bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of 1-D Nanostructures of ZnFe2O4 and ZnO by a Low Cost Self-Catalyzed CVD Method
Authors: Tyagi Nitin , Kumar Ashutosh , Chaudhry Sumedh , Ray Subrata , Varma G.D.
Published: September 2009

Zinc ferrite (ZnFe2O4) is a commercially important material and has wide applications. We report the synthesis of nanostructured ZnFe2O4 and Fe-doped ZnO nanorods via a low cost, open to atmosphere self catalyzed Chemical Vapor Deposition(CVD) method which uses the Vapor-Liquid-Solid (VLS) Mechanism for growth. A mixture of Zinc Oxide, Graphite and Zinc powder, along with the substrates were put at the closed end of a quartz tube and placed in a preheated furnace. The parameters varied were 1.)molar ratios 2.)types of substrates and 3.)the furnace temperature. The characterization was done using FE-SEM, TEM,and XRD. The growth morphology varies along the temperature gradient in the tube, resulting in the formation of ZnFe2O4 nanoribbons (800-750 0C), nanoellipsoids (700 0C) and nanowires (650 0C). Fe- doped ZnO nanorods have also formed as scattered bundles along with the zinc ferrite nanoribbons. This is the first reported synthesis of nanoribbon morphology of ZnFe2O4 . The effective diameter:width ratio of the morphology and the Zn atomic percentage decreases along the temperature gradient. Optimized parameters were:1.)mild steel substrates, 2.)furnace temperature 800 0C and 3.)1:1:0.05 molar ratio of ZnO:C:Zn in the reaction mixture. When stainless steel and gold sputtered steels were used as substrates there was no growth. This proves that iron from the substrate takes an active part in the reaction and is critical for the growth. The simplicity of the setup, control over growth morphology and cheap reagents used give the method potential commercial applications.
Determination of Image Forces in Nanocrystals Using Finite Element Method
Authors: Khanikar Prasenjit , Kumar Arun , Subramaniam Anandh
Published: September 2009

A dislocation near a free surface feels a force towards the boundary, which is called the image force. In this investigation, a simple edge dislocation is simulated using Finite Element Method (FEM) by feeding-in the appropriate stress-free strain in idealized domains, corresponding to the introduction of an extra half-plane of atoms. The strains are imposed as thermal strains in the numerical model using standard commercially available software. The results of the simulation (stress fields and energy) are compared with the standard theoretical equations to validate the model. The energy of the system as a function of the position of the simulated dislocation is plotted and the gradient of the curve is calculated at various points along the curve. This slope corresponds to the image force experienced by the dislocation. The image force can be resolved into a glide component and a climb component, which are determined from the simulation by appropriately positioning the dislocation at various points in the domain. The term image force is used in literature (for the force experienced by a dislocation in the vicinity of a free-surface), because a hypothetical negative dislocation is assumed to exist on the other side of the boundary for the calculation of the force. In the current model no such assumption is required for the determination of the image force. In nanocrystals the dislocation will be proximal to more than one surface and hence the resultant image force experienced by the dislocation is superimposition of these forces. The utilization of the numerical model for the calculation of image forces in nanocrystals requires no further modifications to the simulation methodology as the image force is determined from 'first principles' as a gradient of the energy field.
Patterned Silicon Wafer for Selective β-SiC Nanowire Growth
Authors: Panda Sovan Kumar , Jacob Chacko
Published: September 2009

β-SiC nanowires have been synthesized on etch-patterned wafers in a chemical vapor deposition (CVD) system without using any metal catalyst. The nanowires were grown selectively inside the ‘V-groove’ of etch-patterned silicon (110) substrate which was used as a template for nanostructure growth. Nanowire growth was hardly found on the sample which was not previously etched. The nanowires have a core-sheath structure with the SiC core surrounded by an amorphous SiO2 sheath layer. The etching of the patterned Si (110) wafers was carried out by a 50 % aqueous KOH solution. The SiC growth was performed in a resistively heated atmospheric pressure chemical vapor deposition (APCVD) system by using hexamethyldisilane (HMDS) as the single source for Si and C at 1150oC. The as-grown samples and the patterned wafers were characterized by field emission electron microscopy, energy dispersive x-ray spectroscopy, X-ray diffraction, micro-Raman spectroscopy and Fourier transform infrared spectroscopy. Etching is one of the key factors for nanostructure growth and the patterning in the wafer provides selectivity. The growth process was governed by vapor-solid (VS) mechanism.
Impedance Response of Franklinite Films to Humidity and Propane
Authors: Avila-García Alejandro , Torres-Frausto Carlos
Published: September 2009

Iron-Zinc oxide films were deposited by the well known ultrasonic spray pyrolysis method from an aqueous solution of iron nitrate and zinc acetate ([Zn]/[Fe] = 0.30). A Franklinite structure of these films turned out from XRD measurements. Additional basic characterization with UV-Vis and infrared spectroscopies and AFM was also performed. Electrical measurements under a small alternating current signal (15 mV RMS) were performed under dry air, humid air (53 % R:H.) and humid air plus propane. Frequency scans yielded sensitivities as high as 260% to humidity and  475% to propane at 30 °C. At 250 °C lower sensitivities were obtained, but in all cases the highest values came from the reactive response of the film. From dynamical response measurements, the response time was also assessed. The mechanisms of sensing are discussed as well.
Annealing Effect on Microstructure and Coercivity of YCo5 Nanoparticles Obtained by Mechanical Milling
Authors: Elizalde Galindo José Trinidad , Sato Turtelli Reiko , Grössinger Roland , Matutes-Aquino José Andrés
Published: September 2009

Nanocrystalline YCo5 powders with high coercivity were prepared by mechanical milling and subsequent heat treatment at 820 °C for different annealing times, ta = 2.5, 3.0, 3.5 and 4.5 min, obtaining average crystallite sizes of   17, 19, 32 and 39 nm., respectively. The coercivity values were determined from the hysteresis loops measured at maxima fields of Hm = 5 and 20 T. The highest coercivity was obtained for the sample exhibiting   19 nm, where at room temperature and Hm = 5 T, the coercivity value is of 9.0 kOe. At 77 K and Hm = 5 T, the coercivity increase to 11.8 kOe and for Hm = 20 T, a higher value such as 13.1 kOe was found. The Ms/Mr ratio is enhanced to 0.62 indicating the occurrence of exchange interaction among nanocrystalline magnets.
Effect of Li on the Corrosion Behavior of Al-Cu/SiCp Composites
Authors: Lugo-Quintal Jesús , Díaz-Ballote Luis , Veleva Lucien , Contreras-Cuevas Antonio
Published: September 2009

The corrosion behavior in NaCl solutions at different pH values of Al-Cu-Li/SiCp and Al-Cu/SiCp composites fabricated by co-spraying technique was studied. The corrosion behavior of the composites was also compared with the corrosion behavior of pure aluminum. Corrosion potential measurements and potentiodynamic polarization were used to elucidate the corrosion behavior of the composites. In addition the microstructure and morphology of the composites were studied through X-ray diffraction (XRD) and scanning electron microscope (SEM). It was found that the corrosion rate of Al-Cu-Li/SiCp and Al-Cu/SiCp composites was higher than corrosion rate of pure aluminum for all NaCl solutions tested. Both composites and pure aluminum showed the typical “U” behavior of the corrosion rate as a function of pH. The addition of lithium had little effect on the corrosion behavior of the composites.
Characterization of Friction Stir Welding on Aluminum
Authors: Wong Jerry , del C. Zambrano Patricia , Guerrero-Mata Martha Patrizia , Mucino Victor , Colás Rafael
Published: September 2009

A series of linear and spot stir welding friction tests were carried out on aluminum samples of 1 mm in thickness and area of 100 mm x 27 mm. The tool rotating speed was varied from 2000 to 4000 RPM and the feeding rate from 45 to 67.8 mm/min. The temperature distribution during welding was measured by thermocouples inserted within the aluminum strips. The microstructure of the welded nuggets and the HAZ were analyzed by optical and scanning electron microscopy. Some samples were tested intension to measure the load carrying capacity of the welded bead. Preliminary analyses indicate that the temperature at the heat affected zone increases with the rotating speed.
Crack Disappearance by High-Temperature Oxidation of Alumina Toughened by Ni Nano-Particles
Authors: Salas-Villaseñor Ana L. , Lemus-Ruiz José , Nanko Makoto , Maruoka Daisuke
Published: September 2009

Crack disappearance by high-temperature oxidation was studied in alumina (Al2O3) composites toughened by Ni nanoparticles. This process is performed in air at temperature ranging from 1000 to 1300°C for 1 to 48 h. The results showed that crack disappearance depends on both annealing temperature and time. Complete crack disappearance in this composite was confirmed at lower temperatures for long oxidation period, 1100oC for 48 h, and higher temperature for shorter time, 1300oC for 1 h in air. The crack disappearance mechanism was explained on the basis of the formation of NiAl2O4 spinel on sample surfaces produced by the oxidation reaction during the heat treatment.
Microstructural Characterization of Electro-Deposited CdSe Thin Films
Authors: Thanikaikarasan S. , Mahalingam T. , Srikumar S.R. , Kim Tae Kyu , Kim Yong Deak , Subramaniam Velumani , Asomoza Rene
Published: September 2009

Thin films of CdSe were electrodeposited on tin oxide coated conducting glass substrates at various bath temperatures. The deposited films were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM). X-ray diffraction studies revealed that the deposited films are found to be hexagonal structure with preferential orientation along (002) plane. The microstructural parameters such as crystallite size, R.M.S strain, dislocation density, stacking fault probability were calculated using x-ray line profile analysis technique. The variation of microstructural parameters with bath temperature and film thickness were studied and discussed.
Effect of pH on Composition, Structure and Magnetic Properties of Electrodeposited Co-Ni Alloys
Authors: Mahalingam T. , Sundaram K. , Subramaniam Velumani , Raja M. , Thanikaikarasan S. , Kim Yong Deak , Asomoza Rene
Published: September 2009

Co-Ni alloy thin films were electrodeposited from sulfate baths at various solution pH values (1.5-5.5) ±0.1. The deposition kinetics of the films was studied using linear sweep voltametry (LSV). XRD studies exhibited fcc and hcp phases for Co-Ni alloys deposited at low and high pH ranges, respectively. EDAX studies showed that the cobalt content increased and nickel content decreased with increase in solution pH. The surface morphology of Co-Ni films were analyzed by scanning electron microscopy. It is found that the Co-Ni alloys synthesized at low pH exhibited soft magnetic properties and the films deposited at higher values revealed hard magnetic properties and the results are discussed.
Electrochemical Deposition and Characterization of Cd-Fe-Se Thin Films
Authors: Thanikaikarasan S. , Mahalingam T. , Sundaram K. , Kim Tae Kyu , Kim Yong Deak , Subramaniam Velumani
Published: September 2009

Cadmium iron selenide (Cd-Fe-Se) thin films were deposited onto tin oxide (SnO2) coated conducting glass substrates from an aqueous electrolytic bath containing CdSO4, FeSO4 and SeO2 by potentiostatic electrodeposition. The deposition potentials of Cadmium (Cd), Iron (Fe), Selenium (Se) and Cadmium-Iron-Selenide (Cd-Fe-Se) were determined from linear cathodic polarization curves. The deposited films were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis by x-rays (EDX) and optical absorption techniques, respectively. X-ray diffraction patterns shows that the deposited films are found to be hexagonal structure with preferential orientation along (100) plane. The effect of FeSO4 concentration on structural, morphological, compositional and optical properties of the films are studied and discussed in detail.
Electronic Structure of YFe2 by EELS and Ab Initio Calculations
Authors: Yáñez-Terrazas Emilio , Gallegos-Orozco Veronica , Matutes-Aquino José Andrés , Ochoa-Lara Martha T. , Espinosa-Magaña Francisco
Published: September 2009

The dielectric properties of the intermetallic cubic Laves phase compound YFe2 were determined by analyzing the low loss region of the EELS spectrum in a transmission electron microscope. From these data, the optical joint density of states (OJDS) was obtained by Kramers-Kronig analysis. Since maxima observed in the OJDS spectra are assigned to interband transitions; these spectra can be interpreted on the basis of numerical calculations performed with the Wien2k code, using the Fully-Linearized-Augmented-Plane wave (FLAPW) method within the Local-Spin-Density Approximation. Comparison between experimental results and theory shows good agreement.
Particle Flow Simulation on the Influences of Property Parameters of Semi-Fixed Abrasive Plate on its ‘Trap’ Effect
Authors: Yuan Ju Long , Wang Zhi Wei , Qian Miao , Yu Dong Qiang
Published: September 2009

This paper analyzes the property parameters influences of semi-fixed abrasive plate on the ‘trap’ effect with discrete element simulation by Particle Flow Code (PFC). The effects of the property parameters such as porosity, hardness and size of the abrasive particles, friction coefficient between the abrasive particles and the bonding agent concentration are simulated. The simulation results show that porosity, friction coefficient, bonding agent concentration has great influences on the ‘trap’ effect, while hardness and size of the abrasive particles almost have no effect. Grey incidence analysis is carried to determine the influence degree of porosity, friction coefficient, bonding agent concentration, and the results show that the most important factor is the porosity, followed by the friction coefficient, and then the bonding agent concentration.
Examination to Machining Characteristics of Semi-Fixed Abrasive Plate during the Lapping Process
Authors: Deng Qian Fa , Wen Dong Hui , Yuan Ju Long , Chen Feng
Published: September 2009

The most typical example of hard and brittle material is advanced ceramics, for its ultra-precision machining difficulty and wide applications, now it becomes a focus of attention. Semi-fixed abrasive plate (SFAP) is newly developed tool for machining advanced ceramics; As a result of SFAP abrasion, a gradual change takes place in the SFAP topography to influence on machining results and productivity. The paper shows experiment procedures to evaluate SFAP abrasion rate and workpiece material removal. The results of experiments are discussed and analyzed, it indicates that wet status of SFAP have great influences on the removal rate and SFAP abrasion. Compared with dry status of SFAP, wet status of SFAP can achieve higher processing efficiency.
3D Finite Element Simulation of Hard Turning
Authors: Yue Cai Xu , Liu Xian Li , Jia Dong Kai , Ji Shu Yi , Zhai Yuan Sheng
Published: September 2009

A 3D model is established in this paper to simulate cutting process of PCBN tool cylindrical cutting hardened steel GCr15 using ABAQUS/Explicit. The model effectively overcomes serious element distortions and cell singularity in high strain domain caused by material large deformation by adopting shear failure criteria and element deletion criteria. In this study cutting force, cutting temperature, surface residual stress field as well as side flow are forecasted of hard cutting process with chamfering tool preparation. It shows that satisfactory results could be obtained by FEM. The simulation results provide theoretical basis for studying hard cutting mechanism and selecting the best cutting condition in practical.
Laser Micromachining of Wide Bandgap Materials
Authors: Dai Y.T. , Xu Gang , Li Wei Lai
Published: September 2009

Owing to the large photo energy, 157nm laser is considered as one of promising micro-fabrication tools. In this paper, a micromachining system based on the 157nm laser is introduced. 2D laser direct-writing and 3D micro-structuring experiments are carried out for silica glasses, fibers and diamond. For natural diamond, the ablation threshold by 157nm laser is about 2.0J/cm2. Material removal is dominantly due to photon-chemical effect for 157nm laser ablation. Effectiveness of using 157nm laser for 3D micromachining is clearly demonstrated.
Research on Prediction Model of Surface Roughness in Ultrasonic Polishing Nano-ZrO2 Ceramics
Authors: Zhao Ming Li , Zhao Bo , Wang Yu Qing , Gao Guo Fu
Published: September 2009

The orthogonal test of surface roughness in ultrasonic polishing nano-ZrO2 ceramics was carried out in the present paper. Through the test, the influence of machining parameters on the surface roughness was investigated. The test results showed that the influence of abrasive size on surface roughness is the most remarkable, and the other important factors are the depth of cut, on/off work situation of ultrasonic generator, axial feed speed, and working table speed in turns. Furthermore, through the regressive analysis of test data, an empirical formula of surface roughness was established to select reasonable polishing parameters.
Development of Elliptical Vibration Cutting Technology and its Application to Ultraprecision/Micro Machining of Hard/Brittle Materials
Authors: Shamoto Eiji , Suzuki Norikazu
Published: September 2009

Precision machining, named ‘elliptical vibration cutting’, and its application to ultraprecision / micro machining of some hard / brittle materials are introduced in the present paper. The elliptical vibration cutting has a superior cutting performance in terms of low cutting force, low cutting energy, low heat generation, long tool life for steels, sintered tungsten alloy, etc., and large critical depth of cut for ductile machining of brittle materials such as glasses and single crystal calcium fluoride, etc. Based on these basic advantages, practical ultraprecision / micro machining of the hard / brittle materials is successfully realized by employing the ultrasonic elliptical vibration tools, which have been developed for ultraprecision machining.
3D Profile Measurement of Nanometer Cutting Edges of Single-Point Diamond Tools for Ultra-Precision Machining
Authors: Arai Yoshikazu , Asai T. , Ferdous Sayeda , Gao Wei
Published: September 2009

This paper describes an atomic force microscope (AFM) based instrument for 3D edge profile measurement of single-point diamond cutting tools. The instrument is composed of an AFM unit and an optical sensor for alignment of the AFM probe tip (silicon cantilever) with the diamond cutting tool edge. In the optical sensor, a laser beam from a laser diode along the Y-axis is focused to generate a small beam spot with a micrometer-order diameter at the beam waist, and then received by a photo-detector (photodiode). The tool edge top and the AFM probe tip are brought to the center of the beam waist in the XZ-plane through monitoring the variation of the photodiode output, respectively. Consequently, the AFM tip can be aligned with the tool edge top. Alignment experiments and 3D edge profile measurements of a round-nose type single-point diamond tool are carried out.
A New Internal Magnetic Field Assisted Machining Process Using a Magnetic Machining Jig-Machining Characteristics of Inside Finishing of a SUS304 Stainless Steel Tube
Authors: Zou Yan Hua , Shinmura Takeo
Published: September 2009

This paper proposes a new magnetic field assisted machining process using a magnetic machining jig (permanent magnet tool) to finish the internal surface of thick tubing 5~30 mm in thickness. Because the magnetic machining jig consists of permanent magnets, it can generate a higher magnetic force (finishing force) than conventional magnetic abrasives, and makes possible the internal finishing of thick non-ferromagnetic tubing. First, the principle and the feature of this process were examined. It was compared that the difference of the mechanism of using the conventional magnetic abrasives and magnetic machining jig (magnet tool) was clarified. Next, a processing unit and magnetic machining jig were made, and the processing unit was set on a lathe machine. An experiment was performed on a thick SUS304 stainless steel tubing 5 mm in thickness. In this study, it was clarified that this processing method can improve the roundness of the inside tubing while improving the surface roughness. The results showed that the initial surface roughness of 6.5 μm Ra can be improved to 0.06 μm Ra, and the roundness of the inside tubing can be improved from 187 μm to 89 μm.
Effect of Electrorheological Fluid Assistance on Micro Ultrasonic Machining
Authors: Tateishi T. , Shimada K. , Yoshihara Nobuhito , Yan Ji Wang , Kuriyagawa Tsunemoto
Published: September 2009

Ultrasonic machining (USM) is an effective machining method for hard brittle materials. In the USM process, the slurry is supplied to the gap between the ultrasonic vibrating tool and the workpiece. Materials are removed by the accumulation of small brittle fractures made by the impacts of abrasive grains. In a previous study, we proposed electrorheological fluid (ER fluid) assisted-USM, and the effect of ER fluid-assisted USM was confirmed practically by machining precise micro-holes and micro-grooves on hard brittle materials. In the present paper, in order to confirm the effect of ER fluid assistance for micro USM in more detail, the behavior of abrasive grains in the machining area is observed. The effect of dielectrophoretic force acts on the abrasive grains and the effect of using ER fluid assistance are investigated. As a result, the abrasive grains can closely approach the micro tool by the effect of dielectrophoretic force and be fixed around the micro tool by the effect of ER fluid assistance. Under these conditions, the workpiece is removed primarily by the accumulation of small brittle fractures, and the chipping can be reduced.
Preparation of MoS2/Zr Coated High Speed Steel Tool and its Cutting Performance
Authors: Zhao J.L. , Deng Jian Xin , Yan Pei
Published: September 2009

MoS2/Zr composite coatings were deposited onto M2 high speed steel tools by medium-frequency magnetron sputtered coupled with multi-arc ion plated techniques. The thickness, micro-hardness and coating-substrate adhesion strength of the coatings were studied. Surface morphologies of the as-deposited coatings as well as wear surface features after dry machining tests were investigated. The experimental results indicated that deposition of PVD MoS2/Zr composite coatings onto M2 HSS tools shows higher hardness compared to the pure MoS2 coatings, and exhibits significant enhancement in cutting performance. The wear mechanism of the MoS2/Zr coated tools is mainly delamination of the coating owing to the elevated cutting temperature and friction force.
Study on the Optimization of Deposition Processing Technology of Diamond Coated Tools
Authors: Ma Yu Ping , Chen Ming , Sun Fang Hong
Published: September 2009

Diamond films was deposited on cemented carbide tools with two-step pretreatment method under different distances between the substrates and hot filaments, and the effect of the distance between the substrates and hot filaments on the crystallographic orientation of diamond films and the characteristics of diamond coated tools was investigated in bias-enhanced HFCVD system in this paper. The cutting performance of diamond coated tools was verified by the experiments of cutting particles reinforced aluminum base composite material with 15 vol.% Si as compared with uncoated ones. The quality of diamond film was analyzed by means of Scanning Electron Microscopy(SEM), Raman spectroscopy, and X-ray diffraction. The optimization deposition processing was obtained. The relative intensity ratio of (111) facet and (220) facet in the film tested by XRD was one third. The cutting performance of diamond coated tool was improved significantly when machining the Si particle reinforced aluminum-based metal matrix composite; its lifetime was 30 times longer than that of uncoated one. The work done in this paper was of great practical significance to accelerate the industrialization of diamond films coated WC–Co substrates.
Research on Material Removal Characteristics of Nanoparticle Colloid Jet Machining
Authors: Zhang Yong , Song Xiao Zong , Zhang Fei Hu
Published: September 2009

For producing ultra smooth surface, a nanoparticle colloid jet machining system has been designed and manufactured in which a reversible polymerize and decompose reaction is utilized to remove surface atoms. The material removal characteristics of nanoparticle colloid jet machining were analyzed. A series of removal experiments were conducted to show the characteristics of the material removal in nanoparticle colloid jet machining. A K9 glass sample had been polished by using the nanoparticle colloid jet machining system, and an ultra smooth surface with micro roughness less than 1 nm RMS had been obtained. The experimental results prove that it is suitable to fabricate ultra smooth surface with nanoparticle colloid jet machining.
Experimental Study on Parameter Optimization of Silicon Wafer CMP Using Composite Abrasives Slurry
Authors: Xu Xue Feng , Ma H.T. , Ma B.X. , Peng Wei
Published: September 2009

In order to increase the material removal rate of silicon wafer, composite abrasives slurry was used in CMP. The mechanism of interaction between silica abrasives and polymer particles was analyzed. Small silica abrasives were seen to attach onto the surface of the polymer particles. Composite abrasives slurry was obtained by adding polymer particles into single abrasive slurry. Three key parameters, the concentration of colloidal silica, the concentration of polymer particle and the speed of polishing, which influence the material removal rate of silicon wafer were analyzed by Taguchi method and the optimal parameters were obtained. Experimental results indicated that the maximum material removed rate of 353nm/min was obtained when optimal craft parameters of 5% colloidal silica, 3% polymer particle, 50rpm plate and carrier rotation speed were selected.
Electrochemical Micro Machining of Stainless Steel with Voltage Pulses
Authors: Chen Hui , Wang Zhen Long , Peng Zi Long , Dong Ying Huai , Zhao Wan Sheng
Published: September 2009

The purpose of this paper is to study electrochemical micro machining (ECM) technology on stainless steel. The micro machining of stainless steel is difficult by electrochemical machining, especially in machining deep micro holes, because of an oxide layer formed on the surface. To machining stainless steel, HF is usually used in electrolyte to destabilize the oxide layer. In this paper, ECM of stainless steel by applying short pulses in less toxic and corrosive electrolyte is research. The influence of electrochemical machining parameters such as voltage, current, electrolyte composition to machine stainless steel was investigated. The results showed that the oxide layer can be reduced by adding chloride and complex.
Study on Semi-Fixed Abrasive Lapping of Ultra-Thin Silver Electrode Layer
Authors: Lv Xun , Yuan Ju Long
Published: September 2009

Silver electrode layer of piezoelectric ceramic transducer requires good surface quality and high efficiency. Efficiency of traditional lapping and polishing is very low. Ultra-precision grinding technology is also unsuitable for the thickness of workpiece is extremely thin. Semi bonded abrasive lapping is a new ultra-precision processing method. The new ultra-precise method can achieve good surface quality in short time, and removal stock of workpiece is small. In order to research the optimal technology of semi bonded abrasive lapping about silver electrode layer, this paper research several major processing parameters by experiments. The results show that appropriate processing load can obtain better surface roughness of silver electrode layer，and surface roughness of silver electrode layer has little change with different processing speed. By using ultra-fine semi bonded abrasive plate, 94.08KPa processing load and 40 rpm polishing speed, after 30 minutes, surface roughness of silver electrode layer is 11nm, and removal stock is 11.5μm.
Test Research on Grinding Performance of the New Grinding Fluid in Power Ultrasonic Honing
Authors: Zhu Xi Jing , Lu Zhi Meng , Sun X.D. , Gao Hang
Published: September 2009

Grinding fluid has an important effect in processing work piece, so in view of the new grinding fluid, a large number of tests have been taken in the application of the power ultrasonic vibration honing. The massive experimental study, separated from the work piece’s surface roughness, the work piece’s surface rubbed deterioration layer and the influence to the processing characteristic with different density of the new grinding fluid and so on, discussed the adaptability of the new grinding fluid in power ultrasonic vibration honing processing. The research has been indicated that although the new grinding fluid does not surpass the traditional working fluid, such as emulsion and liquor, in cooling performance, it has a better lubricating property and has the obvious superiority in the working accuracy and the oilstone’s length of life. Therefore the new self-developed grinding fluid is suitable for the power ultrasonic honing processing.
Cathode Design of Aero-Engine Blades in Electrochemical Machining Based on Characteristics of Gap Distribution
Authors: Hua Ji , Li Zhi Yong
Published: September 2009

Cathode design is a difficult problem must be faced and solved in ECM. We develop a new numerical approach for cathode design by employing a finite element method and this approach has been applied in the cathode design of aero-engine blades in ECM. The mathematic models of the electric filed and electrolyte flow filed distribution in EMC process are described primarily. Then the realization procedure of this approach is presented，in which the effects of electric filed and electrolyte flow filed distribution within the inter-electrode gap domain are concentrated. In order to verify the machining accuracy of the designed cathodes, the experiments are conducted using an industrial scale electrochemical machining system. The experimental results demonstrate that the machined blade have high surface quality and dimensional accuracy which proves the proposed approach for cathode design of aero-engine blades in ECM is applicable and valuable.
Optimization Design of Electrical and Magnetic Characteristics of an Ultra-Precision Machine Tool Motorized Spindle
Authors: Lv Lang , Xiong Wan Li , Yuan Ju Long
Published: September 2009

Electrical and magnetic characteristics of motorized spindles have a great effect on machining quality of ultra-precision machine tools. Bad characteristics will result in significant heat losses, low efficiency and large vibration. Study on optimizing electrical and magnetic characteristics of an inverter-fed induction motor is presented in this paper. A method of optimization design of an inverter-fed induction motor is given. The method is used to design a motor used for an ultra-precision machine tool motorized spindle. By comparing the optimal design with the traditional one, it shows that the total electrical and magnetic heat losses are obviously decreased and the efficiency can be improved.
Processing of WC-Co Cemented Carbide Balls by Rotated Dual-Plates Lapping Machine
Authors: Chen De Sheng , Yang Fan , Tang K.F. , Chen Jia Jie , Yuan Ju Long , He X.H.
Published: September 2009

In this paper, the batch processing of Φ35mm WC-Co cemented carbide balls used in one-way value is studied by rotated dual-plates (RDP) lapping machine. On the basis of this innovated equipment, the processing parameters, including abrasive grain, rotating velocity and load, are changed legitimately in experiment. The experimental results show that the abrasive grain is used from big to small, while the rotating velocity and load are gradually reduced in order to improve the uniformity of lapping trace distribution on the ball surface in batch processing. Finally the rational course and parameters are defined, these WC-Co cemented carbide balls satisfy the products’ final demand which means the sphericity error (Rnd) is less than 1μm and the roughness of surface (Ra) is better than 50nm. Because of the feasibility, the precision of final WC-Co cemented carbide balls improves and can be applied in one-way value used in oil exactor.
Simulation of Temperature Field of Oil Film in Super-High Speed Hybrid Journal Bearing Based on FLUENT
Authors: Xiu Shi Chao , Xiu Peng Bo , Gao Shi Qiang
Published: September 2009

The hybrid journal bearing with the high rigidity and rotation accuracy has been used in super-high speed grinding machine in some cases. But the main shortcoming of hybrid journal bearing is the higher temperature rise in the oil film when bearing works, which can lower the bearing capacity and cause the bearing failure due to the drop of oil viscosity and the larger thermal deformation. Fluent is a special CFD soft to simulate and analyze the flow and the heat exchange of liquid in the complex geometrical field. In this paper, the simulations of the temperature field of the oil film in the super-high speed hybrid journal bearing were performed by Fluent based on the mathematical models. The simulation results can not only forecast the flow state and the thermal properties of the bearing oil, but also find the design limitation of the bearing for the more improvement of the bearing design.
Cutting Force Empirical Model of High-Speed Precision Hard Cutting GCr15
Authors: Hu Jing Shu , Zhai Yuan Sheng , Yan Fu Gang , Li Yu Fu , Liu Xian Li
Published: September 2009

In the cutting process, cutting force is one of the important physical parameters, which affects the generation of cutting heat, tool life and surface precision of workpiece directly. In this paper an orthogonal design of experiment and subsequent data is analyzed using high speed finish hard cutting GCr15 whose hardness is 65HRC. Cutting speed is 200-400m/min, to study the influence of cutting parameters on cutting force, cutting force empirical model has obtained from least square method.
2D FEM Estimate of Tool Wear in Hard Cutting Operation: Tool Wear and Simulation of Hard Cutting Process under Steady State
Authors: Yan Fu Gang , Yue Cai Xu , Liu Xian Li , Li Yu Fu , Ji Shu Yi
Published: September 2009

Tool wear plays an important role in cutting process research. It affects the quality of machined surface and cutting parameter to a great extent, such as cutting force, cutting temperature and cutting quiver. In order to predict tool wear in hard cutting process by using FEM method, the character of tool wear during cutting process is presented firstly, and Usui’s tool wear rate model is introduced. Then the FEM model for steady state cutting process using Abaqus is established. FEM model describes the workpiece material characteristic accurately for the process of PCBN tool cutting GCr15 by adoptiving Johnson-Cook constitutive model. Simulation results of steady cutting process offer foundation to simulate tool wear.
Polishing Robot: Status and Outlook
Authors: Wan Yue Hua , Wang Guan
Published: September 2009

The polishing robot can serve the polishing work and realize the fully automation for obtaining much higher polishing efficiency and well-proportioned surface quality which attracts many researchers’ attention. In this reviews, the research status of the polishing robot are summarized. Twenty-eight articles which published these years about the polishing robot are introduced in brief. The robot system for complex surfaces polishing, automation of polishing process for a cavity surface, intelligently automated polishing abrasive polishing, the CAD/CAM-based position/force controller for a mold polishing robot and so on are reviewed. More research on an effective gasbag polishing technique based on the novel spinning-inflated-gasbag polishing tool, which can obtain well-proportioned quality surface and high polishing efficiency is a potential one. Investigations of the polishing robot will be helpful for the readers understand the robotic polishing.
The Slurry for Glass Polishing by Micro Abrasive Suspension Jets
Authors: Liao Yan  Pei , Wang Cheng Yong , Hu Ying Ning , Song Yue Xian
Published: September 2009

The influence of different dispersants and suspending agents of CeO2 polishing powder was investigated, including sodium hexametaphosphate, polyethyleneglycoll, polyacrylic acid, anionic polyacrylamide, and their mixtures. The suspension stability of ceria particles in slurries and the pH dependence were examined by the measurement of zeta potential, sedimentation and viscosity, etc. The material removal rate and surface roughness of different slurries for K9 glass polishing were studied. The slurry mixed by three kinds of dispersants can achieved the maximum material removal rate and the minimum surface roughness.
Research on On-Line Control Strategy for the Wearing Compensation of Polishing Wheel
Authors: Yu H.X. , Xu H. , Yuan Ju Long
Published: September 2009

A novel control strategy for on-line polishing wheel wearing compensation in a polyhedral glass grinding machine is proposed, which is mainly consisted of hybrid feed-forward feed-backward control scheme and adaptive wearing prediction algorithm. It has advantage of eliminating the size excursion of polishing roller during long term operation, while the implementation of high accuracy diameter measurement is unnecessary. Hence it greatly reduces the demand for precise sensor and complicated calculation algorithm. Consequently, surface polishing quality and flexibility of the grinding machine was enhanced greatly. Theoretical analysis and experiment result obtained from a laboratory prototype shows good agreement, which indicates that the proposed control strategy has good performance in polishing wheel diameter compensation applications.
Research Progress of Advanced Machining Technologies for Engineering Ceramics
Authors: Tian Xin Li , Yang Jun Fei , Liu Chao , Zhang Bao Guo
Published: September 2009

Based on the comprehensive summary of latest research achievements of Laser and EDM technologies in home and abroad, the other advanced machining technologies is summarized briefly, such as Ultrasonic Wave, Microwave machining techniques and their composite machining technologies, as well as High-speed (Super High-speed) Grinding, ELID Grinding and Interface Thermal Chemistry Reaction Aided Machining technologies developed on the basis of traditional grinding technology. At last, it is forecasted that the necessary direction of advanced technologies used for ceramics is combinatorial machining technologies of two or more kinds of advanced technologies.
Optimization of Ti-6Al-4V Flank Milling Parameters Using Taguchi Method
Authors: Liu Chang Yi , Yi Jun Jie , Zhou Wen Hui , Chu Cheng Long
Published: September 2009

This paper presents a study of the Taguchi design methodology, which is applied to optimize flank milling operation parameters when machining titanium alloy Ti-6Al-4V in conventional and high speed regimes. This study includes cutting speed, feed rate and depth of cut. Experimental runs are conducted using an orthogonal array of L9(33), with measurement of surface roughness. ANOVA analyses are carried out to analyze the effect of these operation parameters, and the optimal parameters combination is determined by seeking the best surface roughness. The analysis of result shows that the optimal combination for good surface roughness is high cutting speed, low feed rate. Finally, confirmation run verifies the results, which indicated that Taguchi method is both efficient and effective in determining the Ti-6Al-4V flank milling parameters for the optimization with minimum number of trials.
Experimental Study in HSM of Hardened Steel AISI D2
Authors: Qi B.Y. , He Ning , Li Liang
Published: September 2009

Hardened steel is widely used for good mechanical property, but its machinability is bad comparatively. It is efficient to enhance metal removed rate when high speed milling (HSM) hardened steel, but tool wear is rapid. In this paper, high-speed milling experiments were carried out for hardened steel with TiAlN coated tools. The effects of milling parameters on tool wear and surface roughness were studied. The influences of different coolants, such as dry, MQL, cryogenic MQL conditions on HSM hardened steel, were compared with each other, results showed that cryogenic MQL HSM hardened steel had better effects that can better reduce tool wear, extend tool life.
Research on the 3-Axis CNC Ultra-Precision Grinding of Aspheric Mould
Authors: Li Li Jun , Zhang Fei Hu , Dong Shen
Published: September 2009

Parallel grinding is an effective method of aspheric moulds machining which is usually made of industrial ceramic such as silicon carbide (SiC) or tungsten carbide (WC), but if the spherical grinding wheel is not being with precision truing and dressing, the roughness and form accuracy of the ground aspheric surface should get worse, for this reason, in this paper, the influence factors of thoroughness and form accuracy induced by the wheel truing and dressing are studied firstly, and a new 3-axis CNC Ultra-precision grinding system which is based on the PMAC (Programmable Multi-axes Controller) is developed, through simultaneous motion of the controlled X, Z and B axis, the form errors which is induced by the grinding wheel can be improved theoretically, and the aspheric mould machining test shown that the surface roughness of Ra 0.025μm and the form accuracy of P-V 1.15μm are achieved.
Damage Analysis of Cemented Carbide Tool in High Speed Milling Induced by Thermal Stress with Laser Shock
Authors: Wan Yi , Liu Zhan Qiang , Pang J.Y. , Zhao X.F.
Published: September 2009

Damage of fine grained hard metals WC-10%Co was investigated using the laser thermal shock method. Cemented carbide insert was irradiated with a high power laser and scanning electron microscopy was used to characterize the damage in the surface. Stress was analysis with thermo-elastic theory after thermal shock cycles. Crack initiation of cemented carbide was primarily induced by high thermal shock cycles under high rotation speed and low feed rate. Tangential stress played a primary role in crack initiation and it was demonstrated that why the thermal cracks always perpendicular to the cutting edge.
Determination of Minimum Uncut Chip Thickness in Micromachining
Authors: Shi Zhen Yu , Liu Zhan Qiang
Published: September 2009

In micromachining, the uncut chip thickness is comparable to the tool edge radius, and chip won’t be generated if the uncut chip thickness is less than a critical value, besides that, the minimum uncut chip thickness affect many factors such as the cutting force, the chip’s modality, the cutting surface quality, etc. In this paper, a geometric model is developed to predict the minimum uncut chip thickness values. The model accounts for the theory that the critical condition of producing chip is when the friction of the surface deformation asperities is zero. Two situations when the minimum value is larger or smaller than the tool edge radius respectively to predict the minimum value are discussed. The influences of tool edge radius and material’s property on the minimum uncut chip thickness are taken into account.
Study on Cutting Forces in High-Speed Milling of LF21 Aluminum Alloy and Regression Model of Cutting Forces
Authors: Wang Z.H. , Yuan Jun Tan , Hu X.Q. , Xiong X.W.
Published: September 2009

Cutting force is a key factor influencing the machining deformation of weak rigidity workpieces. In order to reduce the machining deformation and improve the process precision and the surface quality, it is necessary to study the factors influencing the cutting force and build the regression model of cutting forces. Firstly, the cutting parameters influencing cutting force are analyzed for LF21. Secondly, how certain cutting parameter influence the cutting component forces (Fx, Fy, Fz) are studied by the correlation analysis and the approach to choosing the right cutting parameters for machining the weak rigidity workpieces are presented. Finally, the regression model of cutting forces based on the cutting parameters is investigated in this paper.
TiAlSiN Coatings Prepared by Hybrid PVD Technology for High Speed Milling of Hardened Steel
Authors: Yu D.H. , Wang Cheng Yong , Cheng X.L. , Song Yue Xian
Published: September 2009

TiAlSiN coatings with different Al content were prepared by hollow cathode discharge ion plating (HCDIP) and medium frequency magnetron sputtering ion plating (MFMSIP) hybrid physical vapor deposition (PVD) coating system. The composition, microstructure, mechanical properties of these coatings were systematically investigated by means of EDX, XRD, SEM, nanoindentation, scratch and tribological tests. It was found that the coatings had (111) or (200) preferred orientation with addition of Al. Proper content of Al led to increase of microhardness and adhesion. The flank wear of carbide end mill coated with TiAlSiN had the least wear than those coated with TiAlN and TiSiN coatings under the high speed milling of hardened steel experiments.
Process Parameters Selection in NC Camshaft Grinding Based on Uniform Design and GA-NN
Authors: Deng Zhao Hui , Zhang Xiao Hong , Liu Wei , Cao De Fang , Cao H.
Published: September 2009

In order to enhance the processing accuracy, the surface quality and the processing efficiency of camshaft grinding, a processing parameters selection in NC camshaft grinding based on uniform design, neural network and genetic algorithm was proposed by using CNC8312A NC camshaft grinder to test training samples. The nonlinear mapping relation between processing requirements (inputs) and processing parameters (outputs) was achieved. By comparing the theoretical values with the output values of the neural network, and analyzing the errors between actual measurement results and processing quality requirements, a satisfied result was obtained by applying the model to actual production.
Experimental Study on High Speed Machining of a Titanium Alloy
Authors: Geng Guo Sheng , Xu Jiu Hua
Published: September 2009

High Speed Machining (HSM) has been proved to be useful in the machining of many materials. This research is concerned with the performance of HSM in the milling of Ti-6.5Al-2Zr-1Mo-1V (TA15) titanium alloy. The tool life and wear mechanism of the milling tool under different cutting speed were investigated, and the influences of cutting speed on the surface integrity and fatigue property of the machined part were studied. According to the experimental results, acceptable tool life can be obtained in a speed range up to 200m/min. The results also show that increasing cutting speed can help to improve the surface integrity and fatigue property of the machined part.