bluuebunny/crossref_metadata_2025 huggingface dataset:
A Safe Use of Explosives by Parting into a Small Amount of Powder
Authors: Fujiwara Masaharu , Fujiwara Kazuhito , Hiroe Tetsuyuki , Hata Hidehiro
Published: March 2009

High explosives are useful material to generate great amount of energy in short time. Since
controlling their releasing energy is hard, the use of explosive is limited to breaking and crushing the
tough structures and processing of bulk materials. However, the reduction of mass of the explosive
powders in a process and the arrangement of pellets with constant intervals provide us the safe
handling, and then those lead the new utility of the explosion, while there are some difficulties
encountered when a small amount of explosive powder is used, such as the initiation regularity of
explosives and the protection of mechanical parts from impact damages. In this paper, the successive
initiation of small explosive was tested by means of the wire explosion that is generated by the instant
release of electric energy from high volt capacitors, and the successful results were obtained under the
controlled condition. The damages of surrounding devices were avoided by using of the initiating
head of the device that had small chamber isolated from the outer atmospheric environment.
Shock Compaction of WC-Co Powder in Metallic Tube
Authors: Tanaka Shigeru , Hokamoto Kazuyuki , Itoh Shigeru
Published: March 2009

The tungsten carbide - cobalt, (WC-Co) powder is compacted and bonded to on a stainless steel
(SUS304) rod by using explosives. In this research, the experiments are conducted using two
methods. They are the method of making the pressure of the explosive act directly on the powder and
the method of explosively driving a metal pipe with high speed to create high pressure acting on
powder. Crack free bulk material was recovered. Heat-treatment was performed on the recovered
sample. After heat treatment, the value of hardness was increased compared with commercial
material.
Influence of Calcination Temperature on the Microstructure of Porous TiO2 Film
Authors: Miki Takeshi , Nishizawa Kaori , Watanabe Eiji , Taoda Hiroshi
Published: March 2009

To obtain porous TiO2 film, the precursor sol was prepared by hydrolysis of Ti
isopropoxide and then complexed with trehalose dihydrate. The porous TiO2 film was fabricated by
dip-coating technique on glass substrates using this solution. The TiO2 film was calcined at 500 °C.
The maximum thickness of the film by one–run dip-coating was ca. 740 nm. The film was
composed of nanosized particle and pore. The porosity of the TiO2 film was increased by the
addition of trehalose dihydrate to the sol. The porous TiO2 films were calcined at various
temperatures. The effects of the calcination temperature on the microstructure of the porous TiO2
film were investigated. The porous film prepared from sol containing trehalose still kept the porous
structure for calcination at 950 °C. The phase transition temperature from anatase to rutile of the
film was shifted from 650 to 700 °C by trehalose addition to the sol.
Fabrication of WC and WC(Co) Codeposited Nickel Composite Coating by Electroplating Method for the Replacement of Chromium Coating
Authors: Kim Dae Geun , Lee Jae Ho
Published: March 2009

The codeposition of fine WC and Co coated WC particles from nickel Watt’s bath has been investigated. Electroplating of Ni/WC and Ni/WC(Co) composites coating were carried out at different current density with variation of particle size. The effect of hydrodynamic conditions of the codeposition of Ni/WC bath has been investigated. The Guglielmi adsorption mechanism is applied to the electroplating of the fine WC and WC(Co) in Ni matrix. The adsorption rate of determination step is controlled by the transferal process of loose adsorption to strong adsorption. The embedded WC concentration can be increased both by increasing electrical current density and additional WC concentration in the bath.
Dehumidification of Air by the Composite Membrane Coated with Hydrophilic Polymer on Inorganic Substrate
Authors: Song Kun Ho , Cho Seong Heon , Lee Kwang Rae
Published: March 2009

A membrane permeable to water vapor was prepared and used for dehumidification of air.
At a given feed flow rate, the permeation ratios were almost independent to relative humidities of
feed stream; The permeation ratios were about 45%, 60%, and 25% at feed flow rate of 50, 70, and
90cc/min, respectively. Permeation ratio might also be enhanced with increasing feed flow rate.
However, the permeation ratio (about 25%) at a feed flow rate of 90cc/min was much less than at
50cc/min (about 45%) and 70cc/min (about 60%). This phenomenon might be explained that a water
film does form at surface of membrane because the amount of water vapor contained in feed stream of
90cc/min was much more than the permeate through the membrane.
Preparation of the Nano-Hydroxyapatite/Chitosan/Konjac Glucomannan Composite as a Novel Degradable Drug Delivery System
Authors: Zhou Gang , Li Yu Bao , Lee Soo Wohn
Published: March 2009

Nano-hydroxyapatite (n-HA)/chitosan (CS)/konjac glucomannan (KGM) composite was prepared by integrating composition and molding. Then, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the physical, chemical and degradable properties of the composite before and after in simulated body fluid (SBF). Moreover, study in vitro test for drug delivery revealed that the amount of released pentoxifylline (1-[5-oxohexyl]-3,7-dimethylxanthine)(PTX) reached a plateau and equaled 80% of the drug loaded in an implant. The newly develop n-HA/CS/KGM composite may serve as a good degradable biomaterial for implantable drug delivery system (IDDS) in bone tissue engineering.
Inter-Granular Residual Stresses in Polycrystalline Aggregates: Finite Element Modelling and Diffraction Post-Processing
Authors: Song Xu , Zhang Shu Yan , Dini Daniele , Korsunsky Alexander M.
Published: March 2009

Most models based on continuum mechanics do not account for inhomogeneities at the
micro-scale. This can be achieved by considering a representative volume of material and using
(poly)crystal elasto-plastic deformation theory to model the effects of grain morphology and
crystallographic orientation. In this way, the relationship between the macroscopic stress state and
the stress state at the grain level can be investigated in detail. In addition, this approach enables the
determination of the inhomogeneous fields of plastic strain, the identification of regions of localised
plasticity (persistent slip bands), grain level shakedown, and the prediction of fatigue crack
initiation using energy dissipation at the micro-scale. Elastic anisotropy is known to promote earlier
onset of yielding, and to increase the magnitude of intergranular residual stresses. The effect of
hardening behaviour of different slip systems on intergranular residual stresses is more subtle, as
discussed in the text. The present study focuses on the analysis average intergranular residual
strains and stresses that arise within the polycrystal aggregate following the application of single or
cyclic external loading. These residual strains can also be evaluated experimentally using diffraction
of penetrating radiation, e.g. neutrons or high energy X-rays, allowing comparisons with the model
predictions to be made.
Synchrotron Energy-Dispersive X-Ray Diffraction Analysis of Residual Strains around Friction Welds between Dissimilar Aluminium and Nickel Alloys
Authors: Jun Tea Sung , Zhang Shu Yan , Golshan Mina , Peel Matthew J. , Richards David G. , Korsunsky Alexander M.
Published: March 2009

Friction welding processes, such as friction stir welding (FSW) and inertia friction
welding (IFW) are popular candidate procedures for joining engineering materials (including
dissimilar pairs) for advanced applications. The advantages of friction welding include lack of large
scale material melting, ability to join dissimilar materials, and relatively low propensity to introduce
defects into the weld joint. For these reasons FSW and IFW have become the subjects of a number
of studies aimed at optimising the joining operations to obtain improved joint strength and reduce
distortion and residual stress. In the present study we used the diffraction of high energy
polychromatic synchrotron X-rays to measure interplanar lattice spacings and deduce nominal
elastic strains in friction stir welds between dissimilar aluminium alloys AA5083 and AA6082, and
in coupons from inertia friction welds between dissimilar nickel-base superalloys IN718 and
RR1000. Energy-dispersive diffraction profiles were collected by two detectors mounted in the
horizontal and vertical diffraction planes, providing information about lattice strains in two nearly
perpendicular directions lying almost in the plane of the plate samples mounted perpendicularly to
the incident beam. Two-dimensional maps of residual stresses in friction-welded joints were
constructed. Apart from the 2D mapping technique, the sin2ψ method (transmission) was also used
in the case of inertia friction-welded joint between nickel alloys. Comparison between the two
results allowed the variation of the lattice parameter with the distance from the bond line to be
deduced. It was found that friction welding of two dissimilar materials with significant strength
mismatch may lead to the creation of a region of compressive stress in the vicinity of the bond line,
in contrast with the behaviour observed for joints between similar materials.
Computer Simulation of Heat Treatment Process for 125MN Plunger
Authors: Mo Chun Li , Ling Jin , Luan Yi Kun , Shen Cai Ping
Published: March 2009

The heavy 125MN Plunger is weight 140 ton, its heat treatment process include two part,
one is heat and another is quenching in order to attain certain hardness on its surface and toughness
on its body. Differential temperature heat process were made in well resistance furnace, the heat
time include warm-up and holding period and high-speed increasing period. The total time is about
30-40 hours.The differential heat treatment process is an essential step in the production of heavy
plunger, and it determines the hardness distribution on the sample surface. In this paper, a program
to calculate real-time temperature during the heat treatment process was developed based on a great
deal of experiments. Using this subroutine program the temperature field of hollow heavy plunger
during differential heat treatment process was calculated. The result shows that the simulated
temperature was agreed with the real temperature in the warm-up and holding period of the heat
treatment process. In the calculation temperature field ,based on the convectional heat transfer
coefficient and radiate heat transfer coefficient, the corrected heat transfer coefficient were
induced to compose comprehensive heat transfer coefficient. The temperature predicted in warm-up
and holding period were correct, the error was below 1%. At the high-speed increasing period, the
time when the external temperature reach enacting was predict accurately. So the computer
simulation can give real time prediction to decide parameters of the heat treatment process. The
result also show that the program developed is sample and applied , it fit for predicting temperature
at workshop real time and it is available to deal with complex process .
Displacement Field Simulation and Deformation Prediction of Longitudinal Straight Seam Welding of Thin-Wall Aluminium Alloys Cylinder
Authors: Zhou Guang Tao , Liu Xue Song , Yan De Jun , Fang Hong Yuan
Published: March 2009

The numerical simulation calculation of longitudinal seam TIG welding of thin-wall
aluminium cylinder was conducted by the FEM software, Marc. Based on the generating of analysis
model, displacement field was quantitatively described. Circular profile of aluminium alloy cylinder
after welding was predicted by the radial displacement. The simulation results showed that the
post-weld deformation for the longitudinal seam of aluminium alloy cylinder was mainly
destabilizing deformation.
Coupled Numerical Simulation on Heat, Flow and Solution Transport in Double-Stream-Pouring Continuous Casting
Authors: Zhang Wei Wen , Zhao Hai Dong , Gao Ji Xiang , Li Yuan Yuan
Published: March 2009

Double-stream-pouring continuous casting (DSPCC) is a novel technique to prepare
gradient composites. In this paper, a two-dimensional steady mathematical model coupled flow, heat
and solution transport in the solidification zone of DSPCC has been established based on the standard
k-ε turbulent model. The variation of thermo-physical properties of the alloys against the temperature
is also considered. The effects of casting speed on the temperature field, velocity field and
composition of the researched composite are analyzed based on the proposed mathematical model.
An experimental 2024/3003 aluminum composite was prepared by using a laboratory-made DSPCC
facility. Selected results of experiment are in a good agreement with that of numerical simulation.
Control of Liquid Level in Tundish of Strip Caster with Automatic Pouring System
Authors: Noda Yoshiyuki , Watari Hisaki , Yamazaki Takanori
Published: March 2009

This paper gives an advanced control to a strip caster with tilting-ladle-type automatic
pouring system. The strip caster has been used for producing ferrous and nonferrous sheets. In the
process, in order to obtain the high-quality products, it is required that the molten metal in the tundish
keep the high liquid level. Therefore, the control system to liquid level in the tundish is proposed in
this present paper. In this approach, the mathematical model from the control input into the motor for
tilting ladle to the liquid level in the tundish is derived by using hydrodynamics. Then, for reaching
quickly the molten metal to the high liquid level and keeping stably the liquid level, the control input
into the motor is designed systematically by using the mathematical model. The proposed control
system has advantage that it can be constructed simply. And, any sensors for measuring the liquid
level are not required in the proposed system.
Intelligent Control Experiment Study for V-Shape Free Bending of Wide Sheet Metal
Authors: Zhao Jun , Su Chun Jian , Guan Ying Ping
Published: March 2009

The main problem in bending process of sheet metal is that it is difficult to control bending
springback accurately. Springback produced from the unloading of bending makes the shape and size
incongruent between bending workpiece and working portion of die. Because the final shape of
bending workpiece is related with the whole deformation process, the geometric parameter of die,
material performance parameter will have great effect on springback. Therefore, the springback
problem is very complicated and the prediction and control of springback is the key to improve the
accuracy of bending workpiece. Taking the V free bending of wide sheet as an object of study, the
neural networks technology and data acquisition system based on LabVIEW are used to establish
intelligent control experiment system for V free bending of wide sheet metal. The control accuracy of
system is high and it provides the basis for the realization of intelligent control for V-shape free
bending of wide sheet metal in practice in future.
Simulation of Three-Dimensional Stress Distribution in Compression Dies
Authors: Huang Chu Yun , Wang Sai Yu , Yang Tao , Yan Xu Dong
Published: March 2009

The stress fields of rectangular and T shape compression dies were simulated by three
dimensional photo-elasticity of stress freezing method. The rules of stress distribution of σx, σy, σz
on the surface of rectangular and T-shaped dies were discovered, and the rules were also found
inside the dies. The results indicate that the stress distribution of rectangular die is similar to that of
T shape die. Obvious stress concentration in corner of die hole was observed. σz rises from die hole
to periphery until it achieves maximum value then it diminishes gradually, and σz between die hole
and fix diameter zone is higher than it is in other position. At the same time, the equations of stress
field of extrusion dies were obtained by curved surface fitting experimental values in every
observed point with multiple-unit regression analysis method and orthogonal transforms. These
works can provide stress distribution model for die computer aided design and make.
Investigation into the Warm Extrusion for Micropart with Laser-Aided Heating Method
Authors: Wang Yun , Xu Zhen Ying , Dong Pei Long , Yuan Guo Ding , Cai Lan
Published: March 2009

The rapid market need of MEMS (Micro Electromechanical System) and metal microparts
are increasing gradually. The plastic microforming has received more interests and applications in
MEMS because it ensures high precision and manufacturing efficiency. However, it raises the higher
demand on the microforming and plastic processing technology. Here we present one new process to
micro-extrude microparts with laser-aided heating method. The new process is to selectively heat the
workpiece with the laser radiation method to the suitable temperature that is between room
temperature and recrystallization temperature, and to extrude the workpiece. This process is
characterized by decreasing the influence of strain strengthening and lowering the resistance to
deformation, and increasing the uniformity of material flow. The key elements of the approach
concerning the warm micro-extrusion and temperature control, such as process parameters, laser
heating system, micro-extrusion die structure, have been advanced. Furthermore, an important aspect
of the research is that the developed system and theory of micro warm extrusion based on laser
heating can be explored for further investigation and understanding of plastic microforming.
A 3D Rigid-Plastic FEM Simulation on Radius of Incremental In-Plane Bending of Strip Metal
Authors: Tang Wen Ting , Jin Li , Zhang Jin , Yang He
Published: March 2009

In-plane bending is an advanced plastic processing technology which controls the uneven
compressing plastic deformation of strip metal harmoniously and forces the strip metal to produce
in-plane bending and to form an open circle. In-plane bending is divided into incremental and
continuous process according to the loading manner. While much attention has been paid to the
continuous in-plane bending techniques and achievements have been made at home and abroad, only
limited experimental investigation has so for been done on incremental in-plane bending by overseas
scholars. In this paper, a 3D finite element simulation based on the rigid-plastic principle is performed
for incremental in-plane bending of pure aluminum sheet with width of 25 ~ 27.5 mm, thickness of
1.5 ~ 3 mm. Influences of technical parameters such as punch inclined angle αp, punch indentation s,
thickness of strip t0, width of strip w0 and strip pitch p on the strip bending radius Rin are studied. The
achievement of this study enriches the uneven deformation theory. It lays a theoretical foundation for
generalization and industrialization of incremental in-plane bending and offers a new idea to the
research and development of the advanced plastic processing technologies.
Application Research on Expert System of Incremental In-Plane Bending
Authors: Tang Wen Ting , Tang Chao Li , Huang Lei , Yang He
Published: March 2009

Incremental in-plane bending is a flexible and laborsaving manufacturing technology for
short production runs in a variety of sizes and shapes. But the technology parameters are interactive
intimately and it is hard to forecast and control the bending radius accurately. Based on the features of
incremental in-plane bending and the advantage of expert system dealing with problems, an expert
system of incremental in-plane bending by designing knowledge base of representation of creation
regulation, reasoning system based on rules and search mechanism and explaining system based on
prefabricating text has been researched and developed in this paper. The system, making use of ADO
technology, Access database and Visual Basic, develops knowledge base, database and reasoning
system. Based on client / server model, the system realizes a seamless link between Visual Basic and
Matlab by using ActiveX. The system can perform functions of bending radius forecasting and
forming program evaluating and optimizing. It has a friendly interface and it is easy to operate and
convenient for maintenance.
A Study of the Microstructure and Grain Size at the Welding Heat Affected Zone of a Ferrite Stainless Steel
Authors: Zhang Shi Xing , Guan Shao Kang , Liu Xin Tian , Mo Chun Li
Published: March 2009

A method of Monte Carlo combined with welding experiments was adopted to study the
grain size and microstructure in welding heat affected zone of the ferrite stainless steel. Firstly, the
kinetic equation of grain growth was established with the experimental data . Then , a simulation
procedure based on the kinetic equation was worked out. Agreement between Monte Carlo
simulation result and the real experiment results was obtained.
Optimization of Welding Process Parameters for Rotating Arc Welding Sensor Based on Genetic Algorithm
Authors: Jia Jian Ping , Zhang Hua , Huang Hui
Published: March 2009

The high speed rotating arc welding sensor (RAWS) driven by motor with air axis is
widely used in seam tracking system. Using the characters of the RAWS, the purpose of this study
based on Genetic Algorithm (GA) is to optimize welding process parameters of the RAWS for
obtaining satisfied seam geometry. The output variables are penetration, width and height of the
seam geometry. These output variables are determined by input variables, which are the welding
current, welding voltage, welding speed, rotating arc radius, rotating arc frequency and rotating arc
direction. Experimentations are made according to the optimal welding process parameters, and the
result shows that the GA is an effective method to optimize the welding process parameters of the
RAWS. The described computational methodology enables obtaining a seam with desired geometry.
The In Situ Study on the Micro-Structural Characters of IF Steel at Early Stage of Recrystallization Using High-Energy X-Ray
Authors: Tong He , Liu Yan Dong , Jiang Q.W. , Ren Y. , Wang G. , Wang Yan Dong , Zhao X. , Zuo Liang
Published: March 2009

High-energy synchrotron diffraction offers great potential for experimental study of
recrystallization kinetics. A fine experimental design to study the recrystallization mechanism of
Interstitial Free (IF) steel was implemented in this work. In-situ annealing process of cold-rolled IF
steel with 80% reduction was observed using high-energy X-ray diffraction. Results show that, the
diffraction intensity of {001}<110> and {112}<110> belong to α-fiber texture component decreased
with the annealing temperature increased while {111}<110> did nearly not change and {111}<112>
increased; the FMTH decreasing and d-space changing with annealing temperature increasing
indicated that the residual stress relaxed completely during recovery.
Casting Process Simulation of the Ball Milling Machine End Cover with a Hug Diameter
Authors: Wang Wen Yan , Xie Jing Pei , Li Ji Wen , Wang Ai Qin , Li Luo Li , Yan Hua , Zhang Hui Min
Published: March 2009

The solidification process, the formation mechanism and distribution law of
microporosity of the ball milling machine head cover made by SVEDALA corporation of USA were
simulated by computer. The Solidworks software was used to generate three-dimensional model of
cast parts and the Hua-casting software was employed to simulate the casting process. The
simulated results show that significant microporosity was found in the middle of two casting heads
and at the place of gudgeon journal because of insufficient chilling degree. The processing
rationality was judged through the computer-aided technology, by which some drawbacks of the
traditional process were overcome and the process design quality was improved.
Superplastic Behavior in Ultrafine-Grained Materials Produced by Equal-Channel Angular Pressing
Authors: Xu Cheng , Kawasaki Megumi , Figueiredo Roberto B. , Duan Zhi Chao , Langdon Terence G.
Published: March 2009

Equal-channel angular pressing (ECAP) is a convenient processing method for refining
the grain size of bulk materials to the submicrometer level. Metallic alloys processed by ECAP
often exhibit excellent superplastic characteristics including superplasticity at high strain rates.
This paper summarizes recent experiments designed to evaluate the occurrence of superplasticity in
representative aluminum and magnesium alloys and in the Zn-22% Al eutectoid alloy.
Characterization of Weldments and Materials Using Thermoelectric Power Measurements
Authors: Park Young Do , Lasseigne-Jackson A.N. , Jackson J.E. , Mishra Brajendra , Olson D.L. , Koenig T.
Published: March 2009

Thermoelectric power coefficient measurement techniques have been developed for
numerous applications to guarantee material integrity by providing a non-destructive electronic
property correlation to material microstructure, phase stability, specific solute additions, and lattice
strain. How the electron concentration, the effective mass, and the dominating scattering
mechanisms allow for non-destructive evaluation of materials will be described. Because
thermoelectric power (TEP) is dependent upon numerous variables, additional non-destructive
techniques are necessary to further characterize or classify the material or weldment. The concept
of an electronic metallography laboratory is developed using additional collaborative NDE
technologies.
Application of Air-Coupled Ultrasonic Techniques Using Carbon/Carbon Composites
Authors: Yang In Young , Yang Yong Jun , Park Jun Woo , Lee Kil Sung , Cho Young Tae , Park Je Woong , Hsu David K. , Im Kwang Hee
Published: March 2009

Carbon/carbon(C/C) composite materials have obvious advantages over conventional
materials, which consist of carbon fibers embedded in a carbon matrix. It’s low density, high
thermal conductivity and excellent mechanical properties at elevated temperatures make it an ideal
material for aerospace applications especially aircraft brake disks. Because of permeation of
coupling medium such as water, it is desirable to perform contact-less nondestructive evaluation to
assess material properties and part homogeneity. In this work, a C/C composite material was
characterized with non-contact and contact ultrasonic methods using automated acquisition
scanner. . Due to the acoustic impedance mismatch found between most materials and air, a major
limitation for air-coupled transducers, through-transmission mode was performed. Especially
ultrasonic images and velocities for C/C composite disk brake were measured and found to be
consistent to some degree with the non-contact and contact ultrasonic measurement methods. 400
kHz frequency through-transmission scans based on both amplitude and time-of-flight of the
ultrasonic pulse were used for mapping out the inhomogeneity in material property. Non-contact
measured results were compared with those obtained by the motorized system using contact drycoupling
ultrasonics and through transmission method in immersion. Results using a proposed
peak-delay measurement non-contact method corresponded well to the ultrasonic velocities of the
contact pulse overlap method.
Determination of Optimum LASER Welding Parameters and the Development of a LASER Welding Technique to Enhance the Lateral Impact Strength of a Spacer Grid Assembly for a PWR Fuel Assembly
Authors: Song Kee Nam , Kim Soo Sung
Published: March 2009

A spacer grid assembly, which is an interconnected array of slotted grid straps welded at
the intersections to form an egg crate structure, is one of the core structural components of the
nuclear fuel assemblies of a Pressurized light Water Reactor (PWR). The spacer grid assembly is
structurally required to have enough buckling strength under lateral loads so that the nuclear fuel
rods are maintained in a coolable geometry, and that control rods are able to be inserted. The ability
of a spacer grid assembly to resist lateral loads is usually characterized in terms of its dynamic and
static crush strengths. Since the crush strengths of a spacer grid assembly are known to depend on
the weld qualities at the intersections of the slotted grid straps, high-tech welding methods, such as
a TIG welding, LASER beam welding or Electron beam welding method, have been used recently
in the nuclear fuel manufacturing fields. In this study, to meet the above requirements, two kinds of
researches were carried out. First, by adjusting the LASER beam welding parameters, an optimum
welding combination of the LASER beam welding parameters was obtained for welding a spacer
grid assembly. Second, a new LASER beam welding technique was proposed to obtain a longer
weld line and a smaller weld bead size by tilting the LASER beam. The buckling strength of the
spacer grid welded by the new LASER beam welding technique was enhanced by up to 30 % when
compared to that by the conventional LASER beam welding method.
A Brief Review of Challenges & Technologies to Weld Dissimilar Metals in Two Industries: The Upstream Oil & Gas and the Automotive
Authors: Marya Manuel
Published: March 2009

In both Oil & Gas (OG) and automotive industries, welding is an essential part of fabrication routes and
the challenges in welding metallic materials are frequently similar. Processes that are fast, robust, and therefore
tolerate variations in process parameters (including operators for manual processes) and materials (i.e.
compositions and properties) are important to reproduce high weld quality and facilitate non-destructive
examinations (NDE). New grades of high-strength alloys, required to be weldable by common processes and
preferably without post-weld heat treatments, are not only needed by both industries, but dissimilar-metal welding
is also becoming unavoidable, thereby demanding for novel processes with either low heat inputs or high-energy
densities. In this paper, technologies for dissimilar-metal welding are examined in reference with both OG and
automotive applications.
Coalescence Characteristics of Fusible Particles in Solderable Isotropic Conductive Adhesives (ICAs)
Authors: Lee Seong Hyuk , Lee Jung Hee , Lee Jin Woon , Kim Jong Min
Published: March 2009

A new hybrid soldering and conductive adhesive joining technology using a fusible lowmelting-
point alloy (LMPA) have been developed. A numerical method for numerical analysis of
fusible particles behavior is proposed to investigate coalescence characteristics of fusible particles
in solderable isotropic conductive adhesives (ICAs). For finding out suitable conditions to obtain
reliable conduction paths, the present study examines the influence of process-related parameters
such as volume fraction and viscosity on coalescence characteristics of fusible particles.
Estimation of Thermal Fatigue Resistance of Sn-Bi (-Ag) and Sn-Ag-Bi-Cu Lead-Free Solders Using Strain Rate Sensitivity Index
Authors: Yasuda Kiyokazu , Shohji Ikuo , Takemoto Tadashi
Published: March 2009

A tensile test was conducted to evaluate thermal fatigue resistances of Sn-Bi (-Ag) and
Sn-Ag-Bi-Cu lead-free solder alloys. The test is based on the strain rate change method to obtain a
strain rate sensitivity index (SRSI), m. The m values were investigated at various strains during the
tensile test, until fracture. The plots of m and strain where m is measured showed a linear
relationship. Therefore, the m value at zero strain, m0, and the gradient of the fitting line, k, were
obtained by extrapolation. Using m0 and k values, an estimation of the thermal fatigue resistance of
the solder joint was attempted. It was believed that m0 and k can be taken as a guide for developing
a new lead-free solder with the excellent thermal fatigue resistance. Moreover, the influences of the
aging treatment on m0, k and the microstructure of the solder were also investigated.
Effects of Process Parameters on Surface Characteristics in Cutting of Cold Rolled Steel Sheets Using a High-Power CW Nd: YAG Laser
Authors: Ahn Dong Gyu , Kim Min Su , Yoo Young Tae , Park Hyung Jun
Published: March 2009

The objective of the present paper is to examine the effects of process parameters, such
as laser power, cutting speed of the laser and thickness of the workpiece, on characteristics of the
cut section in the cutting of cold rolled steel sheets using a high-power Nd:YAG laser with a
continuous wave (CW). From the results of the experiments, the influence of the process parameters
on surface roughness and average striation angle has been quantitatively investigated. In addition,
critical cutting speeds with a minimum surface roughness and a maximum average striation angle
has been obtained. Finally, the optimum cutting conditions for each workpiece thickness have been
estimated to improve both the quality of the cut section and the cutting efficiency.
A Study on Operational Characteristics of SMA Wire Segmented by Thermoelectric Module
Authors: Kim Gwang Ho , Kim Ju Hwan , Lee Sang Hee , Shin Sang Moon , Jeong Sang Hwa
Published: March 2009

The robot industry of the 21st century is focused on humanoid robot. It has more
intelligence and is able to move dexterously like a biological organ than existing sequence robot.
The key technology of this robot is the design of the actuator. To realize the anthropomorphic
motion, artificial muscles, such as shape memory alloy and electro active polymer are used. The
SMA actuator has good power density and simple structure, but the control scheme of the actuator
is difficult. The electro active polymer has good elasticity, but it is difficult to get the required
power. In this paper, the performance according to the motion control of segmented SMA wire is
evaluated. SMA wire is segmented by thermoelectric modules. The displacement of SMA wire
according to load is measured and its hysteresis is surveyed.
Effect of Weld HAZ Softening on Tensile Strength of Welded Joint with Weld HAZ Softening
Authors: An Gyu Baek , Nam Seong Kil , Jang Tae Won
Published: March 2009

In recent time there are vigorous requirements for the use of thick steel plate in various
industrial fields, including shipbuilding industry. Especially, application of TMCP steel plates on
steel structure is progressively increasing now. Welding process with high heat input is necessary to
be used in thick steel assembly for the purpose of the high productivity. However, HAZ softening of
TMCP steel plates has a possibility to reduce the strength of welded joint. In this study, therefore,
the tensile strength of TMCP weldments, having softened HAZ, was examined using the numerical
calculation and experiments.
Analysis of Fatigue Life of SPR (Self-Piercing Riveting) Jointed Various Specimens Using FEM
Authors: Lim Bok Kyu
Published: March 2009

Self-Piercing Riveting(SPR) is becoming an important joining technique for various
material sheets and shapes, of automotive application. Fatigue behavior of SPR connections needs
to be investigated experimentally and numerically to predict SPR fatigue lives. The simulations of
various SPR specimens (Coach-Peel specimen, Cross-Tension specimen, Tensile-Shear specimen,
Pure-Shear specimen) are performed to predict the fatigue life of SPR connections under different
shape combinations. Finite element models of various SPR specimens are developed using a
FEMFAT SPOT SPR pre-processor. The fatigue lives of SPR specimens are predicted using a
FEMFAT 4.4e based on the linear finite element analysis.
Development of Non-Equilibrium Simulation Model of Gas Tungsten Arc
Authors: Shinichi Tashiro , Iwao Toru , Inaba Tuginori , Tanaka Manabu
Published: March 2009

We have developed non-equilibrium simulation model of GTA. In this paper, simulation
results of plasma property of argon GTA at atmospheric pressure are presented and, furthermore,
the reliability of the simulation model is evaluated. As a result, it was revealed that non-equilibrium
characteristic appears in regions close to both electrodes and the fringe of the arc column where the
temperatures decrease below approximately 10000K. It was also found that non-equilibrium region
near the anode surface has thickness of 0.3mm. This result agrees with the simulation result
predicted with one-dimensional electrical sheath model.
Development of a New Testing Method for Assessing the Wear Behaviour of Circular Cutting Discs
Authors: Fernandes Jorge Cruz , Pinto Sergio , Amaral Pedro M. , Rosa Luis Guerra
Published: March 2009

In the present work a new testing method for assessing the wear resistance of matrix
materials employed in the manufacture of diamond tools is presented and discussed. The method
allows assessing the wear behaviour of different metallic matrices by simulating a circular cutting
action of a tool where, instead of a normal abrasive element (matrix impregnated with diamond)
only the matrix material is tested. This method has originated a preliminary model of continuum
abrasive contact layer between a rotating circular element made of a metal matrix and a glass
material. The model allows the determination of the matrix wear rate at different applied forces. To
validate the methodology used, different matrix materials (with different mechanical properties)
have been analysed in relation to the experimental wear rate.
Microstructural Characterization of Eutectoid Steel Strips
Authors: Dobránszky János
Published: March 2009

Investigations of microstructural differences of tempered eutectoid steel strips are presented.
The constituent phases – fine mixture of ferrite and cementite and a small amount of retained
austenite – considerably affect the mechanical properties, especially the resistance to high cycle
fatigue. The amount of retained austenite was determined by XRD and EBSD analysis. Thermoelectric
power (TEP) measurements were performed for 270 different batches of C75S type eutectoid
steel strips. TEP measurement shows characteristically the fine microstructural differences.
The TEP of the investigated samples varied between 5650 and 7030 nV/°C. The amount of retained
austenite can be significantly higher at the surface (20 %) than at the internal part (0-5 %). The sensitivity
of XRD analysis was reduced because of the presence of coarse cementite particles. Using
Cu anode, the measurements were more successful than in case of using Co anode. The EBSD
analysis showed that also samples immeasurable with XRD contain retained austenite, but its detectability
with XRD analysis declines with the coarsening of cementite.
Hyperbolic Model Based Data Evaluation for Magnetic NDE Measurements
Authors: Mészáros István
Published: March 2009

In this paper a new data evaluation technique is presented for non-destructive magnetic
measurements. This method is based on the multiphase hyperbolic model of magnetization and it is
called model based data evaluation (MBDE) technique. The MBDE method allows us to separate
the magnetic contribution of the magnetizing yoke from the measured magnetization curves.
Therefore the determined magnetic properties of the tested sample are independent of the
parameters of the applied magnetic yoke and the lift-off. The proposed method could become a
useful tool in magnetic non-destructive evaluation (NDE).
Qualitative and Quantitative Fractographic Analysis of Dynamically Impacted Si3N4 Ceramics
Authors: Maros Maria Berkes , Helmeczi Nikoletta Kaulics , Dusza Ján
Published: March 2009

Si3N4 is widely used as a structural ceramic, therefore mechanical characterization,
especially in dynamic loading conditions is important task. In the framework of a comprehensive
research work aiming at characterizing the dynamic failure process of Si3N4 based ceramics we
executed instrumented impact tests. Beside determining various mechanical characteristics we
executed failure analysis by fractography, as well. The current paper focuses on the fractographic
analysis of the dynamic failure processes of the investigated Si3N4 based ceramics. A detailed
morphological analysis has been carried out determining qualitative and quantitative features using
macro- and micro-fractography.
Visible Light-Emitting Diodes - The Formative Years
Authors: Allen J.W. , Grimmeiss Hermann G.
Published: March 2009

A brief history of visible light-emitting diodes (LED's) is given, from the first
experimental observations of H.J.Round in 1907 to the mid-1970's when red and green emitters
were in extensive production. Early investigations were empirical. This was changed with the
invention of the transistor in 1947 by the demonstration of minority carrier injection at a forwardbiased
junction, followed by recombination. In 1952 the discovery of the semiconducting behaviour
of III-V compounds introduced a new range of materials. Gallium nitride seemed attractive for light
emission and was investigated at Philips and RCA laboratories but at the time proved to be too
difficult for practical use. Gallium phosphide emerged as the most promising material and groups to
investigate it were set up at SERL in England, Philips Central Research Laboratories in Germany
and Bell Telephone Laboratories in the USA. Zinc and oxygen doping gave red emission. At
Philips, the emphasis was on efficiencies. At SERL the emphasis was on reproducibility for
manufacturable devices and when the conditions for zinc and oxygen doping were strictly
controlled the world's first practical visible LED's were produced at the end of 1961. At Bell
Telephone Laboratories progress was initially slow but with the advent of liquid-phase epitaxial
growth production of red emitters on the scale required became possible. The accidental discovery
of nitrogen doping of gallium phosphide at Bell led to the production of good green emitters. Until
the end of the 1970's, gallium phosphide red and green emitters dominated the LED market.
Subsequent developments to the present day are sketched in outline.
Stacking Faults in SiCf/SiC Composite Obtained by Chemical Vapor Reaction Process
Authors: Florian Marcio , Marques Rodrigo Fernando Costa , Carvalho Luiz Eduardo , Cairo Carlos Alberto Alves , Barelli Nilso
Published: March 2009

SiC fiber-reinforced SiC matrix composite (SiCf/SiC) is one of the leading candidates in
ceramic materials for engineering applications due to its unique combination of properties such as
high thermal conductivity, high resistance to corrosion and working conditions. Fiber-reinforced
composites are materials which exhibit a significant improvement in properties like ductility in
comparison to the monolithic SiC ceramic. The SiCf/SiC composite was obtained from a C/C
composite precursor using convertion reaction under high temperature and controlled atmosphere.
In this work, SiC phase presented the stacking faults in the structure, being not possible to calculate
the unit cell size, symmetry and bond lengths but it seem equal card number 29-1129 of JCPDS.
Oxygen Interstitial Dynamics in Bi2Sr2CaCu2O8+δ Oxides Measured by Mechanical Spectroscopy
Authors: Grandini Carlos Roberto , Ruiz S.L.M. , Silva M.R. , Gimenez J.M.A. , Rubo Elisabete A. A.
Published: March 2009

Many researchers became interested in the discovery of Bi2Sr2CaCu2O8+δ oxides with
critical temperature of around 80 K. It is known that the critical temperature is related to the CuO2
planes of the material. For this reason, the study of the interstitial oxygen in these oxides is of great
relevance. The samples were prepared by means of conventional solid state reactions, through the
stoichiometric mixture of precursory powders. After the sinterization, the samples were submitted
to measurements of density, electrical resistivity, x-ray diffraction, scanning electron microscopy
and energy dispersion spectroscopy, with the objective of performing their characterization. The
measurements of mechanical spectroscopy were performed by a torsion pendulum. The results
show three relaxation processes in the temperature range of 200 and 700 K, with activation energy
of approximately 0.9 eV, which has been attributed to the dynamics of the interstitial oxygen
present in the material.
Fabrication Micro-Nozzle Plates for Inkjet Print Head Using LIGA Process
Authors: Shen Sheng Chih , Lee Chung Jui , Wang Min Wen , Chen Yi Cheng , Wang Yu Jen , Chen Yung Yue
Published: March 2009

This paper presents a novel LIGA-like process to fabricate the nozzle plate for matching
the requirements of the 600 dpi inkjet printhead. This novel fabrication technique reduces the
production cost from 100% current process to 50%. This mass production technique comprises two
main technologies: Ni-Co electroforming and plastic injection molding. The nozzle plate consists
ink channels, ink cavities, and nozzles for enhancing the integrity and excusing the assembly
process. The dimensions of nozzle plate are 4.16mm in width and 7.3mm in length, respectively.
Total thickness of micro-nozzle plates are thickness≦100um(ink channels and ink cavities), and the
diameter and pitch of the nozzle holes are 40±3um and 168±3 um, respectively. Straightly speaking,
for being the main compositions of the 600 dpi inkjet printhead design, the above fabrication
process is qualified enough and capable of yielding satisfactory results.
Analysis of Conventional Spinning Process with Thermal Effects
Authors: Liu Chun Ho , Wang A Cheng , Liang Kuo Zoo , Hsu Sheng En
Published: March 2009

The temperature effect is significant on the metal forming processes; for the quality of
products and the tools life are extremely affected by it. This paper investigates the thermal effects on
the conventional spinning process by the explicit finite element method with transient heat transfer
conditions. The governing equation is based on the updated Lagrangian formulation, the large
deformation theory, and the principle of the conservation of energy. The energy terms in this study
include the plastic strain energy, the frictional sliding energy, and the heat transfer energy. The energy
and temperature distribution of the circular sheet, on the varying boundary conditions of the heat
transformation, are discussed in detail. Furthermore, the various mesh types are examined in the
simulations. With the application of the mass scaling factor technique, the full history of spinning
process is performed successfully. The main benefit of the proposed model will save the tremendous
costs in the die designing and the experimental works. The parameters and techniques using in the
numerical model are helpful for the design of forming process and the coupling thermal-mechanical
analysis.
Deformation Characteristics on Surface Layer of White-Coated Paperboard by Center Bevel Blade Subjected to Pushing Load
Authors: Chaijit Seksan , Yajima Yoshikazu , Kikuchi Kazuya , Nagasawa Shigeru , Fukuzawa Yasushi , Hine Akira
Published: March 2009

This paper describes for breaking behaviors on the surface layer of a white-coated paperboard
during indentation of a center bevel blade. Cutting load response of the paperboard was measured
regarding the indentation depth of the blade and the deformation flow in a side view of the paperboard was
observed by a CCD camera in order to investigate the effect of blade tip angle on the surface failures of the
paperboard. The surface breaking strength of paperboard was analyzed by using Finite Element Method
(FEM). Through the experiment and FEM simulation, the followings were revealed. 1) There is a certain
critical value of tip angle C at which an inflection load response disappears and also the surface failures
are restricted. 2) When the tip angle is less than the C, there is an inflection point as the surface-layer
breaking and its surface breaking point was strongly related to the maximum principal stress on the
surface. 3) After the surface breaking, the deformation flow and its cutting resistance are strongly affected
by the de-laminated and the raised-up of the inner-layer.