bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Modeling of Microstructure Evolution and Dendrite Growth for Al-Si Alloy Casting during Low Pressure Die Casting
Authors: Li Bin , Xu Qing Yan , Liu Bai Cheng
Published: March 2009

A modified Cellular Automaton model was presented to simulate the evolution of
dendritic microstructure in low pressure die casting of Al-Si Alloy, which accounted for the
heterogeneous nucleation, the solute redistribution both in liquid and solid, the interface curvature
and the growth anisotropy during solidification. The free growth of single equiaxed dendrite and the
evolution of multi dendrites with various crystallographic orientations were predicted. The variation
of the dendrite tip velocity and local solute concentration at the solid/liquid interface were analyzed.
The grain morphology of aircraft turbine wheel casting at different specimen points were predicted
and compared with experimental results.
Crack Tip Dislocations and its Shielding Effect
Authors: Tanaka Masaki , Hoshino Yumi , Hartmaier Alexander , Higashida Kenji
Published: March 2009

Two dimensional simulations of discrete dislocation dynamics were carried out to clarify a
shielding effect due to dislocations at a crack tip. The configuration of dislocations around the crack
tip was calculated under the conditions of mode I tensile load at high temperatures. The stress field
around the crack tip due to dislocations was found to be compressive, accommodating mode I stress
intensity at the crack tip. In order to experimentally confirm the stress accommodation, infrared
photoelastic observation was also performed in a specimen pre-deformed at high temperatures. The
experimental result is in good agreement with a simulated infrared photoelastic image derived from
the stress field calculated.
Precise Rolling Force Calculation for the Tandem Cold Mill
Authors: Jiao Zhi Jie , Zhang Hao , Wang Jing , Liu Chui Hong , Liu Xianghua
Published: March 2009

Rolling force is the most important technical parameter for the tandem cold mill. In this
paper, the precise models and calculation process for the rolling force are introduced. The rolling
force model is based on the Bland-Ford and Hill theory, and the roll flatten radius is calculated with
the Hitchcok’s formula. The deformation resistance of the strip is calculated with the model, whose
parameters are decided according to the steel grade. The friction coefficient model is built according
to rolling speed and rolled length of the roll. The rolling force and the roll flatten radius are calculated
with the iterative method. These models are used for online process control of one five-stand tandem
cold mill. Comparing the calculation result and the actual data, the precision of the rolling force
calculation is high.
Mathematical Simulation of Billet Profile during Spray Forming Process
Authors: Ren San Bing , Fan Jun Fei , Le Hai Rong , Zhao Shun Li
Published: March 2009

The parameters of atomizer were obtained from the experiment. Based on the obtained
parameters, a mathematical model was proposed to simulate the growing profile of billet during spray
forming. The model included some process parameters which relate to the shape profile such as
nozzle data, eccentric distance, rotation speed, withdraw speed and so on. After being compared with
the billet shape of experiment, we got good consistent results between the simulation and experiment,
it was found that the results of the simulation is in good consistent with that of the experiment.
Structure and Mechanical Properties of Mg-Zn-RE System Alloys
Authors: Yang Jie , Wang Jun , Xiao Wen Long , Wang Li Dong , Wu Yao Ming , Zhang Hong Jie , Wang Li Min
Published: March 2009

The lightest density of Mg has stimulated renewed interest in Mg based alloys for
applications in the automotive, aerospace and communications industries. However, Mg in the pure
form has relatively low strength, limited ductility and is susceptible to corrosion. Great efforts have
been made to improve the mechanical properties of Mg alloys. Alloying Mg with other elements is
one of the most important methods. An important class of Mg alloys is the Mg-Zn-RE system (RE =
rare earth elements). In recent few decades, a series of new Mg-Zn-RE system alloys have been
obtained, and detailed the structure and mechanical properties of the alloys. In this paper, the structure
and mechanical properties of the Mg-Zn-RE alloys have been summarized. It showed that these alloys
have high strength and they are prospected to be widely used in the future.
Effects of Transformation Stress and Deformation before Austenitization on Nucleation of Intragranular Bainite
Authors: Nakai Kiyomichi , Kanno Norihiro , Asakura Ryo , Sakamoto Tatsuaki , Kobayashi Sengo , Hamada Masahiko , Komizo Yuichi
Published: March 2009

Intragranular bainite is known to be effective to develop toughness greatly in steels.
Effects of aging below eutectoid temperature before austenitization, the deformation before solution
treatment and the duration of solution treatment on nucleation of intragranular bainite have been
examined. In the austenite (γ) region where carbide pre-existed, the stress due to inverse
transformation, ferrite (α) to γ, would be introduced into fine austenitized region with lower transus
temperature to γ, resulting in the introduction of stable small-angle boundary at high temperatures
acting as the nucleation site for intragranular bainite lath. Deformation of α by cold rolling before
solution treatment enhances the nucleation of intragranular bainite, suggesting that the above γ
region through the inverse transformation is easily deformed by the hardened neighboring α. In the
deformed γ region, small-angle boundary would be more easily introduced, acting as nucleation site
for intragranular bainite. Intragranular bainite lath grew and hardness decreased by prolonging the
duration of solution treatment, indicating that transformation stress introduced by the pre-treatment
was influenced by solution treatment. The effect of sulfur addition on formation of intragranular
bainite was also analyzed.
Preparation and Characterisation of TiO2 Thick Films Fabricated by Anodic Oxidation
Authors: Abdullah H.Z. , Sorrell Charles C.
Published: March 2009

Anodic oxidation has been used to make well adhered and porous (≤1 μm pore diameter)
thin films of anatase on titanium using electrolytic solutions with combinations of H2SO4, H3PO4, and
H2O2. The crystallinity, film thickness, and pore size and number increase with time and voltage. The
voltage is limited to ~180 V by electrolysis and/or breakdown and the film thickness is ≤3 μm.
Numerical Simulation of Microstructural Evolution during Aging of Cu-Ni-Fe Alloys
Authors: Avila-Davila Erika O. , Melo-Maximo D.V. , Soriano-Vargas O. , Saucedo-Muñoz M.L. , Victoria-Hernández V.M.
Published: March 2009

The microstructure simulation of spinodal decomposition was carried out in the
isothermally-aged Cu-Ni-Fe alloys using the phase field method. The numerical simulation was
based on a solution of the Cahn-Hilliard partial differential equation by the finite difference method.
The calculated results were compared to those determined by atom-probe field ion microscope
analyses of the solution treated and aged alloys. Both the numerically simulated and experimental
results showed a good agreement for the concentration profiles and microstructure evolution in the
aged Cu-Ni-Fe alloys. The aging process caused the change of initial morphology, iregular and
interconected, to an equiaxial shape of the decomposed Ni-rich phase aligned in the elasticallysoftest
crystallographic direction <100> of Cu-rich matrix.
Phase Transformations in the Metallic Materials Being Electrodeposited and their Application for the Development of Advanced Technologies for Anticorrosive Protection of Canned-Food Steel Sheet
Authors: Girin Oleg
Published: March 2009

It has been found that during the electrodeposition of metallic material a supercooled
metallic liquid is being formed that is solidified at the deposition temperature in the form of a
crystalline or amorphous phase. These phase transformations are proved by the existence in the
electrodeposited metals of metastable structures that correspond to: the amorphous structure of the
solidified metallic liquid, the highly defective crystalline structure of the metal quenched from the
liquid state, and the intermediate modifications that had appeared during the fast crystallization of
the liquid phase of the polymorphous metal. On the basis of this phenomenon there have been
developed the technologies for producing of protective texturally-composite tin electrocoat,
nanostructurally-texturally-composite chromium electrocoat, and amorphous composite chromium
electrocoat on canned-food steel sheet.
Effect of Granule Size in Semi-Solid Slurry on Rheo-Extrusion of A7075 Aluminum Alloy
Authors: Uetani Yasuhiro , Nagata Ryotaro , Takagi Hidetoshi , Matsuda Kenji , Ikeno Susumu
Published: March 2009

Rheo-extrusions of A7075 aluminum alloy were carried out utilizing semi-solid slurries
with different solid granule sizes, which were made by a simple method combined a thin upright
tube with a water-cooled tube. Every structure of slurries was granular and average solid granule
sizes could be controlled by 0.05 to 0.11mm. These slurries were extruded to round bars at
extrusion ratio of 36 and press ram speed of 10mm/s mainly, just after cooling to 833K ( fs > 0.9 ).
All of the slurries could easily be extruded to bars with smooth surfaces at much low extrusion
forces than those of hot-extrusions. Tensile strength of rheo-extruded bars after solution treatment
increased with decreasing of the solid granule size. Peak hardness level at T6 condition equivalent
to that of hot-extrusion could be obtained at the finest solid granule size.
Integrating Process, Material and Business Strategies to Transform a Small-Medium Aluminium Products Manufacturer
Authors: Dover Ian , Baumann H. , StJohn David H. , Dargusch Matthew S.
Published: March 2009

The transformation of Bocar Automotive Products from an aluminium products
fabricator to an innovative manufacturer supplying automakers with accessory product systems has
required the adaptation of forming processes and product capabilities to address the relatively small
volumes in the Australian market, strategic change in the company’s target markets and cultural
change in its internal operations. The strategy for developing new capability in the casting and
forming of aluminium alloy products has taken place over 5 years beginning with the bending of
extruded shapes, progressing into the forming of sheet aluminium alloys and the casting of bumper
bar components, and finally into the integration of these processes into bumper systems for a
number of 4 Wheel Drive models. This paper describes the product design, metal forming and
production changes that Bocar has introduced and integrated with its marketing strategy to become
a recognized innovator in the accessories market in Australia.
Oxidation Behavior and Pack Siliconized Oxidation-Resistant Coatings of an Nb-Based Ultrahigh Temperature Alloy
Authors: Guo X.P. , Zhao L.X. , Guan Ping , Kusabiraki K.
Published: March 2009

The halide-activated pack cementation method was utilized to deposit silicide coatings on a
multicomponent Nb-Ti-Si based alloy. The siliconized temperature was 1150 °C and the holding time
was 10h. Both the specimens with siliconized coatings and without coatings were oxidized at 1250°C
for 5, 10, 20, 50 and 100h respectively. The coating possessed a double layer structure with the
composition of (Nb,X)Si2 (X represents Ti, Cr and Hf), and the outer layer was denser. The major
structure in the outer layer was composed of columnar crystals perpendicular to the interface between
the coating and the substrate, and that in the inner layer was mainly composed of equiaxed crystals. A
transitional layer about 5μm thick was found between the coating and the substrate. After oxidation at
1250°C, the major constituents in the scale were SiO2 and TiO2 and the mole ratio of these two phases
was about 2:1. The thickness of the (Nb,X)Si2 layer decreased and that of transitional layer increased
as the oxidation time prolonged. The siliconized coating exhibited excellent oxidation-resistance at
1250°C within 50 hours.
Enhancement of Fatigue Strength of SAE 1045 Steel by Tempering Treatment and Shot Peening
Authors: Yazdania Sasan , Yoozbashi Nariman , Ebrahimi Alireza
Published: March 2009

Effects of tempering temperature and shot peening on fatigue behavior of SAE 1045 steel
are reported. Tensile and fatigue property measurements are reported for samples tempered and shot
peened at 300 and 550°C. Microstructural studies and fracture surface observations were carried out
by optical and scanning electron microscopes. The experimental results showed that, fatigue
strength increases with decrease of tempering temperature and shot peening treatment. SEM
analyses indicated that all three stages of fatigue fracture affected by tempering treatment whilst
shot peening treatment only have an effect on the crack initiation stage.
The Effects of Nb and Cr Addition on Mechanical and Chemical Properties of Cold-Rolled Ni3(Si,Ti) Intermetallic Foils
Authors: Kaneno Yasuyuki , Takasugi Takayuki
Published: March 2009

Nb and/or Cr added Ni3(Si,Ti) as well as unalloyed Ni3(Si,Ti) intermetallic thin foils (i.e.,
Ni3(Si,Ti), Ni3(Si,Ti)+Nb, Ni3(Si,Ti)+Cr and Ni3(Si,Ti)+Nb,Cr) were fabricated from arc-melted
polycrystalline ingots by thermomechanical process and subsequent heavy cold-rolling. Tensile
property at room temperature as well as at high temperature and oxidization behavior of the
cold-rolled foils with a thickness of ~200μm were investigated. The Ni3(Si,Ti) and Ni3(Si,Ti)+Nb
alloys showed a single-phase microstructure consisting of L12 phase, while the Ni3(Si,Ti)+Cr and
Ni3(Si,Ti)+Nb,Cr alloys exhibited a two-phase microstructure with A1 (fcc) Ni solid solution phase
within the L12 grains. All the cold-rolled foils showed high tensile strength (over 2GPa) at room
temperature although no plastic elongation was observed. The addition of Nb and/or Cr slightly
enhanced the room-temperature tensile strength of the Ni3(Si,Ti) alloy. On the other hand, the
addition of Nb and/or Cr prominently enhanced high-temperature tensile strength as well as
oxidization resistance, while the addition of Cr improved high-temperature elongation.
Effect of Reheating and End Cooling Temperature on Microstructure Refinement in a Low Carbon High Strength Nb-Ti Microalloyed Dual Phase Steel
Authors: Yao L.D. , Li Z.G. , Mao Xing Feng , Tao Xue Li , Wu Kai Ming
Published: March 2009

In this study, a TMCP was attempted to obtain a low carbon high strength Nb-Ti
microalloyed dual phase with low yield ratio at Baosteel. Optical and scanning electron microscopy
was utilized to analyze microstructures. A mixed fine microstructures consisting of acicular ferrite
and martensite/austenite was observed. The austenite maintained a small grain size during reheating
in the temperatures ranging from 1100°C to 1250°C. The growth of austenite was strongly retarded by
Nb and Ti nitride and carbide. The higher end cooling temperature (650°C) had much influence on the
refinement of microstructures, especially the length of ferrite packets, whereas the lower temperatures
(600-500°C) had little effect on the microstructure refinement.
Fabrication Processes and Properties of Highly Pure MgAlON Materials
Authors: Huang Qing , Huang Yong , Wang Chang An , Zhang Hou Xing
Published: March 2009

In this paper, the MgAlON ceramic was fabricated by Spark Plasma Sintering (SPS) and
hot press sintering respectively. The results showed that highly pure and single-phase MgAlON could
be fabricated at lower sintering temperature in a short period through SPS process, compared with the
conventional Hot Press sintering (HP) process. The bending strength of MgAlON specimens prepared
by SPS process was higher than 500MPa while bending strength of HP specimens was much lower.
The open porosity was almost eliminated in SPS MgAlON specimens. Spark Plasma Sintered
MgAlON had a single phase of MgAlON while Hot Press Sintered MgAlON had major MgAlON and
minor AlN and Al2O3.
Microstructure and Electrical Properties of Calcium Copper Titanate Ceramics
Authors: Liu Lai Jun , Fan Hui Qing
Published: March 2009

The effect of stoichiometry, i.e. Ca/Cu ratios (CaCu3xTi4O12, x = 0.8, 0.9, 1.0, 1.1 and 1.2)
on the microstructure and electrical properties was investigated. The grain sizes of CaCu3xTi4O12
composition increased sharply with the increase of copper, from ~1 μm with x = 0.8 to ~50 μm with x
= 1.2. The real part of dielectric permittivity changed dramatically, the pellet with x = 1.0 had the
highest dielectric permittivity ~160, 000 at 1 kHz. Furthermore, the dielectric permittivity of all
pellets was impressively large values (between 10, 000 to 1, 000,000 at 100 Hz) and was nearly
constant over a wide frequency range between 100 Hz to ~100 MHz. However, the dielectric
permittivity of CaCu3xTi4O12 composition is not consistent with the amount of copper and cell
parameters and grain sizes. Impedance spectroscopy exhibited that the CaCu3xTi4O12 composition
had two semicircle at least at high frequency (~ 107 Hz) and low frequency (<100 Hz), respectively.
The grain and grain boundary of the compositions had different impedance and relaxation behavior.
Wear Characteristics of Bulk Ti3AlC2 under Current-Carrying Conditions
Authors: Huang Zhen Ying , Zhai Hong Xiang , Zhang Hua , Zhang Hong Bing
Published: March 2009

The current-carrying wear characteristics of Ti3AlC2 sliding against low-carbon steel were
investigated. Tests were carried out using a block-on-disk type friction tester, with sliding speeds of
20~60 m/s, normal pressures range in 0.4~ 0.8 MPa, and the current intensity of 0 A, 50 A and 100 A.
The Ti3AlC2 showed good current-carrying wear properties. At the sliding speed of 20 m/s, the wear
rate of the Ti3AlC2 (× 10-6 mm3/Nm) was varied in the range of (2.05 ~ 2.41), (2.64 ~ 2.39) and (6.26
~ 3.62), under the current of 0 A, 50 A and 100 A, respectively. Both the surfaces of Ti3AlC2 and the
steel were covered by a frictional film, which was consisted of iron titanate (Fe2.25Ti0.75O4) and
aluminum iron oxide (AlFeO3). The wear rate of Ti3AlC2 with current was composed of two parts: the
interaction of micro-arc ablation and mechanical friction, and the coupled action of thermal and
mechanical effect. Which one will be the main mechanism depends on the material parameters of
Ti3AlC2 and the mechanical parameters such as the normal pressure or the sliding speed.
Sintering and Performance of MgO-CaO Materials with Nano-Sized ZrO2 Addition
Authors: Chen Min , Lu Cai Yun , Yu Jing Kun
Published: March 2009

MgO-CaO materials is one type of the refractories for substitution of MgO-Cr2O3
refractories that has been widely used in metallurgy and cement industries, but the application of
MgO-CaO materials has been inhibited for its poor thermal shock resistance that is often improved by
addition of ZrO2 but it results in increase of the cost. The present work investigated preparation of
MgO-CaO materials by addition of nano-sized ZrO2. The results showed that the densification of the
MgO-CaO refractories was promoted and the direct bonding rate of the materials was increased by
addition of nano-sized ZrO2. The thermal shock resistance of the MgO-CaO refractories was
appreciably improved by modification of the microstructure due to the formed fine CaZrO3
crystallines homogenously locating on the grain boundaries and triple points of the whole
microstructure. The critical amount of ZrO2 addition for the purpose to improve thermal shock
resistance was effective decreased.
High Volume Fraction Carbide Reinforced Copper Matrix Composites for Sliding Contact Applications
Authors: Akhtar Farid
Published: March 2009

This study deals with the processing, microstructure and properties of the carbide
reinforced copper matrix composites. Powder technology was used to successfully fabricate the
composites. NbC particulates were used as reinforcements for copper matrix. The microstructure of
the composite was characterized by scanning electron microscopy. The microstructural study
revealed that the NbC particles were distributed uniformly in the matrix phase. No interface
debonding and micro- cracks were observed in the composite. NbC particles were found in round
shape in copper matrix composite. The composite hardness of 78 HRA was found with 60vol%
NbC content. Electrical conductivity as high as 7%IACS was achieved. The wear performance and
conductivity value predicts that NbC reinforced copper matrix composites can be used as sliding
contact applications.
Preparation of Silica Microcapsules Containing Phase Change Paraffin Wax
Authors: Miao Chun Yan , Lü Gang , Cao Ke , Yao You Wei , Tang Guo Yi , Weng Duan
Published: March 2009

This paper deals with the preparation of silica microcapsules containing phase change
paraffin wax for thermal energy storage and the determination of their thermal properties. The
spherical microcapsule samples respectively containing two types of paraffin wax (with peak melting
temperature of 29.3 °C (type P1) and 35.5 °C (type P2), and the fusion heat of 140 J/g (type P1) and
153 J/g (type P2)) as core and chemically and thermally stable silica as shell, were prepared from O/W
emulsion systems in the presence of polyvinyl alcohol as stabilizer, and sorbitan monooleate and
poilyoxyethylene(20) sorbitan monooleate as emulsifiers. The silica shell formed via hydrolysis and
condensation from tetraethyl silicate with acetate acid as catalyst. The fusion heat of the two samples
is 101 J/g and 112 J/g respectively. Property of adaptable temperature of the as-made microcapsules is
measured through a self-made cell model. The maximum difference between the temperature of the
cell with PCM wallpaper and that of the cell with controlled wallpaper is about 1.1 °C.
Damping Capacities of B/Al Composite Subjected to Thermal-Mechanical Cycling
Authors: Qin Yao Chun , He S.Y.
Published: March 2009

The damping capacities of B/Al composite subjected to thermal-mechanical cycling
(TMC) were studied. The damping capacities, including the mechanical loss Q-1 and the logarithmic
decrement δ , increase with increasing the TMC cycles. The damping capacities of B/Al composite
increase more greatly under the elevated applied stresses at the same temperature interval and cycles.
After the TMC, the damping capacities can increase 10 times than that of as-fabricated B/Al
composite. The damping behavior of B/Al composite under the present test condition is primarily
associated with the interfacial degradation during the TMC.
A Study on Manufacture of SiCp/Fe Composites by Specimen Current Heating Hot Press Sintering
Authors: Wang Gang , Yang Yu Fang , Zong Ya Ping
Published: March 2009

A specimen current heating sintering process was employed to manufacture SiC particulate
reinforced iron matrix composite. The results show that mechanical properties of the composite can
be improved significantly with increasing pressure level, voltage, sintering time. It is found that short
sintering time, fast heating and uniformly heating, surface activation of particles can be accomplished
in specimen current heating hot press sintering to avoid oxidation degradation of Fe powder, and to
produce fine microstructure, which contribute the main reasons for achieving higher density and
higher properties. The best properties achieved so far for the composite are: density is 99.90%, Brinell
hardness is 416HB and tensile strength is 838MPa.
Slab Method Analysis and FEM Simulation on Rotating Compression Forming of Cylinder Considering Coulomb Friction
Authors: Tzou Gow Yi , Chien Wen T. , Huang Ming Nan , Cai Dong Lin
Published: March 2009

An investigation into the compression forming of cylinder using the commercial code
SUPERFORM is developed. The cylinder billet compressed between the upper and lower dies is
meshed by a quadrangle elastic-plastic element. The numerical simulation based on the FEM also
compares with the slab method established by us. In the slab method analysis, the stress distributions
are estimated by considering the coulomb friction between the dies and the cylinder. Throughout this
study, the effects of frictional coefficient, rotating angular speed, reduction and aspect ratio etc upon
the compression force, the effective stress and the effective strain, and velocity field are discussed
systematically. For verifying the validity of two models, comparisons of compression forces based
both modes are carried out to prove the feasibility of both models.
Tensile Behaviour of Nano-Particulate Reinforced Aluminium Matrix Composites at Elevated Temperatures
Authors: Ahmed A. , Neely A.J. , Shankar K.K. , Chan Sammy Lap Ip
Published: March 2009

The tensile behaviour of nanometric SiC particulate (SiCp) reinforced aluminium matrix
composites (AMCs) was examined at room temperature, 215°C and 350°C. These AMCs were
produced via powder metallurgy (P/M) using Al 7075 powder reinforced with different volume
fractions (1 vol.%, 3 vol.% and 5 vol.%) of nano-SiCp. The experimental results exhibit that at room
temperature un-reinforced Al has both maximum strength and ductility whereas the 5 vol.% SiCp/Al
composite has only maximum stiffness. Similar trends were obtained for tests performed at 215°C.
However at 350°C, the 1 vol.% SiCp/Al composite has the highest stiffness. Optical microscopy and
scanning electron microscopy were performed for microstructure study, examination of the SiCp
distribution in the Al matrix and fractography.
Effect of Aluminum Addition on Thermal Properties of Mg/SiCP Composites
Authors: Zhang Yang , Wang Xi Tao , Chen Li , He Xin Bo
Published: March 2009

In this studies, Mg(Al)-50 vol.% SiC particle composites were fabricated by pressure
infiltration with the two different matrix base materials of Mg and Mg-6Al alloy. Thermal
conductivities of the two composites were compared and the effect of addition was studied using
X-ray diffraction and scanning electron microscopy (SEM). The analysis of the X-ray diffraction
shows that the Al-addition to the Mg causes a contraction of the Mg lattice parameters, which brings a
better matching between the matrix and SiC particle. The microstructure and the fracture surface of
the composite were characterized by using SEM. The alloying element Al exists mainly in the form of
α solid solution, which has a uniform distribution in matrix. From calculation, the interfacial thermal
barrier resistance of the Mg-6Al/SiCp composite is about one order of magnitude lower than that of
the Mg/SiCp composite.
Subgrain Boundaries in ECAP Aluminium
Authors: Saxl Ivan , Sklenička Václav , Ilucová L. , Svoboda Milan , Král Petr
Published: March 2009

The effect of ECAP technology on the subgrain structure of coarse-grained pure
aluminium is described by means of the orientation imaging microscopy (the selected lower bounds
of misorientation (disclination) are = 2o, 5o, 10o and 15o). Standard profile and intercept counts
carried out in three suitably oriented and mutually perpendicular section planes and along 18
systematically oriented directions, resp., are used to examine the subgrain and grain structures after
the number of passes N = 2, 4, 8, 12 as well the effect of subsequent annealing (several hours at
473K). The local and overall non-homogeneity and anisotropy of boundary structures have also
been evaluated.
Advanced Plastic Processing Techniques for the Densification of Spray Deposited Preforms
Authors: Chen Zhen Hua , Zhang Hao , Chen Ding , Yan Hong Ge , Chen Gang
Published: March 2009

In the present investigation, several novel techniques including sequential motion
compaction, ceramic rolling and frame-confined rolling have been developed to improve the
formability of spray deposited porous aluminum alloy preforms. The experimental results show that
these techniques can greatly improve the workability of the spray deposited performs. Especially,
sequential motion compaction can be used to densify the preforms of large dimensions which are
difficult to further processing by the traditional techniques to fully dense.
Formation of Ultrafine Grained Structure in SUS 304 Stainless Steel Produced by High Pressure Torsion (HPT)
Authors: Li Jin Guo , Umemoto Minoru , Todaka Yoshikazu , Tsuchiya Koichi
Published: March 2009

SUS 304 austenitic stainless steel was processed by HPT at room temperature with
different rotation speed. It was found that the microstructure evolution and composed phases along
the progress of HPT were sensitive to the strain rate (rotation speed). During deforming with the
low strain rate, the deformation-induced dynamic phase transformation (DPT) from austenite (γ) to
martensite (α’) occurred and the microstructure is characterized by elongated submicron α’ grains
after 10 revolutions. While the euqiaxed nanocrystalline α’ grains were produced after HPT at the
continuously alternative low and high strain rate. XRD analyses showed that multiple DPT of
γ→α’→γ→α’ took place during HPT at the continuously alternative low and high rotation speed.
Based on the experimental results, it was proposed that the euqiaxed ultrafine grained structure
were produced by multiple DPT under the high strain and strain gradient.
Distortion Analysis of Aluminum Alloy for Sheet Metal Forming after Solution Treatment
Authors: Torng Chau Chen , Huang Chi Kong , Chang Hsien Ming
Published: March 2009

The sheet metal parts play important role in aero structures. Due to the requirement of
strength and constraint of weight in aircraft, the aluminum alloy is widely used in sheet metal forming
parts. Most of sheet metal parts form the contour in O-condition, and then solution treat to improve
the strength and mechanical property. The deformation of sheet metal parts usually takes place after
the heating cycle and quenching into the water or solution. The straightening operation will apply to
corrective the contour of parts. Thus, the non-value added operation would increase the production
cost. By using statistical methodology to analysis deformation data of sheet metal parts, this study use
Cause-Effect Analysis to find the relation between deformation and relative factors, such as material,
thickness and contour. The results of this analysis can provide an efficient and economical approach
for the designer, process planner, and technician in manufacturing the sheet metal parts.
Superplastic Deformation Behavior of Spray Formed High Speed Tool Steel at 820°C
Authors: Zhou Can Dong , Fan Jun Fei , Le Hai Rong , Zhang Jing Guo
Published: March 2009

Being examined by tensile tests at 820°C with initial strain rates of 2.5×10-4 s-1, 5.0×10-3
s-1and 1.0×10-1 s-1, the hot-rolled spay formed high speed steel (SF-HSS) had superplastic properties.
With έ=2.5×10-4 s-1and 5.0×10-3 s-1, the σ-ε curves indicate that there has occurred dynamic
recrystallization at the later stage of deformation.The tensile elongation decreases monotonously with
strain rate increasing. The strain rate sensitivity m =dlogσ/dlog έ is about 0.23. In the sub-surface of
fractured SF-HSS samples with έ=2.5×10-4 s-1,, most of holes on the subsurface are observed to
distribute near the carbides and arranged along the tensile axis direction. The interface between coarse
carbides and matrix is very weak sites where the holes are easy to nucleate and connect to cracks
during deformation. In the necked region, fine carbide particles on the grain boundary have pinned the
slip of dislocations and formed dislocation wall inside the grain. Dynamic recrystallization and some
climb of dislocations has occurred. The superplastic deformation mechanism with έ=2.5×10-4 s-1 was
dislocation creep mechanism controlled by dynamic recrystallization. During deformation, the role of
some carbide in the materials was to retard the grain growth and keep SF-HSS having fine equiaxed
grain size and remain stable.
Surface Features in Honing Zirconia Ceramics Using Fine Grains with Ultrasonic Assistance
Authors: Gao Guo Fu , Zhao Bo , Kong Qing Hua , Liu Chuan Shao
Published: March 2009

Experiments on surface features were carried out in honing zirconia engineering ceramics
using fine grains. In ultrasonic honing, the surface fracture ratio increased quickly when the depth of
cut is more than 3 μm, while in common honing it performed an ascending trend from depth of cut 1.5
μm. The value of surface roughness in ultrasonic honing increased along with the depth of cut; while
it descends contrast to the depth of cut when the honing velocity is less than 0.58 m/s in traditional
honing. As for honing velocity over 0.74 m/s, it deceased firstly to the minimal value for depth of cut
1μm, then began to ascend along with depth of cut. The value of surface roughness descended to
minimum value for the range of honing velocity 0.41-0.58 m/s in traditional honing, while the
optimized honing velocity ranged 0.58-0.75 m/s in ultrasonic machining. The surface roughness in
ultrasonic honing was superior to that in traditional honing.
Research on Properties of SiCp/AZ61 Magnesium Matrix Composites in Fabrication Processes
Authors: Yan Hong , Fu Ming Fu , Zhang Fa Yun , Chen Guo Xiang
Published: March 2009

The microstructural structures of SiCp/AZ61magnesium matrix composite were studied in
three different casting processes, and their hardness was measured. The results indicated that
SiCp/AZ61 composites fabricated in stirring melt casting process, compared to those in fully liquid
stirring casting process and in semi-solid stirring casting process, possessed fairly uniform
distribution of SiC particulates and few porosity rate. It was an ideal metal matrix composites
fabricated process. The Vickers hardness of non-reinforcement AZ61 magnesium alloy is higher than
that of semi-solid billet, and the Vickers hardness of SiCp/AZ61 composite is obviously higher than
that of the matrix. In the meantime, the Vickers hardness of SiCp/AZ61 composite can be
continuously enhanced with an increasing of volume fraction of SiC particles.
Microstructure and Properties of Al-Zn-Mg-Cu-Mn In Situ High Strength Alloy
Authors: Cai Yuan Hua , Cui Hua , Li Yong Bing , Hang Jing Feng , Zhang Ji Shan
Published: March 2009

Al-Zn-Mg-Cu alloy containing 2%Mn was made using spray forming method and hot
extrusion. XRD, OM, and SEM were used to investigate the microstructure. Results showed that after
being hot extruded and solid solution treated, the Al alloy matrix had uniformly fine recrystallized
grain with an average size of 8μm. The particles of MnAl6 were formed during the spray forming
process and distributed along the grain boundary. Deformation and spheroidization of MnAl6
particles were occurred during post hot extrusion and solid solution treament, which would be benefit
to the improvement of toughness of Al alloy. When aged at the T6 conditions, the tensile strength of
the Al alloy was increased up to 775MPa with the elongation of 4.3%, the fracture surface consisted
mainly of dimples with a size lower than 500nm.
Synthesis of Tin Oxide (SnO2) by the Oxalate Route: Effects of Addition Method and Ageing
Authors: Taib H. , Sorrell Charles C.
Published: March 2009

Aqueous solutions of tin (II) chloride dihydrate and oxalic acid dihydrate (both 0.04 M)
were prepared and mixed by (1) dropwise addition and (2) instantaneous addition, with both
involving addition of the latter to the former. Following filtering, washing, and drying, the
precipitates were calcined and ground. The particle size and morphology of uncalcined and calcined
tin oxalate were examined by electron microscopy and laser diffraction.
The method of addition was important in that it influenced both the particle size and shape of tin
oxalate. This resulted from the time effect of the ionic collision frequency and the proximity effect
of the diffusion distance. As expected, ageing was important in that it caused grain growth and
reduction of surface area of the tin oxalate. Although there appeared to be an effect of the method of
addition on agglomeration of the tin oxide, this was a result of adsorption of atmospheric moisture,
which depended on the relative humidity of the environment during grinding.
Unsteady-State Solidification under Forced Flow Conditions
Authors: Turchin A.N. , Eskin Dmitry G. , Katgerman Laurens
Published: March 2009

The interaction between flow and progressing solidification front is of great importance,
since it occurs in all casting processes. The present paper provides a better understanding of the
flow phenomena and associated complex effects on solidification in a rectangular cavity under
forced flow conditions, by means of experiments and computer simulations. It is shown that the
cavity-driven flow with solidification is determined by several interacting features. The variation in
bulk flow velocity and initial superheat dramatically changes the macro- and microstructure,
promoting grain refinement, formation of peculiar grain and dendrite morphologies, etc. In
particular, twinned feathery grains are found in the structure formed under certain heat and flow
conditions during solidification. Some correlations between twinned feathery morphology, flow and
solidification parameters are obtained. The effect of flow vortices on progressing solidification front
and their effects on structure evolution are analyzed. Finally, the quantitative correlations between
microstructure, solidification and flow parameters are established.
On Micro Forming by Hydro Spark Forming Method
Authors: Hasebe Tadashi , Imaida Yutaka
Published: March 2009

This paper proposes a seamless microforming technique from 100 micrometer order
bulging all the way down to micrometer-order embossments by using hydro spark forming method.
Sub-millimeter order bulging with 300 and 100 m diameter aluminum thin foils are demonstrated
to be easily available without accurate positioning as in the conventional methods. The present
technique is successfully applicable also to surface embossments of micrometer order, for a coin
surface, an IC chip and hologram surfaces.
A Study on Shock Energy for Concrete Destruction Using Underwater Shock Wave
Authors: Otsuka Masahiko , Okamoto Naoki , Itoh Shigeru
Published: March 2009

In this study, the destruction of concrete block using underwater shock wave generated by
high current is studied. A metal wire was connected to an electrode and a high voltage impulsive current
was passed through it to generate the underwater shock wave. The underwater shock wave was
investigated by optical observation using a high-speed camera and pressure measurement. A comparison
was made on the shock wave generated from the electrode with and without connecting it to a metal wire.
The underwater shock wave generated from electrode without metal wire showed the existence of many
shock waves by continuous plasma within discharge duration, and the duration of the pressure pulse was
long in this case. The peak pressure of underwater shock wave generated from metal wire explosion was
higher than the previous case due to the reaction of metal vapor and water, whereas the pressure duration
was less. The concrete block was efficiently destructed by the effect of underwater shock pressure of
high impulse. The high peak pressure and long duration are necessary for the destruction of concrete
block. It is suggested that high pressure induces crack to the structure, and the long pulse duration
destructs the structure.
Numerical Simulation on Explosive Welding Process Using Reflected Underwater Shock Wave
Authors: Shiramoto Kazumasa , Fujita Masahiro , Ujimoto Yasuhiro , Iyama Hirofumi , Itoh Shigeru
Published: March 2009

The paper describes a numerically simulated result for the explosive welding using
reflected underwater shock wave. Through the numerical simulation, the effective use of reflected
underwater shock wave was clearly suggested and the method to improve the assembly was
demonstrated.
Microstructure Modification of Magnesium Alloys by High Current Electropulsing
Authors: Tanaka Shunsuke , Takemori Yuichi , Tsushida Masayuki , Kitahara Hiromoto , Ando Shinji , Tonda Hideki
Published: March 2009

In this study, effects of high pulse current (current density :>103 A/cm2, applied time: 15 s) on microstructure of magnesium alloys were investigated. A mild steel was also employed as comparison material. Refinement of microstructure by electropulsing was observed in Mg-3B2O3 and mild steel and micro-Vickers hardness of these alloys were increased by modification of microstructure.
Numerical Simulation of Shaped Charges Using the SPH Solver: Jet Formation and Target Penetration
Authors: Miyoshi Hitoshi
Published: March 2009

The SPH (Smoothed Particle Hydrodynamics) solver of the AUTODYN-3D was utilized to
demonstrate a remarkable numerical simulation of shaped charges, specifically the process of jet
formation and target penetration. A shaped charge consists of an explosive, a case and a conical liner.
The Euler solver has been generally utilized for the simulation of the liner collapse process. Though
the axi-symmetric modeling of the liner usually is selected, the actual jet formation process is never so
idealistic. When we choose options consistent with live fire experiments, the SPH solver produces a
more accurate solution over the Euler approach. The SPH method is capable of dealing with problems,
including the free surface, deformable boundaries, moving interface and extremely large deformation.
Calculated hypervelocity particles using the SPH method precisely represented the actual observed jet
formation profiles of shaped charge characteristics. Accurate representations of the jet velocities, a
velocity gradient with the tip traveling much faster than the trail and phase changes of the liner
material were demonstrated. Using the calculated jet particles from the SPH method, the penetration
process was simulated. The calculation was very time-consuming and the results did not conform to
the traditional theories of the penetration. We have been investigating this discrepancy.
Numerical Analysis of Projectile-Launch Tube Wall Friction Effects on Projectile Acceleration in Single-Stage Gun
Authors: Miura Hiroaki , Matsuo Akiko
Published: March 2009

The effects of the friction between the projectile and launch-tube wall in a single-stage gun
are examined by the interior ballistics simulations. The solid/gas two-phase flow code for
two-dimensional axisymmetric calculation is used in the simulations. In this study, one-dimensional
quasi-steady-state elastic relations are applied to the projectile in the estimation of the friction force.
The calculation method is validated by the comparison of the simulated results with the experimental
data such as the histories of the breech pressure and the projectile acceleration. The simulated results
reveal that the impact of the shock waves to the base increases the friction force acting on the
projectile. The large friction force in the tight fit case decelerates the projectile, consequently
intensifying the chamber pressure. The muzzle velocity decreases with the increase of the projectile
diameter, and this appears strongly in the low chamber pressure case.
Transverse Cracking of Layered Structures: Evaluation of Fatigue Crack Propagation
Authors: Náhlík Luboš , Hutař Pavel , Knésl Zdeněk
Published: March 2009

The objective of this paper is to investigate the transverse fatigue cracking of layered
structures. To this end a fatigue crack propagation rate for a crack growing perpendicularly through
the interfaces between individual layers of the structure is estimated. The suggested procedure takes
into account the influence of different material properties of the layers on the stress field around the
fatigue crack and the change of the stress singularity exponent in the special case of a crack
touching the material interface. The assumptions of linear elastic fracture mechanics and elastic
behaviour of the composite are considered. It is shown that the existence of the interfaces can have a
negative influence on the residual fatigue life of layered structures.
Microstructural Parameters in the Theory of Critical Distances
Authors: Taylor David
Published: March 2009

The work described below investigates, for the first time, the link between
microstructural parameters such as grain size and the length constant L which is known as the
critical distance. L is frequently used in the prediction of failure processes such as brittle fracture
and fatigue, initiated at stress concentration features such as notches. Values of L were calculated
using data from the literature on the effect of short cracks and notches in steels and ceramics. In
some cases, simple relationships could be established between L and the grain size, or other
microstructural features. Sometimes L was found to be much larger than anything in the
microstructure and appeared to be related to the size of the damage zone at failure.
Surface Structure and Cells Adhesion on Doped Polyethylene
Authors: Mikulíková Regina , Kolářová Kateřina , Švorčík Václav , Dvořánková Barbora , Sopuch Tomáš
Published: March 2009

The properties of polyethylene doped with Ca2+ salt of oxidized cellulose was studied by
different techniques. FTIR spectroscopy was used for the determination of crystalline phase in
polymer film, surface wettability was determined by standard goniometry and surface morphology
was examined by SEM microscopy. Adhesion of mouse 3T3 fibroblasts on the doped polymer was
studied in vitro. It was found that the polyethylene doped with the cellulose derivative can be
sterilized in boiling water. The number and homogeneity of adhering cells were shown to depend on
the surface wettability and morphology.
Grain Size Estimation in Anisotropic Materials
Authors: Procházka Jaroslav , Ponížil Petr , Saxl Ivan
Published: March 2009

The estimation of grain size (volume) by using computer database of tessellations is
explained and demonstrated. As model material was selected an anisotropic material formed by
compression-moulded pellets of PVC. The pellets were first covered with carbon paste to highlight
borders of grains in final specimen and then moulded; their volumes were exactly known. Standard
profile and intercept counts were carried out on the planar sections of the specimen and used to
estimate the grain size by means of computer database. The obtained estimates were then compared
with the known pellet characteristics.
The estimation of grain volume and of other suitable characteristics by inspection of section planes
is necessary in opaque materials (e.g. metal alloys, crystalline polymers, ceramics), where their
values are inaccessible by direct measurements. The aim of this work is show that the standard
approaches can be improved with the help of a suitably prepared computer database.
X-Ray Micro-Tomography Coupled to the Extended Finite Element Method to Investigate Microstructurally Short Fatigue Cracks
Authors: Ferrié Emilie , Buffière Jean Yves , Ludwig Wolfgang , Gravouil Anthony
Published: March 2009

In this paper we will present how it is possible to couple a 3D experimental technique
with a 3D numerical method in order to calculate the stress intensity factors along the crack front
taking into account the real shape of the crack. This approach is used to characterize
microstructurally short fatigue cracks that exhibit a rather complicated 3D shape. The values of the
stress intensity factors are calculated along the crack front at different stages of crack propagation
and it can be seen that the crack shape irregularities introduce rather important fluctuations of the
values of KI, KII and KIII along the crack front. The values of KI obtained taking into account the real
shape of the crack are significantly different from the ones calculated using an approach based on a
shape assumption