in the oxide scale. For the Hf-bearing coating, some HfO2 particles exist at the interface between the coating and the substrate. But after the cyclic thermal oxidation at 1100°C, the Hf-free coating exhibited better oxidation resisitance than the Hf-bearing coating. The HfO2 blocks between the coat and the substrate may be the crack initiation which leads to the failure of the coating.
High Temperature Strength of Ni-Al-Cr Based Alloys Containing Refractory Elements for Advanced Die Materials
Authors: Kim Won Yong
Published: March 2009

Microstructures and mechanical properties of Ni3Al based intermetallic alloys produced by vacuum arc melting and vacuum induction melting were investigated in terms of phase analysis using scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffractometer and tensile test machine. The duplex microstructural feature consisting of γ’ matrix phase and small intermetallic dispersoids was observed to be distributed over the whole microstructure in the Zr and/or Mo-added samples. From the SEM-EDS analysis of the alloys, it is clearly confirmed that the Mo is solved both into γ’ matrix phase and intermetallic phase while Zr has a role to form an intermetallic Ni5Zr phase for the entire alloys investigated. The ultimate tensile strength of the present alloy was superior to iron-based and Ni-based die materials especially in the high temperature region. The mechanical results obtained will be discussed in correlation with microstructural observations, phase analyses.
Precipitation of Gamma-Prime and Gamma-Double Prime Coherent Phases in Three-Phase Ni-V-Si Alloys
Authors: Kozakai Takao , Aoki C. , Moritani Tomokazu , Doi Minoru
Published: March 2009

Phase separation of γ (A1) supersaturated solid solution into A1, γ’ (L12) and γ” (D022) phases was investigated in two Ni-rich Ni-V-Si ternary alloys by means of transmission electron microscopy. When the alloys are annealed at 1073K, two different sequences of the phase separation are observed, depending on the chemical composition of the alloy: In Ni-17.0at%V-6.9at%Si alloy (A) at the D022 corner of three-phase field, first many D022 particles precipitate aligning along the <110> direction of the matrix and the so-called chessboard pattern is observed, followed by the formation of L12 phase at the interface between D022 and A1 phases. In Ni-12.1at%V-11.3at%Si alloy (B) at the L12 corner of the Gibbs triangle, cuboidal L12 particles precipitate arranging along the <100> direction, and then D022 phase is formed. As the phase separation proceeds, a selective growth/formation of the third phase (L12 in the alloy A, D022 in the alloy B) occurs: In the alloy A, L12 phase grows into D022 particle inside along the diagonal direction of D022 cube which is parallel to the a-axis of D022 tetragonal phase. In the alloy B, D022 forms on the {100} cube face of cuboidal L12 particle, arranging the c-axis of D022 perpendicular to the {100} cube face of L12 phase. As a result of such a selective growth/formation, the first phase D022/L12 is split off into two particles, which results in the formation of laminated structure consisting of D022 and L12 phases. The selective growth/formation is considered to occur so as to maintain the less elastic strain state.
Recrystallization and Grain Growth during Alloy 718 Processing
Authors: Park Nho Kwang , Kim Jeoung Han , Yeom Jong Taek
Published: March 2009

In Alloy 718 ingot cogging process, dynamic and metadynamic recrystallizations, and static grain growth occur, and also the presence of δ phase plays a key role in controlling the grain size. In this study, the evolution of grain structure in VIM/VAR-processed Alloy 718 ingots during post-cogging heat treatments is dealt with. Compression tests were made on VIM/VAR-processed Alloy 718 ingot at temperatures between 900oC ~ 1150oC. Heat treatments were made on the compression-tested specimens, and the variation of grain size was evaluated. Constitutive equations for the grain growth are established to represent the evolution of microstructures. Special attention is paid to the evolution of grain structure under the condition of dynamic and metadynamic recrystallizations, and grain growth. The grain growth rate depends mainly on the presence of δ-phase below the δ-solvus temperature, and on the difference in the grain boundary characteristics above it.
High-Temperature Shape Memory Effect of Ti-(Pt,Ir)
Authors: Yamabe-Mitarai Yoko , Hara Toru , Miura Seiji , Hosoda Hideki
Published: March 2009

Shape recovery and superelasticity of Ti-50at%Pt and Ti-50at%(Pt, Ir), whose martensitic
transformation temperature are above 1273 K, were investigated by thermal expansion
measurement in dilatometer and loading-unloading compression test. The shape recovery was found
in all compounds in at least one of the testing methods. The highest shape recovery, about 4% was
found in Ti-25Pt-25Ir using loading-unloading compression test. On the other hand, superelasticity
was found in only ternary compounds. Larger superelasticity was observed in ternary compounds
with higher Ir contents. Potential of Ti-50Pt and Ti-50(Pt, Ir) as high-temperature shape memory
alloys is discussed.
Evaluation of Post-Weld Heat Treatments to Restore the Corrosion Resistance of Friction Stir Welded Aluminum Alloy 7075-T73 vs. 7075-T6
Authors: Widener Christian A. , Burford Dwight A. , Kumar Brijesh , Talia J.E. , Tweedy Bryan
Published: March 2009

Friction stir welding (FSW) is rapidly becoming accepted as a viable manufacturing
process for aerospace applications. One potential area of concern, however, is the corrosion resistance
of some FSW joints. While the corrosion resistance of friction stir welded 7075 aluminum has been
investigated, and attempts made to enhance its corrosion resistance through different combinations of
starting temper and post-weld artificial aging (PWAA) treatments, a clear approach for selecting
pre-temper conditions and PWAA processing has not emerged. For this investigation, FSW
butt-welds in sheets of 0.125-inch 7075-T73 and 7075-T6 were given a variety of PWAA treatments,
some of which were developed previously by other authors. Thermal treatments were evaluated using
optical microscopy, exfoliation, electrical conductivity, microhardness, tensile, and fatigue crack
propagation testing. An important conclusion drawn from this work is that 7075-T73 can be friction
stir welded and post-weld aged in a manner that produces superior exfoliation resistance and good
mechanical properties without invalidating the bulk parent material temper specified in AMS 2770G.
Coarsening Behavior of Nanometer-Sized Carbides in Hot-Rolled High Strength Sheet Steel
Authors: Funakawa Yoshimasa , Seto Kazuhiro
Published: March 2009

This study deals with a relationship between strength and coiling temperature of
high strength hot-rolled sheet steels consisting of ferrite and nanometer-sized carbides in
order to evaluate the stability of the strength against the variation of the coiling temperature.
Ti-Mo-bearing and Ti-bearing steels were prepared to form (Ti,Mo)C and TiC in ferrite matrix,
respectively. Ti-Mo-bearing steel exhibited the high strength even under the high temperature
coiling while the strength of Ti-bearing steel decreased significantly. Ti-bearing steel just after
transforming at 923K had the same hardness as that at 898K. In addition, hardness of
Ti-bearing steel coiled at 898K decreased significantly by holding at 923K for 8.64ks while
Ti-Mo-bearing steel did not represent a large change in hardness. These results confirm that
(Ti,Mo)C is not coarsened easily by Ostwald ripening at the high coiling temperature unlike
TiC. Consequently the retardation of Ostwald ripening of (Ti,Mo)C is attributed to the small
amount of titanium in solution in Ti-Mo-bearing steel.
Synthesis and Sintering of La0.8Sr0.2CrO3 for the Separator of SOFC
Authors: Hwang Sung Ik , Yoo Kwang Soo , Kim Seon Hye , Kim Chang Sam , Kim Shin Woo
Published: March 2009

The ultrasonic spray pyrolysis method and proper heat treatments were applied in order to
synthesize La0.8Sr0.2CrO3 (LSC) which is one of promising materials for separator in soild oxide fuel
cell in this study. LSC powders that were sprayed at 800oC, heat-treated at 900oC for 5 hrs, ball-milled
and finally heat-treated again at 1200oC for 20 hrs showed the average diameter of 0.3 *m and narrow
size distribution to find particles above 0.5 *m hardly. In addition, the synthesizing temperature of
LSC powders in ultrasonic spray pyrolysis method was 100 lower than conventional ball milling
and drying method. Therefore the proper combination of heat treatment and milling process after
spray pyrolysis was found to be very critical in synthesizing fine and uniform LSC powders. Finally,
the sintering properties of these LSC powders were analyzed and compared with those of
conventional ones.
The Effects of Oxygen Partial Pressure on Interface States and Ferroelectric Properties of PZT/PbO/Si (MFIS) Structures
Authors: Park Chul Ho , Won Mi Sook , Son Young Gook
Published: March 2009

Pt/PZT/PbO/Si with the MFIS structure was deposited on the p-type (100) Si substrate by
the r.f. magnetron sputtering method with Pb1.1Zr0.53Ti0.47O3 and PbO targets. From the X-ray
photoelectron spectroscopy (XPS) results, we could confirm that the partial pressure ratio during PbO
deposition affects the interface condition of PbO/Si and the chemical state of Pb existing at the
surface of the PZT thin film. The maximum value of the memory window is 3.0 V under the applied
voltage of 9V for Pt/PZT (200 nm 400°C)/PbO (80 nm, 300°C)/Si structures with the PbO buffer
layer deposited at the partial pressure of 7:3. From these results, we could assume that the PbO buffer
layers play a role of the diffusion barrier between the PZT thin film and the Si substrate as well as the
seed layer.
Mechanism of PVC’s Solid-Phase Photocatalytic Degradation Enhanced by Plasma
Authors: Li Xiao Jing , Qiao Guan Jun , Chen Jie Rong
Published: March 2009

The solid-phase photocatalytic degradation of poly (vinyl chloride) (PVC) films was
investigated in ambient air. The photodegradation of the PVC and PVC-TiO2 was compared with
that of plasma-treated PVC and plasma-treated PVC-TiO2 performing a weight loss monitoring
and scanning electron microscopic (SEM) analysis. The SEM of the PVC-TiO2 film treated by
plasma showed many cracks on the surface after photodegradation. Furthermore, the surface
wettability and surface structure of PVC after nitrogen plasma treatment was characterized by
contact angle, surface tension, and electron spin resonance (ESR). The experiment indicated that
the surface free energy and wettability of PVC treated by plasma increased greatly. ESR revealed
that the signal of radicals on the surface of the plasma-treated PVC film was enhanced after
treatment. The free radicals on the surface of plasma-treated PVC possibly decreased the activating
energy of photocatalytic reaction, which belongs to the free radicals reaction, because the chemical
activity of the free radicals was high. According to these findings, a mechanism on the
photodegradation of plasma-treated PVC-TiO2 is proposed.
A Study on High Temperature Oxidation of Titanium Alloys in Solid State Bonding Process
Authors: Lee Ho Sung , Yoon Jong Hoon , Yi Yeong Moo
Published: March 2009

The surface oxidation behavior was investigated over a range of solid state bonding
condition of the Ti-6Al-4V ELI alloy. Since the oxides at the bonding interface may prevent the
materials from complete bonding, it is important to understand the oxidation behavior at solid state
bonding condition. The activation energy of oxidation of Ti-6Al-4V ELI is estimated to be 318
KJ/mol in an environment of solid state bonding process. For Ti-6Al-4V ELI alloy, strucutral integrity
of bonding interface without oxides have been obtained at 850°C applying pressure of 3MPa for 1
hour. Solid state diffusion bonding of Ti-15V-3Cr-3Sn-3Al alloy was also obtained under a pressure
of 6MPa for 3 hours at 925°C.
Deposition and Characterization of D-Gun Sprayed WC-Co Coating with Self-Lubricating Property
Authors: Du Hao , Sun C. , Gong Jun , Lee Soo Wohn
Published: March 2009

A WC-Co coating with self-lubricating property was deposited by detonation gun (D-gun) process, using a WC-Co powder doped
with a MoS2-Ni powder, under a proper spray condition. It is proved that the MoS2 composition was kept in the resulting coating by SEM,
XRD and EPMA. Evaluation on sliding wear property indicates that the MoS2 composition plays an important role in lowering both
coefficient of friction and wear rate for the resulting coating, which is confirmed by observations on wear track. It suggests that the
deposition of WC-Co coating with self-lubricating property by D-gun spray is feasible by controlling lubricant powder and spray conditions,
which can exhibit higher sliding wear resistance.
Catalytic Decomposition of Methane: Effect of Various Factors on Catalytic Properties
Authors: Shin Hyun Chang , Kim Hyun Jung , Yun Dong Shin , Yoo Jung Whan , Lee Dong Jin , Lee Seung Ho , Kang Young Jin
Published: March 2009

The effect of various reaction factors such as amount of Ni loaded,
temperature, and variety of supports on the methane conversion were investigated to
obtain higher methane conversion. The high activities were observed over Ni(10
wt%)/SiO2 catalyst and at 650oC of reaction temperature. Catalysts using mesoporous
supports such as SiO2 and MCM-41 showed good catalytic activity and stability.
Effect of Load on the Abrasive Wear of Silica-Filled Epoxy Resin Composites
Authors: Koh Sung Wi , Kim Hyung Jin , Kim Jae Dong , Kim Byung Tak , Hwang Sun Oug , Choi Woo Seok
Published: March 2009

In the present study, the influences of load on the abrasive wear properties of
silica-filled epoxy resin composites were investigated at ambient temperature. The friction
coefficient, wear rate and specific wear rate against SiC abrasive paper were determined
experimentally. The sliding wear tests of the materials demonstrated that the friction coefficient and
the wear rate of silica filled epoxy composites were lower than those of the pure epoxy. The
cumulative wear volume tended to increase nonlinearly with increase of sliding distance and
depended on diameter of the silica particle for all these composites. The friction coefficient and
wear rate were raised substantially with an increase in applied load.
Effects of RPM, Bath Temperature and Anodizing Time in Anodizing for Mg-Al Alloy under Constant Current
Authors: Kim Seong Jong , Kim Jeong Il
Published: March 2009

We studied the effects of solution RPM, bath temperature, and time in anodizing AZ91
under a constant current density of 750 mA/cm2 in a 1 M NaOH solution. In general, increasing the
anodizing time, RPM, and temperature of the bath improved the corrosion resistance. The thickness
of the anodic oxide film likely grew by increasing the time required to generate the active
dissolution reaction. When anodizing at 750 mA/cm2, we evaluated a 300–3600-s range in
anodizing time, 0–1500 RPM, and 296–373 K bath temperatures, and determined that 3600 s,
1500 RPM, and 373 K comprised the optimum conditions.
Effects of Samarium on Microstructure and Mechanical Properties of Mg-Al-Ca Alloys
Authors: Son Hyeon Taek , Lee Jae Seol , Kim Young Kyun , Oh Ik Hyun , Yoshimi Kyosuke , Maruyama Kouichi
Published: March 2009

As samarium addition was increased, α- Mg matrix morphology was changed from
dendritic to equiaxed grains and average value of grain size was decreased from 101.6㎛ to 39.3㎛.
Samarium addition to Mg-5Al-3Ca based alloys resulted in the formation of Mg-Al-Sm thernary
intermetallic compounds at grain boundarys and α-Mg matrix grains. In these alloys, two kinds of
eutectic structure were observed; coarse irregular-shape structure at grain boundary and fine
needle-shape structure in the α-Mg matrix grain. It is found that the yield strength and ultimate
strength showed the maximum value of 109.1MPa and 139.3 at Mg-5Al-3Ca-2Sm alloy,
respectively.
Electromagnetic Absorption Behaviors of Ferromagnetic Fe-Cr Alloy Powder and Polymer Composites in the Radio Frequency Range
Authors: Kim Sang Woo , Lee Sung Jae
Published: March 2009

In order to achieve effectively high electromagnetic absorption in the radio frequency for
the application of the electromagnetic absorber, we investigated annealing effect of microforged
powders on electromagnetic absorption behaviors of ferromagnetic Fe-Cr alloy metal
powder-polymer composites. The power loss in the far field regime was improved with increasing
the microforging time in the frequency range from 50 MHz to near 1 GHz, because the magnetic
permeability was slightly increased in the frequency range due to the high aspect ratio of the
microforged metal powders. At higher frequency more than ~1 GHz, there was no further increased
in power loss because of development of internal strain during microforging process. The magnetic
permeability was significantly increased with annealing temperature due to the reduction of the
lattice strain of the microforged powders. As a result, the electromagnetic absorption of
ferromagnetic Fe-Cr alloy metal powder-polymer composites was highly improved.
Finite Element Analysis for Precision Forging Process of United Transfer Driven Parking Gear
Authors: Lee Geun An , Lim Seong Joo , Kim Dong Jin , Park Yong Bok
Published: March 2009

Forging process is one of the most basic metal forming processes. In this study a new
forging process is applied to fabricate a precision forging product uniting parking and driven gears
in order to obtain lightweight and cost effectiveness of an automobile. Since the united product
using the precision forging process needs high quality and new manufacturing process, 3D
computer simulation by FEM has been used to reduce some trial and errors in experiment and
obtain the deformation, strain, stress and load of the workpiece and die. The study has tried to find
out an optimal process including preform design putting emphasis on tooth filling by DEFORM-3D,
a 3-dimensional rigid-plastic finite element code.
Control of Organic Micropollutants Using Dual Functional Adsorbent/Catalyst System
Authors: Kim Jae Hyuk , Kim Se Jung , Lee Chung Hak , Lee Sang Ho
Published: March 2009

This study focuses on the development of novel catalysts for simultaneous adsorption and
oxidation of micropollutants in aqueous phase. Molecular catalysts were physically immobilized on
the surface or pore of amberlite IRA-400 or powdered activated carbon (PAC). Comparison of
different combinations of catalysts and adsorbents showed that the Fe(III)-TsPc combined with
amberlite had the highest removal efficiency for target compounds. Although the catalyst was
immobilized by electrical attraction, no dissociation of catalyst from adsorbent occurred during the
tests. Amberlite-supported Fe(III)-TsPc shows more than 98% removal efficiency in 40 min. In
homogenous system (suspension of Fe(III)-TsPc in aqueous solution), the oxidation reaction occurred
only in acidic conditions (pH ~ 4.5) and the catalyst deactivation rate was fast. On the contrary, the
reaction was fast in neutral pH and catalytic deactivation was negligible using the
amberlite-supported Fe(III)-TsPc.
Influence of Interlayer on the Corrosion Behavior of Multilayered WC-Ti1-xAlxN Coatings in Deaerated 3.5% Sodium Chloride Solution
Authors: Hong J.H. , Ahn Seung Ho , Kim Jung Gu
Published: March 2009

Multilayered coatings of WC-Ti and WC-Ti1-xAlxN were deposited to form a wear- and
corrosion-resistant surface. The cathodic arc deposition (CAD) method was used to deposit WC-Ti1-
xAlxN coatings with variable Al content onto high speed steel (HSS). Three kinds of WC-Ti1-xAlxN
coatings, each with and without interlayer (Ti/TiN), were prepared. The corrosion behaviors of WCTi1-
xAlxN coatings in a deaerated 3.5% NaCl solution were investigated by galvanic corrosion test
and potentiodynamic polarization test. The porosity of the coatings, both with and without
interlayer, generally decreased with increasing Al content. The multilayer coating with a Ti/TiN
interlayer was responsible for the increased corrosion resistance due to its lower porosity and higher
adhesion strength than the multilayer coatings without interlayer.
Investigation of Thermal Shock Behaviors for Machinable SiC/h-BN Ceramic Composites
Authors: Jin Hai Yun , Qiao Guan Jun , Gao Ji Qiang
Published: March 2009

The SiC/h-BN ceramic composites with different h-BN size were fabricated by Plasma
Active Sintering (PAS) method. For the SiC/ nano-sized h-BN ceramic composites, when the h-BN
content was increased, because the nano-sized h-BN crystals were homogeneously dispersed around
the SiC grains of the matrix, the bending strength and fracture toughness of the composites decreased
slowly, but the hardness decreased sharply, therefore the machinability and thermal shock resistance
were improved noticeable.
Research on High-Purified Lignin Thermoplastics
Authors: Luo Xue Gang , Li Wan Li , Lin Xiao Yan
Published: March 2009

Highly purified lignin with 3000 molecule weight, more than 90% purity, was
obtained from reed pulp, through the use of organic-solvent-circulation method, a newly
lignin separating method. Organic-solvents-circulation method of lignin separation exhibited
faint effects on the molecule structure of lignin. Melting lignin showed pseudoplastic
characteristics. Lignin blending performed excellent processing properties in molding
process.
Residual Stress Measurement of Plasma Sprayed Coating Layers in ZrO2
Authors: Lee Soo Wohn , Zhang Jia , Chen Huang , Song J. S. , Seo Jae Kyo , Yi Zeng , Sekino Tohru
Published: March 2009

Plasma sprayed coatings have been widely applied in modifying surface properties of
metal components. It is also useful to prevent various types of wear, corrosion, erosion and thermal.
But the residual stress is still an important problem which can effect the properties of sprayed
coating. So it’s necessary to find out the reason of residual stress and the relationship between
plasma sprayed condition and residual stress. Plasma spray coating layers with conventional ZrO2
powder was examined to calculate residual stress by X-ray diffraction method with various coating
thickness.
Studies on Rheological Property and Miscibility of Lignosulfonate/Polystyrene Blends
Authors: Zhou Jian , Luo Xue Gang , Lin Xiao Yan
Published: March 2009

Effects of amounts of lignosulfonate and additives and reaction temperature on
thermoplastics of lignosulfonate/polystyrene blends were investigated by rheometer through
measurement of maximal torque, balanced torque and plasticized time. Optimum experimental
parameters for preparation of lignosulfonate/polystyrene blends with excellent thermoplastic
properties were obtained. The results of SEM and IR revealed that miscibility of
lignosulfonate/polystyrene blends was improved, favorable for development of degradable
lignosulfonate-based materials.
Study on the Microstructure of Polycrystalline Silicon Films Treated with Line Shaped Electron Beam
Authors: Fu L. , Gromball F. , Müller J.
Published: March 2009

Line shaped electron beam was used for the recrystallization of nanocrystalline silicon layer
that had been deposited on the low cost borosilicate glass-substrate in this paper. Polycrystalline
silicon films of a 20μm thickness, which are the base for a solar cell absorber, have been investigated.
Tungstendisilicide (WSi2) was formed at the tungsten/silicon interface as well as grain boundaries of
the silicon. WSi2 improved the wetting and adhesion of the silicon melt. The surface morphology of
the film was strongly influenced by the recrystallization energy density applied. Low energy density
resulted in non wetted WSi2/W areas due to the reaction between the silicon melt and the tungsten.
With the increased energy, the capping layer become smooth and continuous due to the pinholes
becomes fewer and smaller. Excess of the energy density led to larger voids in the capping layer,
more WSi2/Si eutectic crystallites, a thinner tungsten layer, and a thicker tungstendisilicide layer.
The Influence of Microstructure on the Friction Properties of Carbon/Carbon Composites
Authors: Xiao Zhi Chao , Jin Zhi Hao
Published: March 2009

Carbon/carbon (C/C) composites with smooth laminar texture pyrocarbon (SL), rough
laminar texture pyrocarbon (RL) and RL pyrocarbon adding particle resin carbon were prepared,
respectively. The open porosities of the composites were measured by Archimedes principle, and
their mechanical and thermophysical properties were tested. The friction properties of the braking
disc prepared from the three types C/C composites were tested at stimulating airplane braking
conditions. The friction coefficient of the SL C/C composites with is 0.26 under normal landing
condition. For the RL C/C composites with open porosity of 13%, the friction coefficients are 0.35,
0.24, 0.29 under normal landing (NL), rejected take-off (RTO), damp landing (DL) conditions,
respectively. The friction coefficients of C/C composites with RL pyrocarbon adding particle resin
carbon (open porosity is 8%) are 0.36, 0.31, 0.36 under NL, RTO, DL conditions, respectively. The
results show that the RL pyrocarbon increases the friction coefficients of the C/C. The addition of
particle resin carbon in the C/C increases the braking efficiency of C/C composites under high energy
landing. Low porosity C/C has better braking efficiency under DL condition.
A Study on Thermal Stabilization of Spent Foundry Sand
Authors: Rhee Seung Whee
Published: March 2009

Thermal stabilization is used to reduce the turbidity of spent foundry sands (SFSs).
Effect of stabilized temperature and thermal stabilized time in thermal stabilization is estimated by
turbidity of SFSs in thermal stabilization. The turbidity of furan sand is 984 FAU and almost 15
times as high as that of other sands such as CO2 sand and green sand. Furan sand contains furan
resin, but CO2 sand and green sand do not use resin chemicals. The turbidity of furan sand can be
reduced by stabilization of furan resin in thermal process. In the process of thermal stabilization,
fixation of furan resin by heating occurs and resin can be in the state of insolubility. The turbidity of
furan sand is sharply decreased within thermally stabilized time of 2 hrs and decreased with
increasing stabilized temperature. Turbidity in thermal stabilized time of 2hrs and stabilized
temperature of 600°C is almost 10 FAU. Hence, thermal stabilization can be applied to reduce the
turbidity of SFSs generated from iron foundry industry.
Effects of Dye Mixing on Photocatalytic Splitting of H2O into H2 and O2 on KTaO3
Authors: Hagiwara Hidehisa , Matsumoto Hiroshige , Ishihara Tatsumi
Published: March 2009

Effects of mixing dye sensitizer for the photocatalytic activity of dye-sensitized
Pt/K0.95Ta0.92Zr0.08O3 was investigated. It was found that the photocatalytic activity was greatly
improved by mixing dye sensitizer on the catalyst, and among the examined combination of organic
dyes, the highest photocatalytic activity was obtained by mixing Cr-tetraphenylporphyrin (Cr-TPP)
and Pentametylene bis[4-(10, 15, 20-triphenylporphine-5-yl)benzoate] dizinc(ΙΙ) (Zn-TPP dimer).
In order to identify the effect of dye sensitizer, photovoltaic behavior of the dye-sensitized KTaO3
was investigated. The lifetime of the photo-exited electron and hole can be improved by coating
with dye sensitizer. Thus, the effect of porphyrinoids would be explained by the improved
efficiency of charge separation.
A Window of Opportunity: Designing Carbon Nanomaterials for Environmental Safety and Health
Authors: Guo Lin , Liu Xin Yuan , Sanchez Vanesa , Vaslet Charles , Kane Agnes B. , Hurt Robert H.
Published: March 2009

Carbon nanomaterials are among the best known and most promising
products of the nanotechnology movement. Some early studies suggest that fullerenes
and nanotubes may pose significant health risks, and this has given rise to an emerging
literature on carbon nanotoxicology. This young field has now begun to yield insight
into toxicity mechanisms and the specific material features involved in those
mechanisms. This paper explores the potential to alter those material features through
post-processing or reformulation with the goal of reducing or eliminating carbon
nanomaterial health risks. The paper emphasizes the important roles of metal content
and bioavailability, carbon surface chemistry, and nanomaterial aggregation state. The
nanotechnology movement has been given a unique "window of opportunity" to
systematically investigate the toxicity of nanotechnology products and to develop
ways to manage health risks before large scale manufacturing becomes widespread.
Changing Morphology and Crystal Structure in Ettringite by Trivalent Chromium
Authors: You Kwang Suk , Ahn Ji Whan , Han Dong Yun , Cho Kye Hong , Kim Hwan
Published: March 2009

Recently, solidification processing by cement material of waste that isn’t only increasing
but also study is now in progress. Ettringite(Ca6[Al(OH)6]2(SO4)3•26H2O), which is a hydration
product of calcium aluminate minerals is highly effective at immobilizing heavy metallic ions
through a substitution mechanism. An aqueous solution containing calcium hydroxide, aluminum
sulfate, and CrCl3(trivalent chromium) was subjected to irradiate by ultrasonic irradiation under
atmospheric pressure to investigate its effect on the synthesis of Cr(III)-ettringite. The verified XRD
(100) peak tended to shift to the left and changed morphology as CrCl3 input.
Characteristic of Carbonation Reaction from Municipal Solid Waste Incinerator Bottom Ash as a Function of Water Content and their Effect on the Stabilization of Copper and Lead
Authors: Ahn Ji Whan , Cho Hee Chan , You Kwang Suk , Han Gi Chun , Um Nam Il
Published: March 2009

Most carbonation processes utilizing municipal solid waste incineration bottom ash
characteristically involve a high water content (over 100%). In this work, we developed an improved
carbonation process, utilizing various water contents. In addition, we investigated the characteristics
of a carbonation reaction using municipal solid waste incinerator bottom ash as a function of water
content and their effects on the stabilization of copper and lead. As a result of such a carbonation
reaction, the effect on the stabilization of heavy metals can be obtained. Due to this, the leaching
concentrations of these were reduced. In a high water content, calcium aluminum compounds via
carbonation reaction adsorbed Cu and Pb ions. Where a low water content (especially 30%) is
present, particle surfaces are surrounded by calcium aluminum compounds of bottom ash as a result
of the carbonation process. The leaching concentration of Cu and Pb were decreased through the
carbonation process.