bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Inert Copper and Silicon Carbide Inserts on Process of Detonation Transmission through Water
Authors: Balagansky Igor A. , Matrosov Alexander , Stadnichenko Ivan , Glumov A.I. , Samsonov A.V.
Published: March 2009

We have investigated the influence of fluoroplastic, copper, and silicon carbide inert
inserts on the process of detonation transmission through water. Active and passive HE charges
were molded from Comp B. On the rear end of the passive HE charge an identification steel
specimen was mounted, which detected presence or absence of detonation. Inert inserts were shaped
as square prisms of varying lengths, and were contained between active and passive HE charges
without any clearance on the way of initiating shock wave with partial overlap of HE cross sections.
It is shown that preloading of a passive HE charge with a shock wave transmitted through copper
or ceramic inserts causes considerable desensitization of the Comp B.
Ceteris paribus, the crash distance of detonation transmission for copper was equal to 74%, and
for silicon carbide – to 60% of the distance for fluoroplastic.
While performing the experiments with ceramic inserts we have observed cumulation
phenomenon, which manifested itself as a hole in identification steel specimen with depth of about
10 mm. The surface of specimen had typical temper colours that demonstrated presence of high
temperatures.
Stress-Induced Martensitic Transformation of Metastable Ti-Nb-Ge Alloys for Biomedical Application
Authors: Kim Han Sol , Kim Won Yong
Published: March 2009

Pseudoelastic behavior of Ti-xNb-yGe alloys, where x=22~28at.% and y=0.5~2.0at.%, was
investigated by controlling martensite start temperature and phase stability of β phase. Cyclic tensile
test was carried out to display a pseudoelastic behavior at room temperature. Determination of the
martensitic transformation temperature (Ms and Mf) and reverse transformation temperature (As and
Af) of the alloys were carried out using differential scanning calorimetry (DSC). Optical microscopy,
X-ray diffraction (XRD) and DSC results revealed that Ge is stronger stabilizer of β-phase than Nb.
XRD spectra of the deformed specimens confirmed that the crystal structure of stress-induced
martensite phase is orthorhombic structured α″. It is concluded that pseudoelasticity of the present
Ti-Nb-Ge alloy is closely associated with phase stability, and metastable β-phase is better to increase
pseudoelasticity than stable one.
The Adhesion Evaluation of Thin Hard Coatings on Tool Steel with Nitride or Non-Nitride Layer Using the Scratch Test
Authors: Lee Chan Joo , Lee Jung Min , Kim Byung Min
Published: March 2009

The deposition of thin hard coating onto tool steel is done to improve the surface properties
such as wear, corrosion. The adhesion strength between substrate and coating is one of important
parameters in practical applications since coating failure affects the lifetime of tool directly. Scratch
test with acoustic emission(AE) technique was performed to evaluate the adhesion strength
qualitative by observing the friction load vs. the normal load curves, the acoustic emission signal
generated by the damage of coatings and the scratch track using an optical microscope. In this study,
the effect of substrate hardness on the adhesion strength was investigated by evaluating critical load
and work of adhesion and observing AE signal and failure mode in scratch track using optical
microscope. Coatings were individually deposited on six substrates by means of physical or chemical
vapor deposition(PVD, CVD) process and TD process. The critical load of the substrates with nitride
layer is higher than without nitride. Although high load causes higher stresses which make flaking
occur in the coating-substrate interface, the work of adhesion of harder substrates is also high.
Because harder substrates have small contact area causing lower the plastic deformation around
stylus.
Effect of MSW Incineration Bottom Ash in Clay Based Ceramics
Authors: Kasuriya Supawan , Jiemsirilers Sirithan , Thavorniti Parjaree
Published: March 2009

The clay-based ceramic was produced by adding with the bottom ash from domestic municipal solid waste incinerator plant in Thailand. The amount of the ash up to 60 wt% was added. The samples were dry pressed and sintered at the temperature range between 1000 and 1125°C. The presence of quartz (SiO2), anorthite sodian (Ca,Na)(Si,Al)4O8, albite (Na(Si3Al)O8) and mullite (Al6Si2O13) was observed in the sample with the addition of the bottom ash. The physical and mechanical properties were also presented. The sintering temperature and the ash addition revealed the effect on the properties of the product.
Properties of Nano-Hybrid Sol-Gel Coating Films Synthesized with Colloidal Silica and Organoalkoxy Silanes
Authors: Na Moon Kyong , Park Hoy Yul , Kang Dong Pil , Ahn Myeong Sang
Published: March 2009

Three kinds of colloidal silica (CS)/silane sol were prepared. Sols are involved with the
kinds of silane with different organic group. Methyltrimethoxysilane (MTMS) has the three methoxy
groups and a methyl group. γ-Glycidoxypropyltrimethoxysilane (GTMS) has the three methoxy
groups and a bulky epoxy group. GTMS was added to two sols with different amount. When sol
reacted for 10 days, viscosity increased dramatically. Trasnmittance of sols reacted for 10 days
decreased rapidly, too. It indicated the stability of sol degraded. Sol-gel coating films were formed on
glass substrate using spin coating procedure with reaction time for 10 days. Coating films were flat
and transparent without cracking. CS/MTMS coating films showed high contact angle. When large
amount of GTMS was added, contact angle decreased due to its epoxy group. No thermal degradation
of CS/MTMS coating film occurred up to 600 oC. CS/MTMS/GTMS coating film degraded at 400 oC
for decomposition of epoxy group which has long organic chain which easily degraded by the thermal
shock.
A Study of Residual Elastic Strain Distribution in an AZ91 Mg Alloy Bar Loaded in Four Point Bending
Authors: Prakash D. G. Leo , Vorster Willem J.J. , Zhang Shu Yan , Korsunsky Alexander M.
Published: March 2009

This paper presents a study of the residual strain field within a high pressure die cast
(HPDC) AZ91 Mg alloy bar subjected to four point bending. The technique employed for this purpose
is high energy synchrotron X-ray diffraction. Strain scanning using polychromatic X-ray beam allows
the collection of multiple peak diffraction patterns and monitoring of small peak shifts as a function of
beam position. These shifts allow collective interpretation in terms of the equivalent macroscopic
residual elastic strain. Residual elastic strain distributions were studied in the sections subjected to pure
bending and also in sections of contact between the sample and the rollers. These experimental results
are compared with the predictions from a finite element analysis of contact and deformation. Good
agreement is found between the modelled and measured results. It is hoped that these results help
improved understanding of complex deformation behaviour of thin-walled HPDC AZ91 components
and provide useful background information for lifing assessment of such structures.
Improvements in Energy Dispersive Diffraction in Respect of Residual Stress Analysis
Authors: Denks Ingwer A. , Genzel Christoph
Published: March 2009

In residual stress analysis (RSA) using energy dispersive (ED) diffraction care has to be
taken of the detector energy stability. For a given detector system it is demonstrated that the energy
position decreases significantly with dead time. Correction of the RSA data both in reflection and
scanning experiments allows a significant improvement in the reliability of RSA under different
conditions. Owing the small diffraction angles in ED experiments, the effect of adjustment errors in
reflection geometry is investigated revealing the need of a wide incoming beam combined with high
collimation of the secondary beam. The differences in the used absorber materials are shown in
respect of sample heating and beam widening due to diffuse scattering.
Effects of Vanadium and Rare-Earth on Carbides and Properties of High Chromium Cast Iron
Authors: Zhao Wen Min , Liu Zhen Xu , Ju Zi Lai , Liao Bo , Chen Xue Guang
Published: March 2009

The type, shape and distribution of carbide take directly effect on the mechanical
properties of high chromium castings. Vanadium is able to stabilize the structure of carbide in high
chromium cast iron, meanwhile the hardness of carbide containing vanadium can reaches about
2800HV. In some cases, vanadium can also refine the microstructure. Rare-earth is able to change
the shape of carbide in cast iron, refine the grain size of ferrite and improve the mechanical
properties of castings. In this experiment, intention of adding vanadium and rare-earth is
modification of mechanical properties with the proper heat treatment technology. With the help of
SEM, the characteristics of carbide, such as shape, distribution and quantity can be observed and
mechanical properties have been improved for better wear-resistance.
Applications of Dyes in Material Science Research
Authors: Cao Zhen Yu , Zhao Feng , Li Xi Yan
Published: March 2009

Dyes are colored organic compounds that are used to pigment fiber or other materials. Dyes are
mainly calssified into natural and synthetic dyes in terms of the origin. Natural dyes include animal
dyes, plant dyes and mineral dyes with such defects as incomplete chromatogram, inconvenient use
and color fading, and thus have been gradually eliminated. In 1856, the 18-year-old young British
scientist Perkin successfully invented the world's first synthetic dyes. He built his own factory and
industrialized synthetic dye production. Over 100 years since then, dye industry has undergone
rapid development, and by 2001 synthetic dyes already have been up to nearly 10,000 varieties. In
2004, the output of total dyes in the world has reached 900,000 tons. Synthetic dyes are used
comprehensively, not only to dye synthetic fibers, but also natural fibesr, fur, leather and man-made
fibers.
Finite Element Analysis of Stress and Strain in Two-Wedge Cross Wedge Rolling Step-Shaft Part
Authors: Xing Xi Dong , Shu Xue Dao
Published: March 2009

Two-wedge Cross Wedge Rolling (TCWR) is a metal processing technology in which a
heated cylindrical billet is plastically deformed into an axial part by the action of two wedges dies
moving tangentially relative to the work piece. The metal deformation process is more complicated
in TCWR than in single-wedge CWR. In this paper, a new and innovative numerical model of
TCWR was developed, using advanced explicit dynamic finite element method (FEM). The whole
TCWR process was simulated successfully, the three-dimensional nonlinear deformation process
including stress and strain variation among the whole stages was analyzed at length, and 4 different
principal stresses, including the first, second, third and von Mises equivalent stresses, at different
billet centers are presented serving as a TCWR design guideline. Experimental result proves that the
finite element simulation in TCWR process is true and this fundamental investigation provides a
multi-wedge guideline in selecting CWR tool parameters and tool manufacturing.
Releasing Algorithm for Volumetric Locking in Metal Forming Process Simulation Based on Element-Free Galerkin Method
Authors: Guan Yan Jin , Wu Xin , Zhao Guo Qun , Lu Ping
Published: March 2009

The meshless methods effectively deal with large material distortion simulation. Based on the
rigid (visco)plastic material model, the element-free Galerkin method (EFGM) is introduced to simulate the
metal forming processes. Aiming at the volume locking and pressure oscillation during EFGM analysis, a
volumetric strain rate mapping method is proposed based on pressure projection method. The releasing
algorithm is established by modifying the volumetric strain rate in the functional equation. The volumetric
strain rate calculated according to velocity field is mapped onto a lower-order space to reduce the number of
independent discrete constrain equations. The numerical example shows that the releasing algorithm can
effectively eliminate the volumetric locking and pressure oscillation without the expense of employing large
support size in the rigid-plastic meshless method.
Numerical Study of Liquid Core Solidification in Influence of Soft Reduction Deformation on Steel Slab Continuous Casting Process
Authors: Luo J. , Lin Xin , Ye Yan Hong , Liu K.W.
Published: March 2009

A two dimensions (2D) multiphase solidification model is used to study the liquid core
solidification in the influence of deformation during soft reduction of continuous casting (CC). The
transient transport equations (mass, momentum and enthalpy) for each phase of a thin steel slab CC
are solved. Four different cases including of density-temperature function and deformation
reduction factor on this CC are simulated. The solidification ending point position of liquid core,
temperature, velocity and fracture of liquid and solid phases are compared. Understandings to the
deformation and liquid core formation mechanism on soft reduction solidification process of CC are
improved.
Thermal Analysis of Whirling Unit Attached to Thread Whirling Machine
Authors: Son Jae Hwan , Lee Young Moon
Published: March 2009

Thread whirling process is a cutting process in which a series of cutting edges on the
whirling ring remove material by turning over the rotating workpiece. Whirling unit attached to a
thread whirling machine influences much on the machining accuracy because the main sources of heat
generation are assumed as bearings, servo motor and chip formation during machining. Analysis of
temperature distribution, thermal deformation and thermal stress of the whirling unit has been carried
out. It is revealed that the highest temperature of 91°C reaches in the bearing and relative
displacement from point A to tool reaches 0.02~0.03mm along X, Y and Z axis. The maximum
thermal stress of 31.9MPa is developed in the unit.
Investigating the Mechanical Property and Rolling Contact Fatigue Life of Diamond-Like Carbon Films on Bearing Steel
Authors: Liu Hong Xi , Jiang Ye Hua , Zhou Rong , Li Zu Lai , Tang Bao Yin
Published: March 2009

Microstructure and properties of plasma immersion ion implantation and deposition
diamond-like carbon (DLC) films on bearing steel substrate were studied. Raman spectroscopy
analysis indicates that PIII&D DLC consists of a mixture of amorphous and crystalline phases, with
a variable ratio of sp2/sp3 carbon bonds, and the sp3 bonds content more than 10%. The
nanohardness (H) and the elastic modulus (E) of DLC films measurement indicate that the
maximum H (E) value is 40GPa (430GPa). The corrosion polarization curves prove that the
corrosion resistance of DLC samples is much better than that of substrate. The friction and wear
behaviors and rolling contact fatigue (RCF) life of these samples show that the friction coefficient
decrease from 0.87 to 0.2; the L10 , L50 , La and L life of treated sample increases by 9.1, 3.2, 2.5 and
2.4 times, respectively. The RCF life scatter extent of treated samples is improved significantly.
Bulk Ultrafine and Nanostructured Materials from Consolidation of Particles by Severe Plastic Deformation
Authors: Xia Kenong
Published: March 2009

The progress in bulk ultrafine and nanostructured materials through consolidation of
particles by severe plastic deformation (SPD) is reviewed. The focus is on the processes of high
pressure torsion (HPT) and equal channel angular pressing (ECAP) with or without the application
of a back pressure. Various materials consolidated are described in terms of their densities,
microstructures and mechanical properties. The important processing parameters and their effects
on the resulting materials are discussed. It is shown that SPD consolidation of particles is an
effective way of producing bulk nanostructured materials although much work is needed to
understand the consolidation behaviour and to design the optimum compositions and
microstructures.
Relationship between Feedrate and Fatigue Life of Al7075-T6 Specimens before and after Shotpeening
Authors: Kim Hyoung Tae , Shin Ki Hoon
Published: March 2009

This paper presents a study on the relationship between feedrate and fatigue life of
Al7075-T6 specimens before and after shotpeening. For this purpose, six groups of specimens, each
of which consists of eight specimens, were first machined at six different feedrates (0.05, 0.10, 0.15,
0.20, 0.25, 0.30 mm/rev). Half of eight specimens in each group were then peened and the others
remained un-peened. Next, the fatigue life was measured by using 4-point rotary bending machine.
One observation was that the fast the feedrate was, the large the mean diameter of a specimen was.
To apply the same bending stresses in all cases, different loading conditions were thus recalculated
and applied to specimens based on their mean diameters. Finally, the effect of feedrate on the
fatigue life was estimated by comparing twelve sets of specimens (six groups times two sets, peened
and un-peened).
Investigation of Wall Thinning Measurement in Steel Plates by Electromagnetic Acoustic Resonance
Authors: Mitani Kinya , Mochizuki Masahito , Toyoda Masao
Published: March 2009

Development of a non-contact method for measuring the degree of corrosion is highly
desired by those who are involved in the maintenance and control of steel structures. Increasingly, it
is expected that application of an electromagnetic acoustic technology that does not require a
coupling medium will meet this demand. Various problems have been reported regarding measuring
thickness of a corroded material using the resonance method. In order to clarify these problems, it is
important to make evaluations based on the resonance spectrum that corresponds to the thickness of
each plate. In this paper, experiments using grooved specimens for a basic investigation were
performed and a new method for wall-thinning measurement based on the resonance spectrum
amplitude was proposed. In addition, examination was performed by using a numerical simulation
about this method’s detection principle.
A Comparative Evaluation of Friction-Welded and Brazed Ti and AISI 321 Stainless Steel Joints
Authors: Baek Seung Wook , Lee Won Bae , Koo Ja Myeong , Lee Chang Yong , Jung Seung Boo
Published: March 2009

Microstructure and mechanical properties of friction welded and vacuum brazed Ti/AISI
321 stainless steel have been evaluated with various welding conditions. Maximum tensile strength
of friction welded joints was approximately 420 MPa with the conditions of 400 MPa of upset
pressure (P2) and friction time (t1) within 2.0 s. Maximum tensile strength of brazed joints was
acquired under the condition of 900 °C brazing temperature and 5 min. brazing time and showed
approximately 275MPa which was about 80% of that of the Ti base metal. Friction welded Ti/AISI
321 joints showed the superior tensile strength than that of brazed Ti/AISI 321 due to thinner
intermetallic compound layer.
A Rate-Dependent Hysteresis Model for Structural Steel (SM490) Considering the Coupled Effect of Strain Rate Hardening and Temperature Rise
Authors: Jang Gab Chul , Chang Kyong Ho
Published: March 2009

In steel structures, the mechanical characteristics and the hysteretic behavior during
dynamic behavior is different to those during static deformation. This is due to the coupled effect of
strain rate hardening and temperature rise. To predict hysteretic behavior of steel structures under
dynamic/cyclic loading such as earthquake, it is therefore necessary to develop a rate-dependent
hysteresis model which can accurately describe the static-dynamic mechanical characteristics
considered the coupled effect of strain rate hardening and temperature rise as well as the hysteretic
behavior.
In this paper, to develop a rate-dependent hysteresis model of SM490(structural steel according to
Korean standard), the monotonic and cyclic loading tests were performed for strain rate. Based on
the test results, the rate-dependent hysteresis model of SM490 was formulated and with the material
parameters used, the model was derived. The validity and the accuracy of the developed model
were verified by comparing between the analyses and the experiments. The comparison results
show that the rate-dependent hysteresis model of SM490 developed by the authors can accurately
predict the static-dynamic hysteretic behavior of steel structures under cyclic loading.
Development of Welding Distortion Analysis Method Using Residual Strain as Boundary Condition
Authors: Ha Yun Sok , Cho Si Hoon , Jang Tae Won
Published: March 2009

There are two ways of conventional thermal distortion analysis. One is thermal elastoplastic
analysis and the other is equivalent forces method based on inherent strain. The former needs
exorbitant analysis time, while the latter cannot obtain stress results and requires more time with
loads modeling on curved plates. To solve those time-consuming problems, a new kind of thermal
distortion analysis method was developed. In this method, inherent strains are devised to be used as
direct input factors as boundary conditions. Suggested analysis method was already adopted at
welding distortion analysis of large hull block, which was considered as impossible.
Fatigue Life Improvement Using Mechanical Post Treatment for Weldment
Authors: Han Seung Ho , Han Jeong Woo , Nam Yong Yun
Published: March 2009

Mechanical post treatments for welded structures have been applied in various industrial
fields and, in most cases, have been found to cause substantial increase in their fatigue strength.
These methods, generally, consist of the modification of weld toe geometry and the introduction of
compressive residual stresses. In hammer peening, the weld profile is modified due to removal or
reduction of minute crack-like flaws; compressive residual stresses are also induced by repeated
hammering of the weld toe region with blunt-nosed chisel. In this study, a hammer peening
procedure, using commercial pneumatic chipping hammer, was developed; a quantitative measure
of fatigue strength improvement was performed. The fatigue life of hammer-peened specimen was
prolonged by approximately 10 times in S=240MPa, and was doubled for the as-welded specimen.
Phase Diagrams of Ni2MnX (X = In, Sn, Sb) Heusler Alloys with Inversion of Exchange Interaction
Authors: Buchelnikov Vasiliy D. , Taskaev Sergey , Zagrebin M.A. , Entel Peter
Published: March 2009

In this work with the help of the phenomenological Ginzburg-Landau theory of structural
and magnetic phase transitions the phase diagrams of Heusler Ni-Mn-X (X = In, Sn, Sb) alloys with
the inversion of exchange interaction are investigated. The investigation shows that the type of the
phase diagrams in Heusler Ni-Mn-X (X = In, Sn, Sb) alloys depends on the value and sign of the
free energy parameters. As it is seen from the analysis of the phase diagrams with the determined
values and signs of the parameters of Landau functional there are thermodynamic paths which allow
to explain experimental phase transitions in Heusler alloys Ni-Mn-X (X = In, Sn, Sb) and Ni-Co-
Mn-X (X = In, Sn, Sb) qualitatively.
Studies on PVC-Clay Mixture as Function of the Temperature Cooking
Authors: Sansosti R. , Vuono D. , Nastro Alfonso
Published: March 2009

In Italy, the amount of thermoplastic materials is 5 million tons. The recovery is
necessary through simple processes with high efficiency. The aim of this paper is to study the use of
plastic material particles in the ceramic industry for the production of light bricks, since this waste
burns during firing at high temperature. The clay is extracted by disused quarry of South Italy and
the PVC is a by-product of polymeric bars production (San Giovanni in Fiore- Calabria). The clay
and the PVC waste were characterised by thermal analysis, X-ray diffraction to identify the
crystalline phases of raw material and EDS analyses to determine the chemical composition.
Mixtures containing waste and clay materials were formed by extrusion and fired in a furnace using
range temperatures of 900°C-1100°C. The obtained final products are bricks of 15 cm of length,
2 cm of thickness and 1.2 cm of height. The physical and mechanical properties were studied. These
properties are used to define process firing temperature. Water absorption and linear shrinkage tests
carried out as a function of the firing temperature.
Evolution of Special Grain Boundaries in Austenitic Steels
Authors: Gaál Z. , Szabó Péter János , Ginsztler János
Published: March 2009

AISI 304 type austenitic stainless steel samples were subjected to different thermomechanical
treatments in order to investigate the effect of thermo-mechanical treatment on the grain
boundary structure of the material. 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 achieving the same deformation with the same number of deformation cycles and same
heat treatment temperature, the application of shorter heat treatment holding time was advantageous
in aspect of grain boundary structure comparing to the thermo-mechanical treatments with longer
holding time. The frequency of the special Σ3n type CSL-boundaries excluding coherent twin
boundaries was significantly decreased by increasing the heat treatment holding time of the samples
from the very short heat treatment periods. Extending the holding time further, the frequency of the
special Σ3n type CSL-boundaries excluding coherent twin boundaries increased and reached the
results applying the shorter heat treatment periods.
Electrical Examination of Silicon Nitride – Carbon Composites
Authors: Fényi Balazs , Arató Péter , Wéber Ferenc , Hegman Norbert , Balázsi Csaba
Published: March 2009

The Si3N4 ceramics are usually known as strongly refractory and enduring materials and
they have typical insulating material properties on room temperature. If reinforcing phase of the
Si3N4 matrix composite is a good electrical conductor, in that case it is worth to investigate the
composite in electrical aspect. In our case carbon nanotubes, black-carbon and graphite with good
electrical conductivity were mixed in the base ceramic. During our electrical investigations DC
resistivity measurements were used to determine the percolation threshold and the conductivity of
the composites. In case of high resistance samples AC impedance spectroscopy was applied. As
result of the impedance spectroscopy capacitive properties were found. In some cases of conductor
samples combined mechanical – electrical measurements were done to study the integrity of the
additions in the matrix.
Calculation of the Liquidus Curves of CaO-Al2O3 Phase Diagram by ESTPHAD Method
Authors: Mende Tamás , Roósz András
Published: March 2009

Using the ESTPHAD (Estimation of Phase Diagrams) method, the liquidus and solidus
curves in the equilibrium phase diagram can be created by thermodynamic based equations. By
these determined equations, the liquidus or solidus temperatures as a function of concentration can
be calculated with the required precision. The main advantages of the ESTPHAD method are as
follows: the parameters of functions can be calculated simply, it gives a precise result and the
calculation time is short.
This paper shows the reconstruction of the liquidus curves of the CaO-Al2O3 phase diagram (0-60
wt% Al2O3 range) by using the ESTPHAD method on the basis of the measured data. The
divergences between the measured and calculated (ESTPHAD) data are less than the given
measurement error (±10 K).
Laser Shock Processing of ENAW 6082 Aluminium Alloy Surface
Authors: Grum Janez , Trdan Uros , Hill Michael R.
Published: March 2009

The present paper treats results of laser shock processing applied to a precipitationhardened
ENAW 6082-T651 aluminium alloy. Processing was performed with a Nd:YLF-yttrium
lithium fluoride crystal laser with power densities of 2 and 4 GW/cm2, producing a pulse of 18 ns.
Laser shock processing experiments were performed with the closed ablation method, the
application of an ablative coating and a transparent tamping medium to obtain a higher shock-wave
pressure. In the first phase, the surface study focused on the record of surface profile with a
roughness gauge and on an evaluation of surface topography at a scanning electron microscope. In
the second phase, residual stresses were measured using the relaxation hole-drilling method at a
processed specimen surface. Then followed measurement of microhardness in the cross section. The
hardening results obtained were evaluated on the basis of variations of residual stresses and of
microhardness, and of macro and microstructural changes of the surface, i.e. the surface layer. The
purpose of processing was to improve fatigue strenght and, consequently, extend the life of a
machine component in operation.
Nonpolar and Semipolar Orientations: Material Growth and Properties
Authors: Masui Hisashi , Nakamura Shuji
Published: March 2009

Nitride-based optoelectronic devices prepared in the c orientation have been successfully introduced to the global marketplace and are changing the way we think about lighting. A part of the research interest has shifted toward nonpolar and semipolar orientations, which has the potential to broaden the scope and impact of this technology. This is because quantum-well structures prepared in nonpolar and semipolar orientations are able to suppress the quantum-confinement Stark effect, which has a negative impact on optoelectronic device performance. The lower crystal symmetry of such orientations provides spontaneously polarized light emission. Despite these attractive properties of nonpolar and semipolar orientations, the corresponding materials growth is not trivial. The present chapter discusses our efforts on growth of III-nitride materials in nonpolar and semipolar orientations and the related material properties.
Evaluation of the Morphology and Magnetic Properties of Cr3+- Doped Ni-Zn Ferrites
Authors: da Silva Valmir José , Santos P.T.A. , Gama Lucianna , Kiminami Ruth Herta Goldsmith Aliaga , Cornejo Daniel R. , Azevedo A. , de Melo Costa Ana Cristina Figueiredo
Published: March 2009

This work involved a morphological, microstructural and magnetic characterization of
nanosized powders and sintered samples of Ni-Zn ferrite doped with chromium. The effect of
substituting Fe3+ for Cr3+ on the final characteristics of the powders and sintered samples was
investigated. The Ni-Zn ferrite powders were prepared by combustion reaction using nitrates and
urea as fuel, based on the concepts of propellant chemistry. The samples were uniaxially compacted
by dry pressing (385 MPa) and sintered at 1200oC/2h, using a heating rate of 5°C/min. The Ni-Zn
powders and compacted samples were characterized by X-ray diffraction (XRD), scanning electron
microscopy (SEM), and the measures of their magnetic properties. The results revealed the
formation of the cubic crystalline phase of the inverse spinel of Ni-Zn-Cr ferrite. The average
crystallite size was 21 nm and 57 nm while the saturation magnetization was 47.0 and 73.1 emu/g
for the powder and the sintered sample, respectively.
Three-Dimensional Printing of Stainless Steel Parts
Authors: Carreño-Morelli Efrain , Martinerie Sebastien , Mucks Lisa , Cardis B.
Published: March 2009

Stainless steel parts have been manufactured by two different layer by layer additive
processes. The first one is a standard three dimensional process, in which metal powders are bound
by selective deposition of binder with a printer head. The second one is a novel process, which is
based on the selective deposition of a solvent on metal-polymer granule beds. The microstructures
of green and sintered parts are characterized by optical and scanning electron microscopy, and the
mechanical properties evaluated by hardness and tensile tests. Solvent on granule printing allows to
reach mechanical properties similar to those of metal injection moulding parts.
Powder Diffraction of Components Subject to Corrosion in Fuse Cutouts with Ceramic Insulation
Authors: Carvalho Alex V. , Scalvi Luis V.A. , Maciel Jorge L.B.
Published: March 2009

Aiming identification of the components most affected by corrosion under saline
environment conditions, we have carried out X-ray diffraction measurements in ceramic and bond
materials, all in the powder form. The ceramic is analyzed before and after thermal annealing at
1000°C, showing the same DRX peaks, although better defined after annealing. Identification
suggests the presence of Al6Si2O13 (Mullite) and SiO2 (Quartz). Analysis of the junction (bond)
material shows similar peaks, but a metallic preponderance is observed. Thermal annealing of the
junction is done at much lower temperature, because it melts in the range 135°C-170°C, when a
whitish smoke begins to show up along with strong sulfur odor.
High Purity Zirconia and Silica Powders via Wet Process: Alkali Fusion of Zircon Sand
Authors: Yamagata Chieko , Andrade João B. , Ussui Valter , de Lima Nelson Batista , Paschoal José Octavio Armani
Published: March 2009

Zircon sand was reacted with liquid caustic soda (50% NaOH) in open vessel at 600 oC
for 2h. The effect of NaOH/ZrSiO4 reactant ratio on the yield of zirconia recovery was verified.
Samples of fusion products water washed were characterized by X-ray diffraction (XRD) to identify
the main compounds formed. Silica powders were obtained via acid catalyzed reaction and zirconia
powders were resulted from crystallization of zirconium oxychoride. Both zirconia and silica
powders were analyzed by XRF (X-ray fluorescence) and BET method. Laser Quasi Elastic Light
Scattering (QLS) technique was used for agglomerate size distribution determination. High purity
and fine zirconia and silica powders were obtained. The specific surface area of zirconia calcined at
550 oC reached ~ 70m2g-1. Silica powder calcined at 800 oC presented a high specific surface area ~
500 m2g-1.
Microstructural Analysis of Petroleum Waste Containing Ceramic Tile
Authors: Pinheiro Bruno C.A. , Holanda J.N.F.
Published: March 2009

In this work is done a study on the sintered microstructure of ceramic tile paste
incorporated with petroleum waste. The raw materials used were kaolin, sodic feldspar, quartz and
petroleum waste. The ceramic tiles containing up to 5 wt% petroleum waste were prepared by
uniaxial pressing and sintered at 1200°C. The microstructural evolution was examined by SEM. In
addition, water absorption, linear shrinkage, and sintered density were determined. The results
showed that the microstructure of the ceramic tiles is influenced by the added petroleum waste.
Formability of the Layer Additive Ceramic Part
Authors: Liu Fwu Hsing , Liao Yunn Shiuan , Wang Hsiu Ping
Published: March 2009

The material in powder state has long been used by selective laser sintering (SLS) for
making rapid prototyping (RP) parts. A new approach to fabricate smoother surface roughness RP
parts of ceramic material from slurry-sate has been developed in this study. The silica slurry was
successfully laser-gelling in a self-developed laser sintering equipment. In order to overcome the
insufficient bonding strength between layers, a strategy is proposed to generate ceramic parts from a
single line, a single layer, to multi-layers of gelled cramic in this paper. It is found that when the
overlap of each single line is 25% and the over-gel between layers is 30%, stronger and more
accurate dimensional parts can be obtained under a laser power of 15W, a laser scanning speed of
250 mm/s, and a layer thickness of 0.1 mm. The 55:45 wt. % of the proportion between the silica
powder and silica solution results in suitable viscosity of the ceramic slurries without precipitation.
Furthermore, the effects of process parameters for the dimensional accuracy and surface roughness
of the gelled parts are investigated and appropriate parameters are obtained.
Evaluation of Surface Finish Affect on Aerodynamic Coefficients of Wind Tunnel RP Models Production with ABSi Material
Authors: Ahmadi Nadooshan A. , Daneshmand Saeed , Aghanajafi C.
Published: March 2009

Nowadays, rapid prototyping (RP) methods are widely used to produce wind tunnel testing
models and thickness of layers is an important parameter that affects the aerodynamic characteristics
of model. This paper described the Affects layer thickness models product with rapid prototyping on
Aerodynamic Coefficients for Constructed wind tunnel testing models. Three models were evaluated.
These models were fabricated from ABSi by a fused deposition method (FDM). The layer thickness
was 0.178mm, 0.254mm and 0.33mm. The roughness of surfaces for each model was 25/m, 63/m
and 160/m (RZ) that determined by perthometer2. A wing-body-tail configuration was chosen for the
actual study. Testing covered the Mach range of Mach 0.3 to Mach 1.2 at an angle-of-attack range of
-4° to +16° at zero sideslip. Coefficients of normal force, axial force, pitching moment, and lift over
drag are shown at each of these Mach numbers. Results from this study show that layer thickness does
have an effect on the aerodynamic characteristics in general; the data differ between the three models
by fewer than 6%. The layer thickness does have more effect on the aerodynamic characteristics when
Mach number is decreased and had most effect on the aerodynamic characteristics of axial force and
its derivative coefficients.
Development of a Constant Temperature Environment Chamber with High Stability
Authors: Fan Kuang Chao , Wang H.M. , Liu Yi Cheng
Published: March 2009

In this study, a constant temperature environment chamber with high stability is proposed.
In the proposed design, the outer temperature is controlled by the air conditioner, the inner
temperature is controlled by the electric current generated to control several thermoelectric cooling
units. The separation design of the environment chamber from the cooling system can reduce the
vibration caused by the thermoelectric cooling elements. This system adopted the Rake’s System
Identification Method to obtain the system model, so that optimum PID parameters can be acquired
from the simulation of Matlab Simulink. The results show that the vibration can be effectively
reduced and the temperature can be controlled within the range of 20±0.007°C in the steady state.
Oxide Spallation in Beta-NiAl Coated Systems under Mechanicalloading
Authors: Harvey Mark , Rambaudon M. , Maurel Vincent , Rémy Luc
Published: March 2009

Thermally grown oxide (TGO) spallation increases the degradation rate of aluminide
protective coatings during thermomechanical cycling. Thermal expansion misfit between TGO,
bond coat and substrate, applied mechanical load in the system, and local instabilities are known
triggers for spallation. Mechanical tests have been performed on coated and oxidised AM1
superalloy. In situ and post mortem study including digital image analysis and SEM were
performed in order to characterise strain fields and associated damage field. Good correlation is
found between oxide strain and damage extent.
Why the Growth Rates of Alumina and Chromia Scales on Thin Specimens Differ from those on Thick Specimens
Authors: Quadakkers W.Joe , Huczkowski P. , Naumenko D. , Zurek J. , Meier Gerald H. , Niewolak L. , Singheiser Lorenz
Published: March 2009

For a number of chromia and alumina forming high temperature alloys and coatings,
recent studies revealed, that in some cases the specimen/component or coating thickness may
substantially affect the growth rates of the surface oxides. For the alumina formers the thickness
dependence is mainly governed by depletion of oxygen active elements such as Y, Zr, Hf, Mg
which are either intentionally added alloying elements or manufacturing related alloy impurities. In
the case of the chromia forming materials, which tend to exhibit a more substantial dependence of
oxidation rate on specimen/component thickness, depletion of minor alloying additions is also an
important factor to be considered. However, for these alloys relaxation of oxide growth stresses by
plastic deformation of the metallic substrates seems to be the dominant parameter which governs
the observed behaviour.
Kinetics of Some Iron-Based Alloys in Industrial CO2: Formation of Wüstite Phase
Authors: Valette Stephane , Menecier Sebastien , Goutier Fabrice , Lefort Pierre
Published: March 2009

This work compares the oxidation behaviour of three iron-based substrates (C40E,
Invar and 304L) in CO2 industrial gas, in order to determine the conditions for producing wüstite
(Fe1-xO), on the basis of kinetic and morphologic studies. For the three alloys at the beginning of the
reaction, wüstite formed under 105 Pa of CO2 following a rate law



 
  

RT
220000
10.2 P e
dt
d( m/S)
CO2 . For 304L, formation of a spinel phase chromite briefly
preceded it during a first step. Magnetite appeared for long times of experiment, in the case of
Invar and 304L. This can be explained by the stopping of iron outer diffusion. These results are
discussed according to the literature and thermodynamic data. They open new fields for coating
these alloys by plasma spray processes.
Cyclic Oxidation Behavior of Sputtered Nanocrystalline Coating with Yttrium Additions in Air
Authors: Yu Ping , Wang Wen , Wang Fu Hui , Zhu Sheng Long
Published: March 2009

K38 nanocrystalline coatings with various amounts of yttrium addition were deposited by
magnetron sputtering. Cyclic oxidation tests were conducted at 800-1000oC in air in order to reveal
the effect of reactive elements on the oxidation behavior of nanocrystalline material. The results
indicated that the influence of yttrium was not observable at 800oC. At 900 and 1000oC, addition of
0.1 wt.% Y decreased the growth rate of scale, while 0.5 wt.% Y addition significantly increased the
oxidation rate of nanocrystalline coating.
Study of the Microstructure and Oxidation Behavior of Chromium Base Alloys Strengthened by NiAl Precipitates
Authors: Royer Laurent , Mathieu Stéphane , Liebaut Christophe , Steinmetz Pierre
Published: March 2009

In this study, chromium based alloys containing a hardening NiAl phase are investigated
from 1100°C to 1300°C in air. The influence of the NiAl content and of the Al/Ni ratio on
microstructure modification and on oxidation behaviour are characterized by metallography and
thermogravimetry. Increasing the Al/Ni ratio leads to a higher Al content in the chromium solid
solution but does not modify the amount of primary NiAl. At high temperature, and for NiAl
content exceeding 16 at%, a duplex oxide layer forms at the surface of the alloys exposed in air,
alumina in the inner part, and chromia in the outer part. The oxidation behavior is discussed
according to oxidation profile and to the thermodynamic predominance diagram of the involved
species.
Use of the Sessile Drop Method to Understand the Behaviour of Self Healing Ceramic Matrix Composite
Authors: Wery Sébastien , Teyssandier Francis
Published: March 2009

Surface and interfacial properties of borosilicate glass/ceramic systems have been
investigated using the sessile drop method. The purpose is to compare and understand the reactivity
of the sealing glass in C / SiC and SiC / SiC composites. A hot wall reactor has been designed to
measure the variation of the contact angle and the spreading kinetic according to the temperature
(500 to 1100°C) and the atmosphere (Ar, Ar + O2 and Ar + H2O). Chemical and morphological
analyses underline (i) the strong reactivity between the liquid and the ceramic, (ii) the influence of
the infiltration process and (iii) the strong influence of the oxidizing agent on the wetting behaviour
of the glass/ceramic systems.
Formation of Pt-Modified γ’-Ni3Al and Re-Based σ-Alloy Coating System and Cyclic Oxidation Behavior of Coated Superalloy
Authors: Narita Toshio , Ford Stewart , Yoshioka Takayuki , Nishimoto Takumi , Izumi Takeshi , Hayashi Shigenari
Published: March 2009

A duplex layer, outer Pt-modified γ’-Ni3Al + γ-Ni and inner multi-barrier σ-
Re(Cr,Ni,W), coating system was formed on a Ni-based single crystal 4th generation superalloy.
Oxidation behavior of the coated alloy was investigated under thermo-cycling conditions, and
analyzed by EPMA and XRD. During cyclic oxidation 1hr at 1100°C and 20 min at room
temperature, a slow growing α-Al2O3 formed for up to 400 cycles and its spallation was rare. The
parabolic rate constant of mass change was 6.3x10-16 kg2m-4s-1. The Pt-modified γ’-Ni3Al + γ-Ni
contained 19Al, 12Pt, 4Cr, and 3Co in at%, and their concentration profiles were almost flat across
the outer layer. The multi-barrier, σ-Re(Cr,Ni,W) contained 40Re, 23Cr, 17Ni, 7Al, 4W, 3.5Mo,
and 3Co in at%. Furthermore, the γ’-Ni3Al containing Pt was newly formed between the multibarrier
and bulk alloy substrate. It was concluded that the σ-Re(Cr,Ni,W) is compatible with the Ptmodified
γ’-Ni3Al in the multi-diffusion barrier coating on Ni-based single crystal, 4th generation
superalloy at high temperatures.
Preliminary Results of the Isothermal Oxidation Study of Pt-Al-NiCoCrAlYTa Multi-Layered Coatings Prepared by Sparks Plasma Sintering (SPS)
Authors: Oquab Djar , Monceau Daniel , Thébault Yannick , Estournès Claude
Published: March 2009

MCrAlY coatings (where M = Co, Ni or Co/Ni) are widely used on turbine blades and
vanes as oxidation and corrosion resistant overlays or as a bond-coating in thermal barrier coatings
systems. MCrAlY are usually fabricated by Plasma Spraying, Physical Vapour Deposition, High
Velocity Oxy-Fuel spraying or electrolytic techniques. The use of emergent Spark Plasma Sintering
technique as a preparation method for NiCoCrAlYTa coatings has been presented previously [1].
SPS technique allows fast development of new coatings with a one-step fabrication of multilayered
coatings. This work presents first results of the long term isothermal oxidation behaviour of Pt-Ni
aluminide/NiCoCrAlYTa multi layered coatings. The obtained coating is dense and homogeneous.
Isothermal oxidation up to 500 h at 1100°C leads to the formation of an adherent alumina scale with
Y-rich precipitates and deep intergranular oxidation.
Hydrogen Detection in Buried Layers of Thermal Barrier Coatings
Authors: Rudolphi Mario , Renusch Daniel , Zschau Hans Eberhard , Schütze Michael
Published: March 2009

Thermal barrier coatings used in airplane engines or land-based gas turbines can show
catastrophic failure (i. e. spallation) typically during cooldown due to thermal expansion mismatch
stresses. However, it is also often noted that spallation occurs minutes, hours, or even days after the
sample is cold. This type of delayed failure, called “desk top spallation” is, up to now, not fully
understood and therefore a field of great interest. Because desk top failure occurs in ambient air, the
working hypothesis is that water vapor from the office environment plays a role. Consequently, a
number of experiments have been designed to verify this hypothesis. The experiments include more
traditional approaches like acoustic emission measurements during cyclic oxidation, but also
innovative new approaches like acoustic emission during water drop testing, and hydrogen
detection at the interface to the thermally grown oxide using ion beam techniques.