bluuebunny/crossref_metadata_2025 huggingface dataset:
Three Rollers – Cone Test. New Possibilities of Wear Calculation
Authors: Zwierzycki Wiesław , Rochatka Tomasz
Published: March 2009

In tests presented in the paper the authors made use of M.M. Chruščov’s concept
of determining linear wear intensity Ih in model systems operating under constant load in which the
contact stresses decrease in the effect of wear. They elaborated the mathematical model binding
vertical approach of samples in four ball apparatus equipped with the three rollers – cone couple
with rollers wear trace dimension. The model was verified in the special experiment obtaining a
very good convergence of results of calculations and the experiment.
Diagnostics of the Mechatronical Systems with Vibration Insulation
Authors: Trumpa A. , Vekteris Vladas
Published: March 2009

The paper’s work examines opportunities of diagnostics of vibroinsulated mechanisms
based on the measurement of mechanical vibration. Vibration insulation systems distort the
diagnostic signal therefore direct diagnostics of vibration of vibroinsulated mechanisms is
impossible. The work’s objective is to analyse the influence of vibration insulation systems on the
diagnostics of such mechanisms and to identify the kinds of parameters on which this influence
depends.
A stand for tests is made for the achievement of this objective; by using the stand the vibration of a
mechanism can be simultaneously measured both directly and via the vibration insulation system.
Diagnostic of Temperature of System of Rotor with Bearings of Sliding
Authors: Cereska A. , Vekteris Vladas
Published: March 2009

An analysis of the influence of the change of temperature of a rotor’s system with bearings of sliding friction to the work of a searching system is presented in this paper. Experimental research to gauge the clearance of change between a rotor and bearing subject to change of temperature and frequency of rotor’s rotating is also presented. A special rig and special implements of measurement for doing measurements is included. Experimental measurements done according to the specially made up methodology is in this paper. Also, the article describes and gives the principal system of measurement and analysis methodology to do the experiment and an analysis was done of results and the gauge of consistent pattern of changes of the searched parameters.
A Digital Control System for the Hydraulic Fatigue Stand SHM 250b
Authors: Słowik J.R. , Kasprzyczak L.M. , Macha Ewald
Published: March 2009

Unreliable and inflexible analog control systems of fatigue test stands applied in
laboratories are being replaced by systems enabling easy development and implementation of new
test ideas. This paper presents a digital control system applied in the fatigue test stand SHM 250b.
It is based on a new electronic system and the I/O board RT-DAQ4/PCI with the software
Matlab/Simulink used for communication with the board. The control system for the fatigue test
stand SHM 250b gives the possibility of performing fatigue tests under controlled strain ε(t), stress
σ(t) and energy parameter W(t) which is calculated from the stress and strain signals. The applied
control system is now used, depending on the performed fatigue tests, and can be developed for
specific needs of material strength analysis.
Tribological Properties of Oils Modified with the Addition of Metal Nanoparticles
Authors: Kotnarowski Andrzej
Published: March 2009

The present paper describes a part of an introductory examination concerning the improvement of tribological properties of base oils (used for lubricating as well as cutting oils compounding) through their composition modification by copper or molybdenum nanoparticles (nanopowder) addition. The results of tribological tests are presented as well as results of an examination of wear amount of elements cooperating in friction couples lubricated with unmodified or modified oils. These results testify to a positive influence of the described oil modification on its tribological properties manifested in friction couples.
Triboelectrical Effects in Frictional Contacts
Authors: Cypko Edward , Kałdoński Tadeusz
Published: March 2009

In the paper results of investigations of triboelectrical effects, proceeding in nonlubricated
contacts, observed as “friction microcurrents”, and also in lubricated contacts - as
“generated potential difference” are presented. Analysis of change dynamics of “friction
microcurrents” and “generated potential difference” is making it possible to direct observation in
real time and estimate the character course of interaction of elements in frictional contact.
The Hybrid Pixel Sensors and Read-Out Electronics
Authors: Navickas R. , Barzdenas V.
Published: March 2009

Hybrid pixel sensors (detectors) have shown to be a valid alternative to other types of Xray
imaging devices due to their high sensitivity, linear behavior and wide dynamic range, and low
noise. One important feature of these devices is the fact that detectors and readout electronics are
manufactured separately. The charge created by the interaction of X-ray photons in the sensor is
very small and has to be amplified in a low-noise circuit before any further signal processing. The
signal induced on the electrodes of the sensor is transferred to the readout chip, where it is
integrated in a charge sensitive amplifier. The issue reviews on physical principles of operation and
design of the hybrid pixel sensors developed on the basis of the silicon CMOS and GaAs MESFETtechnologies.
The authors have designed GaAs charge sensitive amplifiers for hybrid pixel detectors
and show the results of a simulation.
Manganite Sensor for Measurements of Magnetic Field Disturbances of Pulsed Actuators
Authors: Novickij J. , Stankevič V. , Balevičius S. , Žurauskienė N. , Cimmperman P. , Kačianauskas R. , Stupak E. , Kačeniauskas A. , Löffler M.J.
Published: March 2009

Magnetic field sensors based on polycrystalline La0.83Sr0.17MnO3 films were used to measure the magnetic field distribution and disturbances during the operation of an electromagnetic launcher. Hollow cylinders made from dural aluminum and iron were used as propelled objects inside the solenoidal coil. The obtained results revealed the ability of manganite sensors to rapidly measure changing high magnetic fields of arbitrary waveforms.
Analysis of Work Accuracy Dependencies on Design of a Device for Control of Workpiece Dimensions and Compliance at Machining
Authors: Marcinkevičius Andrejus Henrikas
Published: March 2009

Work accuracy dependencies of a new scheme device for automatic dimension control
and follow rest at machining of multi step shaft are analyzed. The device can automatically reset
from control and the support of one step of a shaft to the other and can be used on programmed
cylindrical grinders or lathes. Errors connected with the kinematics scheme and showing in static
and uprising at working of a device are analyzed and ways of their decreasing are shown.
Parametric Sensitivity of MEMS-Gyro
Authors: Kaušinis Saulius , Barauskas Rimantas
Published: March 2009

The paper presents the finite element (FE) modeling approach to sensitivity analysis of MEMS-based gyros. The FE model is employed to both studying the system’s dynamical properties and appreciation of the sensitivity of these to various influencing effects. The sensitivity functions have been obtained for adjusting the geometric parameters of the piezoelectric transducers in order to achieve the desired values of natural frequencies. Results are presented in terms of sensor performance characteristics for various design parameters and modes of operation. The modeling assumptions adopted are tested experimentally on a cantilever-shape test vehicle.
Cavitation Erosion Behavior of 18/8 Stainless Steel after Its Laser Alloying of Manganese
Authors: Szkodo Marek
Published: March 2009

The laser surface alloying of 18/8 stainless steel with Mn, was carried out by 6 kW cw
CO2 laser. The microstructure, chemical composition and phase identification of the modified layer
were examined using scanning electron microscopy, energy dispersive X-ray spectroscopy and Xray
diffractometry, respectively. Cavitation behavior of produced layers was investigated in a
rotating disc facility. Cavitation properties of laser-processed steel were calculated in the initial
stage of erosion, on the surface of about 4 mm2, on which cavitation intensity was constant. As a
property characterizing the cavitation erosion resistance of materials was proposed for the depth of
strain hardening. It was found that presence of manganese in the amount of 7.31% causes the
highest increase hardness after alloying and the lowest depth of strain hardening due to cavitation
loading.
Some Aspects of Sound Propagation in Porous Medium
Authors: Miškinis Paulius
Published: March 2009

The new properties of nonlinear sound propagation in one-dimensional porous medium are presented. For this purpose the one-dimensional equation of nonlinear and nonlocal sound propagation is derived. Its limiting cases are analyzed; the respective asymptotic solutions are shown. The dependence of sound velocity on the dimension of cellular space has been established.
Stress and Strain Analysis of Three-Layer Composites with Interlayer Slip under Hygrothermal Loads
Authors: Zabulionis D.
Published: March 2009

This article deals with the stress and strain state of a three–layer composite material with
interlayer slip subjected to hygrothermal loading. The exact solutions in an explicit function form
that allows one to determine the stress-strain state and deflection of three–layer composite subjected
to hygrothermal loading and by taking this into consideration the interlayer slip is proposed.
Model for Time-Dependent Stress and Strain Analysis of Layered Composite Element
Authors: Zabulionis D. , Balevičius R. , Dulinskas E.
Published: March 2009

The authors have proposed a relatively simple and convenient method for engineering purposes that allows one to simulate time-dependent viscoelastic properties of a multilayered composite element subjected to loading along layer joints. The method proposed is found to be of a good coincidence in comparison with the known analytical solution of a two-layered composite element. Numerical analysis is also performed adopting the model proposed for the deformational response of reinforced concrete elements.
Influence of Ultraviolet Radiation on Erosive Resistance of Modified Epoxy Coatings
Authors: Kotnarowska Danuta
Published: March 2009

The paper presents examination results of erosive resistance of epoxy coatings as well as
epoxy coatings with interlayer modified by glass microspheres after ageing under the influence of
ultraviolet radiation. Glass microspheres used as filler are spherical particles of aluminosilicate,
filled with carbon dioxide and nitrogen, of a diameter not exceeding 0.03 mm and their mass share
in the interlayer is 10 %.
Lithuania's Industry Role in the Curricula of Engineering Education in Mechanics Faculty at Vilnius Gediminas Technical University (VGTU)
Authors: Mariūnas Mečislovas
Published: March 2009

In the paper the industry role in the curricula of engineering education is examined.
There are shown that the information obtained on industry developments trends, product
export/import ratio as well as the level of investments injected into individual industry sub-sectors
helps to make projections as to the number and profile of future professional staff; more
specifically, as to the type of curriculum modules and the university acceptance level. Based on the
information obtained from university graduates and managers from industrial enterprises as well as
other authorities and summarized in an appropriate way, adequate corrections are introduced into
the curriculum module without prejudice to regulations of the Government of the Republic
Lithuania and to the provisions of the Bologna Declaration.
Image Wavelet Transform for PCB Soldering's Quality Evaluation
Authors: Zitkevicius Evaras , Martavicius Romanas
Published: March 2009

An integration degree of modern printed circuit boards (PCB) is continually increasing.
One of the important stages in the manufacturing of electronic devices is component soldering onto
PCB pads. The soldering process is affected by many factors, which may lead to the formation of
undesirable soldering defects. Some kinds of defects including bridge defects are detected visually.
In the current article the possibility of bridge defect detection in a multi-pin surface mount
component PCB images using wavelet transform is analyzed.
Nanocrystalline NiAl-TiC Composites Sintered by the Pulse Plasma Method
Authors: Rosiński Marcin , Michalski Andrzej
Published: March 2009

The paper presents the results of the examination of nanocrystalline NiAl-TiC composites with 25 wt.% and 40 wt.% of TiC. The starting materials were coarse-grained powders which were subjected to mechanical refining to obtain a nano-crystalline grain size. These powders were then sintered using the pulse plasma method. After sintering the NiAl-TiC composites have a density of 99.9% of the theoretical value. The grain size, determined by X-ray diffraction using the Hall-Williamson method; density; hardness and fracture toughness of the composites were investigated. The results obtained showed that the pulse plasma sintered NiAl-TiC have a density very close to the theoretical value and that the nano-crystalline microstructure was maintained. The NiAl-TiC composites containing 25wt.% of TiC have a hardness of 750 HV1 and a stress intensity factor KIC of 7 MPa⋅m1/2, whereas those containing 40 wt.% of TiC have a hardness of 1070 HV1 and KIC of 11.8 MPa⋅m1/2.
Buried Nano - Structured Layers in High Temperature – Pressure Treated Si:He
Authors: Misiuk Andrzej , Surma Barbara , Bak-Misiuk Jadwiga , Raineri Vito
Published: March 2009

The effect of treatment at up to 1400 K (HT) under enhanced hydrostatic pressure (HP,
up to 1.2 GPa) on helium implanted single crystalline silicon (Si:He, He ion dose up to 6x1017cm-2,
energy up to 300 keV) has been investigated by transmission electron microscopy, secondary ion
mass spectrometry, photoluminescence and X-Ray methods. The treatment of Si:He at ≤ 920 K -
HP results in a formation of buried nano-structured layers containing helium filled cavities/bubbles
and numerous extended defects; many less dislocations are created at ≥ 1270 K in Si:He treated
under HP. HP affects the recrystallization of amorphous Si, diffusivity of implanted He and of
implantation-induced defects and thus promotes the creation of more but smaller
He-filled cavities/bubbles as well as other defects near the range of implanted He+.
Microstructures and Mechanical Property of Ni Processed by High-Pressure Torsion and Their Evolution upon Annealing
Authors: Yang Zhi Qing
Published: March 2009

XRD, TEM, microhardness and thermal analysis were carried out on a series of Ni
samples produced by high-pressure torsion (HPT). The evolution of microstructures and their
inhomogeneity were investigated. The local microstrain showed dynamical oscillations as a
function of the HPT rotations, demonstrating dynamical evolution of lattice defects during the
procedure. Both XRD and TEM showed that a small difference in grain sizes remains even after 5
revolutions of HPT with smaller grain sizes at the peripheral region of the sample. The higher
microhardness at the peripheral region is the result of the smaller grain sizes and the higher density
of lattice defects, compared with the central region. Thermal treatment at a heating rate of
20K/min from room temperature to 473K did not result in decreased microhardness, but increased
by about 10% for samples treated with not more than 3 rotations of HPT. The increase in
microhardness was attributed to further grain refinement, the formation of a larger fraction of
high-angle grain boundaries and grain boundaries being closer to equilibrium after recovery.
Features of Twist Extrusion: Method, Structures & Material Properties
Authors: Beygelzimer Yan , Orlov Dmitry , Korshunov Alexander , Synkov Sergey , Varyukhin Viktor , Vedernikova Irina , Reshetov Alexey , Synkov Alexandr , Polyakov Lev , Korotchenkova Irina
Published: March 2009

During the last decade it has been shown that severe plastic deformation (SPD) is a very
effective for obtaining ultra-fine grained (UFG) and nanostructured materials. The basic SPD
methods are High Pressure Torsion (HPT) and Equal Channel Angular Extrusion (ECAE).
Recently several new methods have been developed: 3D deformation, Accumulative Roll Bonding,
Constrained Groove Pressing, Repetitive Corrugation and Straightening, Twist Extrusion (TE), etc.
In this paper the twist extrusion method is analyzed in terms of SPD processing and the essential
features from the “scientific” and “technological” viewpoint are compared with other SPD
techniques. Results for commercial, 99.9 wt.% purity, copper processed by TE are reported to show
the effectiveness of the method. UFG structure with an average grain size of ~0.3 μm was
produced in Cu billets by TE processing. The mechanical properties in copper billets are near their
saturation after two TE passes through a 60º die. Subsequent processing improves homogeneity
and eliminates anisotropy. The homogeneity of strength for Cu after TE is lower than after ECAE
by route BC, but higher than after ECAE by route C. The homogeneity in ductility characteristics
was of almost of inverse character. The comparison of mechanical properties inhomogeneity in Cu
after TE and ECAE suggests that alternate processing by ECAE and TE should give the most
uniform properties.
Equal Channel Angular Pressing, its Effect on Structure and Properties of the Constructional Steel St3
Authors: Borisova Maria , Yakovleva Sofia P. , Ivanov Afanasiy M.
Published: March 2009

The steel St3 was processed by equal channel angular pressing. The structure and properties of the steel after two ECAP passes were determined. The different routes (Bc and C) resulted in different microstructure evolution during the equal channel angular pressing. It has been shown that equal channel angular pressing is a very suitable method for produce materials with good mechanical properties.
Structural Relaxation Processes in Fe40Ni40P14B6 Glass under Continuous Heating
Authors: Tkatch V.I. , Rassolov S.G. , Krysov V.I. , Popov V.V. , Kameneva V.Yu.
Published: March 2009

A set of the techniques, including large- and small-angle X-ray scattering, differential
scanning calorimetry, electrical resistance and microhardness measurements was used to study the
changes in structure of the well-known Fe40Ni40P14B6 metallic glass under continuous heating up to
the crystallization onset temperature. The measurements performed in situ and after rapid cooling
from different temperatures revealed that structural relaxation is a multi-stage process involving
variations of the short-range order, relief of quenched-in stresses, changes of the free volume
concentration and enhancement of the concentration inhomogeneities. The temperature ranges of
each process have been established. Using proposed approximate equation describing the scattering
particles growth at a constant heating rate, it has been shown that the enhancement of phase
separation in the glass investigated is governed by diffusion-limited growth mechanism.
Discountinuity of Plastic Flow Controlled by Magnetic Field in NaCl:Eu Crystals
Authors: Dunin-Barkovskii L. , Morgunov R.B. , Tanimoto Y.
Published: March 2009

An influence of a constant magnetic field (MF) with induction up to 15 T upon macroscopic plastic deformation of diamagnetic NaCl single crystals containing paramagnetic Eu impurity was observed. Effects of MF on instability of plastic flow (on the Portevin-Le Chatelier effect) in quenched NaCl:Eu crystals were found. The MF results in a decrease of the yield stress, a decrease of the probability of the instability appearance, and a decrease of the averaged magnitude of the deformation jumps, as well as in a chaotization of the distribution of the deformation jump magnitudes. The latter can be explained by partial plastic relaxation of internal stresses under MF that was confirmed by dislocations displacement induced by internal stresses in MF. The averaged amount of shear bands observed on the surface of the investigated crystals deformed under MF is half of that in reference specimens.
Relaxation Effects in La2Mo2O9-Based Oxide-Ion Conductors
Authors: Fang Qian Feng , Wang X.P. , Yi Z.G. , Cheng Z.J.
Published: March 2009

The novel oxide-ion conductors (La1-xAx)2Mo2O9-δ (A = Ca, Bi, K, x = 0 ~ 0.075) are investigated
in this paper by internal friction and dielectric relaxation techniques. Two relaxation peaks associated with the
short-distance diffusion of oxygen vacancies were observed, indicating that there are at least two relaxation
processes for diffusion of oxygen vacancies. Doping at La site with different elements shifts both relaxation
peaks toward higher temperature and increases the activation energy of oxygen vacancy diffusion. In the case of
internal friction, the height of the higher-temperature peak (dominant component) decreases with increasing
doping content. In the case of dielectric relaxation, however, the variation of the peak heights as a function of
doping content exhibits a maximum around 2.5 % K and 5 % Bi. After properly doping, the conductivity at low
temperature of doped La2Mo2O9 increases by different degrees, and a peak of the conductivity at 500° C is
observed in the doping content where the highest dielectric relaxation peak appears. Based on the experimental
results and the crystalline structure, the mechanism of oxygen vacancy diffusion in (La1-xAx)2Mo2O9-δ samples
is discussed.
Giant Dielectric Relaxation in Ordered Matrix Systems Depicted by Maxwell-Garnett Formula
Authors: Turik A.V. , Radchenko G.S. , Chernobabov A.I. , Turik S.A.
Published: March 2009

A giant enhancement of the static dielectric permittivity and a giant dielectric relaxation
in a heterogeneous medium consisting of regularly arranged spheroids distributed in the matrix and
described by the Maxwell-Garnett formula were studied. The influence of the inclusions aspect ratio
and their concentration is analyzed. The possibility to apply the obtained results to the theoretical
consideration of different heterogeneous ferroactive materials is proved. It is shown that
observation of the collective dielectric resonance in such media is impossible, and only relaxation
processes are the way of obtaining unusual properties of considered materials. Some valuable
formulae are derived and discussed.
Relaxation of Highly Non Equilibrium Charge Carriers in Crystals by Low-Energy Electron Influence
Authors: Panchenko O.F. , Panchenko L.K.
Published: March 2009

The cascade process describing the energy loss and relaxation or multiplication of highly non-equilibrium secondary electrons and holes in crystalline platinum irradiated by lowenergy electrons is studied. The pair-creation scattering rates are evaluated in the framework of the statistical model taking into account the electron band structure of platinum. Kinetic equations for the excited electron and hole energy distributions are solved numerically in the isotropic scattering approximation for some primary (excitation) energies Ep which do not exceed the plasma energy.
The Self-Organisation of Tetrahedrally Close-Packed Structures in Magnetic Nanocrystalline Tb-Fe and Co-Pd Films
Authors: Kveglis L.I. , Kuzovnikov A.V. , Timofeev I.V.
Published: March 2009

The self-organization of an atomic structure in Tb30Fe70 and Co50Pd50 films possessing
of high values of the perpendicular magnetic anisotropy (PMA) constant (K⊥ ~ 106 erg/cm3) is
investigated by transmission electron microscopy. The crystallization of the films is realized in an
explosive way with formation of different dissipative structures from the initial nanocrystalline
state. In present work the structural model of a thin film in mezzo-scale and the correlation of a
structure with magnetic properties are discussed.
Inelastic Relaxation in Tin Dioxide Thin Films
Authors: Mitrokhin V.I. , Rembeza S.I. , Rembeza E.S. , Rudenko A.A.
Published: March 2009

Internal friction results obtained in thin SnO2 films produced by reactive magnetron
sputtering (thickness of the film ~ 1 μm) and by the dehydration of water solution of tin salts
(thickness of the film ~ 10 μm) are reported. It is suggested that internal friction peak observed in
SnO2 films at around 170 oC is caused by relaxation processes on grain boundaries (average grain
size is 20 nm). The investigation of internal friction in SnO2 films can yield new information about
the structure of thin films.
On-Line Control of Harmonic Oscillations in a Low-Frequency Resonant Mechanical Spectrometer
Authors: Magalas Leszek B. , Piłat A.
Published: March 2009

The on-line control unit is used to ensure high-accuracy computations of the logarithmic decrement. It is shown that the excitation process should be on-line low level real-time controlled during mechanical loss measurements to obtain high precision of the computations and to ensure a short-time excitation process.
The Nonempirical Calculation of the Cation Ordering and Lattice Dynamics in the Solid Solutions of PbSc1/2Nb1/2O3 and PbSc1/2Ta1/2O3
Authors: Zinenko V.I. , Sofronova S.N.
Published: March 2009

An effective Hamiltonian for the study of Sc–Nb(Ta) cation ordering in
PbSc1/2Nb(Ta)1/2O3 solid solutions is worked out. To determine the parameters of the effective
Hamiltonian, a nonempirical calculation is performed within an ionic-crystal model taking into
account the deformation, dipole, and quadrupole polarizabilities of ions. The phase transition temperatures
are calculated by the mean field, the cluster approximations, and the Monte-Carlo method.
Within the same ionic-crystal model, we calculated the high-frequency permittivity, Born dynamic
charges, and the phonon spectrum for completely disordered and ordered phases.
Simulation of the Oriented Crystallisation of Cu/Pd(001) Amorphous Film
Authors: Dmitriev A.A. , Evteev Alexander V. , Ievlev V.M. , Kosilov A.T. , Levchenko Elena V.
Published: March 2009

Crystallisation processes of amorphous Cu-film on Pd(001) substrate have been
investigated by molecular dynamics method. It has been established that the formed structure has
tetragonal distortions; the elastic stresses caused by dimensional misfit of crystal lattices of the
substrate and the film lead to the formation of complex defect structure changing during the
annealing.
3D Lattice Model for the Phase Transition in a Water/Oil/Surfactant/Cosurfactant Mixture
Authors: Elnikova L.V.
Published: March 2009

We propose the Ising-like model treatment for phase transitions in pseudoquaternary solution of SDS (sodium dodecylsulfate), toluene, butanol (cosurfactant) and brine (NaCl), that was investigated by neutron spin echo spectroscopy [1] by Molle and coworkers. We compare the relaxation time and diffusion coefficient in the different kinds of droplet cellular structures in dependence on the correlation length, evaluated by lattice Monte Carlo technique.
Hydrogen Interaction with Dissolved Atoms and Relaxation Properties of Metal Solid Solutions
Authors: Blanter M.S. , Magalas Leszek B.
Published: March 2009

The H(D) atom’s interaction with one another, ‘heavy’ interstitial atoms (O, N, C), and substitutional atoms is analyzed on the basis of strain-induced (elastic) interaction. The interaction energies are calculated for bcc, fcc, and hcp metal solid solutions with regard to the discrete atomic structure of the host lattice. The elastic constants, Born-von Karman constants of the host lattice, and concentration expansion coefficients of the solid solution lattice due to solute atoms, are used as the parameters for numerical input. It is shown that the interaction is long-range, oscillating, and anisotropic. In all cases, the coordination shells of both types - with attraction and with repulsion - exist. The interaction energy dependence on the distance is due mainly to the crystal lattice type. The strain-induced interaction should be supplemented by repulsion in the nearest coordination shells for the case of interstitial-interstitial interaction and by chemical interaction in the case of H-substitutional interaction. Two examples are given for the use of the strain-induced interaction energies in calculations relaxation processes.
Physical Aging of Amorphous Matter: Down to the Nanometric Scale
Authors: Etienne S. , David L. , Duval E. , Mermet A. , Wypych A. , Simeoni G.
Published: March 2009

Different degrees of freedom exist in amorphous matter, and are at the origin of relaxation processes (e.g. structural, mechanical). The effect of physical aging of the glassy network on secondary and primary (and cooperative) relaxation is studied. It is shown that if the temperature of aging is below the liquid glass transition temperature and above that of the secondary relaxation, the strength of this last relaxation changes in a non monotonous complex way while the characteristic time of the primary relaxation increases. This feature is explained taking into account the heterogeneous nature of the glassy network. This concept is in agreement with recent inelastic light scattering observations showing that fluctuations of the elastic constants at the nanometric scale are characteristic of the glassy state.
Plasma Post Oxidation of Nitrocarburized S45C Steel
Authors: Lee Insup
Published: March 2009

Plasma nitrocarburizing and plasma oxidizing treatments were performed to improve the
wear and corrosion resistance of S45C steel. Plasma nitrocarburizing was conducted for 3h at
570°C in the nitrogen, hydrogen and methane atmosphere to produce the ε-Fe2-3(N,C) phase. It was
found that the compound layer produced by plasma nitrocarburising was predominantly composed
of ε-phase, with a small proportion of γ′- Fe4(N,C) phase. The thickness of the compound layer was
about 10 –15 μm and the diffusion layer was about 300 μm in thickness, respectively. Plasma post
oxidation was performed on the nitrocarburized samples with various oxygen / hydrogen ratio at
constant temperature of 500°C for 1 hour. The very thin magnetite (Fe3O4) layer 1-2 μm in
thickness on top of the compound layer was obtained by plasma post oxidation. It was confirmed
that the corrosion characteristics of the nitrocarburized compound layer could be further improved
by the application of the superficial magnetite layer.
A Study on Nitrogen Permeation and Tempering Heat Treatment of AISI Type 409L Ferritic Stainless Steel
Authors: Yoo Dae Kyoung , Lee Hea Joeng , Kang Chang Yong , Kim Kwang Ho , Kim Yung Hee , Sung Jang Hyun
Published: March 2009

Generally, solution nitriding (nitrogen permeation) is not applied to ferritic stainless steel,
which has low nitrogen solubility in the ferrite phase. This study has investigated phase changes,
nitride precipitations and hardness variations of Fe-11Cr-0.1Ti (409L) ferritic stainless steel
following nitrogen permeation and tempering heat treatments. The strong affinity between nitrogen
and Ti enabled the permeation of nitrogen to 409L ferritic stainless steel. The nitrogen-permeated
surface changed to a martensitic phase with a hardness range of between 520 and 585Hv, depending
on the nitrogen permeation temperature and time, while the surface nitrogen content was about
0.04%~0.05%. When tempering the NPSA (solution annealing after nitrogen permeation) treated
specimen at 450 °C, a maximum hardness of 550Hv was obtained, probably due to the precipitation
of very fine rod and square type titanium nitrides, while the minimum hardness of 365Hv was
obtained at a tempering temperature of 650°C, owing to the precipitation of coarse TiN.
Study on the Microstructure and Mechanical Properties of 17-4 PH Stainless Steel Depending on Heat Treatment and Aging Time
Authors: Yoo Wee Do , Lee Jong Hoon , Youn Kuk Tae , Rhyim Young Mok
Published: March 2009

The microstructures and mechanical properties of 17-4 PH stainless steel at each steps of
heat treatment, such as homogenizing, solid solution treatment followed by aging treatment, longterm
aging at 400 °C, and recovery treatment, in order to obtain a better understanding of the
embrittlement phenomena on aging, was investigated. As the homogenizing treatment time
increased, the length of δ-ferrite decreased and elongated shape of δ-ferrite turned to sphere shape
with the decrease of volume fraction. The solution treated specimen mainly consists of lath
martensite with a small fraction of elongated δ-ferrite. The spherical particles existed a little in the
martensite matrix, while no precipitates were found in the δ-ferrite at the solution treated specimen.
As the aging treatment temperature increased, the strength decreased while the toughness increased.
The fcc Cu-rich particles precipitated in the δ-ferrite during the long-term aging at 400 °C after the
solution heat treatment. This precipitation causes the aged hardening after long-term aging
accompanied by decreases in elongation and charpy V-notch energy absorption. The strength and
elongation was restored after recovery treatment and the fcc-Cu precipitated were almost dissolved
into the δ-ferrite matrix.
Erosion Resistance and Its Mechanism for Flame-Hardened 12Cr Steel by High Speed Water Drop Impacts
Authors: Kim G.H. , Lee Min Ku , Kim G.M. , Hong Sung Mo , Kim Wheung Whoe , Rhee Chang Kyu
Published: March 2009

In this study, the water drop impact erosion properties of 12Cr steel surface-hardened
by the flame hardening process have been studied. For this, both the maximum erosion depth de,max
and volume loss Ve with the number of cumulative impacts n have been investigated for the
flame-hardened 12Cr steels with different hardnesses. Typically all the samples showed an
erosion-time characteristic involving an incubation period initially followed by a steady state period.
Compared to those for the as-received 12Cr steel, the flame-hardened ones showed an excellent
erosion resistance to water drop impacts, showing a 2.2~2.8 times higher incubation time ti and 5~8
times lower erosion rate α. In the incubation period the as-received 12Cr steel was deformed by a
ductile depression and ploughing, while the flame-hardened one by fatigue cracks and a brittle
platelet deformation. In the steady state period the damage was progressed by a cleavage fracture
for both the stages.
Optimization of Movable Flame Hardening Process for the Turbine Blade 12Cr Steel
Authors: Kim G.H. , Lee Min Ku , Kim G.M. , Hong Sung Mo , Kim Wheung Whoe , Rhee Chang Kyu
Published: March 2009

In this study, the movable flame hardening process of 12Cr steel for a uniform hardness
and desirable residual stress have been investigated. For this, the temperature cycles have been
controlled accurately as a function of the three processing variables, the flame intensity If, the
scanning velocity Vs and the initial flame holding time th, where the standard surface temperature
Ts,max was maintained at 960oC. The optimized conditions were Vs=0.68mm/s and th=67sec for the
C3H8:O2=5:20 l/min, Vs=0.80mm/s and th=56sec for the C3H8:O2=6:24 l/min, Vs=1.01 mm/s and
th=48sec for the C3H8:O2=7:28l/min, and Vs=1.15 mm/s and th=39sec for the C3H8:O2=8:32l/min.
The optimally flame-hardened surface exhibited uniform distributions of the hardness and residual
compressive stress over the treated area with moderate levels of 470~490HV0.2 in hardness and
-300~-450MPa in residual stress, which were acceptable on the basis of the acceptance criteria of
Siemens AG-KWU and GE Power Generation Engineering.
Micro-Hardening of Carbon Steel with a Direct Diode Laser
Authors: Morimoto Junji , Katoh Yutaka , Fukuhara Shinji , Abe Nobuyuki , Tsukamoto Masahiro , Tanaka Shigeru
Published: March 2009

Surface treatments, surface modification and surface engineering are required to improve the wear
resistance, erosion resistance, friction resistance and corrosion protection. Transformation hardening of metals has
been used since ancient times to increase the hardness and thereby vastly reduce the wear rate of metal surfaces in
use. Today several processes are in use to achieve the controlled heating and rapid cooling required for
transformation process. Transformation hardening is one of the most attractive processes for high power diode
lasers, since their moderate beam quality and their low power density is sufficient for many applications.
Generally laser hardening generates less distortion than conventional methods. In this study, the effect of laser
beam characteristics (beam profile, power density, power etc) was examined on the micro hardening of carbon
steel.
Evaluation of the Life Limit of Standard Hardness Block HRC64 at Ambient Temperature
Authors: Inoue Katsuhiko , Zhang Bin , Yamamoto Atsushi , Tsubakino Harushige
Published: March 2009

The life limit of the standard hardness block of HRC64 made from JIS-SUJ2 steel was evaluated. The HRC64 specimens were annealed at temperatures ranging from 55 to 200C for about 104 h in maximum. The micro-Vickeres hardness decreased with the annealing time at all temperatures after some incubation periods. Transmission electron microscopy (TEM) showed that the microstructure of the specimen before annealing was composed of primary cementite particles, carbide and martensite matrix. After annealing, fine cementite particles of about few tens of nanometers in size were observed. The decrease in hardness during annealing was caused by the precipitation of the cementite. The life limit keeping the standard hardness value at ambient temperature was estimated to be about 3.5-4 years based on extrapolation of the annealing curves at various temperatures.
Effect of Fine Particle Bombarding Treatment Conditions on Surface Origination of Materials
Authors: Miyahara Taku , Egami Noboru , Kimachi Hirohisa , Miyasaka Yoshio , Hatta Koji
Published: March 2009

In this study, we analyzed effect of fine particle bombarding (FPB) treatment conditions on structural transformation close to the material surface and also measured temperature close to the material surface in FPB treatment. As a result, when an intensive condition was used in FPB treatment, a lamellar structure was observed. In other words, dents and bumps are formed in the initial stage of particle collisions on the material surface. Repeatedly processed, the protruded portions are supposed to be then bent over, resulting in an atomized structure. On the other hand, we measured temperature close to the material surface to find temperature rising up to about 600. In addition, when the fine particle collided continuously to the same portion, the specimen reached a melting state. These results indicate that heat generated in FPB treatment has a drastic effect on structural transformation close to the material surface.
State of the Art and Prospects on Laser Clad Multiphase Transition Metal Silicides Wear and Corrosion Resistant Coatings for the Aerospace and Petrochemical Industries
Authors: Wang H.M. , Cai L.X.
Published: March 2009

Wear and corrosion resistant multi-phase transition metal silicides coatings including W2Ni3Si/W5Si3, Ti5Si3/NiTi2, Ti2Ni3Si/NiTi, etc, were developed and fabricated by laser cladding process. Tribological properties were evaluated under dry sliding and reciprocating fretting wear test conditions and the responding wear mechanisms were discussed as functions of microstructure constitutions and test conditions. High temperature oxidation resistance of the coatings was investigated. The coatings exhibited excellent combination of room and high temperature metallic sliding wear resistance, fretting propertiy, metallic tribological compatibility, good oxidation resistance and abnormal wear-load dependence. Applications of the coatings were prospected for the aerospace, petrochemical and energy-processing industries.
Surface Modification of Aluminum Alloys Prepared by Plasma-Based-Ion-Implantation Technique
Authors: Liu Li , Yamamoto Atsushi , Hishida Takanori , Shoyama Hiroaki , Hara Tamio , Tsubakino Harushige
Published: March 2009

The aluminum alloys AA5052, AA5083 and Al-7%Si (AC4C) were nitrided by electron
beam excited plasma (EBEP) technique to improve wear resistance and hardness. The specimens
were characterized with respect to the following properties: wear resistance, hardness of nitrided
layer (AlN layer), surface and cross sectional microstructures. The friction coefficient of nitrided
AA5052 decreased to 0.2 and that of Al-7%Si was improved to 0.1. The AlN layers were
relatively uniformly formed on the AA5052 and AC4C alloys with a thickness of 4.5 μm and 2.5
μm during 2hrs and 5.4 ks, respectively. On the surface of nitrided AA5083, a uniform AlN layer
was not formed due to the high nitriding temperature. The Si3N4 was found in the nitrided AC4C
alloy.
A study on the Surface Properties of Nitrogen Implanted H13 Steel by Plasma Immersion Ion Implantation
Authors: You Y.Z. , Kim D.I. , Chun H.G.
Published: March 2009

The near surface of the H13 steel was implanted by using Plasma immersion ion
implantation (PIII) system at constant bias voltage of −20 kV with varying nitrogen (N+ ) ion dose
(3, 6, 9, 12, 15×1017 ions/cm2 ). The surface properties of the N+ ion implanted steel were
investigated by measuring the microhardness, wear loss and friction coefficient. As increasing N+
ion dose (12×1017 ions/cm2), both wear property and surface hardness were increased. However,
these properties were decreased as the incident ion dose increased over 12×1017 ions/cm2. The
elemental depth profile and surface roughness were obtained with X-ray photoelectron spectroscopy
(XPS) and surface roughness tester, respectively.
Effect of Post Deposition Annealing Temperature on the Optoelectrical Property of ITO Thin Films Prepared by Magnetron Sputter Type Negative Metal Ion Source
Authors: Kim D.I. , Yoo Y.Z. , Chun H.G.
Published: March 2009

Transparent conducting indium tin oxide (ITO) thin films were deposited on glass
substrates by magnetron sputter type negative metal ion source (MSNIS) using ITO target and then
the effect of post deposition annealing temperature on the optoelectrical property of ITO film has
been investigated. The resistivity and optical transmittance of ITO films that prepared at 70°C
(without intentional substrate heating) with optimized deposition condition reached at 6.2×10-4
cm and 80%, respectively. As increasing post deposition annealing temperature, a rapid decrease is
observed in the resistivity. The lowest resistivity of 1.7×10-4 cm and the highest optical
transmittance of 83% were obtained at the post annealing temperature of 300°C. From the XRD and
SEM measurements, the increment of the optical transmittance and conductivity by post deposition
annealing treatment is attributed to the enhanced crystallinity of the ITO film.
Bi-Ge-Sb-Te Films for Reversible Phase-Change Optical Recording
Authors: Lin Su Shia
Published: March 2009

The Bi-Ge-Sb-Te phase-change recording films were prepared by DC magnetron
sputtering of Bi5Ge9Sb68Te18 and Bi5Ge3Sb74Te18 targets, individually. The surface roughness of
Bi5Ge9Sb68Te18 film was relatively low. At the recording speed of 27.92 m/s, the jitter value of
Bi5Ge9Sb68Te18 disk was 21.33%, but Bi5Ge3Sb74Te18 disk could not be recorded. After the aging
test, the reflectivity change (Rbef.−Raft.) of Bi5Ge9Sb68Te18 film was obviously less. It could be found
that the Bi5Ge9Sb68Te18 film was suitable for high-speed recording and showed the better archival
life stability. As the results, the recording performance and archival life stability of phase-change
optical disks were dominated by the composition of recording film.
Austenite Grain Stability of Titanium-Modified Carburizing Steel
Authors: Tanaka Takashi , Fujimatsu Takeshi , Hashimoto Kazuya , Hiraoka Kazuhiko
Published: March 2009

It is important to suppress grain coarsening during the carburizing treatment of automobile components such as gears and shafts so that high strength is maintained and heat treatment distortion is minimized. Two manufacturing methods are often used for the cost reduction. One is the increasing carburizing temperature. The other is the adoption of cold forging instead of hot forging. These methods are likely to result in grain coarsening in the case of conventional steels. It is well known that the key factors to control the grain growth are the initial austenite grain size and the volume and mean size of precipitates. In this study, the grain growth property of Ti-modified steel was investigated to confirm the influence of precipitates, and compared with those of Nb-modified and conventional steels. The influence of forging temperature on the grain growth property in a Ti-modified steel was also investigated.
The Properties of Heavily Al-Doped ZnO Films by Simultaneous rc and dc Magnetron Sputtering
Authors: Lin Su Shia , Huang Jow Lay
Published: March 2009

A radio frequency power (rf) was supplied to ZnO target, and a direct current (dc) power was supplied to Al target for the preparation of heavily Al-doped ZnO (ZnO:Al) films. The advantage of this kind of deposited method is that the Al content could be changed in a wide range. The ZnO:Al films prepared at different dc powers showed different surface morphologies, and corresponded to the different surface roughness. The ZnO:Al films prepared at high dc powers showed the amorphous structures, and resulted in very high resistivity. The resistivity of ZnO:Al film prepared at dc power of 40W was lower (8.52×10-3 -cm). It was mainly due to the relatively higher mobility, which probably resulted from the relatively low surface roughness, and corresponded to the surface morphology in the shape of cobblestone. In addition, the ZnO:Al films prepared at different dc powers showed different optical properties.
Effect of Annealing Temperature on Mechanical Properties of Cold Drawn Pearlitic Steel Wires
Authors: Nam Won Jong , Song Hyung Rak , Park Kyung Tae
Published: March 2009

The effects of annealing temperature and annealing time on mechanical properties of cold
drawn pearlitic steel wires containing 0.84wt% of silicon were investigated. Annealing treatment
was performed on cold drawn steel wires for the temperature range of 200°C to 450°C with the
different annealing time of 30sec, 1min, 15min and 1hr. The increase of tensile strength at the low
annealing temperatures would be related with strain ageing behavior, while the decrease of tensile
strength at the high annealing temperature is due to the spheroidization of cementite plates and the
occurrence of recovery of the lamellar ferrite in the pearlite.
Comparative Study on the Oxidation Resistance between Ti-Al-Si-N and Ti-Al-N Coatings
Authors: Kim Jung Wook , Abraham Sudeep , Kim Kwang Ho , Sung Jang Hyun , Moore John J.
Published: March 2009

High-temperature oxidation behaviors of Ti-Al-Si-N and Ti-Al-N films were comparatively investigated in this work. Two kinds of Ti0.75Al0.25N and Ti0.69Al0.23Si0.08N films were deposited on WC-Co substrates by a DC magnetron sputtering method using separate Ti3Al(99.9%) and Si(99.99%) targets in a gaseous mixture of Ar and N2. Si addition of 8 at.% into Ti-Al-N film modified its microstructure to a fine composite comprising, Ti-Al-N crystallites and amorphous Si3N4, and to a smoother surface morphology. While the solid solution Ti0.75Al0.25N film had superior oxidation resistance up to around 700, the composite Ti-Al-Si-N film showed further enhanced oxidation resistance. Both Al2O3 and SiO2 layers played roles as a barrier against oxygen diffusion for the quaternary Ti-Al-Si-N film, whereas only the Al2O3 oxide layer formed at surface did a role for the Ti-Al-N film. Oxidation behavior and mechanical stability of the films after oxidation were compared between two films using instrumental analyses such as XRD, GDOES, XPS, and scratch test.