bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Sintering Temperature in Physical-Mechanical Behaviour and in Titanium-Hydroxyapatite Composite Sinterability
Authors: Weinand W.R. , Gonçalves F.F.R. , Lima W.M.
Published: March 2009

Mechanical alloying (MA) has been successfully used to produce alloys and
composites with a high homogeneity degree. In current research, titanium (Ti) powder was
mixed with 40, 50% volume of hydroxyapatite (HAp). MA was performed without
atmosphere control, at room temperature, for 4.5 hours of milling time, at rotation speed of
300 rpm. Samples of material were compacted in cylindrical form at 350 MPa and sintered in
2.0 flux air (l/min) at 1000, 1100 and 1200oC during 1 hr. The material’s morphological and
microstructural characterization, in powder form and in sintered material, was performed by
scanning electronic microscope and X-ray diffractometry. Thermal treatments revealed that
sintering temperature affects the microstructure, microhardness and the composition of the
composites evaluated by EDS.
Comparative Study of the Efficiency among Conventional Cyclones and Cyclones with Filter
Authors: Lacerda A.F. , Moroti M.R. , Barrozo Marcos A.S. , Damasceno João Jorge Ribeiro
Published: March 2009

The cyclones are one of the most known apparatus destined to the solid-gas separation.
These equipments are used in the chemistry industry; its popularity is due mainly to the simplicity,
low energy requirements and ability to operate at high temperatures and pressures. One of the aims
of this work was to evaluate the influence of some geometrics variables in the performance of
conventional cyclones and filtering cyclones. The chosen variables were: conic part length (Zc),
the underflow diameter (Du), the overflow diameter (Do) and the finder length (Sc). The cyclones
conventional and with filter were compared and it was observed that the introduction of a filter
main in substitution to the metallic conic part of cyclones allows a appreciable reduction in the
pressure drop and consequently a smaller consumption of energy. The efficiency in the new
cyclone was a little smaller than the conventional equipment.
Structure and Properties of the 32CrMoV12-28 Steel Alloyed with WC Powder Using HPDL Laser
Authors: Dobrzański Leszek Adam , Labisz Krzysztof , Piec Marek , Lelątko Józef , Klimpel Andrzej
Published: March 2009

This paper presents the investigation results of laser alloying and the influence on structure and properties of the surface of the 32CrMoV12-28 hot work steel, carried out using the high power diode laser (HPDL). Structure changes were determined in the work, especially structure fragmentation. Also hardness investigation of the different remelting areas was performed. The reason of this work was also to determine the laser treatment parameters, particularly the laser power, to achieve good work stability and to make the tool surface more resistant for work extremal conditions. Based on microstructural examinations of the obtained material, the distribution of the reinforcing ceramic particles in the hot work tool steel was revealed. Tungsten carbide WC powder was used for alloying. The remelted layers which were formed on the surface of the investigated hot work steel were examined metallographically and analyzed using a hardness testing machine.
Effect of Al2O3 Addition on the Mechanical Properties of Biocompatible ZrO2-Al2O3 Composites
Authors: dos Santos Claudinei , Teixeira L.H.P. , Strecker Kurt , Elias Carlos Nelson
Published: March 2009

In this work, the effects of alumina additions on the properties of the ZrO2-Al2O3
ceramic composites were investigated. Samples of ZrO2 with Al2O3 additions varying
between 0 and 30wt-% were prepared. The powder mixtures were milled, compacted by
uniaxial cold pressing and sintered at 16000C, in air, for 2 hours. The sintered samples were
characterized by their relative density, phase composition and microstructure. As mechanical
properties at room temperature, their Vickers hardness and fracture toughness were
determined: In all sintering conditions and Al2O3 amounts, the samples presented relative
density higher that 99%. The Al2O3 addition produces a linear increase of the hardness,
reaching values between 1350 and 1610 HV for the addition of 0 and 30% of alumina,
respectively. The fracture toughness was near to 8 MPam1/2 in all conditions. The phase
composition, microstructure and relative density were correlated in order to interpret the
mechanical properties obtained.
Effect of Calcination Conditions on Phase Formation of Calcium Phosphates Ceramics Synthesized by Homogeneous Precipitation
Authors: Lazar Dolores Ribeiro Ricci , Cunha Sandra Maria , Ussui Valter , Fancio E. , de Lima Nelson Batista , Bressiani Ana Helena A.
Published: March 2009

Phase composition of calcium phosphate ceramics is a characteristic directly
related to the biological response of implants due to the differences in mechanical and
biochemical properties of these compounds. In this sense, it was evaluated in this work the
crystalline phase evolution of calcium phosphates samples synthesized by wet precipitation
route. Fixing Ca/P atomic ratio as 1.67, precipitation was carried out from heated aqueous
solutions of calcium chloride and ammonium hydrogen phosphate, in ammonium medium
(pH = 10). After washing and drying steps, calcination was performed at 600 to 1100 oC for 1
and 3 hours. Milled and pressed powders were sintered at 1250 oC for 1 hour. Samples were
characterized by X-ray diffraction, chemical analysis, scanning electron microscopy, gaseous
adsorption, laser diffraction and apparent density measurements. Results indicate the
formation of a biphasic calcium phosphate ceramic containing hydroxyapatite as a major
phase and β - tricalcium phosphate, the later obtained by heat treatment above 600 oC.
Combustion Synthesis of α-Al2O3 Powders
Authors: de Freitas Normanda Lino , Fagury-Neto Elias , Lira Hélio Lucena , Gama Lucianna , Kiminami Ruth Herta Goldsmith Aliaga , de Melo Costa Ana Cristina Figueiredo
Published: March 2009

Among ceramic materials, the alumina has high importance because of its characteristics of resistance and refractory. The possibility to improve the final characteristics of this material, open possibilities for new applications. The aim of this work is to synthesize (α-Al2O3) alumina powders by combustion reaction and to evaluate the effect of the urea content in the final characteristics of the α-Al2O3 powders. Three compositions were studied : a) stoichiometric, b) with 10% of urea reduction and c) with 20% of urea reduction. The initial solution composition was based on the total valence of the reagents by using chemical concepts of the propellant. This powders were characterized by X-ray diffraction (XRD), granulometric determination by laser diffraction, nitrogen adsorption by BET, scanning electron microscopy (SEM), infrared spectroscopy (IR) and helium picnometer. The results showed that the urea reduction change the temperature of the reaction from 525 to 463oC , the characteristics of the powders, and principally the reduction of the particles size.
Nanosize Nickel Ferrite Particles Synthesized by Combustion Reaction: Evaluation of Two Synthesization Routes
Authors: Ramalho M.A.F. , de Melo Costa Ana Cristina Figueiredo , Gama Lucianna , Kiminami Ruth Herta Goldsmith Aliaga , Hernandez E.P. , Cornejo Daniel R. , Rezende S.M.
Published: March 2009

Ultrafine magnetic nickel ferrite particles have a significant potential for use in
many applications such as magnetic recording media, ferrofluids, microwaves, catalysis and
radar-absorbing coatings [1, 2]. Nickel ferrite powders with a nominal NiFe2O4 composition
were synthesized by combustion reaction and an evaluation was made of the effect of two
different conditions of synthesis on the nanostructural and magnetic characteristics of the
resulting powders. Two synthesization routes were studied. The first, NFB, involved the
preparation of the powder using a Pyrex beaker heated directly on a hot plate at 480°C until
self-ignition occurred. By the second route, NFC, the powder was obtained under the same
synthesization condition as the NFB route, but a vitreous silica basin was used. The resulting
powders were characterized by X-ray diffraction (XRD), nitrogen adsorption by BET and
scanning electron microscopy (SEM). The first route, NFB, proved more favorable to obtain
powders with high surface area and, hence, smaller crystalline sizes (5.70 nm) and a
superparamagnetic behavior. The NFC route confirmed the feasibility of obtaining powders
with a crystalline size of 18.00 nm and a magnetic behavior. Saturation magnetization was
33.18 emu/g and the coercivity field was 25.63 Oe for powders obtained by the NFC route.
Sintered Valve Seat Inserts – Microstructural Characterisation
Authors: Jesus Filho E.S. , Jesus Edilson Rosa Barbarosa , Salgado Lucio , Jesus S.L. , Colosio Marco Antonio , Santos José Carlos , Yoshida S. , Sartori C.H. , Rossi J.L.
Published: March 2009

This work presents aspects related to new sintered materials for valve seat inserts
application. Two types of materials were evaluated. The materials were made using powder
metallurgy technique from a basic mixture of high-speed steel (AISI M3/2), iron and carbide
powders. The microstructures of these materials before and after heat treatment are presented.
Under the heat treatment condition, the activation of the diffusion mechanism among phases was
promoted and a better distribution of the Cu phases along the matrix was achieved. The results
indicate that the materials under development have a potential for commercial application as valve
seat inserts.
A New Algorithm to Refresh File Aggregates in Distributed Enterprises
Authors: Yu Bao Qin , Wang Tai Yong , Zhang Jun , Li Guo Qin
Published: March 2009

The cost budget of distributed enterprises depends on large quantities of operating data and aggregates data. Policymakers of these enterprise groups work out their cost budget according to their subjective judgement and experience. The reasons for their doing so are that scattered data memory is short of unified format and standardization and that current data fail to reflect their dynamic changes,etc. Here for the benefit of policymakers of the concerned enterprises and by making use of the cost of the enterprise logistics, analysis of the cost management and that of development of decision support prototype system are being conducted.The technical management of distributed date warehouse, heterogeneous data source in the integrated subsidiary and heterogeneous model based on my ETL design ,that is based on a kind of new data algorithm which is developed by utilizing mode matching and data-filtering technology. It can accelerate the speed of data renewal, filter the heterogeneous data , seek out different sets of data ,and offer the data basis for further decision from policymakers. It has been proved to be efficient by its successful application in the corporation working on distributed enterprises.
The Applications of RFID Technology in Logistics Management and Constraints
Authors: Zou Chao , Jiang Cheng Yu
Published: March 2009

Radio frequency identification (RFID) is a new material identification technology. RFID
has a greater number of benefits than its predecessor, the bar code. It is not universally adopted in
many industries due to its high cost hitherto. Whereas, RFID is advantageous because it does not
require line-of-sight scanning, it acts to reduce labor levels, enhances visibility, and improves
inventory management. This article briefly introduced component, principle and characteristic of
the RFID technology, and analyzed and introduced more foregroundful application of RFID in
modern logistics. RFID technology is combined with network technical and database technology, it
will be extensively applied in stock tache, storage tache, transportation tache, retail tache of
logistics system. In addition, this paper also discussed the factors which restrain RFID technology
from being broadly applied. The uppermost problem faced by RFID technology is the cost of RFID
chip, then it comes to the potential intervention of people’s privacy incurred by the use of RFID
technology. Otherwise, lack of uniform criteria definitely affects the development of RFID
technology.
A Model for Comparative Analysis of Inventory Costs of JIT and EOQ Purchasing in the Ready Mixed Concrete Industry
Authors: Wu Min , Xu Mao Zeng
Published: March 2009

A model for comparing the inventory costs of purchasing under the economic order quantity (EOQ) system and the just-in-time (JIT) order purchasing system in existing literature concluded that JIT purchasing was virtually always the preferable inventory ordering system especially at high level of annual demand. By expanding the classical EOQ model, this paper shows that it is possible for the EOQ system to be more cost effective than the JIT system once the inventory demand approaches the EOQ-JIT cost indifference point. The case study conducted in the ready-mixed concrete industry in Singapore supported this proposition.
An Integrated Method for Product Material Selection Considering Environmental Factors and a Case Study
Authors: Cao Hua Jun , Liu Fei , Li Cong Bo , Liu Chun
Published: March 2009

Materials have very important influence on the environmental impact of the product life
cycle from production to disposal and recycling. The environmental factors should be considered
when product materials are selected, in order to improve the environmental friendliness of products.
Due to the complexity of product material selection considering technical, economic and
environmental factors, it is transformed into a decision-making problem. An integrated
decision-making index system is presented, and a multi-objective decision-making framework
model is established according to the index system. An algorithm integrating grey relation analysis
(GRA) and analytic hierarchy process (AHP) is used to aid the decision making process. A material
selection case of the housing of an electronic device is introduced, which shows the feasibility and
effectiveness of the model and method presented.
Research on Analyzing and Coding Technology of Manufacturing Information Resource Based on Granularity-Structure
Authors: Jiang Jian Jun , Wang Jun Biao , Jiang Cheng Yu
Published: March 2009

This paper constructs the organization model of manufacture information resource (MIR) using the granularity structure (GS) analysis method. Based on the model, the expression technique of MIR based on metadata and the coding realization technique are analyzed. MIR expression mode achieves flexibility unification using the object-oriented (O-O) coding structure solution. The result proves that the technique of analyzing and coding to MIR based on GS has provided an effective method to standardize the MIR organization under the development mode of product life cycle (PLC).
Research on Innovative Product Design System Based on QFD and TRIZ
Authors: Lu Cong Da , Liao Zhi Ping , Jiang Shao Fei , Liu Gao Jin
Published: March 2009

This paper presents an innovative product design system based on Quality Function
Development (QFD) and Theory of Inventive Problem Solving (TRIZ in Russian abbreviation).
House of Quality (HOQ) is the core of QFD. To make QFD more practical and operable for small
and medium-sized companies, a simplified model of HOQ is proposed. A set of reasoning scheme
for inferring requirements relationships is adopted to facilitate constructing the HOQ. The
contradiction in the process of mechanical design is defined by TRIZ as physical contradiction and
technical contradiction. These two contradictions are solved through contradiction matrix and
inventive principles of TRIZ. The innovative design system mainly uses the tool of contradiction
matrix to solve the bottle techniques attained from QFD. By taking the HOQ as its interface the
integration between QFD and TRIZ is realized. After conducting quality function development, two
outputs can be obtained. They are the technical measure needing improvement and the technical
measure that is getting worse while improving the former one. These two measures are taken as
inputs of TRIZ module to analyze and solve the problem of product design.
Precision Forging of Casting AZ31 Magnesium Inner Spur-Gear
Authors: Li Hong Bo , Huang Mu , Luo Jun Ting , Zhao Jun
Published: March 2009

Based on the two-stage forming technology, the casting AZ31 Magnesium alloy bar was
forged into cylindrical straight inner gear between the temperature 250°C-400°C. At 250°C, the teeth
of the inner gear are almost formed. But there are some cyclic cracks on the surface of the sample.
When improving the temperature above 300°C, the surface quality of the sample has greatly
improved. According to the result of this experiment, the best temperature range for forging AZ31
magnesium gear is 280°C to 380°C.The forming load gradually reduced with the temperature
improved. At 250°C, the forming load is 93t. At the 400°C, the forming load reduces to 80t.The initial
grain size of AZ31 magnesium alloy bar is 22μm. The microstructure evolution during the warm
deformation was observed by optical microscopy (OM). It is demonstrated that the grain refinement
happened during the deformation process.
Research of Mechanism of Chipping in Step Tapping of Superalloy Based on Wavelet Analysis
Authors: Han Feng Qi , Li Guang Jun , Pang Xiang Sheng , Li Zhi Zun , Zhang De Yuan
Published: March 2009

Stepping tapping is a new tapping mode for Nickel-based superalloy GH4169. Longer
life of tap and higher machining efficiency can be obtained. But chipping of tap is very prevalent. In
this paper, the mechanism of chipping in step tapping is investigated. Based on the wavelet analysis
of the signals of tapping torque, the load applied to the tap in every stage of the period of motion is
studied. It is found that chipping is prone to occur at the moment when the rotating direction of tap
shifts from forward to backward, which is caused by the too large and rapidly changed tensile stress
on cutting edge. The excessive wear of cutting edge results in the too large tensile stress. To reduce
the wear, the backward rotating angle of tap should be selected to be smaller than 100°.
Fabrication and Characterization of HA/CNT Bioceramics
Authors: Meng Yan Hua , Tang Chak Yin , Tsui Chi Pong
Published: March 2009

A new kind of Hydroxyapatite (HA) composites was fabricated using a hot-press method
in which carbon nanotubes (CNTs) were introduced to the HA ceramic matrix to improve the
mechanical properties of the resulting composites. The CNTs were treated using a mixture of nitric
acid and sulfuric acid. A homogeneous dispersion of the CNTs in the HA matrix was achieved
through dispersing them in the solution of surfactant. The bioactivity of the samples was tested. The
microstructures of HA/CNT ceramic composites and the sample surfaces after immersion in SBF
were characterized by SEM. The results showed that the introduction of the CNTs into HA ceramic
matrix could produce positive strengthening effect without impairing the biological properties of the
HA ceramic.
Comparison of Bending Strength for Metal-Diamond Composites of Two Bond Matrices
Authors: Yu Yi Qing , Tie Xiao Rui , Xu Xi Peng
Published: March 2009

The present study was undertaken to examine the effects of metal coatings on the surfaces
of diamond crystals embedded in two kinds of bond matrix. Diamonds with or without coatings were
incorporated into two matrices for hot-pressing, thereby forming four kinds of diamond composites.
The transverse rupture strength (TRS) of the composites was measured to assess the bending strength
of the composites. SEM and EDS were used to analyze the fractured surfaces of the composites. It was
found that the TRS of the composites containing coated diamonds increased in both bond matrices.
But the coatings in the bond matrix without rare earth increased TRS a little more than the case with
rare earth due to a different failure mechanism of metal coatings.
Study of the Removing Depth of the Polishing Surface Based on a Novel Spinning-Inflated-Ballonet Polishing Tool
Authors: Ji Shi Ming , Yuan Qiao Ling , Zhang Li , Jin Ming Sheng , Zhang Xian , He Hai Ping , Wan Yue Hua , Pang Zhang Jiong , Yuan Ju Long
Published: March 2009

In the field of the mold-curved free surface polishing, how to control the removing depth of the polishing surface exactly is one of the important problems to be solved. In this paper, a mould automatic polishing system that is developed on Motoman-NL20 robot is used to make theoretical analysis and experimental research on the removing depth of the polishing surface based on a novel Spinning-Inflated-ballonet Polishing tool for curved surface of mould. Firstly, FEM (finite element analysis) software is used to emulate three kinds of situation in the process of polishing, then the model of surface removing depth of SBCT polishing is established. At last, through the analysis and comparison, the result of emulation and experiment has a remarkable consistency which accords with the model established by formal theory. This indicates the correctness of the model.
Research on the Inverse Dynamics of the Flexible Multi-Body Systems for the Hybrid Polishing Kinematics Machine Tool
Authors: Yu Miao , Zhao Ji
Published: March 2009

The hybrid polishing kinematics machine tool (HPKMT) which is made up of “3 axes
parallel + 2 axes series” is developed with the specially designed elastic polishing tool system for
the polishing operation on the free-form surfaces by using the characteristic of the elastic polishing
adequately by the authors. In order to control the HPKMT effectively, its characteristic of the
kinematics and dynamics need be known deeply. Moreover, the problem of inverse dynamics is the
theory foundation to apply dynamic control of the HPKMT. The analysis of the inverse of
mechanism is the important part in the research of dynamics. On the basis of the differential
equations of flexible multi-body dynamics, this paper discusses on the condition of knowing the
trace, posture and velocity for the end of bodies how to solve the constraint force and constraint
moment of each joint on the 3- PTT parallel mechanism and two-joint series mechanism.
Development of a Control System on 5-Axes Automatic Scanning for Nondestructive Ultrasonic Test
Authors: Wei Juan , Xiao Jie , Ma Hong Wei
Published: March 2009

A system is developed on a 5-axes automatic scanning for ultrasonic test. It is a system
with the host-slave and open-loop mode that contains PC and a 5-axes drive card based on single
chip microcomputers. The system drives five stepper motors to carry the detector moving
paralleling the normal direction of the detected surface to complete the detect task.
The Study of Collateral Damages in the Process of Femtosecond Laser Micromachining Single-Crystalline Silicon
Authors: Wang Yan Shen , Dong Shen , Yang Yan Qiang , Liang Ying Chun , Wang Bo , An Wei Wei , Zheng Zhi Ren
Published: March 2009

Femtosecond laser pulses are irradiated on a single-side polished single-crystalline silicon
wafer. Metamorphic zone appears around the ablated zone and the morphology changes gradually in
the metamorphic zone. Typical phenomena of thermal ablation such as melt-resolidification and
subtransparent glassy materials occur in the marginal area of the ablated zone. No apparent changes
are found among microscopic morphologies of the ablated, metamorphic and unirradiated zones.
There are flaws and spallations on the smooth back surface of the wafer, which are caused by the
stress inside the sample. Nanomechanical properties of the sample surface hardly change in the small
scope of the backside around the ablated zone. While regular changes occur in large scope, which is
the conjunct result of such stresses caused by many different collateral damages.
Research on the Chatter Suppression During Machining Thin-Walled Complex Blades
Authors: Ren Jun Xue , Zhang Ding Hua , Shi Yao Yao , Wang Zeng Qiang
Published: March 2009

This paper presents a new method for chatter suppression during finishing thin-walled
blades. Traditionally auxiliary support is used to increase the stiffness of the structure, however, the
shrink or dilate effect of the packing material, such as wax and rosin, is difficult to control, so the
machining precision could not be assured. Based on the principle of stiffness optimization principle,
the rigidity of the cantilever blade tip and leading/trailing edge region are improved with the
non-uniform allowances distribution. The milling experiments have showed that the proposed
strategy could be successfully used to realize the suppression of chatter vibration during flexible
parts machining.
Study on Formalizable Aircraft Assembly Process Planning Knowledge
Authors: Qiu Hong Jun , Tao Hua , Yang Bin Tang , Gao Xiao Bin
Published: March 2009

Domain knowledge representation is various and domain-concerned. The aircraft
assembly process planning (A2P2) is a special domain, a lot of things should be taken into account,
and the knowledge representation of A2P2 is complicated. It is focused on the knowledge
representation of A2P2 in this paper. Based-on case, the framework of A2P2 knowledge is
presented. The main considerations of A2P2 are analyzed, the transformation and reassembly of
native A2P2 knowledge is studied, the features of A2P2 is acquired, and the formalizable
framework of A2P2 is proposed. With BNF, a formal description of A2P2 knowledge is given.
Thermal Elasto-Plastic Asperity Contacts of Layered Media
Authors: Tong Rui Ting , Liu Geng , Zeng Quan Ren , Liu Tian Xiang
Published: March 2009

A thermal elasto-plastic asperity contact model is investigated in this paper, which takes
into account the steady-state heat transfer and the asperity distortion due to thermal elasto-plastic
deformations. A hard coating and a soft coating are applied to study the correlations between
contact area and contact pressure, average gap and contact pressure, coating thickness and contours
of the contact stress distribution et al. The effects of material properties, the coating thickness,
frictional coefficient, and the heat input combinations on the stress distribution are investigated and
discussed. The results may help to make an appropriate choice of the hard coating thickness.
Cutter Optimal Selection of CAPP System Facing to the Modern Manufacture
Authors: Li Lan , Liu En Fu , Jin Qing Su
Published: March 2009

The modern manufacturing industry requires the cutting process to reduce the quantity of
pollutants, to ensure the product quality, to make good use of the resource and energy, and to satisfy
the need of productivity and economy at the same time. The cutter reasonable selection is one
important method of improving cutting capability. Therefore, it can solve efficiently the new
problem in machining process to think of synthetic effect with quality, economy, resource and
environment at the same time. Furthermore, because the process in metal cutting is variable and the
influence of most factors can not be confirmed, the fuzzy assessment based on fuzzy integrate can
select more justified cutter in cutting process.
Fabrication of Fiber-Reinforced CPC Composite Artificial Bone by RP/RT
Authors: Lian Qin , Li Di Chen , Lu Bing Heng
Published: March 2009

Self-hardening calcium phosphate cement (CPC) could not be used to repair a large
segmental defect in a load-bearing bone because of its brittleness and weak shock resistance as well as
ultra-minute pores. Recent studies incorporated fibers into CPC to improve its strength. A novel
approach by rapid prototyping and rapid tool technique (RP/RT) was used in this paper to fabricate
fibre-reinforced CPC composite artificial bone. The subsequent mechanical experiments
demonstrated that the compressive strength of the CPC-fiber artificial bone was 24MPa, which was
significantly higher than 6MPa for CPC control without fiber. And in-vivo experiment about canine
radius repair proved that the implanted CPC-fiber artificial bone enabled to provide short-time
reinforced mechanical strength, while the degraded fibers created new macropores for new tissue
ingrowth. In summary, the CPC-fiber artificial bone may facilitate bone ingrowth and its four times
increase in strength may help extend the use of CPC to larger bone repairs in moderately
stress-bearing locations.
Modeling of Mold Filling Process of Al Casting and Validation with X-Ray In-Situ Observation
Authors: Zhao Hai Dong , Ohnaka Itsuo
Published: March 2009

To describe the shape and location of free surfaces in the mold filling simulation,
parameters including volume filled ratio, surface dimensionless distance, and surface filled ratio for
the DFDM (Direct Finite Difference Method) elements were proposed. A model of mold filling
process was established, considering the mass, momentum and heat transfer in the vicinity of free
surface. It had been applied to an experimental Al casting. In-situ observation and record of actual
mold filling process of the casting with special X-ray apparatus were carried out, and were used to
validate the simulation results. The validation showed that the model could predict the mold filling
process well. It was found that back pressure of gas in the mould cavity had minor effect on change
of liquid flow when using pressurized feeding system and sand mould with good air permeability.
Study on the New Tooth Profile of Silent Chain
Authors: Xue Yun Na , Wang Yong , Wang Xian Lun
Published: March 2009

The polygon action and the meshing impact of silent chain can be reduced by the change of
the link plate structure. However, the change of the link plate structure may result in the complexity
of manufacture. A new modified involute profile for sprocket is put forward based on the law of
motion between the link plate and the driving sprocket. The modified involute profile is obtained by
use of a unified program between VB and AutoCAD. The kinematic and dynamic simulation of silent
chain with the new profile is performed by use of ADAMS. The results show that the polygon action
of silent chain mechanism can be reduced and the smoothness of the silent chain drive is effectively
improved as the sprocket is of the new modified involute profile.
Prediction of Shot Peen Forming Parameters of Integral Aircraft Wing Panels
Authors: Zhang Xian Jie , Wang Jun Biao , Wang Yong Jun , Qiao Ming Jie
Published: March 2009

In this paper, algorithms are presented for predicting peen forming parameters of integral
aircraft wing panels with complex airfoil shapes. The peen forming deformation is divided into
stretching deformation and bending deformation. The stretching deformation is assumed to result
from the tensile strain within the plane panel, and the bending deformation corresponds to the
difference of maximum and minimum curvature of the airfoil surface. The distribution of the
forming tensile strain within the panel is obtained by optimal mapping of the airfoil surface in the
sense that the stretching deformation energy from the plane panel to its spatial shape is minimized.
In order to fit the nonlinear relation between the peening parameters and the deforming parameters,
a back-propagation (BP) artificial neural network (ANN) is modeled with input parameters of
thickness, curvature, tensile strain, etc, to predict the peening parameters of coverage, air pressure
and intensity. Experimental peen forming data are given to train the BP ANN. It’s verified that the
predicting methods are effective.
Aqueous Processing of Textured Silicon Nitride Ceramics by Slip Casting in a Strong Magnetic Field
Authors: Zhu Xin Wen , Uchikoshi Tetsuo , Sakka Yoshio
Published: March 2009

Recently, textured microstructure has received particular interest in the processing of advanced Si3N4 ceramics because of significant improvement in the mechanical properties and thermal conductivity. This work will report a highly textured β-Si3N4 ceramic by aqueous slip casting in a magnetic field and subsequent pressureless sintering, using commercial α-Si3N4 raw powder and a mixture of Y2O3 and Al2O3 as sintering aids. To obtain the well-dispersed Si3N4- Y2O3-Al2O3 slurries, polyethylenimine (PEI) was chosen as a dispersant. Effects of the sintering aids, PEI amount, pH and stirring time on the stability of the Si3N4 slurries were studied. It is shown that PEI is an effective dispersant for stabilizing the Si3N4-Y2O3-Al2O3 slurries that does not show a time-dependent behavior at an optimum pH ≈ 10, compared to the case in the absence of PEI. Using the 30 vol% Si3N4-Y2O3-Al2O3 slurries stabilized with 1.5 dwb% PEI at pH 10, the highly textured β-Si3N4 with 97 % relative density could be obtained by slip casting in a magnetic field of 12 T and subsequent sintering at 1800 oC for 1 h. The textured microstructure is featured by the alignment of c-axis of β-Si3N4 crystals perpendicular to the magnetic field, and the Lotgering orientation factor, f, is determined to be 0.8.
Design of Porosity Level for Porous Si3N4 Ceramics Manufactured by Nitriding and Post-Sintering of Si Powder Compact
Authors: Park Young Jo , Choi Eugene , Lim Hyung Woo , Kim Hai Doo
Published: March 2009

Prediction of porosity level for the Si3N4 filter substrate manufactured by reaction
bonding of Si compact and subsequent post-sintering was attempted and its validity was verified by
comparison between calculation and measurement. Both are well matched in the specimens of asnitrided
and low temperature post-sintering, while few percents higher measurement in high
temperature post-sintered specimens resulted from weight loss during the process.
Formation of Barrier Ribs via Micro Molding Process Using UV-Curable Paste
Authors: Kim Yong Seog , Koh Tae Gum , Kim Yoo Seong
Published: March 2009

In an attempt to reduce processing cost and to improve the resolution of PDPs, a micro mold transfer processing route for barrier ribs of plasma display panel was attempted. In this study, the parameters that may cause defects during the process were identified, which include the shrinkage during the UV curing process, stress due to the evaporation of organic components, and sintering shrinkage. Considering such parameters, a UV curable paste was developed and the barrier ribs of PDPs were successfully processed via the process. This work demonstrated the possibility of a build-up route in manufacturing barrier ribs of PDP
Resistance to Abrasive Wear of Materials Used as Metallic Matrices in Diamond Impregnated Tools
Authors: Konstanty Janusz , Kim Tai Woong , Kim Sang Beom
Published: March 2009

Metal-bonded diamond impregnated tools are being increasingly used in the processing
of natural stone, sawing and drilling concrete and brickwork, road repair, petroleum exploration,
production of ceramics, cutting frozen foods, etc. Although the main tool wear mechanisms seem to
be well identified, the scientific background is still inadequate and extensive fundamental research
has to be carried out to better understand how the tool performs in actual applications.
This work attempts to address the complex issues of modelling the abrasive wear of the metallic
matrix under laboratory conditions. In view of the generated wear data, it becomes evident that a
comprehensive characterisation of the matrix’s susceptibility to wear by 2-body and 3-body
abrasion can be reliably assessed in a quick and inexpensive manner; whereas tests carried out on
diamond impregnated specimens may assist in the prediction of the tool life in abrasive
applications.
Friction and Wear Behaviors of WC-Co/WC-Co Pairs in Air
Authors: Hosokawa Hiroyuki , Nakajima Takeshi , Shimojima Koji
Published: March 2009

To investigate sliding friction and wear behaviors of WC–Co/WC–Co pairs containing
different WC grain sizes, the ball-on-disc test in air were carried out for WC-Co containing WC
grain sizes of 0.5 μm (F.G.) and 1.5 μm (C.G.). The results show that the wear volume of F.G. pin
for F.G. pin/C.G. disc is larger than that of F.G. pin for F.G. pin/F.G. disc due to higher friction
coefficient, and the surfaces after wear test are richer in oxygen compared to those before test.
Furthermore, the wear debris, which is composed of nona-scale grains, after the wear test are
remarkably richer in oxygen than to those before test. The diffraction pattern reveals sharp ring
Synthesis of Aluminum Monohydroxide Nanofiber by Electrolysis of Aluminum Plates
Authors: Woo S.H. , Lee Min Ku , Rhee Chang Kyu
Published: March 2009

Aluminum hydroxides were synthesized by a simple electrolytic reaction of aluminum
plates. The aluminum monohydroxide, boehmite(AlO(OH)), was predominantly formed by the
application of an electrical potential above 30V, while the mixture of the bayerite(Al(OH)3) and
boehmite(AlO(OH)) phases were formed below 20V. The boehmite has a clear fibrous structure
which is controlled on a nanometer scale. On the contrary, the bayerite consists of the typical
hourglass or semi-hourglass shaped coarse crystals as a result of an aggregation of the various
crystals stacked together. The specific surface area of the boehmite nanofiber was remarkably high,
reaching about 300m2/g.
Atomization Using a Pressure-Gas-Atomizer
Authors: Achelis Lydia , Uhlenwinkel Volker , Lagutkin S. , Sheikhaliev Sh.
Published: March 2009

An update and the latest results on molten metal atomization using a Pressure-Gas-
Atomizer will be given. This atomizer combines a swirl-pressure atomizer, to generate a liquid
hollow cone film and a gas atomizer to atomize the film and/or the fragments of the film. The paper
is focused on powder production, but this atomization system is also applicable for deposition
purposes. Different alloys (Sn, SnCu) were atomized to study the characteristics of the Pressure-
Gas-Atomizer. The powders produced were analyzed by laser diffraction and image processing.
Among other parameters, the molten metal mass flow (~140 – 200 kg/h), the gas mass flow and the
atomizer design were varied. The results include the effects of these variances on particle size and
particle shape.
The Synthesis of Maghemite and Hematite (γ-Fe2O3, α-Fe2O3) Nanospheres
Authors: Dar M.A. , Ansari S.G. , Wahab Rizwan , Kim Young Soon , Shin Hyung Shik
Published: March 2009

Maghemite and hematite nanospheres were synthesized by using the Sol-gel technique.
The structural properties of these nanosphere powders were characterized by X-ray diffraction
(XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy
(FESEM),and pore size distribution.Hematite phase shows crystalline structures.The mean particle
size that resulted from BET and XRD analyses were 4.9 nm and 2 nm. The field emission scanning
electron microscopy shows iron-oxide powder is composed of nanosized particles, but in nanosized
aggregates (agglomeration of particles). It can be seen from transmission electron microscopy
that the size of the particles are very small which is in good agreement with the FESEM and the Xray
diffraction. TEM and FESEM confirmed that the iron-oxide powder is composed of sizes from
8 nm to 10 nm. The BET and pore size method were employed for specific surface area
determination.
Wear Resistance Properties of Tungsten Carbide/Stainless Steel Composite Materials Prepared by Pulsed Current Sintering
Authors: Kawakami Yuji , Tamai Fujio , Enjoji Takashi , Takashima Kazuki , Otsu Masaaki
Published: March 2009

Austenitic stainless steel has been used as a corrosion resistance material in tough
corrosive circumstance. However, austenitic stainless steel has poor wear resistance property due to
its low hardness. Tungsten Carbide alloys (WC) are widely used as tooling materials, because of
their high hardness and excellent wear resistance property. In this investigation, we apply powder
composite process to obtain hard layer of Stainless steel. The composite material was fabricated
from planetary ball milled WC powder and SUS316L stainless steel powder and sintered by Pulsed
Current Sintering (PCS) method. We also added TiC powder as a hard particle in WC layer.
Evaluations of wear properties were performed by pin-on-disk wear testing machine, and a
remarkable improvement in wear resistance property was obtained. The weight loss rate of the
composite was 1/10 of SUS316L. In addition, it was found that TiC hard particle addition has a
positive effect on the wear resistance property. EPMA investigation showed good dispersion of WC
hard phase and TiC hard particle with SUS316L matrix.
High Temperature Microstructural Stability of Si3N4 in TiAl Alloys
Authors: Choi Jee Hoon , Lee Dong Bok
Published: March 2009

Alloys of Ti-50 at.% Al with (3 and 10)wt.% Si3N4 particles were prepared by a
mechanical alloying-spark plasma sintering (MA-SPS) method. The matrix consisted primarily of
TiAl, Ti2AlN, TiN. Si3N4 was unstable in the matrix and started to decompose forming a Ti5Si3
reaction layer on the surface of former Si3N4 particles during sintering and heat treatment at 1373 K.
Structure and Properties of MASHS Titanium Aluminide–Based Powder Alloyed with Chromium
Authors: Talaka Tatsiana , Ilyuschenko Alexander , Letsko Andrey , Hasak Tatsiana
Published: March 2009

Structure and properties of MASHS powder Ti-46Al-8Cr, at. %, have been investigated.
The powder is characterized by the multiphase dispersed strengthened structure with coherent
precipitates/matrix bonding. Main structural constituents of the powder are titanium aluminides
alloyed with chromium: γ-TiAl(Cr), Al0,67Cr0,08Ti0,25 and α2-Ti3Al(Cr). Average powder
microhardness is 313 HV0.25. High-quality detonation coatings with high hardness (940-1100 HV)
and low porosity (less than 1%) have been obtained from the synthesized powder. The coatings
exhibit good oxidation behaviour at 900°C.
Recent Advances in Dry-Bag Cip Equipment
Authors: Kishi Yoshikazu , Miyashita Yasuhide , Manabe Yasuo , Fujikawa Takao
Published: March 2009

Dry-bag CIP process has become a very popular method in the large volume production
of powder compacts in the P/M and ceramic industries. Intensive technological research on the Drybag
equipment has been carried out to improve the dimensional accuracy and the productivity. In
this study, the rubber mold design technology with FEM simulation during pressing has been
introduced, in order to achieve higher dimensional preciseness, and criteria for the selection of Drybag
equipment, namely the In-line type or Off-line type, have been established based on the powder
flowability index proposed by Carr. Based on these research results, high productivity Off-line Drybag
CIP equipment, which can realize good dimensional accuracy with high productivity, was
developed even for non granulated powders with poor packing density. This paper describes the
research results and the present status of the most advanced Off-line Dry-bag CIP equipment
technologies.
Characteristics of Nanostructured WO3-CuO Powder Mixture Produced by Ball Milling
Authors: Azimi H. , Ahmadi E. , Hadavi S.M.M.
Published: March 2009

Usual process for production of W-Cu nanocomposite is ball–milling and sintering of W and Cu mixed powder. Recently, mechanochemical process (MCP) using WO3 and CuO powders have been developed. In the present work, the influence of the ball-milling time from 1 to 30 hour, milling atmosphere such as Argon and Hexane as Process Control Agent (PCA) and weight ratio of ball to powder on characteristics of WO3-CuO was studied. The microstructure of WO3–CuO powder prepared by milling was investigated by x-ray diffraction (XRD) and scanning electron microscopy (SEM). Results show that, the grain sizes of the WO3 and CuO in the ball-milled powder mixture were significantly decreased with increasing the milling time. Those of each oxide ball–milled in Argon and Hexane atmosphere for 30 and 20 hour were about 98 and 84 nm, respectively. After milling of 20 hour in Hexane as PCA, the powder had a homogeneously mixed structure and the average size of WO3– CuO powders was determined to about 230nm.
Fabrication of TiH2 Powders from Titanium Tuning Chip by Mechanical Milling
Authors: Jang Jin Man , Lee Won Sik , Ko Se Hyun
Published: March 2009

In present work, manufacturing technologies of titanium hydride powder were studied for
recycling of titanium tuning chip and for this, attrition ball milling was carried out under H2
pressure of 0.5 MPa. Ti chips were completely transformed into TiH2 within several hundred
seconds that is very short time comparing to that in the previous report. Dehydrogenation process
TiH2 powders is consist of two reactions: one is reaction of TiH2 to TiHx and the other
decomposition of TiHx to Ti and H2. The former reaction shows relatively low activation energy
ranged from about 100 KJ/mol to 250 KJ/mol and it is suggested that the reaction is caused by
introduction of defects due to milling. In case of TiH2 powders that hardly contains defects,
decomposition of TiH2 to Ti and H2 occurs directly without the reaction of TiH2 to TiHx and
activation energy is very large as much as 929 KJ/mol.
Precipitation Behavior of γ" in Severely Plastic Deformed Ni-Base Alloys
Authors: Kim Il Ho , Kwun S.I.
Published: March 2009

The precipitation behaviors of γ″(Ni3Nb) in four Ni-base alloys were investigated. The
four alloys were forged Ni20Cr20Fe5Nb alloy, mechanically alloyed Ni20Cr20Fe5Nb alloy, IN 718
alloy and ECAPed(equal channel angular pressing) IN 718 alloy. Aging treatment was employed at
either 600°C or 720°C for 20 hrs. The TEM observation and hardness test were performed to
identify the formation of γ″. The precipitation of γ″ was noticed after aging at 600°C for 20 hrs in
the mechanically alloyed Ni20Cr20Fe5Nb alloy and ECAPed IN 718 alloy, while it was observed
after aging at 720°C for 20 hrs in the forged Ni20Cr20Fe5Nb alloy and IN 718 alloy before ECAP.
It seemed that the lower aging temperature for γ″ precipitation in the mechanically alloyed
Ni20Cr20Fe5Nb alloy and ECAPed IN 718 alloy than in the forged Ni20Cr20Fe5Nb alloy and IN
718 alloy before ECAP appeared to be due to the severe plastic deformation which occurred during
mechanical alloying or ECAP.
Solid-State Synthesis of Mg2X (X=Si, Ge, Sn and Pb) via Bulk Mechanical Alloying
Authors: Aizawa Tatsuhiko , Song Ren Bo
Published: March 2009

Magnesium base alloys and compounds are attractive for various applications as a functional material. In particular, a series of binary system by Mg2X (X = Si, Ge, Sn and Pb) has fascinated many researchers and engineers by its thermoelectric properties and semi-conductive performance. Many barriers in its processing rejects precise investigation of these types of semiconductive compounds: high vaporizing pressure and mechanical adhesion of magnesium, reaction of germanium and tin with crucibles, and, difference of melting point among elements, X. Solidstate processing via the bulk mechanical alloying enables us to directly fabricate these Mg2X semiconductive materials in high density performs. The precise control of chemical composition leads to an investigation on the dilution and enrichment of X in Mg2X. Two types of solid-state reactivity are introduced: e.g. synthesis of Mg2Si from an elemental mixture Mg – Si, which is a nucleationcontrolled process, while synthesis of Mg2Sn from Mg – Sn is a diffusion-controlled process. The thermoelectricity of these Mg2X is evaluated for discussion on the validity and effectiveness of this new PM route as a reliable tool for fabrication of thermoelectric compounds.
Densification Mechanism of Warm Compaction for Iron-Based Powder Materials
Authors: Qu Sheng Guan , Li Yuan Yuan , Xia Wei , Chen Wei Ping
Published: March 2009

An apparatus measuring changes of various forces directly and continuously was
developed by a way of direct touch between powders and transmitting force component, which can
be used to study forces state of powders during warm compaction. Using the apparatus, warm
compaction processes of iron-based powder materials containing different lubricants at different
temperatures were studied. Results show that densification of the powder materials can be divided
into four stages, in which powder movement changes from robustness to weakness, while its degree
of plastic deformation changes from weakness to robustness. The proposed densification
mechanism may provide an insight into understanding of warm compaction process.