bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Lubricants on Precision Planing of Tungsten Carbide Using Mono-Crystalline Diamond Tool
Authors: Yui Akinori , Matsuoka Hiroshi , Okuyama Shigeki , Kitajima Takayuki , Okahata Go
Published: September 2011

Rubbing tests between a diamond stick and a tungsten carbide plate and planing experiments of cobalt-free tungsten carbide using a mono-crystalline diamond tool are conducted, and the effect of lubricants on tool wear is investigated. Five kinds of lubricants such as: sulfur-base extreme-pressure additive; dimethyl-silicone; oleic acid; zinc dialkyldithiophosphate (ZnDDP); and chemical solution type coolant (FGC950) are chosen for the lubricants. Through the rubbing experiments, diamond stick wear is the greatest when using dimethyl-silicone, followed by FGC950 and it is the least using ZnDDP. On the other hand, tool edge chipping is the greatest when using FGC950, followed by sulfur-base extreme-pressure additive and it is the least using ZnDDP. Through the planing experiments, tool chipping is dominant in diamond-tool wastage in comparison with abrasive wear. Tool life is the longest when using ZnDDP and obtained surface roughness is 0.022 mm Ra after 177 m planing.
Creep-Feed Grinding of Tungsten Carbide by Using Resin-Bonded Nickel-Coated Diamond Wheel
Authors: Pak Abbas , Abdullah Amir
Published: September 2011

Force and specific energy are important factors in all abrasive machining operations especially in creep-feed grinding of hard materials. They have a high influence on the wheel wear, grinding accuracy, grinding temperature and surface integrity. This paper investigates the effect of grinding technological parameters on grinding force and specific energy in up-cut creep-feed grinding of cemented tungsten carbide with 20% cobalt using a resin-bonded nickel-coated diamond wheel. It was observed that increase of feed rate resulted in grinding force increase and specific energy decrease. Increased wheel-peripheral speed resulted in minor decrease of grinding force and specific energy increase.
Particularities of Grinding High Speed Steel Punching Tools
Authors: Krajnik Peter , Drazumeric Radovan , Badger Jeffrey , Kopač Janez , Nicolescu Cornel Mihai
Published: September 2011

A simulation model of a punch grinding process has been used to determine optimal parameters to reduce grinding cycle time and achieve a constant-temperature no-burn situation. Two basic outputs of the simulation model include arc length of contact and specific material removal rate that are both time-variant. A thermal model is included in the simulation to calculate maximum grinding temperature rise. The simulation-based optimization can help to avoid thermal damage, which includes thermal softening, residual tensile stress, and rehardening burn. The grindability of high speed steel (HSS) is presented in terms of specific grinding energy versus undeformed chip thickness and maximum temperature rise versus specific material removal rate. It is shown that for a given specific material removal rate lower temperatures are achieved when grinding fast and shallow. Higher temperatures, characteristic for slow and deep grinding, soften the material leading to a lower specific grinding energy, especially if grinding is timid. Lowest values of specific grinding energy can be achieved in fast and shallow grinding at aggressive grinding conditions.
Filter-Less Purification of Grinding Fluid by Using PGA Based Flocculant
Authors: Ninomiya Shinichi , Iwai Manabu , Suzuki Kiyoshi
Published: September 2011

Water soluble coolant has been widely used as machining fluid owing to its environment- friendly characteristic, fine protection property and low price. However, as this type of coolant is perishable, a large amount of labor is required for its maintenance of the coolant. Moreover, in high precision machining, separation of minute machined chips generated during grinding and machine oil from the coolant is indispensable, and a special filtering-device and other equipments are necessary. In this paper, a method to purify water-soluble grinding fluid using PGA based flocculant was examined. As a result of experiments, it was clarified that the suspended matters such as grinding swarf or free abrasive grains in the fluid can be removed at the collection rate of more than 99%. A new filter-less coolant purification technology was established by combined use of micro bubble coolant.
Study on the Effects of Abrasive and Coolant-Lubricant Types on Minimum Quantity Lubrication-MQL Grinding
Authors: Tawakoli Taghi , Hadad M.J. , Daneshi A. , Sadeghi M.H. , Sadeghi B.
Published: September 2011

In dry grinding, as there is no coolant lubricant to transfer the heat from the contact zone, generation of surface damages are not preventable. Promising alternatives to conventional flood coolant applications are also Minimum Quantity Lubricant (MQL) or Near Dry Machining (NDM) or Semi Dry Machining (SDM). This research has been conducted to study the influence of the abrasive and coolant-lubricant types on the minimum quantity lubrication (MQL) grinding performance. One type of CBN and three types of conventional wheels (corundum) were tested. The tests were carried out in presence of fluid, air jet and eleven types of coolant-lubricants, as well as in dry condition. The results indicate that the finest surface quality and the lowest grinding forces could be obtained when grinding with CBN wheels. In the case of conventional wheels, the coarser wheel induces much proper grinding results.
Wire Cutting Tool Concepts for Steel Machining
Authors: Denkena Berend , Köhler Jens , Ermisch Andreas
Published: September 2011

Wire cutting, originally developed for the processing of natural stone, is increasingly used for the machining of reinforced concrete and metallic structures. In this field of application the diamond wire sawing tools are subjected to a higher-than-average wear. Furthermore the metallic bonding of the cutting beads is not suitable for machining metallic structures, because of a missing self-sharpening effect. Within this paper, conventional wire sawing tools are investigated in pure steel structures. These tools are supposed to be suitable for the cutting process in accordance to their tool concept. The manufacturing process and the grain sizes have an influence to the tool performance. From these investigations requirements for a new tool concept will be derived.
Wheel Based Temperature Measurement in Grinding
Authors: Brinksmeier Ekkard , Eckebrecht J. , Wilkens A.
Published: September 2011

The chip removal process in grinding is characterized by intensive friction and plastic deformation leading to the risk of thermal damage of the surface-layer of the machined part. Thus productive and reliable grinding processes need effective monitoring. The difficult to access contact zone between the grinding wheel and the workpiece led to extensive research work on the temperature measurement in the grinding arc. In order to develop a tool integrated temperature monitoring system a new approach was undertaken which makes use of the measurement of infrared-radiation to monitor the temperatures in the grinding arc. The presented research work shows promising results suitable for an industrial applicable system for temperature measurement in grinding. The optical transmission of the infrared temperature information in combination with a fast detecting infrared sensor bares the potential to establish a highly miniaturized measuring system which is easy to integrate in any grinding wheel at comparably low production costs.
Ultra High-Speed Cutting Experiment under the Cutting Condition that Cutting Speed Exceeds Plastic Wave Speed of Workpiece
Authors: Shinozuka Jun , Sando Masato , Horie Tasuku
Published: September 2011

Raising a cutting speed to above speed of a plastic wave of a workpiece material induces the high levels of the hydrostatic stresses in the shear zone, because a plastic wave traveling there becomes a shock wave. In order to ascertain the cutting phenomena occurring under the ultra high-speed cutting condition, the cutting experiments of a pure lead with cutting speeds of up to 140 m/s are performed with a high-speed impact cutting tester developed. The experimental result reveals that the cutting mechanism, especially chip formation, changes remarkably and the friction angle at the tool-chip interface rises in the ultra high-speed cutting. It can be explained that these phenomena arise from the plastic shock wave in the shear zone.
Aid of End-Milling Condition Decision Using Data Mining from Tool Catalog Data for Rough Processing
Authors: Kodama Hiroyuki , Hirogaki Toshiki , Aoyama Eiichi , Ogawa Keiji
Published: September 2011

The uses of data mining methods to support workers decide on reasonable cutting conditions has been investigated in this work. The aim of our research is to find new knowledge by applying data mining techniques to a tool catalog. Hierarchical and non-hierarchical clustering of catalog data as well as multiple regression analysis was used. The K-means method was used and on the shape presented in the catalog data and grouped end mills from the viewpoint of the tool's shape, which here means the ratio of dimensions has been focused. The numbers of variables were decreased using hierarchical cluster analysis. In addition, an expression for calculating the better cutting conditions was found and the calculated values were compared with the catalog values. There were three cutting conditions: conditions recommended in the catalog, conditions derived by data mining, and proven cutting conditions for die machining (rough processing).
An Experimental Study on the Effects of Ultrasonic Assisted Drilling on Chip Characteristics and Tool Life
Authors: Vakili Azghandi Bijan , Razfar M. Reza
Published: September 2011

Ultrasonic assisted drilling has made remarkable achievements in recent years. Improvements in many fields have been considered by researchers and a way forward lies in applying the results in industries. In this recent experimental study, the effect of ultrasonic assisted drilling was reviewed. The material was high-alloyed steel X20Cr13 and for more accurate comparison between drilling with or without vibration, ordinary HSS tools were used and the vibrations were imposed to the workpiece. Also, the test structure was designed using numerical calculations and FEM method. The critical criterion was to have vibration in longitudinal mode and in the direction of the tool feed, reaching a peak at the cutting point. The results have shown significant changes in chip characteristics and tool life subsequently. The length of chip decreased and this improvement automatically leads to many other progresses in the procedure amongst which there is an extended tool life. The other progresses were higher surface quality, less burrs on edge of the holes and less drilling force which are not in the scope of this paper.
Prediction of Surface Roughness Using Back-Propagation Neural Network in End Milling Ti-6Al-4V Alloy
Authors: Zhang Song , Li Jian Feng
Published: September 2011

Surface roughness plays a significant role in machining industry for proper planning of process system and optimizing the cutting conditions. In this paper, a back-propagation neural network (BPNN) model has been developed for the prediction of surface roughness in end milling process. A large number of milling experiments were conducted on Ti-6Al-4V alloy using the uncoated carbide tools. Four cutting parameters including cutting speed, feed per tooth, radial depth of cut, and axial depth of cut are used as the inputs to develop the BPNN model, while surface roughness corresponding to these combinations of different cutting parameters is the output of the neural network model. The performance of the trained BPNN model has been verified with the experimental results, and it is found that the BPNN predicted and the experimental values are very close to each other.
Precision Polishing of Micro Mold by Using Piezoelectric Actuator Incorporated with Mechanical Amplitude Magnified Mechanism
Authors: Chee Sze Keat , Suzuki Hirofumi , Okada Mutsumi , Yano Takeshi , Higuchi Toshiro , Lin Wei Min
Published: September 2011

Demands of precision molds with complicated microstructures for digital devices such as DVD pick-up system, medical devices such as μ-TAS and solar optics etc. are increasing [1 - 5]. The structured molds must be polished after grinding or cutting in order to improve the surface roughness. In this paper, a two dimensional low frequency vibration (2DLFV) polishing actuator using PZT is proposed and developed. The 2DLFV consists of 4 mechanical amplitude magnified actuators (MechaTrans), a multilayer stacked piezoelectric actuator (PZT) incorporated with mechanical transformer, and a center piece. Mechanical transformer is a kind of flexure hinges structured that magnifies the stroke of the multilayer stacked piezoelectric actuator around 7 times to 120 μm. With this actuation, the tool vibrates in a circle trajectory to achieve polishing effect. In the polishing experiments, tungsten carbide molds (workpieces) are polished with diamond slurry. The surface roughness of the work pieces and polishing efficiency are evaluated. From the experimental results, it was found that low frequency vibration especially 2DLFV is a useful polishing system for micro structured mold.
Investigation of a Polishing Pad and a Carrier Film for Decreasing Edge Roll Off of Workpiece
Authors: Satake Urara , Wang Wen Xiao , Enomoto Toshiyuki , Tabata Norikazu
Published: September 2011

Demand for diminishing edge roll off of workpiece has rapidly increased, especially in polishing silicon wafers and glass disks. However, the conventional polishing technologies cannot meet the demand. To address this problem, the influence of carrier film properties and that of polishing pad properties on the stress distribution near the workpiece edge were investigated using finite element methods. Based on the analytical results, double-layered polishing pads having an extra-fine fiber thin layer and a hard polymer layer were developed. Polishing experiments on silicon wafers and glass plates showed that the developed polishing pads achieved high finishing efficiency and extremely flat surface near the edge.
Buffing Performance Analysis of Viscoelastic Polymer with Sensor-Less Polishing Pressure Control
Authors: Igarashi Keisuke , Sato Masayuki , Kakinuma Yasuhiro
Published: September 2011

Viscoelastic polymer with high scratch resistance has been developed for coating material of product. Due to some particular characteristics such as viscoelasticity, it is difficult to finish the polymer coated surface. In the present circumstances, its polishing process is carried out by the trained technician and depends on the skill like adjustment of the polishing pressure according to the situation. To realize automation of the polishing, high-precision and highly-responsive force control is required firstly. Typically force control is done with force sensor. However when external sensor is used, there are some problems such as high-cost, reduction of machine stiffness and thermal drift. The thermal drift which is caused by polishing heat prohibits accurate measuring of force. The purpose of this research is to develop the polishing pressure control method without any additional sensor. In addition, applying the control method to buffing machine, buffing performance of viscoelastic polymer is experimentally analyzed.
A Novel Desktop Device for Lapping Milled Micro Thin-Walled Structures
Authors: Zhang Peng , Wang Bo , Jackson Mark J. , Mao Xing
Published: September 2011

Current requirements for producing highly precise and ultra-smooth micro structured surfaces of small parts are proposed in certain situations. The following question arises: how to make a highly precise and ultra-smooth micro-structured surface with high efficiency and low cost? Novel desktop lapping and polishing devices should be developed to satisfy these requirements. In order to improve the surface topography and remove the surface damaged layer of a highly precise and ultra-smooth micro thin-walled structure after milling with the width of 150 μm and the depth of 10 μm, a novel lapping desktop device is designed and developed. There are two key points in the design of the lapping desktop device: one is the vertical coupled macro-micro movement axis; the other is the fixture with a thin and flexible hinge structure, which has the capability of measuring both force and displacement as a double-feedback sensor to control both the micro lapping force and the depth of lapping. The experimental results show that the surface topography of the micro thin-walled structured surface is much improved after lapping, and that the three-dimensional surface roughness decreased from 329 nm to 82.2 nm.
Study on Internal Magnetic Field Assisted Finishing Process Using a Magnetic Machining Jig for Thick Non-Ferromagnetic Tube
Authors: Zou Yan Hua , Liu Jiang Nan , Shinmura Takeo
Published: September 2011

This paper describes an internal finishing process for thick non-ferromagnetic tube (10~20 mm in thickness) by the application of a magnetic field-assisted machining process using a magnetic machining jig (permanent magnet tool). In this study, a new automatic inner surface finishing system was developed, and to achieve smooth surface roughness and high form accuracy, a multiple-stage machining which contains of rough machining and precision finishing was carried out. Especially, in order to improve the form accuracy the rough processing time was made longer compared with the research in the past. The experiments were performed for a thick SUS304 stainless steel tube 10 mm in thickness. The results showed that surface-roughness and form accuracy were able to be improved greatly, the initial surface roughness of 4.9μmRa can be improved to 0.01 μmRa and the roundness of inside tube can be improved from 206 μm to13μm.
Study on Surface Roughness in Micro End Milling of Mold Material
Authors: Shizuka Hiroo , Okuda Koichi , Nunobiki Masayuki , Inada Yasuhito
Published: September 2011

The effects of cutting conditions on the surface roughness in a micro-end-milling process of a mold material are described in this paper. Micro-end-milling operations were performed under different cutting conditions such as feed rate and depth of cut, in order to investigate the factors that had the greatest influence on the finished surface during micro-end-milling. It was revealed that the surface roughness begins to deteriorate when the radial depth of the cut exceeds the tool radius. In addition, it was found that this phenomenon is peculiar to micro-end-milling processes.
Analysis of Effective Cutting-Edge Distribution of Grinding Wheel Based on Topography of Working and Ground Surfaces
Authors: Sakamoto Haruhisa , Nakamura Kyoko , Sasaki Yoshinori , Shimizu Shinji
Published: September 2011

In this study, the determination method of the number of the effective cutting-edges had been proposed based on the measurements of working surface topography and the grinding force. Furthermore, its validity is made clear based on the topographical analysis of the ground surface roughness of pure copper, which is excellent in transcribing the working surface. From the results, the following are found out: The ground surface topography contains the periodical component, which is originated in the grinding and dressing conditions, on the fractal noise component. The cutting traces by each cutting-edge can be countable from the ground surface profile, and then, the number of the effective cutting-edges is identified at one line within the working surface. On the other hand, the number of the effective cutting-edges also can be identified based on the working surface, but, this method requires the determination of the typical grain shape. From the experiment, it is confirmed that the grain shape should be almost spherical for making the numbers of the effective cutting-edge identified from the working and ground surfaces equal.
Effect of Tool Tilting Angle on Tool Wear and Surface Roughness in Micro Ball End Milling
Authors: Hamaguchi Kazuya , Kagata Yuji , Shizuka Hiroo , Okuda Koichi
Published: September 2011

This paper describes the effect of the tool tilting angle on the tool wear and the surface roughness in micro ball end milling. The cutting tests of hardened stainless steel were carried out by using of the micro ball end mill with radius of 100mm under the conditions of tilting angle from 0° to 45°. The spindle speed was fixed in a constant of 120,000 min-1. The feed per tooth, axial depth of cut and radial depth of cut were also fixed. The flank wear, the surface roughness and the cutting force were investigated. As a result, the maximum width of flank wear of the micro ball end mill tended to decrease with an increase in the tilting angle of spindle. The surface roughness became almost constant not depending on the tilting angle of the spindle.
A Study of Material Removal Process in Abrasive Waterjet Milling
Authors: Dadkhahipour Keivan , Wang Jun
Published: September 2011

An experimental investigation of the material removal process in abrasive waterjet (AWJ) milling is presented. The experiment was conducted on an amorphous glass for milling channels of controlled depth. It is found that the channels are formed through four different zones, i.e. an opening zone, a steady-cutting zone, a unsteady-cutting zone and a finishing zone. The effect of process parameters on the channel formation process and the major milling performance measures (depth of cut and material removal rate) is then discussed. It is found that AWJ milling is a viable process for machining applications and the milling performance can be reasonably controlled through the selection of process parameters.
Experimental Research on the Surface Roughness of Metal Kerf by Abrasive Waterjet Cutting
Authors: Zhu Hong Tao , Huang Chuan Zhen , Zhang Shu Guang , Wang Jun , Che Cui Lian
Published: September 2011

In this paper, a comprehensive experimental investigation on the surface roughness of metal kerf in abrasive waterjet cutting metal material is presented. Orthogonal experimental design method and analysis of variance are utilized in researching the effects of processing parameters on the roughness of smooth zone. By analyzing, it could be concluded that lower waterjet pressure, smaller cutting speed and abrasive grit, larger abrasive flow rate and appropriate standoff are favorable to generate smooth metal kerf. A verification experiment was conducted using an optimizing cutting condition. The result indicates that the surface roughness of metal kerf has been improved effectively.
Evaluation of Hard Materials Using Eco-Attributes
Authors: Mamunur Rashid Md. , Sharif Ullah A.M.M. , Tamaki Junichi , Kubo Akihiko
Published: September 2011

Hard materials based on Alumina (AN), Silicon Carbide (SC), Boron Carbide/Nitride (BC/N), Zirconia (ZN), and alike are often used to produce abrasive grains and coat cutting tools. These materials improve the performance of grinding/machining operations by providing an enhanced productivity, a longer grinder/tool life, and a better surface finish. On the other hand, they might leave some burdens on the environment. Therefore, eco-attributes (i.e., energy consumption, CO2 emission, NOX/SOX emission, water usage, recycle fraction, etc.) of these hard materials should be used to make an informed decision. This study deals with this issue and provides an evaluation of AN, SC, BC/N, and ZN based hard materials in terms of CO2 emission, NOX emission, SOX emission, and water usage. The outcomes of this study are useful for analyzing grinding and other abrasive processes for achieving eco-manufacturing.
Development of Electric Rust Preventive Machining Method -Water Using for Machining: Improvement of Water Recycle System-
Authors: Nishikawa Naohiro , Sato Yoshimi , Kato T. , Karita K. , Hagihara Y. , Yoshihara Nobuhito , Okawai H. , Kato H. , Iyama Toshirou , Mizuno Masahiro , Tsukamoto Shinya
Published: September 2011

Currently, the machining fluid includes several chemicals such as cutting oil and grinding oil is used for the machining. However, such the machining fluid that is caused enormous disposal cost and environmental load, should reduce using. Therefore, in this investigation, electric rust preventive machining method which uses only water for machining fluid is developed. Because using only water without extreme pressure agents, oil and so on, this method decreases disposal of waste machining fluid. In this paper, the system to remove impurities from a used machining fluid, and to reuse machining fluid is designed. To reproduce water efficiently, the order of arranging the filter is changed. In consequence, it has been efficient when the filtration filter is set up first, and the activated carbon filter is set up in the second. In addition, the reproduction of the water when the supply pressure is 0.75 MPa is verified by using this system. As a result, the water which passed a water recycle system, the impurities such as iron, conductivity, turbidity, colour decreased, and purification of the water is possible for this system. And, 5.2 L/min refined water recycle is achieved.
Ultraprecision Mass Fabrication of Aspherical Fresnel Lens by Glass Molding Press
Authors: Zhou Tian Feng , Yan Ji Wang , Masuda Jun , Kuriyagawa Tunemoto
Published: September 2011

Glass molding press (GMP) was applied to the fabrication of glass aspherical Fresnel lens for high-efficiency mass production. A pair of molds for the Fresnel lens was precisely fabricated on the Nickel Phosphorous (Ni-P) plating layer by the single diamond cutting with multi-axis machining center. A kind of low transition temperature (Tg) glass was heated to several tens degree centigrade above its Tg and compressed between the two molds. In this way, the shape of the mold was replicated to the glass lens surface. The molding process was simulated by finite element method (FEM), and the molding condition was optimized to minimize the residual stress.
Deformation Behavior Simulation in Laser Forming of Titanium Sheet -Influence of Free Edge on Deformation Behavior in Laser Forming-
Authors: Nunobiki Masayuki , Okuda Koichi , Takagawa Toshiyuki , Shizuka Hiroo
Published: September 2011

In this research, deformation behavior of titanium sheet in laser forming was simulated. In preliminary experiments, we had carried out single-straight-line bending and investigated the relationship between the bended angle and the laser processing conditions. It was clarified that the bended angle formed by laser forming to the free edge became larger than the angle formed by laser forming to the center, even if laser scanned in same processing conditions. To investigate the influence of the free edge, heat-transfer analysis and structural analysis were carried out by using a finite element analysis software ANSYS 11.0. It was confirmed that the bended at the free edge became large because the plastic strain of the lower surface has decreased greatly more than the strain of the upper surface decreases.
Study on Surface Roughness Muring Metal Manufacturing Process
Authors: Jiang Zheng Yi , Wang Shu Jun , Wei Dong Bin , Li Hei Jie , Xie Hai Bo , Wang Xiao Dong , Zhang Xiao Ming
Published: September 2011

In the paper, a crystal plasticity finite element method (CPFEM) model was developed based on ABAQUS to analyse the surface roughness transfer during metal manufacturing. The simulation result shows a good agreement with the experimental result in the flattening of surface asperity, and the surface roughness decreases significantly with an increase of reduction with considering friction effect. Lubrication can delay surface asperity flattening. The effect of surface roughness on produced metal defect (crack) was also studied, and the surface roughness affects the crack initiation significantly in cold strip rolling. In addition, the surface roughness variation along the metal plate width contributes to stress distribution and then inhibition of crack nucleation.
An Experimental Study on a Flexible Grinding Tool
Authors: Vogt C. , Sinzinger S. , Adelsberger H. , Maurer R. , Schneider F. , Mandler R. , Kuepper L. , Rascher R. , Sperber P.
Published: September 2011

This paper reports on results of experiments on BK7 glass materials with a novel tool for fine grinding of faces for optical purposes. The ball-shaped toolcomprises of a plastic wheel, several elastic layers and a polyurethane compound with diamond abrasives, which was developed and provided by OptoTech. Removal test runs led to samples with very smooth surfaces without sub surface damages. The tool’s elastic properties enable dwell time assisted grinding.
Finite Element Analysis (FEA) of Honeycomb Sandwich Panel for Continuum Properties Evaluation and Core Height Influence on the Dynamic Behavior
Authors: Rahman Hammad , Jamshed Rehan , Hameed Haris , Raza Sajid
Published: September 2011

Finite element analysis of honeycomb sandwich panel has been performed by modeling the structure through three different approaches. Continuum properties are calculated through analytical solution and verified through FE analysis of bare core. In addition to that the thickness of core has also been varied in all the three approaches in order to study its effect on vibration analysis of sandwich structure.
Horizontal Patterns of Single Wall Carbon Nanotubes by Simple Filtration Method
Authors: Mohammad Munir , Khan Mohammad Bilal , Khan Zaffar M. , Cavalli Gabriel , Adhikari Damitha , Silva Ravi
Published: September 2011

This work demonstrates the horizontal patterning/alignment of single wall nano tubes (SWNTs) using simple filtration method. In the quest of vertical alignment of SWNTs to fabricate the vertically aligned CNT-membrane, this horizontal patterns as observed by simple filtration technique has been achieved. These horizontal patterns are key arrangements sought in the electronic field and fabrication of CNT-nano composites of required characteristics. In this work SWNTs purified/oxidized treatment with nitric acid at 120-122°C. Oxidized SWNTs further reacted with Octadecyl amine at same temperature to make them significantly dispersible/soluble in solvents especially in Tetrahydrofuran (THF). These modified SWNTs dissolved in THF by sonication and uniform black color solution was obtained that did not settle upon prolonged time of standing. This solution is subsequently filtered through 0.2 micro porous PTFE filter using long neck sintered funnel for horizontal alignment. The inter tube gap between CNTs is initially filled by the precursor reactive vapor stream that is consolidated as a solid polymer through insitu polymerization. Transform Infrared (FTIR) analysis was performed to find the attached functional groups. Alignment of functionalized SWNTs collected on PTFE filter was analyzed by Field-emission scanning electron microscopy (FE-SEM). Ordered horizontal patterns were observed. The contemporary horizontal alignment techniques being used are tedious and need very special facilities. The current method is comparatively quite simple and large quantities of CNTs can be aligned to advantage.
Co-Ferrite (CoFe2O4): A Material with High Magnetostriction Produced by Sol-Gel Method
Authors: Mehmood Nasir , Grössinger Roland , Turtelli Rieko Sato , Raza Muhammad Aamir , Khan Sohail Afzal , Choudry Sajid Raza
Published: September 2011

Polycrystalline Co-ferrite was produced by modified citrate gel method. Samples were afterward heat treated at different temperatures upto 1300°C. The XRD pattern shows that all samples exhibit a single phase spinel structure and improvement and sharpness in intensity of peaks with increasing annealing temperature. Measurement of hysteresis loops demonstrate that after the heat treatment a saturation magnetization of 60- 84 emu/gis obtained. Measurements of the longitudinal magnetostriction gave values between 20 ppm and 130 ppm. Magnetostriction increases gradually with increase in annealing temperature and becomes highest when the saturation magnetization values are larger.
Numerical Modeling and Simulation of Delamination Crack Growth in CF/Epoxy Composite Laminates under Cyclic Loading Using Cohesive Zone Model
Authors: Ijaz Hassan , Khan M Aurangzeb , Saleem Waqas , Chaudry Sajid Raza
Published: September 2011

This paper presents the mathematical modelling of fatigue damage able to carry out simulation of evolution of delamination in the laminated composite structures under cyclic loadings. A new elastic fatigue damage evolution law is proposed here. A classical interface damage evolution law, which is commonly used to predict static debonding process, is modified further to incorporate fatigue delamination effects due to high cycle loadings. The proposed fatigue damage model is identified using Fracture Mechanics tests like DCB, ENF and MMB. Simulations of delamination under fatigue loading are performed and results are successfully compared with reported experimental data on HTA/6376C unidirectional material. Delamination crack growth with variable fatigue amplitude is also performed and simulation results show that the proposed fatigue damage law can also accommodate this variable amplitude phenomenon. A study of crack tip behaviour using damage variable evolution is also carried out in this paper. Finally the effect of mesh density on crack growth is also discussed.
Development of Resin Infusion Process for Ultralight Large Composite Structures
Authors: Khan Zaffar M. , Yahya Ghulam , Umer M. , Khan Bilal , Tahir Faraz
Published: September 2011

Resin Infusion process is an affordable process for developing composite structures but resin impregnate is made difficult by its large size of engineering products. This research demonstrates development of large structures such as body of a high performance automobile in a single step resin infusion process. Three different scaled down models of the car were developed according to user’s technical requirements focusing on minimal weight, air drag and aesthetics. Pro E and ANSYS were used to determine the optimal shape, geometry, size, aesthetics and strength. The digital model of exterior shape of car body was developed through coordinate measuring machine using selected model instead of Pro-E modeling due to time constraints. The digitized data was used for development of Pro-E model. The Pro-E model was scaled up to generate CAD drawings for tool development. Different stations were marked on the model and sliced virtually for development of pattern. After developing pattern, the mold was manufactured from carbon and glass / polyester composites for prototype manufacturing of the car body. The prototype manufacturing involved placement of specific number of carbon layers as perform on female side of the mold. The vacuum sucked the resin through a number of carefully selected entry ports. Multiple resin delivery ports ensured effective resin distribution and impregnation. After curing the cutting, trimming and drilling operations were carried out to finish car body to actual size. Polyacrylic wind shield was thermoformed in convection current oven according to streamlined geometry of car body. The car body was integrated with the compatible floor panels and accessories. The crumble zone shock absorber in the bumper was manufactured using successive layers of Nomex® honeycomb and PVC rigid foam to dampen the accidental shock. The successful test runs were made to qualify the car body according to user’s technical requirements.
Enhanced Dielectric Response in Polyurethane Based All-Organic Nanocomposite
Authors: Wang Jing Wen , Chen Tao , Wei Nan , Wu Cong Cong , Li Shu Qin
Published: September 2011

A high dielectric constant nano-composite was fabricated using polyurethane (PU) as matrix and poly (p-chloromethyl styrene) (PCMS) grafted with copper phthalocyanine oligomer (CuPc, a planar multiring semiconductor with dielectric constant>105) (name the grafting product as PCMS-g-CuPc) as filler. According to the TEM-observed morphologies, PCMS-g-CuPc balls (~80 nm) distribute uniformly in PU matrix, while in PCMS-g-CuPc balls the PCMS acts as “matrix” which contains dispersed CuPc particles with a average size of ca. 25nm [1/20 of that of CuPc in simple blend of PU and CuPc (PU/CuPc)]. At 100Hz, the dielectric constant of the nanocomposite reaches 345, almost 7 times higher than that of PU/CuPc. The enhanced dielectric response in the nano-composite can be explained by the remarkably strengthened interface exchange coupling effect as well as the Maxwell-Wagner-Sillars polarization mechanism due to the significantly reduced CuPc particle size in the nano-composite.
Synthesis and Characterization of Processable Polyimide Titania Nanohybrids
Authors: Saeed Malik Adnan , Lodhi Zulfiqar H. , Khan Aziz Ullah , Asghar Wasim
Published: September 2011

A new aromatic diamine monomer {4-amino [4-(diphenylamino) phenyl] anilino} phenyl amine (DPA -4) were synthesized in high yield and purity. {4-amino [4-(diphenylamino) phenyl] anilino} phenyl amine (DPA -4) monomer were reacted with Tetra carboxylic dianhydride (BT) leading to the formation of polyamic acid, followed by the preparation of polyimide/Titania hybrid films through non-hydrolytic sol-gel method. The synthesized polyimide were considered as blank & compared with the nano-hybrids derived from polyimides/Titania blends of different TiO2content. Synthesized polyimide showed excellent solubility in aprotic solvents like DMF, DMSO, NMP, and DMAC proving best processibility in various applications. Polyimide exhibited excellent thermal stability and its glass transition temperature was 450°C & 5% weight loss is in the range of 500°C~600°C. The thermal stability of Polyimide/Titania composites decreased slightly with increase of TiO2content. Result show decrease in thermal stability of nano-hybrids caused by the decomposition of catalytic activity of Titania & incomplete imidizations of polyamic acid. The absorption band of PI-O-Ti bonds in FTIR spectra of hybrids films revealed the formation of hybrid inorganic network between polyimide and TiO2.Scanning electron microscopy results indicated that the nanometer-scaled inorganic domains were homogeneously dispersed in polyimides matrix due to the introduction of TiO2.The studies on the optical properties of hybrids films indicated the red-shift to the absorption band increased with increasing TiO2content, while all the hybrids films maintained their transparencies. This kind of hybrid materials has potential commercial application in the field of opto-electronics appliances.
Study on Thermal Assisted Direct Bonding of Glasses for Lab-on-Chip Application through Surface Activation Process
Authors: Chen Qiu Ling , Chen Qiu Ling , Ferraris Monica
Published: September 2011

Surface treatment before glass bonding is an important and critical issue for glass-based lab-on-chip fabrication. In the present article we verified five different activation methods for obtaining sound thermal assisted direct bonding (TADB) on glasses. Glass surface has been investigated by means of water contact angle, X-ray photoelectron spectroscopy (XPS). The optimum surface activation method for TADB on glasses was found to be H2SO4:H2O2(3:1 by volume) followed by HNO3. By using the TADB optimized activation method, the glass bonding strength higher than 32MPa was obtained with a glass the roughness of 50 nm.
Effect of Stretching Temperature on Proteolysis, Expressible Serum and Titratable Acidity of Mozzarella Cheese
Authors: Ying Miao , Jing Liu , Zheng Zhao
Published: September 2011

The impact of stretching temperature on proteolysis, titratable acidity and expressible serum of Mozzarella cheese during storage at 4 °C was determined. Three vats of cheese with three different stretching temperatures (75 °C, 85 °C, 95 °C) were made in one day. Cheese making was replicated on three different days as a randomized block design. Cheeses stretched at temperature of 95 °C had the lowest values of titratable acidity. Nitrogen soluble in pH4.6 acetate buffer and 12% TCA increased for all cheeses with age, but the rates of increase were slower in cheese stretched at higher temperature. This indicated that the coagulant and starter culture were heat inactivated during stretching at higher temperature. The amount of expressible serum obtained on centrifugation at 12500 rpm for 60 min at 25 °C decreased during aging, corresponding to an increase in water-binding properties. However, the rate of decrease was much lower in cheese stretched at higher temperature, which indicated the persistence of poor water-binding properties.
Buckling Analysis of the Tube Compression-Bending Member in Elastic-Plastic State with ANSYS
Authors: Jiang Zhi Cai , Qu Wei Lian
Published: September 2011

Stability is an important issue in steel structure design.When the steel member is subjected to elastic-plastic instability, the axial compression stiffness reduces with the increasing axial pressure and bending moment at end. Therefore, the authors analyze the process of steel member that is instable in elastic-plastic state in this paper by studying the degradation laws of axial compression stiffness. The eigenvalue buckling and nonlinear buckling analyses of axially compressed member and compression-bending member are carried out by using commercial package ANSYS in this study. The relationship curve between the axial force at end and the axial compression stiffness and the relationship surface among the axial pressure at end, bending moment at end and the axial compression stiffness are determined respectively. The made observations indicate that it is feasible to analyze the process of the steel member that is instable in elastic-plastic state by investigating the degradation properties of axial compression stiffness, which becomes lower with axial pressure at end and bending moment at end.
Analysis of Aerodynamics Characteristic of High Length-to-Diameter Ratio Missile
Authors: Peng Zhi Ling
Published: September 2011

On the basis of analysis of aerodynamics characteristic of high length-to-diameter ratio missile on the fly, Study the stability of elastic vibration.
The Research on Ship Positioning’ Thruster Allocation Based on Evolutionary Algorithm
Authors: Chi Hong Fu
Published: September 2011

Ship Positioning’s Thruster Allocation is a nonlinear programming problem with nonlinear equality and inequality. Morgan's direct thruster allocation method is simple and allocation's speed is quick. And Sequential Quadratic Programming, evolutionary algorithm is used to solve more complex performance index and constrains, however, load balance is not considered. In this paper, performance index is improved considering load balance. And evolutionary algorithm is used to solve the problem. Results show that search time is long. In the future, heuristic based on solved problem operator should be used to decrease time of evolutionary algorithm. For example, setting forbidden operator to eliminate unfeasible solutions. Sequential Quadratic Programming could be used to solve the problem presented in this paper with improved performance index.
A Photochromic Diarylethene with Five and Six-Membered Aryl Units
Authors: Tong Zhi Peng , Pu Shou Zhi , Cui Shi Qiang
Published: September 2011

A photochromic diarylethene bearing a six-membered aryl unit 1-[(2,5-dimethyl-3-thienyl)]-2-[2-methy-4-(3,5-difluorophenyl)-phenyl]perfluoroyclopentene (1a) was synthesized and its photochromic and fluorescent properties were also investigated in detail. The results showed that this compound exhibited reversible photochromism, changing from colorless to red after irradiation with UV light, in which absorption maxima were observed at 521 and 536nm in hexane and PMMA film, respectively. The fluorescence intensity decreased along with the photochromism upon irradiation with 297 nm light in hexane.
Synthesis and Photochromic Properties of a Novel Diarylethene Derivative
Authors: Zheng Chun Hong , Pu Shou Zhi , Fan Cong Bin , Liu Wei Jun
Published: September 2011

A new red diarylethene compound, 1,2-bis[2-n-hexyl-5-hydroxymethyl -3-thienyl]-perfluorocyclopentene (1o), was synthesized and its photochemic properties and fluorescence were studied. Specifically, photochromism in solution and in poly-methylmethacrylate (PMMA) amorphous films were investigated. The results showed that it exhibited good photochromism in both solution and PMMA amorphous film under photoirradiation. In addition, the compound exhibited relatively strong fluorescence that can be useful for the design of the fluorescence molecule switch.
Numerical Simulation of Micro Flow Field of Micro Injector
Authors: Mu Li Li , Xue Ning
Published: September 2011

In order to research the effects of digital micro droplet injected by the piezoelectric ceramic inertial driver, the calculation model of micro flow field of micro injector was established based on the VOF model of multiphase flow. The calculation selected the implicit segregated solver and the standard k-e model was used in turbulence of the micro-nozzle. The governing equation was separated in first order upwind, and solved by PISO algorithm. The flow pattern of the micro channel fluid and the dynamic evolution process of the micro droplet generation in the plus wave driving were researched.
A Microscopic Model of the Asymmetric Neck Growth during Sintering Process upon the Asymmetric Particle Arrangement
Authors: Niu Yu , Xu Feng , Hu Xiao Fang , Li Yong Cun , Zhao Jing , Zhang Zhong
Published: September 2011

A kinetic Potts Monte Carlo model was used to investigate the microstructural evolution of a three particles configuration during sintering. The a series of peculiar phenomena was observed and analyzed quantitatively, which indicated that even if the particle shape and the contact area are both completely symmetrical, the asymmetric neck growth will arise due to a special particle arrangement. Although the linear relationship between neck size logarithm and time logarithm was consistent with the traditional theory, a slower neck growth rate comparing with that of the two sphere model displayed a result of the asymmetric neck growth. The analysis of the particle rotation was made to confirm the occurrence of the asymmetric neck growth. It was firstly observed that the morphology of the grain boundaries became bevel, and the reason for this morphology was discussed. All the special phenomena have proved that the asymmetric particle arrangement about the contact area can trigger the unstable neck growth.
A Molecular Switch Based on a Blue Photochromic Diarylethene
Authors: Liu Wei Jun , Wang Wei Ping , Liu Gang
Published: September 2011

A new blue photochromic diarylethene compound, 1-[5-(3,5-difluorinphenyl)-2-methyl-3-thienyl]-2-[5-(3-cyanophenyl)-2-methyl-3-thienyl]perfluoroclopentene (1a), was synthesized and its photochemical properties were investigated in detail. The results demonstrated that the compound has good photochromism in solution and in PMMA amorphous film, and good fluorescence and optical storage properties.
Effect of Cooling Rate and Iron Content on the Solidification Structures of Copper-Iron Alloys
Authors: Li Bao Mian , Zhang Hai Tao , Cui Jian Zhong
Published: September 2011

The effect of cooling rate and iron content on the solidification structures of copper-iron alloys had been investigated in this paper. The results show that the morphology of as-cast structure is mainly determined by iron content and the grain size is affected by both the iron content and cooling rate. The as-cast structure is obviously refined and its morphology changes gradually from columnar grains to equiaxed ones with the increase in iron content. When iron content is greater than 3% (in mass%) the as-cast structure is composed wholly of equiaxed grains. With the increase in cooling rate the as-cast structure is gradually refined and primary γ-Fe phase is gradually scattered uniformly throughout the matrix.