bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of an Intelligent Auto-Turning Controller for Precision Machining
Authors: Wang Shih Ming , Yu Han Jen , Ouh Si Chi
Published: July 2011

In this study, simulation based on a theoretical model was made to investigate the influence of inertial effect and friction force to CNC machine’s accuracy and to explore the functions of related control parameters. By using empirical method, an auto-tuning system that can on-line tune the CNC control parameters based on the detected weight of workpiece was developed. In addition, an on-line weight identifying system was also developed. After integrating the two systems, an intelligent parameter-tuning system which can be directly implanted into CNC controller was developed. Experimental results have shown that the system can effectively improve the accuracy of a machine tool through on-line control parameter tuning.
Frequency Pulse Period and Duty Factor Effects on Electrochemical Micromachining (EMM)
Authors: Malapati M. , Sarkar A. , Bhattacharyya B.
Published: July 2011

Electrochemical micromachining (EMM) appears to be promising as a future micro machining technique since in many areas of applications; it offers several advantages including electronic, biomedical and MEMS/NEMS applications. Present paper will highlight the influence of various EMM process parameters i.e. machining voltage, electrolyte concentration, frequency pulse period and duty factor on machining performance criteria e.g. material removal rate and machining accuracy to meet the micromachining requirements. Some of the experiments had been carried out on copper to investigate the most effective zone, which gives high machining accuracy with appreciable amount of material removal rate. Attempt has also been made to study and compare the surface condition of the machined micro-holes through SEM micrographs. From the analysis of test results and SEM micrographs it can be observed that optimum value of frequency pulse period is about 200 μsec and duty factor is about 20% which will produce accurate micro-holes with highest possible amount of material removal.
HVOF Coating of Diamalloy 2002 and 4010 on Carbon Steel Sheets: Microstructure Examination
Authors: Al-Shehri Y.A. , Hashmi M.S.J. , Yilbas Bekir Sami
Published: July 2011

HVOF two layer coatings consisting of Diamalloy 2002 (top layer) and 4010 (bottom layer) onto carbon steel sheets are carried. The microstructure and chemical composition of the resulting coatings are examined using the Scanning Electron Microcopy (SEM) and Energy Dispersive Spectroscopy (EDS). The indentation tests are carried out to evaluate the microhardness and surface elastic modules of the resulting coatings. It is found that the coating produced for Diamalloy 2002 results in higher hardness and elastic modules than that corresponding to Diamalloy 4010.
Design and Manufacture of Vacuum Forming Moulds
Authors: Naher Sumsun , Derham Paul
Published: July 2011

This paper presents an investigation of the positive vacuum forming process. Previous research has indicated requirements of a draft angle of at least two to five degree and a depth to width ratio of not greater than 1:1. For specific formed geometry that required smaller draft angles and greater draw depths these limitations may make the positive vacuum forming process not applicable. The overall aim of this work was to allow the process to become more versatile. This work focused on three prototype moulds which were designed, manufactured, tested and analysed with a view to over come the present process limitations. Moulds were made of wood with a size of 68 x 68 x 75mm. Air holes of 1 and 10mm diameter were drilled in to these moulds in different positions. Polypropylene terephthalate glycol (PETG) materials was used to make the final product via the vacuum process. To release the product from the mould a constant 8bar pressure was applied. Proper time to make the final products and the quality of the final product were investigated. It was found that moulds with air holes opening in all surfaces resulted in shorter cycle times, lower air pressure and better quality of formed parts. It was also found in this work that a zero draft angle and as well as 1:1.1 draw depth was possible to achieve in the vacuum forming process.
Oxidation and Corrosion Resistance of Nanocrystalline Copper Deposit Produced by Pulse Electrodeposition
Authors: Saremi M. , Abouie M.
Published: July 2011

Pulse electrodeposition was used to produce nanocrystalline (nc) copper from copper sulfate electrolyte with saccharin as additive. The grain size of nanocrystalline coatings was determined using x-ray diffraction and atomic force microscopy (AFM) which was about 30 nm. Microcrystalline copper deposits were also produced by direct current electrodeposition processes and compared with pulse plated ones. Corrosion behavior of the coatings was investigated using polarization and Impedance measurements in different solutions. The oxidation test was carried out at 650°C in an electrical furnace. It was demonstrated that the nanocrystalline film was markedly superior to regularly grained films made by direct current (DC) plating; nanocrystalline deposits show higher corrosion resistance and much higher oxidation resistance.
Modeling, Analysis and Fatigue Life Prediction of Lower Suspension Arm
Authors: Rahman M.M. , Noor M.M. , Kadirgama K. , Maleque M.A. , Bakar Rosli A.
Published: July 2011

This paper was presented the finite element modeling, analysis and fatigue life prediction of lower suspension arm using the strain-life approach. Aluminum alloys are selected as a suspension arm materials. The structural model of the suspension arm was utilizing the Solid works. The finite element model and analysis were performed utilizing the finite element analysis code. TET10 mesh and maximum principal stress were considered in the linear static stress analysis and the critical location was considered at node (6017). From the fatigue analysis, Smith-Watson- Topper mean stress correction was conservative method when subjected to SAETRN loading, while Coffin-Manson model is applicable when subjected to SAESUS and SAEBRKT loading. From the material optimization, 7075-T6 aluminum alloy is suitable material of the suspension arm.
Feasibility Study of CAD and CAM Technology in Garments Industries of Bangladesh
Authors: Baral Lal Mohan
Published: July 2011

The Computer Aided Design and Computer Aided Manufacturing are the modern innovative technology in garments manufacturing like all other manufacturing sectors. Garments CAD is specially used for pattern designing and marker making. On the other hand CAM is used for fabric cutting and other manufacturing sections. Before implementing those new technologies, manual system was widely used in garments sector. In recent time some large garments factories of Bangladesh are starting to adopt CAD and CAM technology. Beside that a huge number of medium and small size factories are using manual system yet. This paper presents a feasibility study of CAD and CAM technology in above mentioned different size factories in Bangladesh. The Study is carried out in respect of production procedure, required man power, production/hr, product quality, production efficiency, and production cost. The practical investigation and data shows the scenario that all types of garments industries are not capable to use CAD & CAM and also not even profitable for them.
Numerical Simulation of Electromagnetic Stirring Effect on Flow Pattern of Metal Melt
Authors: Namaki H. , Seyedein S. Hossein , Afshar Moghadam M.R. , Ghasemzadeh R.
Published: July 2011

In this study, a mathematical model was developed to simulate 2-D axisymmetric melt flow under magnetic field in a cylindrical container. The modeling of this process required the simultaneous solution of the turbulent Navier-Stokes equations together with Maxwell equations. The flow pattern in liquid bath was obtained using a two-equation κ-є turbulent flow model, which was further used to obtain the solute distribution. The governing differential equations were solved numerically using finite volume based finite difference method. The computed results, were found to be in good agreement with the measurements reported in the literature. The effect of stirring parameters on temperature homogeneity of the melt have been discussed and presented.
Comparative Study of the Strain Signal and the Edited Strain Signal
Authors: Abdullah Shahrum , Ismail Napsiah Binti , Nuawi Mohd Zaki , Nizwan Che Ku Eddy , Abdullah Mohd Fazuri
Published: July 2011

This paper presents the comparative study between the strain signal and its edited signal. In this study, a fatigue strain loading was measured on an automobile coil spring, and the purpose to analyse this component is because it been identified as one of the critical component in an automobile. The strain signal editing process was performed by removing low amplitude cycles contained in the original signal using the short-time Fourier transform (STFT) method. This low amplitude cycles were eliminated based on the cut-off level of the signal energy distribution in the time representation. The original and edited strain signals were then analysed for predicting the fatigue damage of the coil spring. A comparison study of the fatigue damage and the most damaged zone obtained from the strain signal and the edited strain signal was also carried out. It was found that, the prediction of the fatigue damage and the most damages zone for both signals was same. Hence, the shortened signal can be used in the laboratory fatigue testing for the purposes of accelerated fatigue testing.
The Tredgold Method in Reverse Engineering to Check the Assembly of a Conical Spur Gear Using CAD
Authors: Belarifi Farid , Bayraktar E.
Published: July 2011

Defining and generating a working drawing of a conical spur gear to replace an original piece requires geometrical and dimensional constraints, especially when the cutting module is determined by reverse engineering. We propose an approach using Computer aided design (CAD) to establish the drawing definitions and to verify the assembly of the conical spur gear. We have developed the model drawing according to the standard International Standard Organisation (ISO), in which we introduce a new non-existent coast into the current dimensioning and check the assembly using the Tredgold method, which transforms a conical spur gear into a model cylindrical spur gear, to which the equations for parallel cylindrical gearing can be applied. This method determines a good estimate if the couple of gear verifies the specified geometrical conditions of assemblies. We present the developed algorithms, as well as the results of applications of various programs.
Geometric Modeling and Multi-Axis NC Machining for Custom-Made Femoral Stem
Authors: Lee Jeng Nan , Lee Rong Shean , Chang Kuan Yu
Published: July 2011

In this paper, a design system combining clinical experience and engineering knowledge was developed for the manufacture of custom-made femoral stem. The medical image of the hip obtained according to the patient X-rays. The geometric parameters for femoral stem were established based on the canal flare index. The necessary constrains based on surgical experience were integrated into the CAD system. The rapid prototyped model was built as the reference for review. Through the application of CAM software, the interference-free toolpath and the cutter location for multi-axis NC machining are generated. In order to establish the interface between the design and the manufacture of femoral stem, the postprocessor for multi-axis machine tool is developed. The cutting simulations with solid model are performed to verify the generated toolpath. It is also verified through the trial-cut with model material on a five-axis machine tool.
Application of Multi-Objective Genetic Algorithm (MOGA) for Design Optimization of Valve Timing at Various Engine Speeds
Authors: Mohiuddin A.K.M. , Rahman Md. Ataur , Shin Yap Haw
Published: July 2011

This paper aims to demonstrate the effectiveness of Multi-Objective Genetic Algorithm Optimization and its practical application on the automobile engine valve timing where the variation of performance parameters required for finest tuning to obtain the optimal engine performances. The primary concern is to acquire the clear picture of the implementation of Multi-Objective Genetic Algorithm and the essential of variable valve timing effects on the engine performances in various engine speeds. Majority of the research works in this project were in CAE software environment and method to implement optimization to 1D engine simulation. The paper conducts robust design optimization of CAMPRO 1.6L (S4PH) engine valve timing at various engine speeds using multiobjective genetic algorithm (MOGA) for the future variable valve timing (VVT) system research and development. This paper involves engine modelling in 1D software simulation environment, GT-Power. The GT-Power model is run simultaneously with mode Frontier to perform multiobjective optimization.
Mechanical Assessment of Dissimilar Diffusion Joints of CP-Ti to Stainless Steel
Authors: Soltan Mohammadi M.R. , Kashani Bozorg S.F.
Published: July 2011

Dissimilar joints between CP-Ti and 304stainless steel were produced using diffusion welding technique in the temperature range of 800-950 °C, under a uniaxial pressure of 7 MPa in argon atmosphere. Mechanical assessment of the joints was carried out employing shear testing. The shear strength was found to be a function of joint surface area and volume fraction of brittle intermetallic phases such as σ, FeTi, and Fe2Ti which were detected by scanning electron microscopy and energy dispersive spectroscopy. Increasing the temperature and time of the diffusion welding process increased joint surface area and accelerated elemental diffusion across the joint interface which enhanced the shear strength value. However, as the volume fraction of the brittle intermetallic phases and Kirkendall voids increased at higher temperature and time, the bond shear strength decreased. Optimum shear strength was found to be 168 MPa which related to the joint produced at temperature and time of 900°C and 30 min, respectively.
Erosive Wear of Glass Fiber and B2O3 Reinforced Epoxy Composites
Authors: Bagci Mehmet , Imrek Huseyin
Published: July 2011

In this experimental study, erosive wear behavior of epoxy-resin dipped composite materials reinforced with glass fiber and B2O3 (borax) under different impact velocities, erodent sizes, and erodent striking angles along the fiber direction were investigated. The tests which involved slightly rounded and irregular silicon oxide (SiO2) particles having two different sizes of approximately 250 and 500 , were conducted at two different impact velocities of approximately 20 m/s and 40 m/s, two different fiber directions (0o and 45o) and six different impingement angles of 15o, 30o, 45o, 60o, 75o and 90o. In the test results, erosion rates were obtained as functions of impact velocities, striking angles, fiber direction and particle sizes. In addition, the microscopic views showing worn out surfaces of the glass fiber reinforced epoxy composites were scrutinized.
HVOF Coating of Inconel 625 Blended with WC: Fracture Toughness Measurement
Authors: Al-Taha Z.Y. , Hashmi M.S.J. , Yilbas Bekir Sami
Published: July 2011

HVOF coating finds application in industry to protect the surface from the harsh environments such as high temperature, corrosion, and abrasion. In the present study, HVOF coating consisting of Inconel 625 powders blended with WC particles and sprayed on to 304 steel is carried out. The mechanical properties, such as elastic modules and fracture toughness, of the resulting coating are determined using the indentation tests. The influence of the mass fraction of WC on the fracture toughness and elastic modulus of the coating are also examined. It is found that addition of WC particles in Inconel 625 powder enhances the fracture toughness of the resulting surface. This is attributed to increased elastic modules and hardness.
Effects of Operational Parameters and Heat Treatments on the Aluminum-Steel Explosively Welded Composite Plates
Authors: Akbari Mousavi Seyed Ali Asghar , Dashti A.A. , Halvaee A.
Published: July 2011

Explosive welding process is one of the effective methods in order to weld two dissimilar materials. Aluminum-steel composite was undergone heat treatments at temperatures between 2000C-5000C. In this study, the effects of explosive ratio and stand-off distance on the shape of the interface were studied. Moreover, the effects of various heat treatments on the interface strength are studied. The study shows that the type of the explosive, the magnitude of explosive ratio and standoff distance produces various interfaces with or without intermetallic compounds. The results show that effects of heat treatment on the aluminum-steel bond strength is depended upon the type and microstructure of straight, wavy and continuous melt produced at the interface. Moreover, the study shows that heat treatment gives rise to produce the brittle intermetallic compound of FeAl3 which lowers the weld strength. Having produced the smooth interface would reduce the heat treatment effects on lowering the weld strength.
Debinding Process of a Starch-Based Binder in Metal Injection Moulding
Authors: Abolhasani Hooman , Muhamad Norhamidi
Published: July 2011

In this study, a combination of starch, glycerol, linear low density polyethylene (LLDPE) and other additives was utilized as the binder composition. The effect of different parameters such as thickness, temperature and time on debinding process of green parts was investigated. Discs of different thicknesses consisting of 2, 2.7 and 3 mm were submitted to the water bath in order to obtain curves of time versus remaining mass of binder. Moreover, the injected tensile bar test specimens was utilized to observe specially the effect of temperature on rate of binder extraction from the green parts. The experiments were conducted at three sets of temperatures including 70, 80 and 90°C. The rate of binder removing considerably increased by decreasing the thickness of the discs. On the other hand, proportion of removed binder in injected tensile bar specimens increased in higher temperatures. The debinding process was successfully performed on injected tensile bars and the components did not suffer from any cracks and swellings. Moreover, the results show that more than 80% of the binder system can be extracted in 6 hours, which is in the acceptable time range. The investigation confirms that from the viewpoint of debinding, starch has a good potential as a binder component in MIM process.
Effect of Mould Runner and Coating on Graphite Nodule Characteristics and Hardness of Thin Wall Ductile Iron
Authors: Jafari Hassan , Idris Mohd Hasbullah , Ourdjini Ali , Bakhsheshi Rad Hamid Reza , Khayat Ardestani Seyed Sadegh , Ahmadshoar Vali
Published: July 2011

Due to its attractive characteristics, thin wall ductile iron (TWDI), has been increasingly considered as a preference for reducing material consumption in order to save energy and contribute less environment pollutions as well as decreasing costs. In this research, the effect of two mould runner gating systems and mould coating on graphite nodule characteristics and hardness values of TWDI casting was studied. Strip samples with various thicknesses of 2.3, 3.3, 4.5, 5.4, 6.5, 7.5 and 8.5 mm were casted into CO2 Silicate moulds designed by two gating systems namely stepped and tapered runners. Half of the moulds were coated by graphite-based zircon material to investigate the effect of mould coating on the graphite nodule qualities and quantities. The molten metal prepared contained carbon equivalent (CE) of 4.29% and was poured at the temperatures of 1450°C. Optical microscope (OM) and Clemex Image Analyzer (CIA) were used to evaluate graphite nodule count, roundness and diameter of the nodules of the TWDI cast samples. Brinell hardness test was performed on all samples. The results show that roundness and graphite nodule counts in the microstructure of the samples produced in stepped runner gating system and uncoated mould decrease whereas graphite nodules diameter shows opposite behaviour. Furthermore, molten metal experienced a superior fluidity in coated moulds. Moreover, the TWDI samples achieved a significant improvement in the value of hardness.
Grain Growth Evaluation in HAZ of Welded Pipes Using Dimensionless Parameters and Optimum Pre-Exponential Constant for Seam Weld and Seamless Pipes
Authors: Aalami-Aleagha M.E. , Rasaee S.
Published: July 2011

Kinetic strength in grain growth is evaluated for HAZ of welded pipes. Austenite grain growth is dependant on the thermal cycle and the material properties. In this research the influence of thermal cycle is evaluated using characteristic time constant and characteristic temperature. These dimensionless parameters were calculated for the points lying in HAZ using temperature/time profile derived from Rosenthal equation for the heat transfer. The grain growth is assumed diffusion controlled and Arrhenius temperature dependency is applied for the rate of growth in grains. In an experimental investigation the welded pipes were sectioned longitudinally and the grain size in parent metal and HAZ were measured based on ASTM E 112 by using Planimetric Counting. The obtained data was compared with the result of the model and the appropriate kinetic constant which is calibrated the equation of grain growth is introduced for the seam weld and seamless pipes.
Mathematical Modeling of Turbulent Fluid Flow and Mass Transfer in a Steel Continuous Casting Tundish
Authors: Sharifi N. , Seyedein S. Hossein , Aboutalebi Mohammad Reza
Published: July 2011

In continuous casting process, tundish operates as a refining finisher. Different flow modifiers can be used in order to optimize cleanliness of liquid steel. To study the effect of various flow modifiers such as dam, weir, inlet shroud and etc., a three dimensional mathematical model was developed to simulate turbulent flow inside the tundish. The computed flow field was further used to model the transient mass transfer in the melt flowing in the tundish. The residence time distribution (RTD) of particles was determined by mass transfer model. The performance of the model was evaluated by experimental data obtained by a physical model. The verified model was used to evaluate the effect of location and size of different flow modifiers on flow pattern and particles residence time and consequently on tundish performance.
Analysis of Temperature Distribution on Warm Forming of Aluminum-Magnesium Alloy
Authors: Ozturk Fahrettin , Arslan Mehmet A.
Published: July 2011

In this study, a temperature distribution of 5083-O aluminum-magnesium (Al-Mg) alloy is analyzed at various die and blank initial temperature conditions using finite element analysis approach. Temperature distribution results of the blank reveal that the dies must be heated to predetermined temperatures for successful warm forming, even the blank is kept at room temperature.
Effects of Cooling Condition on Hot Tearing during Investment Casting
Authors: Norouzi Saeid , Farhangi Hassan
Published: July 2011

In the present study, the effect of cooling condition on hot tearing tendency and hot tearing fracture surface morphology were investigated. Results show that, the hot tear fracture surface characteristics are nearly similar under different cooling conditions. The hot tear surface exhibits two main features; the brittle region and the ductile region. The results also indicate that cooling condition has multifaceted effects on hot tearing phenomenon. Increasing cooling rate increases the thermal gradient, which raises the hot tearing tendency; concomitantly it decreases the grain size and dendrite arm spacing which increases the strength of the material. The occurrence of hot tearing phenomenon under different cooling conditions is discussed and evaluated based on the competition between these opposing factors during the solidification process.
A Study on Cooling Characteristics of AC4C and AC7A Casting Material for Manufacturing Tire Mold
Authors: Yoon Hee Sung , Yang Ho Dong , Oh Yool Kwon
Published: July 2011

This study investigated on the cooling characteristics of AC4C aluminum alloy and AC7A aluminum alloy used as a casting material for manufacturing automobile tire mold by experiment. The metal mold device by gravity casting method was manufactured. AC4C casting material and AC7A casting material were heated in smelting furnace at about 650°C and 670°C, and then they injected into the metal mold device when the melting process was completely finished, respectively. When the melted casting material was completely injected into the metal mold device, the temperature inside the casting was measured by 9 measurement points. Also, when the temperature inside the casting was measured approximately 500°C during the cooling process, the casting is separated to metal mold device and carried out cooling at normal temperature. The separating time from metal mold device of AC4C casting material and AC7A casting material have been taken 25 minutes and 15 minutes, respectively. The final cooling time of AC4C casting material and AC7A casting material have been taken 400 minutes and 380 minutes, respectively. Accordingly, AC7A casting material is able to improve on productivity than AC4C casting material because production time was decreasing.
Studies on the Effects of the Potential Sweep Rates and pH on the Corrosion Rate of Polyaniline Coated Steel
Authors: Mahmoudian M.R. , Alias Yatimah , Basirun Wan Jeffrey
Published: July 2011

Polyaniline (PAni) film was successfully electrodeposited on the surface of steel substrates in oxalic acid electrolyte by cyclic voltammetry at different potential sweep rates (dE/dt) (10, 20 and 30 mVs-1) and different pH values (1.55, 2.55 and 3.55). The coated steel with PAni was characterized by Field Emission Scanning Electron Microscopy (FESEM) and Fourier Transform Infrared Spectroscopy (FTIR) techniques. The corrosion resistance of the electrodeposited layers was evaluated by potentiodynamic polarization in 0.1 M NaCl aqueous solution. The results showed that with increasing pH and sweep rate the amount of corrosion rate decreased and increased respectively. Moreover, the correlation between variation of anodic charge (Qa) with pH and sweep rate has been evaluated. The variation of anodic charge confirmed that the growing rate of polymer decreased with increasing sweep rate and pH. The result of potentiodynamic polarization showed that the coated steel with synthesized PAni in pH 3.5 and sweep rate 0.01Vs-1 had better protective properties against corrosion.
A FEM Based Numerical-Experimental Study for Determining Strength Properties by Micro Indentation of a Metal Matrix Composite
Authors: Ayari F. , Bayraktar E. , Chevalier J.P.
Published: July 2011

The recently developed indentation techniques are awfully advantageous as they are performing in determination of hardness and local elasticity modulus for particular conditions; also they are being able to deal with small sample sizes. This technique is well used to characterize mechanical properties as hardness, elasticity and creep for coating thin layers. Experimental comparison of common nano and micro scales for hardness evaluation has been performed on metal samples and discussed in details in the literature review [1-3]. In fact, it was well detailed that instrumented indentation was found advantageous in both repeatability and a number of measured parameters over classical hardness methods for different materials. As far as thin materials are being very used in various industrial fields, the mechanical characterization moves to micro level scale, with micro-indentation tests of thin films and from Newton -to- micro Newton for loading conditions. A big step forward has been reached for load-depth monitoring during loading and unloading in indentation cycle. Nowadays, hardness and Young’s modulus can be easily defined using Oliver-Pharr [4-5] equations based on a micro scratch test of a very thin film. In this paper an experimental study is conducted and has been validated with a numerical FE model based on a micro indentation test of a metal matrix composite material 110A, used in aeronautic applications.
Evaluation of Compressive Strength of Eggshell Hydroxyapatite
Authors: Ibrahim W.M.A. , Mohamad Kasim A.S.
Published: July 2011

This paper presents an in-vitro evaluation of compressive strength of a locally produced hydroxyapatite from eggshell. Hydroxyapatite (HA) is a mineral that naturally occur in form of calcium apatite with the formula Ca5 (PO4)3(OH) but it is usually written as Ca10(PO4)6(OH). Hydroxyapatite (HA) is an example of bioactive ceramics that most commonly used in the bone implantation, as coating on prostheses or as bone filling material. Eggshell waste is available in huge quantity from food processing, egg breaking and hatching industries. This material goes as waste products and leads to pollution since it is microbial action in the environment and it is simply burned as organic waste that releasing CO2. By utilizing this organic waste that has high content of calcium carbonate, the cost of high quality of calcium source for preparation of hydroxyapatite can be reduced. At the same time, recycling of eggshell can be done. Many methods have been introduced to convert the calcium carbonate of eggshell to hydroxyapatite. Hydrothermal method technique has been selected to convert the calcium carbonate obtained from the eggshell since the procedure to transform it is simple and straight forward. An addition, the material that been used is not so expensive as compared to other method. Mechanical properties such as compression strength will be done to compare the synthetic hydroxyapatite in the market and hydroxyapatite from the hen’s eggshell.
Recovery of Zinc from the Final Slag of Steel's Galvanizing Process
Authors: Dakhili Nafiseh , Razavizadeh Hekmat , Salehi M.T. , Seyedein S. Hossein
Published: July 2011

With the rising cost of zinc reaching historic levels, more emphasis is being placed on technologies to increase the efficient utilization of zinc. One area targeted for increased efficiency is in-house recycling of metallic zinc industrial wastes. The largest consumer of zinc is the hot-dip galvanizing of steel. Large amount of zinc slag containing more than 50% zinc, are accumulated during galvanization processes at the surface of molten zinc bath and is usually skimmed manually. At First, The pyrometallurgical recovery of zinc from slag samples was carried out, and parameters affecting recovery processes such as time, temperature, and flux percentage were studied. The results obtained revealed that zinc metal is successfully recovered from these secondary resources. The recovery efficiency is 70% for zinc waste materials having a particle size diameter of + 1.25 mm. An optimum percentage of 25% weight of ammonium chloride fluxing agent was obtained. The optimum temperature for the recovery process was 700°C.
The Effects of Material Thickness and Deformation Speed on Springback Behavior of DP600 Steel
Authors: Toros Serkan , Kilic Suleyman , Ozturk Fahrettin
Published: July 2011

In the present study, the effects of deformation speeds, sheet thickness, and widths on the springback were investigated experimentally and numerically using a 60o V-shaped bending for DP600 steel. Results reveal that the springback was significantly decreased with increasing thicknesses and deformation speed including 125 mm/min in the range of 5-500 mm/min. The effects of widths on springback were found to be inconsiderable.
Influence of Filler Types on Mechanical Properties and Cure Characteristics of Natural Rubber Composites
Authors: Wongsorat Wittawat , Suppakarn Nitinat , Jarukumjorn Kasama
Published: July 2011

Natural rubber (NR) was reinforced with three types of filler: carbon black, calcium carbonate, and sisal fiber. NR composites were prepared on a two-roll mill. Filler content was 20 phr. Mechanical properties and cure characteristics of NR composites were studied. All NR composites had higher maximum torque than NR. NR filled with carbon black showed the highest maximum torque. However, scorch time and cure time of the NR composites were not much affected by filler types. In addition, influence of fiber treatment (alkalization) on mechanical properties and cure characteristics of sisal fiber-NR composites was investigated. Alkali treated sisal fiber-NR composite exhibited higher tensile properties and hardness than untreated sisal fiber- NR composite due to improved adhesion between the fiber and NR matrix. Moreover, alkali treated sisal fiber-NR composite had superior specific modulus and strength than NR composites filled with carbon black and calcium carbonate.
Specific Heat Capacity Measurement of Al / SiCp Composites by Differential Scanning Calorimeter
Authors: Karthikeyan B. , Ramanathan S. , Ramakrishnan V.
Published: July 2011

Various materials are used to achieve a good “Thermal Control System” (TCS) of spacecraft. The performance of the TCS totally depends upon the thermal behaviour of the materials used in the elements of TCS. The measurements of the thermal properties of materials are fundamental for better understanding of the thermal design. Differential Scanning Calorimetry (DSC) is the most widely used thermal technique for obtaining a wealth of information about a material, especially for the specific heat measurement of a material. Stir casting technique was used to fabricate the 7075 aluminum alloy and 7075 Al / SiCp composites. The heat flow response is recorded as a function of actual sample temperature range from -1000 C to 4000 C. Specific heat characteristics of 7075 Al reinforced with different volume fraction of silicon carbide composites fabricated by stir casting method was analyzed.
Lateral Extrusion of Gear-Like Components with Radial Tooth Profile: Metal Flow Simulation and Analysis
Authors: Haghighat H. , Almasi D.
Published: July 2011

The process of lateral extrusion of gear-like components with radial tooth profile has been studied in this paper. The material flow in extrusion die cavity has been simulated using the SuperForge of FVM simulation package. The results of simulation have shown that the material fills the die cavity in two stages: Parallel movement to the end of toothed die cavity and fills the rest of shaped die cavity. Each stage of deformation has been analyzed by using slab method of analysis and the extrusion load values for each punch stroke have been estimated. Finally, comparisons between present theoretical results and experiments of other researchers’ work have been carried out to illustrate the validity of this proposed model.
The Effects of High Energy Radiation on the Tensile Properties of Rubber Toughened Nanocomposites
Authors: Jamal N.A. , Anuar Hazleen , Razak Shamsul Bahri A.
Published: July 2011

Composites based on high density polyethylene (HDPE), ethylene propylene diene monomer (EPDM) and Organically Modified Montmorillonite (OMMT) clays were made by melt compounding followed by compression molding. Mechanical properties, X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) were used to characterize the nanocomposites. The addition of clay, compatibilizer agent, Maleic Anhydride Polyethylene (MAPE) and irradiation technique, High Energy Electron Beam (EB) considerably improved the properties of nanocomposites. Tensile Strength and Modulus (MPa) were found to increase significantly with increasing clay content and decreasing as the clay content exceeds 4 vol%. The largest improvement in nanocomposite tensile properties occurred at clay loading of 4 vol% (2-8 vol%) with irradiation technique. The d spacings of the clay in nanocomposites were monitored using XRD and the extent of delamination was examined by TEM. TEM photomicrographs illustrated the intercalated and exfoliated structures of the nanocomposites with OMMT, MAPE and irradiation process.
Cold Deposition of Zinc Sulfide Optical Waveguides Using Thermoelectric Device
Authors: Salleh Saafie , Rutt Harvey N. , Dalimin M.N. , Salleh Muhamad Mat
Published: July 2011

Zinc sulfide (ZnS) thin films as the waveguide medium have been deposited onto oxidized silicon wafer substrates at cold temperature (Tcold = –50oC) and ambient temperature (Tambient = 25oC) by thermal evaporation technique. The surface morphology of ZnS films were pictured with an atomic force microscopy (AFM) and the surface roughness were calculated from the AFM images. The propagation losses of the samples were measured using a scanning detection technique attached to a prism coupler. The AFM results revealed that the surface of cold deposited ZnS film is rougher than the surface of ambient deposited ZnS film. The propagation losses of the cold deposited ZnS waveguide are consistently lower than the ambient deposited ZnS waveguide at all measured wavelengths.
Performance Evaluation of PCBN in End Milling of AISI D2 Hardened Steel under Room and Preheated Machining Conditions
Authors: Lajis Mohd Amri , Nurul Amin A.K.M. , Karim A.N. Mustafizul , Ginta Turnad L.
Published: July 2011

In this paper, the tool life and tool wear performance of PCBN tool in end milling of AISI D2 hardened steel under room and preheated machining conditions is presented. The tool life and tool wear patterns were examined through tool maker microscope and scanning electron microscope. The results show that the dominant modes of tool wear observed were flank wear, chipping, and notch wear. The main wear mechanisms were abrasion, adhesion, and diffusion promoted by high stress and cutting temperature. It was also observed that longer tool life and higher volume metal removed could be achieved when employing higher preheating temperature.
Prediction of Recycle Method Using Relevance Vector Machine
Authors: Noor M.M. , Kadirgama K. , Rahman M.M. , Maleque M.A.
Published: July 2011

Life cycle engineering is the engineering and design of products and processes to minimize the cost and environmental impact for the life cycle phases of a product. Relevance Vector Machine method (RVM) is used to determine recycling strategy (reuse, service, remanufacture, recycle with disassembly, recycle without disassembly and disposal). Seven parameters (wear – out life, technology cycle, level of integration, number of parts, reason for redesign and design cycle) were considered as the input for the RVM model. Three electronic equipments were selected to be examined such as vacuum cleaner, washing machine, television. All the results verify previous literature study. The prediction model predicts the end of life (EOL) strategies quite closely with real industry practices.
FE Simulation and Experimental Study of Tube Hydroforming Process for AA1050 Alloy at Various Temperatures
Authors: Naeini Hassan Moslemi , Liaghat Golam Hosein , Hashemi Ghiri S.J. , Seyedkashi S.M.H.
Published: July 2011

Considering the necessity of using light weight, high strength and corrosion resistant materials, automotive and aerospace industries need to use advanced production technologies. Hydroforming has been regarded as one of the new technologies in forming of aluminium and magnesium alloys. These alloys have very low formability at room temperature which will be improved at elevated temperatures. In this paper, AA1050 aluminium alloy tube is numerically and experimentally investigated at different temperatures. Thickness distribution in forming zone is studied under different thermal conditions. Numerical results have been verified by experiments and there is a good agreement.
Performance of Nitrogen Gas as a Coolant in Machining of Titanium
Authors: Hamedon Z. , Mon Thet Thet , Sharif S. , Venkatesh V.C. , Masri A.R.M. , Sue-Rynley E.
Published: July 2011

Machining of titanium and its alloys is still the subject of research and researchers’ interest despite some improvement in its machinability from several machining methods. This research presents performance of nitrogen gas in machining titanium. Machining of titanium is carried out on conventional turning center with triangular insert and holder according to ISO designation. Compressed nitrogen gas contained a cylindrical tank is supplied to the cutting zone via speciallydesigned valve that controls pressure and volume of nitrogen. The gas outlet pipe of diameter 2 mm is directed to just-above the tool rake face. During machining, the gas is supplied with high pressure so that the cutting zone receives an effective cooling as well as the chip will easily break. The effectiveness of this new cooling strategy is demonstrated by tool condition after machining, and also by comparing with performance of conventional coolant. The result is found to be excellent in terms of relative amount of tool wear. The cutting insert has surprisingly been almost intact when using nitrogen gas as coolant whereas tool wear at failure state has occurred with conventional coolant for the same machining parameters.
Study of Surface Roughness of Pieces of Magnesium UNS M11311 Obtained by Dry Turning Using ANOVA
Authors: Rubio E.M. , Sáenz de Pipaón J.M. , Villeta M. , Sebastián M.A.
Published: July 2011

The work presents a study of surface roughness of pieces of magnesium UNS M11311 obtained by dry turning. The study is focused in repair operations of this type of materials when they are used as inserts of metalic hybrid components. Therefore, the main limitations of this research are the values of the cutting conditions used; especially low in comparison with the usually values of these parameters used in the production of the magnesium. The followed methodology consists of a series of tests of dry horizontally turning carried out with tools of different coatings and under different cutting conditions. The design of experiments has been made by means of fractional factorial orthogonal designs and the analysis of the results by the ANOVA method. The principal result is one ranking for the combinations of cutting conditions and tool coatings based on the surface roughness expected given by the mathematical model. As first conclusion, it is possible to affirm that, the best surface finishes are obtained for low feeds. Cutting tools used in the machining of other types of materials (steel, stainless steel) can be used obtaining a quality of the surface finish similar to that obtained with tools for specific use of non-ferrous metals.
Optimization of Precision Grinding Parameters of Silicon for Surface Roughness Based on Taguchi Method
Authors: Abdur-Rasheed Alao , Konneh Mohamed
Published: July 2011

Silicon being a typical hard-brittle material is difficult to machine to a good surface finish. Although ductile-mode machining (DMM) is often employed to machine this advanced material but this technique requires the use of expensive ultra-precision machine tools therefore limiting its applicability. However, by proper selection of grinding parameters, precision grinding which can be performed on conventional machine tools can be used to generate massive ductile surfaces thereby reducing the polishing time and improving the surface quality. Precision grinding should be planned with reliability in advance and the process has to be performed with high rates of reproducibility. Therefore, this study investigated the effect and optimization of grinding parameters using Taguchi optimization technique during precision grinding of silicon. Experimental studies were conducted under varying depths of cut, feed rates and spindle speeds. An orthogonal array (OA), signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) were employed to find the minimum surface roughness value and to analyze the effect of the grinding parameters on the surface roughness. Confirmation tests were carried out in order to illustrate the effectiveness of the Taguchi method. The results show that feed rate mostly affected the surface roughness. The predicted roughness (Ra) of 34 nm was in agreement with the confirmation tests. Massive ductilestreaked surface was also found corresponding to the minimal surface finish determined from the optimal levels.
Study on Carburizing and Quenching Cracks of Large Low-Alloy Gears
Authors: Pang Zi Rui , Yuan Hai Lun , Xu Jin Wu , Wang Cheng Ming
Published: July 2011

Technology and metallographic of three kinds of representative gears were analyzed in this paper according to characteristics of carburizing and quenching, and technology problems met with during the carburization process of large low-alloy gears in Citic Heavy Industries Co., Ltd were also taken into account. Three conclusions are demonstrated through experimental results. Firstly, although carburization technology is normal, grinding cracks can be caused by hard particles included in matrix. Secondly, if carbon concentration of carburization layer is too high or too steep in carburizing technology, carbide will aggregate in reticular or structural stress will not be average during the subsequent quenching technology. And therefore grinding cracks are caused. Moreover, retained austenite of surface layer and subsurface layer will be over standard and thus grinding cracks will be caused if quenching temperature is too high during quenching technology after carburizing.
Grey Prediction on Sheared Edge Quality in Precision Blanking Process for Micro IT Parts
Authors: Wang Bo , Chen Jing Bo
Published: July 2011

Sheared edge quality of micro IT parts is an important standard to evaluate product quality. In this paper, a prediction model of sheared edge quality based on grey prediction is studied. By mapping the stroke and the burr width to be the time increment and the eigenvalue of grey system, the grey prediction model was established. The dynamic regularity of burr in actual production was attained from the precision blanking experiment and the prediction of burr width was performed. The results show that the model can predict burr width accurately and needs less sampling data. Thus, it is fit for the requirement of manufacturing.
Numerical Simulation of a First Normal Stress Difference-Based Model for Shear-Induced Crystallization of Polyethylene
Authors: Wang Jin Yan , Chen Jing Bo , Shen Chang Yu
Published: July 2011

The paper presents a numerical simulation for the isothermal flow-induced crystallization of polyethylene under a simple shear flow. The effect of flow on crystllization is considered through the simple mathematical relationship between the additional number of nuclei induced by shear treatment and the first normal stress difference. Leonov viscoelastic model and Avrami model are used to describe the normal stress difference and the crystallization kinetics, respectively. It is found that the short-term shear treatment has a large effect on the crystallization dynamics of polyethylene , but the effect of the intensity of the shear flow is not infinite ,which shows a saturation phenomenon, namely, the accelerated degree of crystallization tending to level off when the shear rate or shear time is large enough.
Experimental Study on Water Stability of Asphalt Mixture
Authors: Yuan Yu Qing , Gao Dan Ying , Zhao Jun , Tang Ji Yu , Zhai Shao Hua
Published: July 2011

To improve water stability, we mixed asphalt mixture with cement, slag micro powders and lignin fibers, respectively. The Marshall immersion and freeze-thaw splitting tests were carried out. It is shown that cement replacing mineral powders can improve the water stability of asphalt mixture, especially at the content of 1/3 mineral powders, with a Marshall stability of 11.50 kN and a soaking residual stability of 92.46%, increasing by 10.79% and 6.58%, respectively, than those without any cement. According to the results of cement replaced by slag micro powders, its stability increases by 1.38kN, and the soaking residual stability is 90.64%, but the freeze-thaw splitting tensile strength slightly decreases. It is indicated that the water stability of the asphalt mixture can be improved by adding 0.3% lignin fibers, the soaking residual stability increasing from 86.75% to 97.41% and the ratio of freeze-thaw splitting tensile strength rising from 60.94% to 80.29%. It is concluded that the best effect can be reached by adding 0.3% lignin fibers.