bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of the Al-Cu-Co and Al-Cu-Ni Ternary Intermetallic Powders via a Solid-Liquid Reaction Ball Milling Technique
Authors: Chen Ding , Cai Jian Guo , Wu Wei , Chen Gang , Yan Hong Ge
Published: March 2009

Al-Cu-Co and Al-Cu-Ni ternary alloy nanopowders were prepared via a self-developed
solid-liquid reaction milling technique. The milling balls were made of the metals with highest
melting point for each alloy systems. And the binary alloy melts of other two elements were used as
raw materials. Formation regularities of Phases in the milling process were investigated and
solid-liquid reaction mechanism of ternary alloy systems was discussed.
Mechanical Properties of Zr-Added Fe-Al Intermetallic Alloys Containing Large Second Phase Particles
Authors: Machida J. , Kobayashi Satoru , Kaneno Yasuyuki , Takasugi Takayuki
Published: March 2009

Mechanical properties of thermomechanically fabricated D03 Fe-33Al and B2 Fe-38Al
intermetallic alloys containing Zr were investigated by means of tensile test and microhardness
measurement. The Zr-added ternary alloys showed fine-grained microstructure containing large
(Fe,Al)12Zr τ1 phase particles, while the binary alloy showed a single-phase microstructure consisted
of coarse recrystallized grains. By introducing the large τ1 phase particles to Fe-Al matrix,
tensile strength at room temperature as well as at high temperature (873K) was enhanced but tensile
ductility at both temperatures decreased. On the other hand, it was found that vacancy hardening
which was significant in the alloys with high contents of Al (i.e., Fe-38Al) was reduced by the large
τ1 phase particles.
Microstructure and Plastic Deformation Behavior of Ni3V Single Crystals
Authors: Hagihara Koji , Mori Mayumi , Umakoshi Yukichi
Published: March 2009

Plastic deformation behavior of Ni3V with D022 structure was examined using the single
crystals containing two dominant variants of three. At [557] loading orientation, {111}1/6<112]
twinning is dominantly operative at low temperatures, but {111}1/2<112] slip is activated at high
temperatures accompanied by a rapid drop of yield stress.
Microstructure and Mechanical Properties of In718 Alloy Produced with Twin-Scanning Atomizer
Authors: Li Zheng Dong , Zhang Guo Qing , Li Zhou , Xu Wen Yong , Yao Rui Ping , Yuan Hua , Zhang Yong
Published: March 2009

Sound billets were produced at BIAM with a twin-scanning spray forming facility.
Microstructure and mechanical properties of In718 alloy produced with this technology were
examined. Both tensile strength and stress rupture properties are excellent with the rupture life even
doubled after received a direct aging heat treatment.
Effect of Isothermal Forging on Microstructures and Mechanical Properties of Nb-Si In Situ Composite
Authors: Kang Yong Wang , Qu Shi Yu , Han Ya Fang , Song Ji Xia , Tang Ding Zhong
Published: March 2009

Nb-Si based in-situ composites have great potential for the application of high temperature
structure components. In this paper, the influence of microstructure on the compression behavior of
Nb-Si in-situ composite forged at high temperature was studied. The alloy with nominal composition
of Nb-12Si-24Ti-4Cr-4Al-2Hf was consumable arc-melted, and then isothermal forged at 960°C.
Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and X-ray diffraction
(XRD) were used to characterize the microstructure, composition and phases. The compressive
behaviors at 1250°C were carried out by Gleeble thermo-mechanical simulator. The results showed
that the microstructures were inhomogenous in the different sections of the ingot, and no evident
directional texture formed, and the main phases were niobium solid solution, Nb5Si3 and Ti5Si3.
However, no macro-elements segregation in the ingot was observed. The compression strength was in
the range of 140-360MPa. BSE observation showed that irregular-shaped Nb5Si3 and Ti5Si3 phases
distributed in Nb solid solution and the size of Nb5Si3 in three tested samples was 10μm. Large size of
eutectoid texture existed in the sample with strength of ~140MPa. On the contrary, in the sample with
higher strength of 360MPa, eutectoid structures were hardly detected. The results suggested that the
strength decreased gradually with size increase of eutectoid structure.
Effect of Lower Final Rolling Temperature on Mechanical Properties of V-N Microalloyed Mild Steel
Authors: Qing Jian Qing , Wu Bao Qiao , Wu Jie Cai , He Yi
Published: March 2009

The samples of V-N microalloyed mild steel were obtained in duo mill with the normal
deformation rate and the normal rolling temperature except final rolling temperature, which is at
780°C, 730°C and 680°C respectively. The tensile test was carried out and the microstructure was
observed with optical microscope. It was found that the mechanical properties improved dramatically
compared with normal process, the final rolling temperature is more than 900°C. The main reason is
the fine grain size and second phase particles. With the final rolling temperature decreasing, the
mechanical property further improves until the final rolling temperature of 700°C.
Oxidation Behaviours of MoSi2 Single Crystal at the Temperatures of 773K and 1473K
Authors: Zhang Lan Ting , Shan Ai Dang , Wu Jian Sheng
Published: March 2009

MoSi2 is a potential high temperature structural materials and shows excellent oxidation
resistance at high temperatures. To explore its oxidation behaviour and mechanism, MoSi2 single
crystals were prepared and investigated in the present work. The experimental results showed that
different from its polycrystalline, MoSi2 single crystal showed good oxidation resistance at both 773
and 1473K. Near parabolic law of oxidation kinetics was followed for all the investigated surfaces of
MoSi2 single crystal. The close-packed (110) surface of MoSi2 single crystal showed the best
oxidation resistance at both temperatures. After exposure at 773K, the molybdenum oxide formed on
the (110) surface of MoSi2 single crystal was found to be Mo4O11 instead of MoO3 formed on the
other surfaces. Morphology observation showed a columnar growth of Mo4O11 on the (110) surface.
No difference was found on the oxide formed for different surfaces of MoSi2 single crystal at 1473K.
Microstructures and Mechanical Properties of Ti-48Al-2Cr-2Nb-xW
Authors: Seo Dongyi , Bulmer S. , Saari H. , Au Peter
Published: March 2009

The microstructures and mechanical properties of three powder metallurgy Ti-48Al-2Cr-
2Nb-xW alloys (where x=0, 0.5, and 1 atomic percent (at.%)) are presented. The results indicate that
a solution heat treatment combined with controlled cooling generate a fully lamellar (FL)
microstructure without the formation of detrimental Widmanstätten or massively transformed γ
phases. Aging causes coarsening of the FL microstructure in the alloys containing 0%W and
0.5%W, while almost no coarsening occurs in the 1%W sample. The addition of W to the base
composition results in the formation of precipitates at the lamellar interfaces and grain boundaries
during aging which helps stabilize the FL microstructure. The amount of W and the aging time
affect the room temperature hardness values and tensile properties.
The Comparative Effectiveness of Nb Solute and NbC Precipitates at Impeding Grain Boundary Motion in Nb-Steels
Authors: Hutchinson Christopher R. , Zurob Hatem , Sinclair Chad W. , Bréchet Yves
Published: March 2009

The comparative effectiveness of solute Nb and NbC particles at impeding grain
boundary motion is treated theoretically. It is shown that, for a steel containing ~0.05 at% Nb (~0.1
wt%Nb), under typical recrystallization conditions, solute Nb is more effective in the ferrite,
whereas in the austenite, depending on the exact recrystallization temperature, either solute Nb or
NbC precipitates may be more effective.
Novel Aluminium Nitride Surface Coatings Formed on Aluminium
Authors: Kent Damon , Schaffer Graham B. , Drennan John
Published: March 2009

A new nitriding method has been devised which requires only a simple vacuum furnace
and enables direct nitridation of solid aluminium without any prior surface treatment. It can be used
to produce thick aluminium nitride surface layers on aluminium, under nitrogen at atmospheric
pressure. A critical element of the process is the use of a magnesium vapour source that
reduces/disrupts the natural, protective oxide film on the aluminium surface and facilitates nitriding.
The nitride surface layers form through two distinct modes, one growing outward from the
aluminium plate surface and the other growing into the aluminium. Studies of the nitride layers
utilizing optical microscopy, TEM, SEM, XRD and XPS have been conducted. Details of the
composition, structure and growth as well as possible mechanisms for the nitride formation are
presented. Understanding of the reaction may have important implications for the production of
wear resistant coatings on bulk Al as well as for the production of Al/AlN composites.
Preparation and Characterization of β-SiAlON Ceramics from High Aluminium Fly Ash via Carbothermal Reduction-Nitridation
Authors: Li Jin Hong , Ma Hong Wen , Cao Ying
Published: March 2009

In this work, β-sialon ceramics were prepared from high-aluminium fly ash via
carbothermal reduction-nitridation (CRN) and the physicochemical properties of the materials such as
bulk density, apparent porosity, water absorption and flexural strength were also discussed. The
results showed that the percentage of β-sialon phase in the product decreases as the temperature
increases from 1400°C and the weight of the sintered specimen experienced an increase during
1350°C~1450°C due to the nitridation reactions, and followed by a gradual decrease till 1550°C for
the decomposition of β-sialon. It is indicated that the optimum sintering temperature to obtain the
highest yield of β-sialon ~93% lies in 1400°C~1450°C. The SEM images revealed that the prepared
β-sialon sintered at 1400°C were mainly in shape of elongated prisms, typically ~5μm in length and
0.5~1μm in width. As the temperature increased to 1500°C and above, β-sialon decomposed and the
new phases of SiC and AlN were formed at 1550°C as confirmed by XRD.
XRD and HRTEM Study of Zirconia Nanoparticles Synthesized by Laser Ablation
Authors: Abe Hiroaki , Kobayashi Hiroyuki , Katano Yoshio , Iwai Takeo , Sekimura Naoto
Published: March 2009

To investigate doping-free zirconia, pulsed laser ablation technique was applied to
synthesize pure zirconia nanoparticles. Various experimental parameters were investigated by means
of microscopic, spectroscopic and diffractmetric techniques to reveal morphology and production
yield. It is successful to form cubic and monoclinic phases at nanometer-scale fine particles. The
cubic phase has relatively small lattice parameters than the stabilized zirconia.
Basalt Reinforced Plastics: Some Operating Properties
Authors: Abashidze G.S. , Marquis Fernand D.S. , Chikhradze N.M.
Published: March 2009

Results of the investigation of composite materials of new type, based on basalt fiber and polyester
resin, are presented, in particular, a long-term resistance of the material in corrosive media: in
caustic soda as well as in sulphuric and nitric acids of 1% concentration has been estimated. The
service life of given composite is recommended in above-mentioned media.
Chemical In Situ Synthesis of Aluminum Alloy Composites
Authors: Reddy Ramana G. , Kumar V.
Published: March 2009

Aluminum alloys were reinforced with AlN particles using a novel chemical in situ
technique. Thermodynamic analyses were made to identify the conditions for the in situ formation
of the AlN in Al alloys. Experiments were conducted in the temperature range of 1173-1473 K by
injecting ammonia gas. The composites with AlN quantity varying from 5 to 51 wt % were
produced. Effect of process variables such as gas injection time, flow rate of ammonia gas and
temperature of the alloy melt on the formation of AlN was studied. Increase in either injection time
or flow rate of the ammonia gas increased the nitride content. AlN particles with an average size of
500 nm were produced. The measured Vickers hardness of the composites formed increased with
increasing AlN content. The amount of AlN experimentally formed is in good agreement with the
thermodynamically predicted data.
Structure of Natural Nano-Laminar Composites: TEM Observation of Nacre
Authors: Sumitomo Taro , Kakisawa Hideki , Owaki Yusuke , Kagawa Yutaka
Published: March 2009

Nacre is a natural composite material making up the inner structure of mollusk shells. It has been of
great interest in materials research due to its mechanical properties far exceeding that of its individual
components: well ordered plates of aragonite (a CaCO3 polymorph) within an organic polymer
matrix. Generally the aragonite plates had been treated as single crystals and mechanical behavior
explained as the result of micro-scale mechanisms between plates and matrix. However, recent work
has shown that the plates themselves are made up of smaller nano-scale structures, which are also
thought to contribute to the bulk properties. In this work, transmission electron microscopy (TEM)
was used to observe the nano-scale structure of nacre from abalone. “Nanograins” of aragonite
surrounded by organic material was observed, showing composite structure within aragonite plates.
Rapidly Solidified Thick Deposit of Fe-B-Cr Alloy by Plasma Spraying
Authors: Hoshiyama Yasuhiro , Hirano Kentaro , Miyake Hidekazu , Murakami Kenji
Published: March 2009

Fe-B-Cr alloy powder in diameter of 32-53 μm made by argon atomization is low-pressure
plasma sprayed to produce a rapidly solidified iron base composite deposit with finely dispersed
boride particles. The constituents of the as-sprayed deposit formed on a water-cooled substrate are α
phase and amorphous phase that are supersaturated with chromium and boron due to high cooling rate
during solidification of the melt. Heat treatment of deposit at 873K leads to decomposition of the
amorphous phase, resulting in the formation of Fe3B. The deposit heat treated above 1073K is
composed of α phase and (Fe,Cr)2B. The as-sprayed deposit produced on a non-cooled substrate
consists of α phase and (Fe,Cr)2B. The fine precipitates of about 0.1 μm in the as-sprayed deposit
coated on a non-cooled substrate are boride. As deposit temperature increases, the coarsening of the
precipitate particles results in lowered hardness of deposits.
Microstructure and Properties of Porous CMCs Prepared by HIPing the Pyrolyzed ZrO2/ Si / Phenol Resin Composite
Authors: Sharif Muhammad Akhtar , Sueyoshi Hidekazu
Published: March 2009

A novel two-step process was used to investigate the microstructure and properties of
porous CMCs prepared by HIPing the pyrolyzed composites of commercially available ZrO2 (TZ-
3YS), silicon powders and phenolic resin. In the first step, preforms with 70, 80 and 90 mass % of
ZrO2 powders were prepared by the pyrolysis of ZrO2 / Si / Phenol Resin composites at 850 oC in
vacuum. And, then the pyrolyzed preforms were HIPed at 1400 oC for 30 minutes in Argon
atmosphere under a pressure of 50 MPa to fabricate the porous CMCs, in the second step. XRD
analyses suggested the formation of β-SiC in the composites below the melting point of silicon.
SEM photographs showed that spherical pores of several μm in diameter were uniformly distributed
in the matrices of composites and crystals of β-SiC with facets were observed in the pores. EDS
analyses showed that the crystals were composed of Si and C with 1 : 1 atomic ratio suggesting that
crystal are SiC. The maximum hardness (13.78 GPa) was achieved from the composite with 90
mass % ZrO2, which is more than that of bulk hardness of ZrO2 (10-12 GPa).
Enhanced Wear Resistance of CFRP Laminates via Carbon Nano-Particles Dispersed Surfaces
Authors: Tanimoto Toshio
Published: March 2009

The wear behavior of CFRP laminates with nano-particles dispersed surfaces of Al2O3 or carbon has
been investigated and compared with that of conventional CFRP which is without particles
dispersed surfaces. As a result of comparison, it is shown that the CFRP laminate with Al2O3
nano-particles dispersed surfaces inherently had low coefficient of friction and high sliding wear
resistance. The measured value of specific wear rate was 3.5x10-7mm3/Nm, independently of sliding
time. The wear behavior of CFRP laminates with carbon nano-particles dispersed surfaces has been
more effectively improved. The measured specific wear rate of this material was in the range of 10－
7mm3/Nm in spite of comparatively small amount of nano-particles dispersion, which is relatively
good as tribomaterial. For the successful application of this method, it is essential to explore the
optimum amount of Al2O3 or carbon nano-particles to be dispersed onto prepreg surfaces. The
deflocculation of the agglomerated particles and their homogeneous dispersion and good
impregnation are the key points in this technology.
Flexural/Twist Anisotropy Influence on Elastic Instability of a Plate Composite Laminate
Authors: Raška Jan
Published: March 2009

The flexural/twist anisotropy, present in most balanced, symmetric laminates with angle
play layers, have an important influence on elastic instability of plate composite. The maximal
compression load can be reduced up to 13% in comparison with the orthotropic plate. The
anisotropy changes also the deformation mode form.
Based on the finite element studies, we developed an empirical law – the relation between the
knockdown factor, the anisotropy factor and the plate geometry. The knockdown factor is defined as
the ratio between the maximum loads of the anisotropic plate and of the orthotropic one. In this
way, the semi-analytic instability calculation approach is based on analytical linear bifurcation
theory with orthotropic properties and on empirical consideration of the flexural/twist anisotropy
effect by the knockdown factor.
Dynamic Mechanical Thermal Properties of a New Metal/Polymer Composite for Fused Deposition Modelling Process
Authors: Song W.Q. , Masood Syed H.
Published: March 2009

This paper introduces an entirely new metal based composite material for direct rapid
tooling application using Fused Deposition Modelling rapid prototyping system with desired
mechanical and thermal properties and characteristics. The paper specifically describes the results of
the dynamic mechanical thermal analysis (DMTA) of this new metal/polymer composite material,
consisting of iron particles in nylon type matrix, for use in FDM process and with the aim of
application to direct rapid tooling for injection moulding. The work represents a major
development in the direction of direct rapid tooling for reducing the cost and time in tooling
manufacture for injection moulding.
Strength Prediction for Jute Polyester Composite for Transverse Fiber Reinforcement
Authors: Shaikh A.A. , Channiwala S.A.
Published: March 2009

The composites are very useful in present era due to weight saving and economy of
construction by tailoring material to structural application. In order to save the crop from extinction
and to ensure a reasonable return to the farmers, non-traditional outlets have to be explored for the
jute fiber. Jute fiber due to its adequate tensile strength and good specific modulus enjoys the right
potential for usage in composites. In the present work the experimentations were conducted for the
strength of composite by varying volume fraction of fiber in the range of 12 % to 42 %. The tensile
strengths of specimen were measured as per ASTM D 3039-76, and the amount of voids fraction is
measured to evaluate actual contributing volume fraction of fiber and volume fraction of matrix.
The prediction of strength is proposed by considering efficiency terms f η and m η representing
effective contribution of fiber and matrix and an additional efficiencies t1 η and t 2 η representing
effectiveness from fiber and matrix for transverse reinforcement case. The results are also compared
with FEM results obtained using standard package ANSYS and IDEAS. The results obtained by
experiments are observed to be within 0.9 % with developed model and 2.85 % and 3.21 % with
ANSYS and IDEAS simulated results. The deviation of proposed model is observed under
predictive for experimental data available in literature while the experimental results obtained in
present work is also found to be on lower side to that of available predictive models from literature.
Effect of Intermittent Heating on Creep Behaviour of Advanced 9-12%Cr Power Plant Steels
Authors: Sklenička Václav , Kuchařová Květa , Svoboda Milan , Saxl Ivan
Published: March 2009

Critical high temperature components of machines and structures are often subjected to
complicated load and temperature histories. The closest laboratory simulation of service loading
conditions involves creep under nonsteady temperatures and stresses. For example, the start up and
shut down cycles can be well simulated by temperature variation by use of intermittent heating tests.
Such approach is illustrated by recent experimental results on advanced high creep strength 9-
12%Cr ferritic-martensitic steels (P91, P92 and E911). A comparison between the creep
characteristics of nonsteady and monotonously creep specimens has revealed no significant
deterioration of the creep strength and fracture resistance of these steels in power-law (dislocation)
creep.
Manufacturing Technologies for Small Lot Size, Short Cycle Time and Low Cost
Authors: Cooper Khershed P.
Published: March 2009

New manufacturing methods involving direct fabrication processes seem ideal for mass
customization or “just-in-time” production. The use of tool-less means of production ensures
reduced lead-time and lower cost. Besides, they provide flexibility in design and fabrication, which
are essential for small lot sizes. However, part quality and production reliability are challenges that
must be met. When adapted to the micro-factory paradigm, direct manufacturing can be made
portable and capable of remote manufacturing. The benefits of miniaturization are savings in
materials and energy consumption, but the increased surface area to volume ratio has implications
for material behavior, especially mechanical strength. The newest incarnation of direct
manufacturing is direct digital manufacturing or DDM, which involves localized deposition of
material or energy and the creation of heterogeneous objects with digital means of control. DDM
seeks spatial control of macrostructure, composition, texture and properties with the possibility of
producing materials with unusual behavior, functionally gradient structures and integrated
component devices. For DDM, multi-material design, precision in deposition, shaping and removal
and understanding of heterogeneous material behavior are challenges.
Effects of Friction on Precision Forging Process of Blade with a Damper Platform
Authors: Liu Yu Li , Yang He , Gao Tao
Published: March 2009

A blade with a damper platform, with excellent anti-vibration characteristic and high
efficiency, has become one of the most important types of blades being developed in the aeronautical
engines. During the precision forging process of this blade, the friction between dies and workpiece
has important effects on metal flow, deformation defects, load and energy etc. So researching the
effects of friction conditions on the forging process of blade with a damper platform has been a crucial
problem urgent to be resolved. In this paper, the precision forging process of titanium alloy blade with
a damper platform under different friction conditions has been simulated and analyzed based on the
DEFORM-3D software platform. The obtained results reveal the influence laws of friction on
temperature field and load-stroke curves, and provide a significant basis for determining
technological parameters of the blade forging process.
A New Method to Produce Superfine and Nano-Sized Fe Powders: Spark Plasma Discharge Process
Authors: Ge Chang Chun , Yu Jun , Shen Wei Ping , Cheng Cheng , Ni Guo Hua , Meng Lu Lu , Li Ming , Zhang Cheng Xu , Meng Yue Dong
Published: March 2009

Superfine and nano-sized Fe powders were prepared by a spark plasma discharge process
in deionized water. The powders were characterized by Field Emission Scanning Electron
Microscope (FESEM) with Oxford Inca EDX, and X-ray diffraction (XRD). The experimental results
indicate that the powders prepared by the process have a bimodal size distribution, high purity, single
phase, good spherical shape and high yield.
Optimization of Particle Size and Distribution by Hydrostatic Extrusion
Authors: Lewandowska Małgorzata , Wawer Kinga
Published: March 2009

Hydrostatic extrusion (HE) as a method of metals forming is known for about 100 years.
Recently, it has been utilized as an efficient way of grain size refinement down to nanometer scale.
In the case of engineering metals, HE processing alters not only grain size but also second phase
particles such as intermetallic inclusions and precipitates. During HE processing, these particles
significantly change their size, shape and spatial distribution. These changes are accompanied by
improvement in properties of processed metals such as fatigue and fracture toughness. In the present
work, changes of second phase particles induced by HE are described in a quantitative way for
aluminium alloys. Their impact on mechanical properties is also discussed.
Effect of Shear Deformation on Deformed Microstructures of Austenitic Grains
Authors: Inoue Tadanobu , Yin Fu Xing
Published: March 2009

Electron backscattered diffraction analysis has been used to investigate the effect of shear
deformation on microstructural evolution of a Ni-30Fe alloy during hot deformation. The alloy was
compressed by 50% or 75% in thickness at a strain rate of 1/s in a single pass at 1023K using a hot
compression simulator. Three-dimensional finite element analysis was carried out to evaluate
inhomogeneous strain distribution introduced in the specimens by the simulator. As the equivalent
strain increased, the fraction of high angle grain boundaries (HAGBs) with misorientaions between
15o and 30o increased almost in the similar way regardless of the presence of shear strain. The fraction
of HAGBs having misorientations in excess of 30o increased mainly at the expense of low angle grain
boundaries with misorientations smaller than 15o. Such the expense occurred at much higher rate
with shear strain than without shear strain. The shear component is effective to develop HAGBs in
austenite grain interiors.
The Study on the Microstructure Characters of Pure Iron during Cold Rolling by High Energy X-Ray Diffraction
Authors: Liu Yan Dong , Tong He , Jiang Q.W. , Ren Y. , Wang Yan Dong , Zuo Liang
Published: March 2009

The microstructure characters of pure Iron during cold rolling were studied by HEXD
(high-energy x-ray diffraction). The experimental result shows that the Debby ring of HEXD before
cold rolling is discrete and very strong, the discrete diffraction points become continue and smooth
with the increase of cold rolling reduction. The {001}<110> textures transform to the {001}
texture after cold rolling, in this process the grains divisional are analyzed by the HEXD result.
Influence of Microshot Peening on Surface Layer Characteristics of Cold Tool Steel
Authors: Harada Yasunori , Fukaura Kenzo , Aoki Toshinori , Yokoi Daien , Haruna Yasushi
Published: March 2009

Shot peening is a surface treatment and improves the performance of engineering
components. More recently, a new type of microshot has been developed to enhance peening effect.
In the present study, the influence of microshot peening on the surface layer characteristics of cold
tool steel was investigated. In the experiment, the microshot peening apparatus with a heating furnace
was produced experimentally. The projective method of the microshot was a compressed air type.
The peening microshots of 0.1mm diameter were cemented carbide and the workpiece was
commercially cold tool steel SKD11. Surface roughness, compressive residual stress, and hardness in
the peened workpiece were measured. The effect of microshot peening on the fatigue strength of cold
tool steel was also examined. The use of hard microshot such as cemented carbide was found to cause
a significantly enhanced peening effect for cold tool steel.
X-Ray Study on Mg-Sm Alloy Produced by HPT
Authors: Gotoh Masahide , Kitagawa Kazuo , Dobatkin Sergey V. , Hirose Yukio
Published: March 2009

The purpose of this study is to reveal the cause of hardening of magnesium base alloys by
the high pressure torsion processing (HPT) using X-ray diffraction. HPT was applied to Mg base
alloys of the Mg-Sm system (2.8-5.5 mass %Sm). HPT was performed under pressure 4GPa at 20 oC
and 200 oC. HPT results in significant strengthening of the Mg-Sm alloys due to the formation of sub
microcrystalline structure. The dynamic recrystallization was realized through the pole figure
measurement and the photograph of X-ray back scattering. The Mg supersaturated solid solution
decomposition during HPT was observed by the X-ray profile analysis and the calculation of lattice
constants of the Mg phase.
Analysis of Deformation Textures and Microstructure in ECAE Processed Copper Single Crystals via Route C
Authors: Wang Gang , Wu Shi Ding , Wang Yan Dong , Zong Ya Ping , Esling Claude , Zuo Liang
Published: March 2009

Equal channel angular extrusion (ECAE) is an effective means of producing
ultrafine-grained materials with extraordinary mechanical properties. Texture evolution and
microstructure in pure copper single crystals processed by ECAE for up to five passes via route C are
investigated to understand mechanisms of plastic deformation and grain refinement during ECAE.
The experimental textures after the third pass ECAE process recovers that after one pass ECAE
process. The main textures approaches a stable one after four passes of ECAE process via Route C
while the intensity of main texture components decreases gradually. Local TEM-OIM measurements
shows that grain subdivision in ECAE-processed samples occurs with the formation of many low
angle grain boundaries.
Effects of Addition of V and Nb on Ω in High Cr Ferritic Steels
Authors: Mitsuhara Masatoshi , Yoshida Yu , Ikeda Kenichi , Nakashima Hideharu , Wakai Takashi
Published: March 2009

Creep tests and microstructural observations in several high Cr ferritic steels bearing V
and Nb were carried out in order to investigate effects of addition of V and Nb on , which is a
coefficient of method. Creep strength was improved with increasing the V content and was slightly
lowered by increasing the Nb content. in all the steels bearing V or Nb was lager than that in
fundamental steel. The dependence of on the amount of additions was different between V and Nb.
In steels bearing V, became larger with increasing V content. In steels bearing Nb, became
smaller. These results revealed that corresponds to the creep strength, indicating that the value of
can be estimated using the strengthening effects of the additive element.
Synthesis of Tin Oxide (SnO2) by Precipitation
Authors: Taib H. , Sorrell Charles C.
Published: March 2009

Aqueous solutions of tin (II) chloride dihydrate and oxalic acid dihydrate were prepared
and mixed using two protocols: (1) fixed former concentration and variable latter concentrations
and (2) fixed latter concentration and variable former concentrations. Following filtering, washing,
and drying, the precipitates were calcined and ground. The calcined powders were characterised in
terms of mineralogy and the particle size and morphology of the resultant tin oxide particles and
agglomerates. The morphologies of the uncalcined tin oxalate also were examined.
In nine of the ten samples, the tin oxalate precipitates consisted of prismatic elongated crystals. In
the remaining sample, the low concentrations of solutions probably resulted in the crystallisation of
smaller equiaxed particles. Regardless of the particle size or shape of the tin oxalate, the resultant
particle size of the tin oxide was ~75 nm and the morphology was consistently spherical. The
consistent particle size is attributed to the low solution concentrations used.
The tin oxide particles were heavily agglomerated into plates of ~0.5 μm diameter. This
morphology probably resulted from the plastic deformation during grinding of the calcined tin
oxide, which was likely to have been subject to surface water adsorption on the fine particles.
Under the experimental conditions investigated, there were no particle or agglomerate size
dependencies on the solution concentrations and mixing method.
Shock Wave Chemical Reactions; Synthesis of Carbon Nitrides
Authors: Sekine Toshimori
Published: March 2009

A series of shock recovery experiments up to ~50 GPa were performed on reactions to form carbon
nitrides. Nitrogen-rich starting materials, included a C-N-O amorphous precursor, dicyandiamide, melamine,
and a mixture of carbon tetrahalide and sodium dicyanoamide, were used and the recovered samples were
investigated by X-ray diffraction technique, elemental analysis, transmission electron microscopy and so on.
Experimental results showed formation of a new carbon nitride, high stability of melamine up to a shock
pressure of 37 GPa, and production of amorphous C-N materials with a highest N/C ration of 1.26 from the
reaction between carbon tetrahalide and sodium dicyanoamide. We extended to the system C3N4-Si3N4 based
on the recent results on synthesis of spinel-type nitrides. Shock wave chemical reactions provide a route for
synthesizing novel materials including not only high-pressure phases but also metastable, unique substances.
Properties of Cubic Si3N4 Obtained by Shock Synthesis
Authors: Blank V.D. , Deribas A.A. , Lvova N.A. , Bagramov R.H. , Kulnitsky B.A. , Perezhogin I.A. , Prokhorov V.M. , Silvestrov V.V. , Yunoschev A.S.
Published: March 2009

The cubic γ-Si3N4 phase was synthesized by the shock technique from the hexagonal β-Si3N4 phase. The thermal stability of the γ-Si3N4 was investigated during heating in vacuum up to 1773 K. An exothermal heat effect was found at 1690 K and structural investigations revealed complete transformation of γ-Si3N4 to β-Si3N4. Corresponding heat effect value was estimated as 51.3±7.7 KJ/mol. The high-pressure-high-temperature treatment (P=13 GPa, T=1300-2300 K) was applied to γ-Si3N4 to make bulk polycrystalline non-porous samples. It was found that temperatures below 1623 K do not change content of the cubic γ-Si3N4 while temperatures above 2273 K decrease it substantially. Mechanical properties of these bulk samples were measured by acoustic wave and nanoindentation techniques. The maximum values belong to cubic γ-Si3N4: hardness 39-44 GPa, Young’s modulus 475 Gpa and bulk modulus 263 GPa. Equilibrium γ-β line position in P-T phase diagram was estimated by using data obtained in this work. The equilibrium pressure at T=300 K was estimated as P300=7.0±2.0 GPa.
Observation of High Velocity Oblique Collision of Titanium and Stainless Steel Plates by Using Gas Gun
Authors: Manikandan P. , Hokamoto Kazuyuki , Ghaderi Seyed Hadi , Thadhani Naresh N.
Published: March 2009

The jet formed from the high velocity collision of metal plates have proven both scientifically unique and of potential interest, although the underlying deformation mechanism remains less firmly established. In this study, oblique collision of titanium and stainless steel observed by high-speed camera is discussed. The nature of jet, its velocity and its existence at low velocity are all discussed and theoretical developments are connected. Microstructural studies are done on the sample welded using gas gun and a comparison with explosive welded sample is made.
Optimal Design of Shock Compaction Device
Authors: Kim Young Kook , Hokamoto Kazuyuki , Itoh Shigeru
Published: March 2009

In order to achieve an optimal design of shock compaction device, various designs of parts
are attempted. For the height of water container that creates an underwater shock wave and a reflected
wave, a characteristic of underwater shock wave is evaluated by means of numerical analysis. It is
found that the underwater shock wave and the reflected wave became one wave with higher shock
pressure in the case of water container (height 21.5 mm). Also, the evaluation for a powder container
is experimentally tried in consideration of reuse.
Detonation Behaviors of Nitromethane with Various Initiating Shock Pressure
Authors: Hamashima Hideki , Osada Akinori , Itoh Shigeru , Kato Yukio
Published: March 2009

Some liquid explosives have two different detonation behaviors: high velocity detonation (HVD) or low velocity detonation (LVD). The detonation behavior depends on the level of the initiating shock pressure. The detailed structure of LVD in liquid explosives has not yet been clarified. A physical model was proposed that LVD is not a self-reactive detonation, but rather a supported-reactive detonation from the cavitation field generated by precursor shock waves. In this study, high-speed photography was used to investigate the detonation behavior of nitromethane (NM) with the various initiating shock pressures. Stable LVD was not observed, only transient LVD was observed. A very complicated structure of LVD was observed: the interaction of multiple precursor shock waves, multiple oblique shock waves, and a cavitation field. Multiple shock waves propagating in non-detonating NM were observed for shock pressures below the range required for LVD, while above the LVD range HVD was observed.
Low-Temperature and High-Temperature Anomalies in Temperature Shift of Stress-Lifetime Fatigue Curves
Authors: Kohout Jan , Vĕchet Stanislav
Published: March 2009

Most families of S-N curves determined at various temperatures present certain general
regularities on whose basis the Basquin equation describing finite-life S-N curves can be
generalized for various temperatures. This equation can be represented by straight lines with
common slope if log-log fit for stress vs. temperature dependence is used. Deviations from these
straight lines (anomalies) are evidence that additional degradation mechanisms are effective besides
fatigue, whose temperature dependences differ from the mentioned temperature dependence of
fatigue strength. In high-temperature region it is most often cyclic creep, in low-temperature region
athermal processes of plastic deformation can play significant role in fatigue failure.
The Half-Cycle Slip Activity of Persistent Slip Bands in Polycrystals
Authors: Weidner A. , Tirschler W. , Blochwitz C. , Skrotzki Werner
Published: March 2009

The development of the volume fraction of cumulated persistent slip bands (PSBs) in
cyclically deformed nickel polycrystals was investigated in dependence on the number of cycles
using scanning electron microscopy (SEM) and atomic force microscopy (AFM). It was shown that
there is a large scatter of the volume fraction of PSBs from grain to grain. Three different tendencies
for the development of the volume fraction with increasing number of cycles were distinguished. It
was shown that there is a correlation of the orientation of the primary slip systems with the volume
fraction of cumulated PSBs and the activation of PSBs during half-cycle deformation.
Multi-Fractal Features of Fatigue Crack Surfaces in Relation to Crack Growth Rate
Authors: Sekerešová Zuzana , Lauschmann Hynek
Published: March 2009

Texture of a fatigue crack surface is strictly related to crack growth rate. Cracks in
specimens from aluminum alloy were studied. Two types of information were used: SEM images of
fracture surfaces, and 3D reconstructions of fracture surface morphologies. Sets of equidistantly
focused images obtained by an optical microscope served as the basis for 3D reconstruction.
Multiparametric fractal analysis was applied to characterize crack surfaces. A vector of fractal
features represented each image or 3D reconstruction of selected locations of fracture surfaces. For
estimating fractal characteristics, the box-counting method in 3D was used in all cases, [1].
Multilinear regression was used to express the relation between crack growth rate and feature
vectors, with satisfactory results for both crack surface representations.
Micromechanical Dynamic Influence of Rigid Disk-Shaped Inclusion on Neighboring Crack in 3D Elastic Matrix
Authors: Mykhas'kiv Victor V. , Khay O. , Sladek Jan , Sladek Vladimir , Zhang Chuan Zeng
Published: March 2009

A 3D time-harmonic problem for an infinite elastic matrix with an arbitrarily located
interacting rigid disk-shaped inclusion and a penny-shaped crack is analyzed by the boundary
integral equation method. Perfect bonding between the matrix and the moving inclusion is assumed.
The crack faces are subjected to time-harmonic loading. The boundary integral equations (BIEs)
obtained are solved numerically by the implementation of regularization and discretization
procedures. Numerical calculations are carried out for a crack under tensile loading of constant
amplitude, where an interacting inclusion is perpendicular to the crack and has the same radius.
Both the normal crack-opening-displacement and the mode-I stress intensity factor are investigated
for different wave numbers and distances between the crack and the inclusion.
The Analysis of the Stress and Displacement Field near the Surface Crack Tip Terminating Perpendicular to the Interface between Two Orthotropic Materials
Authors: Profant Tomáš , Ševeček Oldřich , Kotoul Michal
Published: March 2009

The evaluation of the generalized stress intensity factor (GSIF) and T-stress for the case
of the surface crack terminating perpendicular to the interface between two orthotropic materials is
considered. The combination of the discretization, numerical and analytic methods is used. The
discretization method, such as common finite element method (FEM), is served to include the
boundary condition to the GSIF solution and to describe the remote stress and displacement field
region with the low influence of the singularity of the crack tip. The Lekhnickii-Eshelby-Stroh
(LES) formalism is used to derive the approach solution for the near stress field of the crack tip and
the singularity problem in an orthotropic 'trimaterial' using the Schwartz-Neumann's alternating
technique. The problem of the stress singularity is treated as a non-linear eigenvalue problem, which
leads to the characteristic equation for the stress singularities of the form rδ −1 , 0 <δ <1. Two ways
of the evaluation of the GSIF are presented, using the reciprocal theorem ψ -integral) and the crack
model by means of continuous distribution of dislocations. Both results are compared for a specific
material. The continuous distribution of dislocations technique is also used for determination of the
T-stress.
Aggregatization of Frenckel Defects in Ni and Intermetallide Ni3Al
Authors: Starostenkov Mikhail D. , Medvedev Nikolay , Pozhidaeva Olga
Published: March 2009

The formation of Frenckel pairs - vacancies and interstitial atoms takes place during
external high energetical influence. The accumulation and aggregatization of point defects is noticed
only at definite conditions. Vacancies form volume vacancy tetrahedrons and interstitial atoms form
segregations. The conditions of the formation of point defects complexes on the basis of Frenckel
pairs were studied by the methods of molecular dynamics in the dependence on temperature and
intensity of external influence. Their possible role in the process of deformation and fracture of
materials under study were evaluated. Comparison analysis of their stability was made for clusters
of interstitial atoms. When the cluster had about 130 interstitial atoms, crowdion complexes were
energetically profitable.
Modeling of Cracks Crossing an Interface between Dissimilar Elastic Anisotropic Materials
Authors: Kotoul Michal , Profant Tomáš , Ševeček Oldřich , Krejcir Martin
Published: March 2009

Matched asymptotic procedure is used to analyze crack crossing a sharp interface
between dissimilar elastic anisotropic materials. The link to the configurational forces approach is
suggested.
Microstructure and Mechanical Behavior of Severely Deformed F.C.C. Metals
Authors: Gubicza Jenő , Dobatkin Sergey V. , Bakai Z. , Nguyen Quang Chinh , Langdon Terence G.
Published: March 2009

The correlation between the microstructure and the mechanical behavior of ultrafinegrained
face centered cubic (f.c.c.) metals processed by equal-channel angular pressing (ECAP) was
studied. It was found that the maximum value of the yield strength obtained at high strains is
determined by the shear modulus and the saturation value of the dislocation density according to the
Taylor equation. It was also revealed that the value of the parameter α in this equation decreases
with decreasing stacking fault energy, indicating the effect of different geometrical arrangements of
dislocations in the grain boundaries. In addition, it was shown that for ECAP processed Cu, the
ductility decreases with increasing strain but at extremely high strains the ductility is partially
restored due to a recovery of the grain boundary structure.
Optical Behaviors of Novel Amorphous Ge – S – AgI Layers
Authors: Monchev Boris , Petkov P. , Boev V. , Petkova T.
Published: March 2009

The novel bulk glasses from the chalcohalide Ge-S-AgI system have been synthesized.
From the as-prepared samples amorphous films have been deposited by vacuum thermal
evaporation. The amorphous nature of the studied bulk and layered materials has been proved by Xray
diffraction. The composition of the synthesized bulk chalcohalide glasses and corresponding
amorphous thin films has been ascertained by means of Auger electron spectroscopy. The
morphology and uniformity of the deposited layers have been investigated using scanning electron
microscopy. The basic optical properties of the studied glassy films have been defined. Variations
in the optical behaviors as a function of the composition have been derived. Experiments related to
optical recording in the investigated Ge-S-AgI layers has been implemented. The diffraction
efficiency as a function of various recording beam intensities has been obtained.
Near-Field Study of Hot Spot Photoluminescence Decay in ZnS:Mn Nanoparticles
Authors: Grmela Lubomír , Tománek Pavel , Škarvada Pavel
Published: March 2009

The local spatial distribution of photoluminescence due to the creation of hot
luminescence centers was measured in the optical near-field by Scanning near-field optical
microscope at emission peaks of materials (λ =595nm), which is due to the luminescence of Mn2+ in
ZnS. The excitation bandgap of ZnS forms exitons, and these excitons get the center of Mn2+
through nonradiation dominates, by means of transition of 4T1 – 6A1 luminescence. This spectrum is
evidence that Mn2+ has been incorporated into the ZnS nanoparticles. In comparison with the bulk
ZnS:Mn phosphors these nanoparticles have clearly higher luminescent efficiency with its
luminescent decay time at least 4 orders of magnitude slower. It means that the oscillator intensity
of luminescent centers in ZnS:Mn nanocrystal enhances at least 4 orders of magnitude than that in
corresponding bulk ZnS:Mn.
Surface Modification of Hydrogels and Cell Adhesion
Authors: Kolářová Kateřina , Kasálková Nikola , Dvořánková Barbora , Michálek Jiří , Švorčík Václav
Published: March 2009

Polymer hydrogels have many different functions in the field of tissue engineering and
medicine. Modification of 2-hydroxy-ethyl-methacrylate (HEMA) and 2-ethyl-oxy-ethylmethacrylate
(EOEMA) by plasma treatment performed in Ar atmosphere at RT for 0-400 s was
studied using different techniques. Sample ablation was determined by gravimetry, surface
wettability and aging by goniometry, chemical structure by FTIR spectroscopy and surface
morphology by AFM microscopy. The plasma modification changes the sample surface
morphology. In vitro cultivation shows that the plasma treatment changes the proliferation of human
LEP cells.
Fractal Analysis of Fragmentation Patterns of Glass Plates
Authors: Davydova Marina , Davydov Denis
Published: March 2009

In the present work, the statistics of fragmentation is being studied in experiments with
thin glass plates under uniformly distributed quasi-static loads. For this purpose the original
pneumatic setup was manufactured. The glass plate is placed into a "sandwich" in order to fix the
fragmentation pattern after unloading and to photograph it by a digital camera. A photoimaging and
computer processing technique are used to assess the fragment areas and the total crack length.