bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of RE on Microstructure and Electrochemical Corrosion Behavior of Arc Sprayed Zn-Al-Mg Coating
Authors: Zhu Zi Xin , Chen Dong , Xu Bin Shi
Published: July 2011

Cored wires and arc spraying technique were used to produce Zn-Al-Mg-RE alloy coatings on low carbon steel substrates. The effect of RE (where RE is Rare Earth) on the microstructure and electrochemical corrosion behavior of coatings was investigated comparing with Zn-Al-Mg coatings. With addition of RE, the Zn-Al-Mg-RE coating has denser microstructure and fewer porosity. But RE has no discernible effect on the adhesion strength between coating and substrate. The Zn-Al-Mg-RE coating has superior corrosion resistance compared to Zn-Al-Mg coating due to the formation of more compact and uniform corrosion products. The role of the RE elements appears to be associated with the self-sealing process and the refinement of the coating microstructure.
A Research on Mobile Agent Technique and Application Development
Authors: Chen Jia Jun , Xing Chang Feng , Liu Gao Feng , Cheng Zhi Feng
Published: July 2011

Mobile agent (MA) is an offspring of distributed technology combined with agent technology and it is a intelligent agent with mobility. So it has good application potential in distributed network. The appearance and characteristics of mobile agent are presented, and then three standards and criterion related to the mobile agent are summarized. Five representational mobile agent platform (MAP) are discussed and their communication paradigm and structure, providing service and characteristics are compared. Finally, the application potential, deficiencies of current research and the possible trend of mobile agent technology (MAT) are discussed.
Prediction of Wear Volumes to 45 Steel of NBR Based on Neural Network
Authors: Luo Xuan , Wang Shi Jie , Lv Xiao Ren
Published: July 2011

The wear to orthogonal metals of NBR is the main cause of affecting the endurance of ESPCP. The rotational speed, load and temperature are main influence factors of the wear of 45 steel. The BP neural network model used in the forecast of the 45 steel wear volume was established. The 45 steel wear volume was obtained using friction and wear machine under different experimental parameters. The wear volumes of different experimental parameters were forecasted using BP neural network. The results indicate that it is feasible to forecast the rotational speed, load and temperature to 45 steel wear volume.
The Analysis of Flow Characteristics for the High-Speed Train with Strong Crosswind Using CFD
Authors: Liu Yong , Cao Ning Ping
Published: July 2011

High-speed trains are easily got overturned in strong crosswind. This paper aims to analyze the fluid field of high-speed train under different distortion angles by using computational fluid dynamics (CFD), hybrid grid method and finite volume method. The results shows that the vortexes roll by the separated airflow are alternating occur and develop along the body from the top and bottom. It causes a strong affect to the lateral stability of the train.
Research on Hydro-Pneumatic Balanced Suspension of Multi-Spindled Vehicle
Authors: Yang Lin , Zhang Jun Wei , Chen Si Zhong
Published: July 2011

A hydro-pneumatic balanced suspension is proposed based on the structural features of general hydro-pneumatic suspension and balanced suspension. Two types of suspensions mathematics models are built and differential equations of motion are derived with Lagrange-Equation. Performance of the two suspensions is simulated with the software of MATLAB. The results show that ride performance of vehicles is improved using hydro-pneumatic balanced suspension. Therefore, hydro-pneumatic balanced suspension is more suitable for multi-spindled vehicles.
The Effect of Surface Treatment on the Mechanical Properties of Glass Fiber Reinforced Polyamide 6 Composite
Authors: Bao Jun , Li Jian
Published: July 2011

The effect of fiber surface modification on the fatigue strength of a glass fiber reinforced polyamide-6 has been investigated. Tension axial fatigue tests were conducted with specimens extracted from injection moulded plates. Results show the variation of the fatigue strength as a function of the fiber concentration. The experimental data, the tensile tests have shown the effective improvement of interfacial adhesion between the fiber surface and the matrix.
Research on the Flow Boiling and Heat Transfer of Ethanol in a Corrugated Mini-Channel
Authors: Chang Wei , Zhang Shu Sheng , Tian Shuai , Huo Meng Jia
Published: July 2011

Based on the establishment of a two-dimensional model, a numerical simulation was conducted in this paper to study the flow boiling and heat transfer characteristics of ethanol in a corrugated mini-channel. User defined functions were employed to describe the key processes of heat and mass exchange at the phase interface. Bubble growth profile was monitored over time and its influence on system pressure drop and heat transfer coefficient was also analyzed. The simulation result shows that the nucleation sites tend to distribute near the internal peaks of the heating wall due to the enhanced local turbulence. The system pressure drop increases over the heating time and fluctuates within a certain range. The heat transfer coefficient decreases with increasing quality, and this trend is consistent with the result of similar experimental studies.
Study of the Microstructure of High-Entropy Alloys AlFeCuCoNiCrTiX (x=0, 05, 1.0)
Authors: Sun Hong Fei , Guo Nana , Wang Can Ming , Li Zhong Li , Zhu Hai Yun
Published: July 2011

The microstructure of high-entropy Alloys AlFeCuCoNiCrTix (x=0, 05, 1.0) with different titanium contents had been studied. The results showed that: (1) The microstructure of AlFeCuCoNiCrTix exhibited the trend from dendritic structure to eutectic-cell structure as the titanium contents increasing and spinodal decomposition, nanoprecipitation and amorphous phase can be also observed; (2) Composition segregation appeared (especially Cu) and Ti promoted the segregation of Cu; (3) Alloys was consisted of FCC and BCC, and phases gradually converted from FCC+BCC1 to FCC+BCC1+BCC2 with addition of titanium and BCC2 became the leading phase; (4) Both ordering and spinodal decomposition coincided due to the difference of atomic size and high entropy effect.
Effect of Liquid Oxidation Surface Treatment on Bonding Properties of Wood/Polyethylene Composites
Authors: Teng Xiao Lei , Di Ming Wei
Published: July 2011

In this paper the surface of wood/polyethylene (PE) composites were treated by liquid oxidation, and the structure of surface for wood/polyethylene composites before and after treatment was characterized by contact angle, fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM); combined with bonding strength test, the effect of concentration for handling solution and addition of oxidant on bonding properties of wood/polyethylene composites was also investigated. The results showed that the contact angle of surface for wood/polyethylene composites reduced and the surface wettability had been improved after liquid oxidation; the -C-O- and C=O functional groups were formed on the treated surface and the surface roughness increased; meanwhile, the shear bonding strength for the treated sample increased significantly after treatment. And these changes would be more obvious when enhancing the concentration of handling solution and adding oxidant.
The Research on Chaotic Signal Tracking Algorithm for SR-UKF-PF
Authors: Tao Qian , Zhu Lin Hu , Pan Bo
Published: July 2011

In view of the difficult in the chaotic signal detection and track in the low signal-to-noise(SNR) environment, a modified SR-UKF-PF is developed that has much better robustness than the traditional SR-UKF and gets almost the same performance as the Particle filter. The main idea of this algorithm is to calculated by the system state transition matrix and the error covariance matrix which are gained from the SR-UKF and the sequential fusion to construct the importance density function of the particle filter. Then the importance density function can integrates the latest observation into system state transition density, and the proposal distribution can approximate the posterior distribution maximumly. To demonstrate the effectiveness of this model, simulations are carried out based on tracking algorithm for the typical chaotic time series of low dimension chaos mapping and super chaos mapping. The simulation results show that this algorithm can overcome the flaw that it is hard to get the optimization importance density function in the particle filter and significantly improves the accuracy of state estimation, and demonstrates the superiorities of particle filtering in the low SNR.
Load and Deformation Properties of Steel Fiber Reinforced Concrete ShearWall
Authors: Zhao Jun , Wang Li Jun , Gao Dan Ying
Published: July 2011

The numerical simulation by nonlinear finite element method(FEM) was adopted to analyze the behavior and the influences of the volume fraction of steel fibers and the strength of steel fiber reinforced concrete on the load capacity and the deformation performance of reinforced concrete shearwalls.The effect of steel fiber on the FEM was determined. The results show that with the increase of the volume fraction of steel fibers, the crack load, bearing capacity and ductility coefficient of steel fiber reinforced concrete shearwalls increase gradually. With the increase of the strength of steel fiber reinforced concrete, the bearing capacity and ductility coefficients of steel fiber reinforced concrete shearwalls decrease.
Strain Fatigue Behavior of Thin-Walled Tubes of Zr-1Nb and Zr-4 and Thin Plates of N18 at Elevated Temperatures
Authors: Jia Qi , Cai Li Xun , Bao Chen
Published: July 2011

Thin plates and small thin-walled tubes of zircaloys are used as fuel cladding materials of nuclear reactors. In order to prevent buckling of plate or tube specimens of zircaloys under cyclic strain loading, a set of self-invented clamps were used for strain fatigue tests of small thin-walled tubes of Zr-4 and Zr-1Nb at elevated temperature. Depending on axial control strain, a new strain fatigue test method named as (equivalent strain)-SF(strain fatigue) was developed for thin funnel-like plate specimens of N18 zircaloy with double side notches. A series of monotonic tension tests for the three kinds of zircaloys at different temperatures and strain fatigue tests for Zr-4 and Zr-1Nb at 375°Cand for N18 at 20°C,300°Cand 500°C were carried out. Monotonic and cyclic constitutive relations and Manson-Coffin life-estimating expressions for these zircaloys are given. ES-SF method has no Poisson effect and has better accuracy to predict strain fatigue behavior.
Simulation for Fatigue Crack Propagation Behavior Based on Low Cycle Fatigue Critical Damage
Authors: Bao Chen , Cai Li Xun , Huang Xue Wei
Published: July 2011

Based on low cycle fatigue critical damage, a numerical procedure for predicting stable fatigue crack propagation behavior of materials and structures was developed, which was named as LFF (LCF: Low Cycle Fatigue + FCP: Fatigue Crack Propagation + FEA: Finite Element Analysis) in this work. In the LFF method, stress and strain amplitude of nodes located at the plastic zone in the crack growing direction and fatigue damage of these nodes were firstly computed from a finite element code ANSYS. Then, by assuming a discontinuous step of propagation in the process of fatigue crack propagation, the stable fatigue crack propagation behavior of materials and structures could be estimated. Experiments on low cycle fatigue and fatigue crack propagation for Cr2Ni2MoV, TA12 and TC4 alloys were employed to certificate the applicability and validity of the LFF method. The results show that the LFF method is suitable for the estimation of stable fatigue crack propagation of a CT specimen with a straight crack under mode Ⅰloading and with a slant crack under mixed mode Ⅰ and Ⅱ loading.
Numerical and Experimental Study of Two-Layered Tube Forming by Hydroforming Process
Authors: Seyedkashi S.M.H. , Liaghat Golam Hosein , Naeini Hassan Moslemi , Mahdavian S.M. , Hoseinpour Gollo M.
Published: July 2011

Hydroforming is an advanced process in automotive and aerospace industries to form metal tubes into desired shapes by high pressure fluid. The formation of a two layered tubes has been investigated both numerically and experimentally by a pressurized fluid fed into the internal tube through a nonlinear path with no axial feeding. The experimental setup including two units of die clamping system and pressure intensification system has been designed and built in Tarbiat Modares University. The internal and external layers of hydroformed tubes are used aluminum and copper alloys respectively. Effects of different friction conditions on tubes formability have been investigated. Finite element simulation is performed with LS-Dyna FE explicit code using ETA/Dynaform as the preprocessor. The simulation results show that the part can be formed successfully with the internal pressure of 61 MPa. The finite element results are in agreement with experimental results. It is also shown that imposing high friction condition for external tube and low friction condition for internal tube both will fail more likely.
The Predictive Model of Surface Integrity in End-Mill Grinding for High-Speed Milling
Authors: Wang Yung Cheng , Chen Chen Hsiang , Lee Bean Yin
Published: July 2011

The grinding precision of end-mill is dependent on the surface roughness of the corresponding rake face and relief face. This precision will be influential in the surface roughness of workpiece and tool life of end-mill in high-speed milling. Firstly, the experiment of high-speed milling for SKD61 tool steel has been performed in the different cutting condition, and the end-mills have the different surface roughness. From the experimental results, it has shown that small relief surface roughness will decrease tool flank wear (increase tool life). The surface integrity of end-mill is very important for high-speed milling, so the different grinding parameters of end-mill have been utilized in the grinding experiment. Finally the surface roughness analysis model of the end-mill relief could be established by a polynomial network. The predictive model of surface roughness can be used to analyze the grinding precision of end-mill.
Optimisation of Cruciform Test Specimen for Biaxial Tensile Testing of Sheet Metal
Authors: Tiernan Peter , Hannon Alan
Published: July 2011

One of the most restricting aspects of the biaxial tensile test for sheet metal is the design of the cruciform specimen. Although specimens of the cruciform type have previoussly been investigated quite extensively, no standard geometry for the cruciform specimen exists. Using a specifically designed pantograph apparatus for operation in a standard tensile testing machine, various cruciform specimens were analysed experimentally. Finite element modelling of the specimens was also conducted to establish optimum specimen geometry. Through a process of optimisation, a standard cruciform specimen was designed which can be used to accurately predict the mechanical behaviour of cold rolled low-carbon steel when formed in multiple directions simultaneously.
Improvement of Surface Roughness in End Milling of Ti6Al4V by Coupling RSM with Genetic Algorithm
Authors: Patwari Anayet Ullah , Nurul Amin A.K.M. , Alam S.
Published: July 2011

Titanium alloys are being widely used in the aerospace, biomedical and automotive industries because of their good strength-to-weight ratio and superior corrosion resistance. Surface roughness is one of the most important requirements in machining of Titanium alloys. This paper describes mathematically the effect of cutting parameters on Surface roughness in end milling of Ti6Al4V. The mathematical model for the surface roughness has been developed in terms of cutting speed, feed rate, and axial depth of cut using design of experiments and the response surface methodology (RSM). Central composite design was employed in developing the surface roughness models in relation to primary cutting parameters. The experimental results indicate that the proposed mathematical models suggested could adequately describe the performance indicators within the limits of the factors that are being investigated. The developed RSM is coupled as a fitness function with genetic algorithm to predict the optimum cutting conditions leading to the least surface roughness value. MATLAB 7.0 toolbox for GA is used to develop GA program. The predicted results are in good agreement with the experimental one and hence the model can be efficiently used to achieve the minimum surface roughness value.
CO2 Laser - MIG Hybrid Welding of Titanium Alloy
Authors: Brandizzi Marco , Satriano Annunziata Anna , Tricarico Luigi
Published: July 2011

CO2 laser - Metal Inert Gas (MIG) hybrid welding process was investigated in the butt welding of Ti-6Al-4V titanium alloy sheets of 3.0mm in thickness. Using a Design of Experiment (DoE) approach, bead on plate tests were planned with the aim to analyze the effect of laser and laser-MIG welding parameters on the bead shape, hardness profiles in the weld cross section and welding efficiency. Butt welds performed in correspondence of the bead on plate working conditions which assure the complete penetration of the samples, the absence of undercuts and the maximum welding efficiency, confirm the results of the bead on plate tests and highlights the gap bridging ability of the hybrid welding process.
Effect of Synthesis Temperature on Phase and Morphological Characteristics of Hydroxyapatite Nanoparticles
Authors: Kazemzadeh R. , Behnamghader Aliasghar , Hesaraki Saeed
Published: July 2011

In this research hydroxyapatite powder was synthesized by wet chemical method using calcium nitrate and diammonium hydrogen phosphate precursors at 2, 20, 50 and 90⁰ C. Phase composition, morphological aspects and particle size have been investigated using X-ray diffraction method (XRD), Fourier transform infra red spectroscopy (FTIR) and scanning electron microscopy (SEM). For the low synthesis temperature, products with low degree of crystallinity were obtained and the phases like calcium deficiency hydroxyapatite (CDHA) and hydroxyapatite were formed. In higher temperature ranges, higher degree of crystallinity was measured. For these samples, crystallite sizes estimated by scherrer formula and measured directly by SEM were found to be less than 100 nm. The synthesis temperature of 90°C has showed better results from crystallinity point of view. Considerable crystallinity of the powders produced in this research is almost comparable to that of conventional heat treatment used for enhancing the crystallinity.
Optimization of Micro Metal Injection Molding SS 316L for the Highest Green Strength by Using Taguchi Method
Authors: Ibrahim Mohd Halim Irwan , Muhamad Norhamidi , Sulong Abu Bakar , Jamaludin Khairur Rijal , Mohamad Nor Nor Hafiez , Ahmad Sufizar
Published: July 2011

Micro metal injection molding which is a new develop technology has attract most researcher where it becomes among the promising method in powder metallurgy research to produce small-scale intricate part at an effective process and competitive cost for mass production. Due to highly stringent characteristics of micro MIM feedstock,the study has been emphasized in investigating the optimization of highest green strength which plays an important characteristic in determining the successful of micro MIM. Stainless steel SS 316L with D50 = 5.96μm was used with composite binder, which consists of PEG, PMMA and Stearic Acid. From rheological characteristic and highly significant parameter through screening experiment, feedstock with 61.5% with several injection parameters were optimized such as injection pressure(A), injection temperature(B), mold temperature(C), injection time(D) and holding time(E). Besides that, interaction effects between injection pressure, injection temperature and mold temperature were also considered to optimize in the Taguchi’s orthogonal array. Analysis of variance (ANOVA) in terms of signal-to-noise ratio (S/N-larger is better) for green strength was also presented in this paper. Result shows that interaction between injection temperature and mold temperature(BxC) give highest significant factor followed by interaction between injection pressure and injection temperature(AxB). Single factor that also contributes to significant optimization are mold temperature(C), injection time(D) and injection pressure(A). This study shows that Taguchi method would be among the best method to solve the problem with minimum number of trials.
Fabrication of Silicon Nanopillar Sheet for Cell Culture Dish
Authors: Ali Mohammad Yeakub , Hajar Nurul
Published: July 2011

This paper discusses the fabrication of nanopillars using focused ion beam (FIB) sputtering. A 25 keV Ga+ FIB was used to machine the nanopillars. A reversed bitmap method was used to fabricate nanopillars where it milled the substrate all over except the nanopillar area. The height of the nanopillars ranges from 1 to 5.5 μm with aspect ratio of 1-6. Empirical relationship of taper angle, aspect ratio and height of the nanopillar were established. Taper angle was found to be reduced as the height of the nanopillar increased. The taper angle of nanopillars depends on the acceleration voltage, probe current and dwell time.
Synthesis and Characterization of Nano Hydroxyapatite
Authors: Sarfraz S. , Naseem B. , Amin S. , Mujahid M.
Published: July 2011

Hydroxyapatite (HA) is considered to form major component of bones and teeth. Synthesis of hydroxyapatite (Calcium phosphate, Ca10(PO4)6(OH)2) was carried out to produce nano powders. The size and shape of nano particles was controlled during synthesis by using templates of Cetyl Trimethyl Ammonium Bromide (CTAB). A cationic surfactant, CTAB creates micellar structures which would act as nano reactors for the synthesis of nano scale HA. Yield of the final product has also been examined by varying the surfactant concentration. X-ray diffraction data revealed characteristic peaks of HA, where a predominantly hexagonal lattice structure could be deduced. FTIR was used to observe the various chemical groups present in the product. Scanning electron microscope was used for the characterization of nano particles.
The High Temperature Fatigue Behavior of Inconel-738LC Material Deposited Thermal Barrier Coating
Authors: Park Jung Hong , Ku M.S. , Kim Jeong Suk , Lee K.H. , Song Y.S. , Kang Myung Chang
Published: July 2011

This work investigated the thermal fatigue behavior of Inconel-738LC material deposited thermal barrier coating by Vacuum Plasma Spray(VPS). The Inconel-738LC material which is widely used as a turbine parts is a CoNi-based superalloy with CoNiCrAlY bond coating and ZrO2-8wt%Y2O3 ceramic top coating. The microstructure of coating layer was analyzed by SEM/EDS and XRD. Thermal fatigue tests were performed using compact tension specimens at 550°C, 750°C, 950°C with the load frequency of 10Hz. The fatigue crack growth behavior was characterized depending on number of cycles. The crack growth rate was found to be greater at lower frequency and higher temperature.
Particle Dynamics and Heat Transfer at Workpiece Surface in Heat Treatment Fluidised Beds
Authors: Gao Wei Min , Kong Ling Xue , She F.H. , Hodgson Peter D.
Published: July 2011

The particle behaviour in a heat treatment fluidised bed was studied by the analysis of particle images taken with a high speed CCD digital video camera. The comparison of particle dynamics was performed for the fluidised beds without part, with single part and with multi-parts. The results show that there are significant differences in particle behaviours both in different beds and at different locations of part surfaces. The total and radiative heat transfer coefficients at different surfaces of a metallic part in a fluidised bed were measured by a heat transfer probe developed in the present work. The structure of the probe was optimized with numerical simulation of energy conservation for measuring the heat transfer coefficient of 150-600 W/m2K. The relationship between the particle dynamics and the heat transfer was analysed to form the basis for future more rational designs of fluidised beds as well as for improved quality control.
Electrodeposition of Tin Using Tin(II) Methanesulfonate from a Mixture of Ionic Liquid and Methane Sulfonic Acid
Authors: Kee Yang Kok , Basirun Wan Jeffrey , Lee Koay Hun
Published: July 2011

The electrodeposition of tin from Tin (II) Methane Sulfonate (MSA) with varying concentration in air and water stable 1-Butyl-1-Methylpyrrolidinium Trifluoro-Methanesulfonate, (BMPOTF) ionic liquid at room temperature was studied. Cyclic Voltammetry served to characterize theelectrochemical behavior of tin reduction and oxidation. The diffusion coefficient of stannous ions in the mixture of BMPOTF ionic liquid and MSA based electrolyte obtained via Randles- Sevcik was approximately 2.11X 10-7 cm2/s. Electroplating on copper panel was conducted under different current densities to determine BMPOTF based tin plating solution current efficiency. Mixture of BMPOTF and MSA based tin plating solution gave current efficiency as high as 99.9%. The deposit morphology of the mixture BMPOTF and MSA based tin coated substrates was observed by using EDX and SEM. A dense, fine and polygonal grain structure was obtained.
Preparation of Carbon Fibres for Aluminium Composites
Authors: Kozera R. , Bieliński J. , Broda A. , Boczkowska Anna , Kurzydlowski Krzysztof Jan
Published: July 2011

In this work, the results of studies on the preparation of carbon fibres (Tenax HTA40) for composites with an aluminium alloy matrix are presented. In the first step of preparation, the epoxy sizing was removed to assure adhesion of the Ni-P coating as a barrier to prevent the formation of brittle Al4C3. Removal of the sizing also decreases the risk of gas formation underneath the metal coatings in contact with the liquid metal matrix. Methods of sizing removal included annealing in air (300-600°C) and dissolving in solvents (acetone, toluene) and in inorganic solutions (HNO3, H2O2, NaOH), followed by SnCl2/PdCl2 activation are described. It was found that the chemical removal of epoxy sizing from carbon fibres is not an appropriate method for further studies on the electroless metallisation of carbon fibres. The thermal treatments in air atmosphere seem to be more useful for removing epoxy sizing. The result of the present studies was the optimisation of the temperature of the annealing of carbon fibres as 400-500oC. The morphology of the carbon fibre surface before and after sizing removal was characterised using SEM and in terms of the mass loss. A glycine-buffered electroless bath was used for the Ni-P coating of the fibre with a wide range of deposition rates and alloy compositions (2-12 wt% P). An advantage of electroless plating is that the process is carried out without electrical current. The coating is deposited as the result of the controlled reduction, which is catalysed by the metal being deposited. Two different pH values of metallisation baths were selected (pH=4.5 and pH=8.5). The time of Ni-P deposition ranged from 5 to 30 minutes. The process parameters were optimised for Ni-P coatings on 1D carbon fibres and 2D/3D woven fabrics. It was found that the process developed can be used for 2D and 3D woven fabrics.
An Evaluation on Processing of Metal Matrix Composites (Al2O3/AC8A) by Low-Pressure Infiltration
Authors: Tulugan Kelimu , Hwang Ho Jun , Rong Hua Wei , Park Won Jo
Published: July 2011

At present many researches are about low density and high strength material, Metal Matrix Composite (MMC) is one kind of high performance material which is very popular and can fit that condition very well. In this study, matrix material is Al alloy and Al2O3 short fiber is reinforcement, volume fractions of Al2O3 short fiber is 10, 15 and 20 %. Manufacture by a low-pressure infiltration method. And the performance is evaluated by microstructure observation, porosity ratio and relative density. It is found that the porosity ratio can be effectively adjusted by the infiltration temperatures and the loads of Al2O3 short-fibres, exhibiting a minimum of 2 for 10% loading at 700°C. Meanwhile, the relative density of composites reached to be a maximum of 98% for 15% loading at 700°C. The low porosity ratio and high density of composites are reasonably attributed to the proper processing techniques.
Integral Approach and Numerical Improvement to Calculate Carbon Concentration Profiles in Carburising
Authors: Gao Wei Min , Kong Ling Xue , Hodgson Peter  D.
Published: July 2011

The carbon diffusion in steel, where the carbon diffusivity varies with the carbon content, was solved with the integral methods under the third boundary condition. The variation of carbon diffusivity in steel with the carbon content was described with two different functions, linear dependence and exponential dependence. The integral approximation for both cases was improved with the numerical computation to more accurately predict the carbon profiles. The integral solution is more accurate than the formulation based on the assumption of a constant diffusivity or those based on the assumption of a constant diffusivity and/or constant carbon content at part surface. It is also more easily used in practice than the numerical method to describe the carburising process and predict the carbon content at steel surface and carbon profiles in treated layer.
Effects of Powder Synthesis Method on the Sinterability of Hydroxyapatite
Authors: Aw K.L. , Tolouei R. , Singh Ramesh , Tan Chou Yong , Yeo Wei Hong , Kelvin H. , Sopyan Iis , Teng Wan Dung
Published: July 2011

The sinterability of hydroxyapatite (HA) powder synthesized through a novel wet chemical method (HAp) and a wet mechanochemical method (HAwm) was investigated over a temperature range of 1000oC to 1400oC in terms of phase stability, bulk density, hardness and fracture toughness. The results indicated that the sinterability of HAp powder were significantly better than HAwm powder. Moreover, the XRD traces of HAwm sintered samples showed signs of decomposition into TTCP when sintered at 1300oC and above. Densification of ~98% of theoretical density was attained by HAp compacts at 1100oC while the HAwm compacts exhibited only ~96% of theoretical density even at 1350oC with no significant increase of density at 1400oC. The Vickers hardness of HAp showed increasing trend for temperature range of 1000oC to 1100oC with the compacts attaining HV of ~7 GPa at 1100oC. Subsequently, the hardness decreased with increasing sintering temperature though the value does not dropped below ~5 GPa. Similarly, HAwm compacts showed an increasing trend from 1000oC to 1300oC with the largest HV attained was ~4.57 GPa. Further increased in sintering temperature resulted in the decreased of Vicker’s hardness. Moreover, the HAp samples reached a maximum fracture toughness of ~0.9 MPam1/2 at 1050oC while the HAwm attained maximum KIc of only ~0.7 MPam1/2 at 1300oC.
Computer Aided Process Planning for Machining the Gears
Authors: Byotra Deepak , Bhushan Rajesh Kumar
Published: July 2011

Bulk of power transmitting metal gears of machinery is produced by machining processes from cast, forged or hot rolled blanks. It includes a number of versatile machining operations that use a milling cutter, a multi tooth tool to produce a variety of configurations. The aim of the computer aided process planning (CAPP) is to develop a programme for milling cutting processes. This paper reveals the hybrid approach to computer aided process planning for milling and grinding operations on gear blank, so that the plan can be generated taking into account the availability of machines and the material. The developed computer aided process plan has reduced the set up time and machining time by 40.90 and 30.15 % respectively.
Virtual Simulation and Remote Desktop Interface for CNC Milling Operation
Authors: Afzeri  , Sutjipto Agus Geter E. , Muhida R. , Konneh Mohamed , Darmawan
Published: July 2011

Advanced development of computer network through Internet brings the technology to Manufacturing. Increasing the demand for effectively use of the production facility requires the tools for sharing the manufacturing facility by remote operation of the machining process. This paper introduces the methodology of machining technology for direct remote operation of networked milling machine. The tools including virtual simulation using CAD model, remote desktop protocol and Setup Free Attachment for remote operation of milling process are proposed. Accessing and monitoring of machining operation is performed by remote desktop interface and 3D virtual simulations. Capability of remote operation is supported by an auto setup attachment with a reconfigurable pin type setup free technology installed on the table of CNC milling machine to perform unattended machining process. The system is designed using a computer server and connected to a PC based controlled CNC machine for real time monitoring. A client will access the server through internet communication and virtually simulate the machine activity. The result has been presented that combination between real time virtual simulation and remote desktop tool is enabling to operate all machine tool functions and as well as workpiece setup.
Application of Finite Element Method in Optimal Design of Flip-Chip Package
Authors: Lin Yong Cheng , Xia Yu Chi
Published: July 2011

More and more solder joints in circuit boards and electronic products are changing to lead free solder, placing an emphasis on lead free solder joint reliability. Solder joint fatigue failure is a serious reliability concern in area array technologies. In this study, the effects of substrate materials on the solder joint thermal fatigue life were investigated by finite element model. Accelerated temperature cycling loading was imposed to evaluate the reliability of solder joints. The thermal strain/stress in solder joints of flip chip assemblies with different substrates was compared, and the fatigue life of solder joints were evaluated by Darveaux’s crack initiation and growth model. The results show the mechanisms of substrate flexibility on improving solder joint thermal fatigue.
A Quality Steps for a Sustainable Development: Case of Food Processing
Authors: Yamina Fedali , Noureddine Bourmada , Djebabra Mebarek
Published: July 2011

The activities of companies are executed according to the integration of multiple internal and external tensions in different communities and various branches of industry. In this context, innovations seem necessary to remain effective and to adapt itself to the constant evolutions of the markets. Sustainable development can be an opportunity to throw policy of innovation and place the sustainable development in the heart of strategic reflection of the company. Therefore, it constitutes an indispensable asset to strengthen the dialogue and the opening on the word in which we evolve. The integration of the idea of durability in the food processing industry by the implementation of a common system of management of the risks according to the food codex and by means of the method HACCP (Hazard Analysis and Critical Control points) aims at ensuring a better quality of life through the implementation of actions centered on health, by the control of the food chains. Our contribution, which becomes integrated into context, consists in bringing to light the factor health as a pillar into interface with the other themes to know the social, the economy and the environment.
Environmental Diagnostic for a Sustainable Development
Authors: Money Abdelmoumene , Noureddine Bourmada
Published: July 2011

In the context of sustainable development, this paper presents a methodologie for an economic and environmental evaluation within a cementry by applying life cycle analysis (LCA) method. We have to sum up the impacts and make a constat of economical activities which spread up on environment. The constant degradation of environment and many environmental desasters have given to the environment theme an increasing importance. The economic grawth represents a danger from the point of view of ressources (soil-water-energy), of pollution, and over exploitation of natural systems have became a new research theme. It is determinant to know if this methodology can in suffisant manner, concretises and be adapted to pratical application(s) for this, the integration of a demarch , or a tool which undergoing this analysis, in order of obtaining results which can be interpretated. The LCA built a precise diagnosis of development methods of a technology or a product and suggests mecanisms and measures of sustainable development which will move forward the entreprise.
Reconfigurability Approach in Manufacture of Moulds and Dies
Authors: Oke A.O. , Abou-El-Hossein Khaled A. , Theron N.J.
Published: July 2011

Manufacturing of moulds and dies based on the rigid and traditional arrangement of dedicated workstations in a production system can no more stand the test of time. The dynamic and competitive nature of the market is compelling managements in the industry to look for a manufacturing system that (1) will ensure high quality product, (2) will pave way for a quick changeover to a new setup to be able to accommodate the new products, (3) will ensures short lead times in product/process changeover, and (4) that will make its product come out at a relatively low cost. An emerging strategy that might enable industries to cope with the rapidly changing product specifications is based on reconfiguring the manufacturing systems. A manufacturing strategy that is based on reconfiguration of the manufacturing systems may help accommodate emergent product changes in short periods at the lowest possible costs by combining certain levels of flexibility and customised automation. In this paper the principles of reconfigurability is being considered for mould and die making industry.
A Material and Product Audit Method for Determining the Level of Quality
Authors: Darestani S. Avakh , Ismail M.Y. , Ismail N. , Yusuff R.M.
Published: July 2011

This paper introduces a method for evaluating material and product quality. The method is developed based on the normal distribution. For quantitative variable, the method divides the tolerance zones to 3 parts according to normal distribution ±3𝜎 and assigns different scores to tolerance region. For qualitative variables, the method take decision base on the fact that the measurement result can be occurred on two states as accept or reject. Therefore, a Level of Quality (LOQ) will be measured for the product quality based on the measurement of different samples of lot by quantitative and qualitative variables. The method is validated by a numerical example included 2 dimensions.
Bistable Characteristics of Liquid Crystal Devices with Patterned Alignment Films
Authors: Bin Lias Jais , Kimura Munehiro , Akahane Tadashi
Published: July 2011

The photoalignment technology for the alignment of liquid crystal molecules has lately gathered much attention because its advantages over the conventional rubbing of polyimide coating and several different approaches for the realization of photoalignment have been presented. Due to its non-contact nature, a photoalignment eliminates generation of dust and electrostatic charges as well as mechanical damage to the surface. Up to now, the study of the photoalignment effect has been focused mostly on uniform substrates through linearly polarized light. With the aim to achieve such a bistable liquid crystal device by means of unpolarized UV light, we have proposed a single-step laser patterning on a photoalignment layer using a photomask to achieve an equilibrium configuration of LC molecules in contact with a periodically patterned substrate. The patterns were formed by stripes of alternating random planar and homeotropic anchoring in a sub-micron scale on the order of 0.5 micron. We proposed two possible configurations of bistable LC cells that can be obtained by combination of micro-patterned surface formed with alternating random planar alignment with either planar alignment or homeotropic alignment surfaces. In this study, we have investigated the alignment properties and switching behaviours of both proposed models.
Resource Allocation, Batching and Dispatching in a Stochastic Flexible Job Shop
Authors: Al-Turki Umar M. , Arifusalam Shaikh , El-Seliaman Mohammed , Khan Mehmood
Published: July 2011

The problem of resource allocation and scheduling is considered for a flexible job shop composed of several work centers with multiple identical machines. Each machine has its own setup time that depends on the current and the arriving batch types. The optimal number of machines at each center and the optimal batch size for each job type is to be determined for several dispatching rule. The objective of the study is to assist the scheduler in selecting the best dispatching rule with respect to a desired performance measure along with its corresponding batch size and optimum number of machines in each center. Several measures are considered including the average flow time, sum of earliness and tardiness, and the number of tardy jobs. The simulation package ProModel is used to build the model and its optimization tool called SimRunner is used for optimization.
Investigation on Constant and Variable Feed Speeds Effects in Ring Rolling Process Using 3D FEM
Authors: Anjami Nassir , Basti Ali
Published: July 2011

Although cold ring rolling (CRR) process is largely used in the manufacturing of profiled rings like bearing races, research on this purpose has been scant. In this study, based on a validated finite element (FE) model, CRR process is simulated regarding the variable and constant feed speeds of the mandrel roll which lead to constant and variable values of the ring's diameter growth rates respectively using a 3D rigid-plastic finite element method (FEM). Major technological problems involved in the process including plastic deformation behavior, strain distribution and its uniformity, Cockcroft and Latham damage field and final outer diameter of ring are fully investigated. The results of simulations would provide a good basis for process control especially feed speed controlled mills and guiding the design and optimization of both cold and hot ring rolling process.
The Effect of Lithium on the Microstructure and Morphology of Fe-Rich Intermetallic Compounds in 360 Cast Alloy
Authors: Nasiri N. , Emamy M. , Bigdeli M.
Published: July 2011

In this study, the effect of small additions of lithium on the microstructure and morphology of Fe-containing intermetallic compounds in A360 alloy has been investigated. Different Fe contents (1, 1.5 and 2%) were added into A360 alloy, and Li concentrations also varied from 0 to 0.5 wt. %. The image analysis results showed that, the maximum length of β-Al5FeSi plate in Li-modified specimens is changed significantly in comparison with non-modified ones. It is evident that the maximum reduction in the average length of Fe containing platelets occurs in specimens with 2% Fe. Also, the lowest changes in the length of intermetallic phases -as Fe content decreases- occur in the 0.5 wt% Li. At higher Li concentrations, the presence of Al-Li-Si intermetallics in the microstructure can provide undesirable condition. This intermetallic can be so damaging in mechanical properties especially in coarse shapes.
Numerical and Experimental Research on the Flexible Forming of Metal Sheet Using Magnetic-Driving Plasma Arc
Authors: Xu Wen Ji , Song Wen Qing , Wang Xu Yue , Meng Jian Bing , Wang L.J.
Published: July 2011

Flexible forming of metal sheet using plasma arc is a new technique which forms parts by thermal stress without moulds and external force. To improve the surface quality of formed parts, a magnetic-driving plasma arc (MDPA) was applied in monitoring the distribution of heat flux. A mathematical model was developed to study the variations of temperature fields and deformation fields with MDPA and merely with plasma arc, which was validated by the forming experiments. The results indicated that the swing amplitude of MDPA increased linearly when the exciting current Ie < 1.2 A, and the distribution of heat flux with MDPA was more uniform than that merely with plasma arc in the heating zone, which avoided the possible partial melting and ablation of metal sheet. Moreover, the “U-shape” occurred with MDPA, and the material accumulation with MDPA was smaller than that merely with plasma arc on the surface of metal sheet.
Microstructure and Mechanical Properties of Twist Extruded Pure Aluminum Processed by Post-Rolling
Authors: Ranjbar Bahadori S. , Akbari Mousavi Seyed Ali Asghar , Shahab A.R.
Published: July 2011

Interest in processing of bulk ultrafine-grained materials has grown significantly over the last years. Severe plastic deformation processes such as twist extrusion have been the essence of these researches and used to decrease the bulk grain size. The bulk gain size can reduce if twist extrusion process combines with a conventional forming technique. In this study, the effects of reduction by employing the rolling process after the twist extrusion method were considered. The twist extrusion process of the commercially pure aluminum sample was carried out using a twisted die with 60º die angle, and the samples were processed through rolling subsequently. As a result of rolling, average microstructure grain size decreased significantly and the hardness amount increased accordingly
Effects of Bismuth Oxide on the Properties of Calcium Phosphate Bioceramics
Authors: Yeo Wei Hong , Singh Ramesh , Tan Chou Yong , Aw K.L. , Tolouei R. , Kelvin H. , Sopyan Iis , Teng Wan Dung , Hoque E.
Published: July 2011

The aim of this work is to study the phase stability and sinterability of bismuth oxide (Bi2O3) doped HA ranging from 0.05 wt% to 1 wt%. The green samples were sintered in air at temperature ranging from 1000oC to 1400oC. In this experiment, the results from XRD analysis revealed that the stability of HA phase was disrupted when addition of 0.3, 0.5 and 1.0 wt% Bi2O3 were used and when samples sintered above 1100oC, 1000oC and 950oC, respectively. In general, HA containing 0.5 wt% of Bi2O3 and when sintered at 1000oC was found to be beneficial in enhancing densification, Young’s modulus, Vickers hardness and fracture toughness. Throughout the sintering regime, the highest value of relative bulk density of 98.7% was obtained for 0.5 wt% Bi2O3-doped HA when sintered at 1000oC. A maximum Young’s modulus of 119.2 GPa was observed for 0.1 wt% Bi2O3-doped HA when sintered at 1150oC. Additionally, 0.5 wt% Bi2O3-doped HA was able to achieve highest hardness of 6.04 GPa and fracture toughness of 1.21 MPam1/2 at sintering temperature of 1000oC. Furthermore, the Young’s modulus of HA was found to vary linearly with bulk density.
Elucidating the Effects of Helical Passageways in Abrasive Flow Machining
Authors: Wang A Cheng , Chen Kuan Yu , Cheng Ken Chuan , Chiu H.H.
Published: July 2011

Conventional AFM have difficulty achieving uniform roughness of an axial distribution in circular hole polishing due to limited unitary axial motion of abrasive media. Therefore, this work develops mechanism designs for different passageways to obtain multiple flowing paths of an abrasive medium, whose flowing behavior enhances polishing effectiveness by increasing the abrasive surface area and radial shear forces. The motion of the abrasive medium is studied by utilizing the design of the mold cores, which mold shapes include the circular passageway and helical passageway. The optimum design of the different passageways is then verified using CFD-ACE+ numerical software. Analytical results indicate that the optimum design is the mechanism with a passageway of six helices. Furthermore, surface roughness measurements demonstrate the increase in uniformity and the roughness improvement rate (RIR). Experimental results for surface roughness indicate that roughness deviation of six helices passageway of approximately 0.1001 m Ra is significantly better than those on a circular passageway of around 0.1760 m Ra. Additionally, the six helices passageway is also superior to circular passageway in reducing roughness improvement rate (RIR) by roughly 85% compared with RIR 75% for the circular passageway.