bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling, Fabrication, and Characterization of Planar Inductors on YIG Substrates
Authors: Haddad Elias , Martin Christian , Joubert Charles , Allard Bruno , Soueidan Maher , Lazar Mihai , Buttay Cyril , Payet-Gervy Beatrice
Published: September 2011

This paper presents the design, fabrication, and characterization of micro planar inductors on a microwave magnetic material (YIG). Planar spiral inductors were designed for monolithic DC-DC converters in System-In-Package with 100 MHz switching frequency (1 W, Vin= 3.6 V, Vout= 1 V). A microwave magnetic substrate (YIG) serves as mechanical support, and also presents a double purpose by increasing inductance value and reducing electromagnetic interferences (EMI). This last point is critical to improve the behavior of a switching mode power supply (SMPS). In order to obtain an optimal design for the inductor, geometrical parameters were studied using Flux2D simulator and an optimized 30 to 40 nH spiral inductor with expected 25 mΩ RDC, 3 mm2 footprint area was designed. Subsequently, samples have been fabricated by electroplating technique, and tested using a vector network analyzer in the 10 MHz to 100 MHz frequency range. Results were then compared to the predicted response of simulated equivalent model.
RBS Study of Multilayer Structure Material of Si/SiO2 Nano Films
Authors: Roumie Mohamad , Abboudy Sayed , Al Sabbagh Maryam , Abu-Safe Husam , Soueidan Maher , Nsouli Bilal
Published: September 2011

An absorber-emitter system was fabricated using a multi-layer structure of amorphous silicon and silicon oxide thin films. The layers were deposited using RF magnetron sputtering system. The thin films were alternated in a periodic structure to form a one-dimensional photonic crystal. Each period in the crystal consisted of one layer of 57 nm thick silicon and a 100 nm thick silicon oxide layer. Several samples were prepared consisted on different periods (N= 1, 2, 3, 4, 5 and 10). Rutherford Backscattering Spectrometry technique (RBS) was used to verify the number of layers and their alternation, checking the thicknesses and determine the real stoichiometry in each layer of Si and SiOx.
Swift Quantification of Fenofibrate and Tiemonium methylsulfate Active Ingredients in Solid Drugs Using Particle Induced X-Ray Emission
Authors: Bejjani Alice , Nsouli Bilal , Zahraman Khaled , Assi S. , Younes Ghassan , Yazbi F.
Published: September 2011

The quantification of active ingredients (AI) in drugs is a crucial and important step in the drug quality control process. This is usually performed by using wet chemical techniques like LC-MS, UV spectrophotometry and other appropriate organic analytical methods. However, if the active ingredient contains specific heteroatoms (F, S, Cl…), elemental IBA like PIXE and PIGE techniques, using small tandem accelerator of 1-2 MV, can be explored for molecular quantification. IBA techniques permit the analysis of the sample under solid form, without any laborious sample preparations. In this work, we demonstrate the ability of the Thick Target PIXE technique for rapid and accurate quantification of both low and high concentrations of active ingredients in different commercial drugs. Fenofibrate, a chlorinated active ingredient, is present in high amounts in two different commercial drugs, its quantification was done using the relative approach to an external standard. On the other hand, Tiemonium methylsulfate which exists in relatively low amount in commercial drugs, its quantification was done using GUPIX simulation code (absolute quantification) The experimental aspects related to the quantification validity (use of external standards, absolute quantification, matrix effect,...) are presented and discussed.
Poly(3-alkylthiophene) Nanofibers for Photovoltaic Energy Conversion
Authors: Bertho Sabine , Oosterbaan Wibren D. , Vrindts Veerle , Bolsée Jean Christophe , Piersimoni Fortunato , Spoltore Donato , D'Haen Jan , Lutsen Laurence , Vanderzande Dirk , Manca Jean V.
Published: September 2011

The use of nanostructured non-conventional semiconductors such as conjugated polymers and metal oxides (e.g. TiO2), opens promising perspectives towards a new generation of solar cells based on the concept of donor:acceptor bulk heterojunctions. In this concept donor material and acceptor material form interpenetrating networks allowing light absorption, charge transfer and charge transport throughout the entire bulk of the thin film. Since nanomorphology is of crucial importance for this type of solar cells, in this contribution the use of nanofibers in bulk heterojunction solar cells is explored in order to obtain highways for charge transport. We investigate in particular the use of P3AT (poly(3-alkylthiophene)) nanofibers and show that the polymer fraction aggregated into fibers can be easily controlled by temperature. We find an optimal efficiency at intermediate fiber fraction and show that it can be linked to the morphology of the active layer.
Relationship between the Compressive and Tensile Strength of Recycled Concrete
Authors: El Dalati Rouba , Matar Pierre , Haddad Sara , Hage Chehade Fadi
Published: September 2011

Concrete recycling consists of crushing the concrete provided by demolishing the old constructions, and of using the resulted small pieces as aggregates in the new concrete compositions. The resulted aggregates are called recycled aggregates and the new mix of concrete containing a percentage of recycled aggregates is called recycled concrete. Our previous researches have indicated the optimal percentages of recycled aggregates to be used for different cases of recycled concrete related to the original aggregates nature. All results have shown that the concrete compressive strength is significantly reduced when using recycled aggregates. In order to obtain realistic values of compressive strength, some tests have been carried out by adding water-reducer plasticizer and a specified additional quantity of cement. The results have shown that for a limited range of plasticizer percentage, and a fixed value of additional cement, the compressive strength has reached reasonable value. This paper treats of the effect of using recycled aggregates on the tensile strength of concrete, where concrete results from the special composition defined by our previous work. The aim is to determine the relationship between the compressive and tensile strength of recycled concrete.
Effect of Slag Content and Hardening Accelerator Dosage on the Physico-Mechanical Properties of Cement and Concrete
Authors: Derabla Riad , Mokrani Imen , Benmalek Mohamed Larbi
Published: September 2011

Our contribution consists at the study of the effect of (0 %, 0.2 % and 0.34 %) dosage of an hardening accelerating plasticizer (Plastocrete 160, produced by Sika Aldjazair) on the properties of normal mortar and concretes prepared with portland cement artificial of Hadjar Soud cement factory (Skikda – Algeria) with addition of (10 % and 20 %) of granulated blast furnace slag finely crushed of the El Hadjar blast furnace (Annaba - Algeria). The tests are focused to the physical and mechanical characteristics of elaborated materials to knowing: setting time, porosity, water absorption capacity and the test of compressive strength at 2, 7 and 28 days. The results obtained show clearly the reliability of the additive used to accelerate the hardening and to obtain high strengths at early age, which increase by increasing of the additive dosage. For the slag, its low hydraulic capacity does not make it profitable than at the long term (beyond 28 days).
Probabilistic Analysis of Slope Stability towards the Slip by the Kinematic Method
Authors: Zeroual Fatima , Belabed Lazhar
Published: September 2011

The check of the stability of banks towards the slidings always crosses by the adoption of empirical global safety factors result, generally, of the study of the break along the deep surface of sliding. The mechanical model suited to this mode of break is subject to controversy. In this article we propose a mechanical model of calculation for the break along the deep surface of sliding based on the kinematic method of the stiff solids (limit analysis). A comparison of this model proposed with the conventional model was led according to the statico-probability concept of security. The reliability of the system is expressed by means of the indication of reliability β.
Characterization and Aging Test Methodology for Power Electronic Devices at High Temperature
Authors: Ibrahim Ali , Khatir Zoubir , Dupont Laurent
Published: September 2011

Power electronic modules are key elements in the chain of power conversion. The application areas include aerospace, aviation, railway, electrical distribution, automotive, home automation, oil industry ... But the use of power electronics in high temperature environments is a major strategic issue in the coming years especially in transport. However, the active components based on silicon are limited in their applications and not suitable for those require both high voltages and high ambient temperatures. The materials with wide energy gap like SiC, GaN and diamond, have the advantage of being able to exceed these limits [1,2]. These materials seem adequate to extremely harsh temperature environments and allow the reduction of cooling systems, but also the increasing of switching frequency.
Influence of HfO2 Control Oxide ALD Precursor Chemistry for Nitride Memories
Authors: Nikolaou Nikolaos , Dimitrakis Panagiotis , Normand Pascal , Ioannou-Sougleridis Vassilios , Giannakopoulos Konstantinos , Mergia Konstantina , Kukli Kaupo , Niinisto Jaakko , Ritala Mikko , Leskela Markku
Published: September 2011

In this work we report on the structural and electrical properties of SiO2/Si3N4/HfO2 memory stacks with emphasis upon the influence of Atomic Layer Deposition chemistry used for forming the HfO2 blocking layer. Two HfO2 precursor chemistries were employed, the tetrakis- (ethylmethylamino)hafnium (TEMAH) and the bis(methylcyclopentadienyl)methoxymethylhafnium (HfD-04). Ozone was used as the oxygen source. The structural characteristics of the stacks were examined by means of TEM and GIXRD. Comparative studies conducted with the use of platinum gated capacitors showed that the samples grown using TEMAH have an increased electron trapping ability in comparison to the HfD-04 ones. While the two structures exhibit similar Write/Erase and retention characteristics, The samples grown from TEMAH can sustain more repeated W/E cycles (> 3×105 in the 10V/-11V, 10 ms regime) compared to the samples grown from HfD-04 (< 104 W/E cycles). This difference in endurance characteristics is attributed mainly to the different deposition temperatures used with these two precursors and the nature of the interfacial layer they produce between the Si3N4 and the HfO2 layers.
Low Cost SU8 Based Above IC Process for High-Q RF Power Inductors Integration
Authors: Ghannam Ayad , Bourrier David , Viallon Christophe , Parra Thierry
Published: September 2011

This paper presents a new process for integration of high-Q RF power inductors above low resistivity silicon substrates. The process uses the SU8 resin as a dielectric layer. The aim of using the SU8 is to form thick dielectric layer that can enhance the performance of the inductors. The flexibility of the process enables the possibility to realize complex shaped planar inductors with various dielectric and metal thicknesses to meet the requirements of the application. Q values of 55 at 5 GHz has been demonstrated for an inductance value of 0.8 nH using a 60 µm thick SU8 layer and 30 µm thick copper ribbons.
U-Patch Antenna for RFID and Wireless Applications
Authors: Saad R. Abi , Melhem Zeina , Nader Chadi , Zaatar Youssef , Zaouk Doumit
Published: September 2011

in this paper, we propose a new multi-band patch antenna structure for embedded RFID (Radio Frequency Identification) readers and wireless communications. The proposed antenna is a dual band microstrip patch antenna using U-slot geometry. The operating frequencies of the proposed antenna are chosen as 2.4 and 0.9 (GHz), obtained by optimizing the physical dimensions of the U-slot. Several parameters have been investigated using Ansoft Designer software. The antenna is fed through a quarter wavelength transformer for impedance matching. An additional layer of alumina is added above the surface of the conductors to increase the performance of the antenna.
Low-Temperature Joining Technique as Interconnection Technology for Power Electronics
Authors: Amro Raed
Published: September 2011

There is a demand for higher junction temperatures in power devices, but the existing packaging technology is limiting the power cycling capability if the junction temperature is increased. Limiting factors are solder interconnections and bond wires. With Replacing the chip-substrate soldering by low temperature joining technique, the power cycling capability of power modules can be increased widely. Replacing also the bond wires and using a double-sided low temperature joining technique, a further significant increase in the life-time of power devices is achieved.
Low Frequency Noise Analysis in Advanced CMOS Devices
Authors: Jomaah Jalal , Fadlallah Majida , Ghibaudo Gérard
Published: September 2011

A review of recent results concerning the low frequency noise in modern CMOS devices is given. The approaches such as the carrier number and the Hooge mobility fluctuations used for the analysis of the noise sources are illustrated through experimental data obtained on advanced CMOS generations. Furthermore, the impact on the electrical noise of the shrinking of CMOS devices in the deep submicron range is also shown.
Wireless Energy Transfer Using Zero Bias Schottky Diodes Rectenna Structures
Authors: Marian Vlad , Adami Salah Eddine , Vollaire Christian , Allard Bruno , Verdier Jacques
Published: September 2011

This paper presents several RF-to-DC converter topologies and compares their performances based on measurements made on fabricated prototypes. A medium range wireless low power transmission experiment is presented. A low power DC-DC boost converter designed rectenna-generated energy conditioning is also discussed.
Contribution of the Luminescence Phenomena of nc-Si to the Performances of the Industrial mc-Si Solar Cells
Authors: Zerga Abdellatif , Benyelles Kamila
Published: September 2011

In this study, we attempt the contribution of the silicon nanocrystal nc-Si luminescence phenomena to the performance of the conventional mc-Si solar cells. These nc-Si are embedded in the hydrogenated silicon nitride dielectric layers. The experimental results are obtained by different characterizations. They show that the optimum temperature is around 720°C with a good homogeneous distribution of nc-Si (3-5nm). However, to validate our results on silicon solar cells, we deposited silicon-rich silicon nitride layers on p-type (0.5ohm.cm) and diffused POCl3(40ohm/sq) substrates. Then, we performed thermal annealing at 720°C under mixture of gas (N2/H2) during one hour. The I-V measurements are carried out after the screen printing metallization and they showed 0.4% increase of the absolute efficiency.
Non-Thermal Plasma Treatment of Contaminated Surfaces: Remote Exposure to Atmospheric Pressure Dielectric Barrier Discharge Effluent
Authors: Limam Soukayna , Kirkpatrick Michael , Odic Emmanuel
Published: September 2011

Iatrogenic infections due to contaminated medical devices are significant problem in the field of medicine, and have motivated the search for alternative surface disinfection/sterilization methods and technologies. During the last decade, a strong effort has been made in the field of non-thermal plasmas, including fundamental work from a physical, but also biological point of view. Non-thermal plasmas are used in industry for the modification of surface properties such as to improve wettability and adherence, and also for the deposition of thin films. The present work considers the treatment of surfaces contaminated by either bacteria or proteins with the effluent gas exiting from an atmospheric pressure dielectric barrier discharge. The discharge reactor consisted of a coaxial cylindrical geometry DBD reactor energized by a 30 kHz applied voltage. The effluent gas was used to treat surfaces contaminated with Escherichia coli (strain DH10B) or RNAse A (124 amino acids, 13.7kDa, known to be thermal-resistant). Results show that the decontamination of surfaces by the effluent gas from a humid argon DBD is effective, and that the effectiveness is greater the closer the biological samples are placed to the DBD source. The results also indicate that the mechanism of bacterial inactivation is based on a combination of stable oxidative species such as ozone and hydrogen peroxide as well as shorter lived species such as hydroxyl radical.
Analysis of Physical, Chemical and Microbiological Pollution in one Right Click
Authors: Tabet Antoine , Khoury Antonio
Published: September 2011

Current researches on the topic of indoor air pollution are moving towards expertise and prevention. Therefore it seems so critical to invest in the area of expertise and create a measuring device performing chemical, physical and bacteriological analysis in one click. Our choice of development towards this system of information management is oriented towards a modular system which can simultaneously transmit on real-time the analysis in the internet. Our production work has used several solutions and analyzed several possible methods such as microprocessor that has shown its reliability. The electronic system worked well even with some problems solved at the level of detection of particles α, β and δ. The solution NO-IP as for the transfer of data over the Internet has been successfully tested. In the same way we have been constrained to achieve measurement campaigns to verify the ability of the device to give consistent values. These campaigns were conducted on the Beaulieu of the University of Rennes 1, given the size of the site; it gives us a fairly comprehensive range of situations. These measurement campaigns extended for several months, with the purpose of comparing and analyzing the various results. These campaigns offer an opportunity of testing the operation of the aircraft and assessing the performance, knowing that all measures were compared to the device certified EN (Gasman). For the development of our device, we specify the direction and scope of the study area, analyze the existing level of detection performed and technical data manipulated, obtain a comprehensive description of the electronic system and reach a reasoned choice of a solution type of development. This allowed us to develop a multifunction prototype which objective is to control the quality of indoor air pollution in habitations. This device admits the same principle as product modem M2M (Machine to Machine). Through processes M2M, machinery (measuring instruments (device) and air handling system) is already able to communicate among them without human intervention. Given this new world of service, the management of environmental risks becomes more responsive.
Use of Cork Waste as Biosorbent for Hexavalent Chromium
Authors: Sfaksi Zoubeida , Azzouz Nourreddine , Abdelwahab Ahmed
Published: September 2011

The biosorption by cork powder is considered as a new method for heavy metal removal from industrial waste waters such as chromium tanning factories. The aim of this study is to evaluate the efficiency extent of this method using a cork powder as biosorbent for hexavalent chromium Cr(VI). The Fourier Transform Infrared spectroscopy (FTIR) analysis permits to distinguish the type of functional groups likely to participate in metal binding. A linear form of BET isotherms for all the three used temperatures (25, 35 and 45°C) and a pseudo-second-order Lagergren equation of adsorption kinetics are obtained. Other experimental results highlight the meaningful influence of parameters such as contact time, pH and concentrations of the solution, on chromium adsorption rate that reach a 97% value under definite conditions particularly a pH of 2-3 values.
Preparation and Characterization of High-Copper Restorative Dental Alloys Corrected
Authors: Al Sarraj Ziyad S. A. , Atiyah Riyadh I.
Published: September 2011

A series of restorative dental alloys related to the ternary system Ag-Sn-Cu were prepared using high purity 99.99% elemental constituents. The effect of increasing the copper concentration on the micro-structural and mechanical properties of conventional dental amalgam alloy was investigated. Copper content was varied in the range of 10-30wt% and that of silver in the range of 40-60wt%, while tin percentage was kept constant between 28-30wt%. Selected desired compositions were weighed, melted, and homogenized for 1h in fused-alumina crucible using wire-resistance tube furnace at 1100oC under an inert atmosphere of argon gas. Two types of alloys were prepared, the first one was by quenching in water the alloy melt from a peak temperature of 725oC, while the second type was by slow furnace-cooling of the melt down to the room temperature. Annealing of the alloys at 350- 400oC for 24 hrs was also conducted to enhance the growth of the γ-phase. The resultant alloys were then cooled to room temperature (R.T) and milled mechanically to obtain a powder having particles sizes in the range between 30-80μm. The resultant powdered alloys was then stress-relieved at 100oC for 1h. XRD analysis, optical microscopy, micro hardness, and compression strength tests were all used for the characterization and properties determination at different Cu-concentrations for the as-prepared and amalgamated alloys in addition to the powders.. The obtained relative values for the above-mentioned properties were closely related to those listed in the literatures and lies between those of mechanically-milled and those of spherical particles. Also the γ2 – phase was disappeared at high copper content of > 20wt%.
Potential of TaOXNY Thin Films Deposited by Reactive Sputtering as Antireflective Coatings: Composition and Optical Properties
Authors: Zoubian Fadi , Tomasella Eric , Bousquet A. , Sauvage Thierry , Eypert C.
Published: September 2011

Tantalum oxynitride thin films are deposited by radio-frequency magnetron sputtering using a pure tantalum target under argon/oxygen/nitrogen gas mixture. The argon flow is kept constant while the oxygen and nitrogen flows are changed simultaneously in a way to keep constant the total flow of these reactive gases. We succeed to deposit TaOxNy films with stoichiometry ranging between those of TaN and Ta2O5. All films are deposited at room temperature and are amorphous. Spectroscopic ellipsometry and UV-visible spectrometry investigations show a direct relation between the optical properties and the stoichiometry of the films. In particular, the results show a variation of the refractive index from pure tantalum nitride-like films (3.76) to tantalum pentoxyde-like films (2.1), which confirms the possibility to deposit graded antireflective coatings with tantalum oxynitride.
Nature and Role of Various Si-Based Sensitizers for Er3+ Ions in Silicon-Rich Silicon Oxide Thin Films
Authors: Cueff Sebastien , Labbé Christophe , Watanabe Kentaro , Dierre Benjamin , Sekiguchi Takashi , Rizk Richard
Published: September 2011

This study focus on the nature of different Si-based sensitizers for Er3+ ions in Silicon- Rich Silicon oxide thin films. The samples were first analyzed by Cathodoluminescence technique to probe all emitting centers in the films. Some of these centers were found to be potential sensitizers for Er3+ ions, such as Silicon Oxygen Deficient Center and Non-Bridging Oxygen Hole Center, in addition to the well-known Silicon-nanoclusters (Si-nc). The influence of the thickness was subsequently examined, revealing that the formation of Si-nc is inhibited for films thinner than 100 nm and this led to less sensitization of the Er3+ ions. We demonstrate that the introduction of a SiO2 buffer layer can overcome this issue and increase the luminescence of Er3+ ions by a factor of five for films thinner than 50 nm that are usually used for electrically-driven photonic devices.
Compliance at the GaSb/GaP Interface by Misfit Dislocations Array
Authors: El Kazzi Salim , Desplanque Ludovic , Coinon Christophe , Wang Yi , Ruterana Pierrre , Wallart Xavier
Published: September 2011

We study the initial growth of 10 monolayers (MLs) of GaSb on a (001) GaP substrate. Transmission electron microscopy and reflection high energy electron diffraction analysis show that an Sb-rich GaP surface promotes the formation of a 90° misfit dislocation array at the epi-substrate interface. Using atomic force microscopy, we investigate the influence of the growth temperature and the growth rate on the formation and the shape of GaSb islands.
Ceramic Balls Machining by Centerless Grinding Using a Surface Grinder
Authors: Wu Yong Bo , Xu Wei Xing , Fujimoto M. , Tachibana T.
Published: September 2011

This paper proposes a novel method for machining ceramic balls by centerless grinding technique performed on a surface grinder. In this method, a compact unit consisting mainly of an ultrasonic shoe, an ultrasonic regulator, a relay controller, a blade, a stopper and their respective holders is installed on the worktable of a surface grinder to conduct centerless grinding operations of ceramic balls. The ultrasonic shoe and regulator are produced by bonding a piezoelectric ceramic device (PZT) onto a metal elastic body, and when two phases of AC voltage are applied to the PZT an elliptic motion occurs on their end-faces which can be used to control the ball rotational motion in the radial and axial direction of the wheel, respectively. The function of the relay controller is to regulate the alternating current “on” and “off” time which is applied on the regulator for achieving the whole spherical surface grinding process. A grinding unit was actually constructed and it was experimentally confirmed that the ball rotational speed can be controlled well by the shoe or regulator. Grinding tests were subsequently carried out and the obtained results indicated that the constructed grinding unit performed well on actual ball centerless grinding operations.
High Speed Grinding of Nickel-Based Superalloy with Single Diamond Grit
Authors: Chen Z.Z. , Xu Jiu Hua , Ding W.F. , Cheng Z. , Fu Y.C.
Published: September 2011

Nickel-based superalloy plays an extremely important role in gas turbine engines in aerospace industry. To understand the high and super high speed grinding mechanism of nickel-based superalloy, the single-grit grinding mechanism is needed to be investigated. Previous studies on single grit were all carried out by mean of cutting or scratching. In this work, a novel experimental set-up of single-grit grinding had been developed to meet the reality of the complex kinematic grinding process. Grooves and collected chips were investigated in grinding of a typical nickel-based alloy GH4169 with wheel speed up to 150 m/s. The groove integrity is improved by increasing the grinding speed even though the chip thickness is kept constant. The typical serrated chips were observed and the frequency of chip segmentation increases linearly with the increasing of the grinding speed. Under high and super high grinding, the thermal softening due to the high temperature in adiabatic shear zone contributes to accelerate the chip formation and leads to decrease the grinding force.
Research on Workpiece Surface Temperature and Surface Quality in High-Speed Cylindrical Grinding and its Inspiration
Authors: Li Bei Zhi , Zhu Da Hu , Zhou Zhen Xin , Zhang Qiang , Yuan Yi Chu
Published: September 2011

The temperature in cylindrical grinding contact zone is difficult for measurement. Relative to the fixed workpiece in surface grinding, the workpiece rotation in cylindrical grinding brings challenges to the temperature measurement. In grinding titanium alloy, more heat will be generated, and due to the poor thermal conductivity of this material, it is easy to make the high temperature rise in the grinding zone. The high surface temperature and its distribution along the depth of the workpiece have great impacts on the grinding burn, metamorphic layer and residual stress. In order to improve the surface quality of machined parts, based on the undeformed chip thickness, this paper proposed a quadratic curve heat flux distribution model to predict the surface temperature distribution in the grinding of titanium alloy (TC4). Experimental results showed that the quadratic curve model under the condition of the measured grinding power, can predict the temperature distribution in the cylindrical grinding zone. Meanwhile, it specifically discussed the impact of the wheel speed on the TC4 surface roughness and the stress distribution, and found the "high-speed" definition in high-speed grinding should be distinguished from the traditional way only judged by the wheel speed, different workpiece materials should be with different "speed" ranges for acquisition of better machining quality.
Corrosion Wear Characteristics of ELID-Ground Co-Cr Alloy with Applying Abrasion by Ultra High Molecular Weight Polyethylene (UHMWPE)
Authors: Mizutani M. , Hisamori Noriyuki , Mizuno T. , Ezura A. , Ohuchi I. , Ohmori H. , Fujiwara K. , Doi K. , Kuramoto K.
Published: September 2011

The purpose of this paper is to evaluate the surface properties and corrosion behavior of Co-Cr alloys ground by employing Electrolytic In-process Dressing (ELID) grinding; this evaluation was carried out by abrading the alloy surfaces using ultra high molecular weight polyethylene (UHMWPE). The evaluation results showed that ELID grinding can be used to perform mirror finishing on Co-Cr alloys. ELID grinding also showed its ability to create a stable modified layer which improves corrosion wear characteristics on the workpiece surface.
A Quick-Test Method to Determine the Grinding Wheel Topography Based on Acoustic Emission
Authors: Weingaertner Walter Lindolfo , Boaron Adriano
Published: September 2011

A quick-test method for the determination of the topographic characteristics of a CBN grinding wheel is developed based on acoustic emission technology. For implementing the strategy, an acoustic emission (AE) monitoring system was integrated into a 3 axis CNC grinding machine. A computer with specific software allows the signal acquisition and visualization of the AERMSsignals, which are originated through interferences between the grinding wheel and dressing tool in a range of a few micrometers. The acquired AERMSsignals from these interferences are used in order to establish an on-line map from the grinding wheel periphery, indicating the active cutting grains during the contact amid grinding wheel and dressing tool. The implementation of such activity supported by AE has led to satisfactory results regarding the required time to evaluate the strategy as well as the verified correlation with different grinding topographies caused by changes in the dressing parameters.
Grinding Monitoring through Thermal Acoustic Emission Signatures
Authors: Chen Xun , Mohamed Arif , Folkes Janet
Published: September 2011

This paper presents recent development in acoustic emission (AE) technique for grinding process monitoring. It demonstrated the similarity of thermal acoustic emission feature existing in grinding processes and laser irradiation tests. An innovative concept that grinding process can be monitored by using thermal AE signatures from laser irradiation tests has been proposed. Based on such idea, an artificial neural network (ANN) was built and the results showed that grinding performance variation due to wheel wear can be identified by using the ANN. This development could bring great benefits by reducing experimental works in the preparation of an ANN for grinding monitoring.
Heat Transfer in Grinding-Hardening of a Cylindrical Component
Authors: Nguyen Thai , Zhang Liang Chi , Sun Da Le
Published: September 2011

A three-dimensional finite element heat transfer model incorporating a moving heat source was developed to investigate the heat transfer mechanism in grinding-hardening of a cylindrical component. The model was applied to analyze the grinding-hardening of quenchable steel 1045 by two grinding methods, traverse and plunge grinding. It was found that the heat generated can promote the martensitic phase transformation in the ground workpiece. As a result, a hardened layer with a uniform thickness can be produced by traverse grinding. However, the layer thickness generated by plunge grinding varies circumferentially. The results are in good agreement with the experimental observations.
Numerical Study on Constant-Flow Hydrostatic Water Bearing for a Machine-Tool Table
Authors: Okahata Go , Okuyama Shigeki , Yui Akinori
Published: September 2011

Precision machine tools using hydrostatic water bearings are superior to those using hydrostatic oil bearings in terms of environmental protection, worker’s safety, and cost. As for hydrostatic water bearings, a constant-flow type is more suitable than a constant-pressure type. However, the hydrostatic water bearings applied for machine tools are few cases, and there are only a few reports concerning the constant-flow bearings. In this study, sustaining force of the constant-flow hydrostatic water bearing pad is computed numerically by using ANSYS FLUENT. Then the solutions evaluated by the simple analytical models, which were proposed previously, are examined by comparing them with the numerical result. Additionally, an improved analytical model is proposed.
Deformation Mechanisms and Abrasive Machining of Nanoscale Thin Film Multilayered Solar Panels: A Focused Review
Authors: Huang Han
Published: September 2011

The machining of thin film multilayered solar panels is facing a great challenge in industry due to the low machining efficiency, and a timely solution is needed if this approach is to progress further. The successful employment of a new machining technology for the solar panels requires comprehensive understanding of the deformation and removal mechanisms of nanoscale multilayered materials, which has never been previously achieved. This paper reviewed the understanding of mechanics of nanoscale multilayer structures, and reported the recent progress on the development of abrasive machining technologies forthin film multilayered structures.
Drilling of Borosilicate Glass with Feedback Control Based on Cutting Force
Authors: Ohzeki Hiro , Arai Fumihito
Published: September 2011

This paper deals with drilling of borosilicate glass with feedback control based on cutting force, in order to provide a basis for defect-free machining of through-holes on borosilicate-glass plates. In this work a machining system which can be operated at a predetermined cutting force by changing the feed rate based on cutting force measured by a piezoelectric type of cutting dynamometer was developed. Subsequently, drilling tests of borosilicate glass was carried out with the developed system. Based on the results of the drilling tests, It has been confirmed that feedback control based on cutting force has the possibility of defect-free drilling of borosilicate-glass plate under specific conditions.
An Investigation on the Chemical Effect in Chemo-Mechanical Polishing
Authors: Jin X.L. , Zhang Liang Chi
Published: September 2011

This paper develops a statistical model to analyze the chemical effect on the material removal rate (MRR) in chemo-mechanical polishing of material surfaces (MS). It was considered that the chemical effect comes into play through a passivated layer on the MS. It was found that the effect of such layer on MRR depends on the mean particle radius, the elastic modulus of the pad, and the hardnesses of the passivated layer and the workpiece material.
Research on the Polishing Performance of CMP Slurry for the Sapphire Crystal
Authors: Gao Shang , Kang Ren Ke , Jin Zhu Ji , Dong Zhi Gang
Published: September 2011

Aiming at the problems such as metal ionic contamination, poor dispersion property and low material removal rate (MRR) in the chemical mechanical polishing (CMP) process for sapphire crystal, a proper CMP slurry based on the organic basis was studied in this paper. Through the single-factor experiment, the effect of different abrasives, pH regulators, dispersants and active agents on the surface roughness and material removal rate (MRR) were studied and a fine CMP slurry was developed. The polishing performance of developed CMP slurry was also researched by comparing the MRR and the surface roughness of sapphire crystal with that polished using the KA-901 CMP slurry. The results show that the MRR and the surface roughness corresponding to the developed slurry were all better than KA-901 slurry, and the developed CMP slurry has a good application prospect.
Tribological Aspects of Chemical Mechanical Polishing Diamond Surfaces
Authors: Jin Zhu Ji , Yuan Z.W. , Li Q. , Wang K.
Published: September 2011

Mechanical energy may initiate and accelerate chemical reaction in chemical mechanical polishing (CMP). To study the effect of mechanical energy on the chemical reactions, a special friction measuring system was designed in this paper. The system could measure the local friction to reduce the error caused by resultant force. The effects of rotational speed, polishing pressure and the concentration of oxidant on friction and material removal rate were investigated. The results showed that the system could accurately measure the friction of small area diamond film in CMP process. The frictional system was in a mixed lubrication state since the value of the friction coefficient located in the range of 0.060~0.065.
Studies on the Lapping of Polycrystalline Diamond Compact (PDC)
Authors: Sowers Jason , Fang Alex
Published: September 2011

Researching the effect that certain parameters have on the lapping process is crucial to understanding the fundamental material removal mechanisms and implementing a procedure that most efficiently produces desired results. This study examines the lapping procedure for polycrystalline diamond compacts (PDCs). Tests were conducted using different sample carriers, PDC arrangements, and abrasive size distributions. Previous studies have focused on the material removal rate (MRR), which is of interest, but this study also examines the MRR uniformity within a group of PDCs lapped together. The goal of this research was to determine the optimal lapping conditions and PDC arrangement required to achieve the highest productivity. Results indicate that a hard specimen carrier is necessary to produce PDCs with uniform MRRs, and the number of PDC samples in a carrier can be increased with certain design constraints kept in mind.
Calculation of the Contact Stiffness of Grinding Wheel
Authors: Yamada Takazo , Morgan Michael N. , Lee Hwa Soo , Miura Kohichi
Published: September 2011

It is considered that the contact stiffness between the grinding wheel and the workpiece depends on the number of the abrasive grains in contact with the workpiece and the support stiffness of a single abrasive grain. In this paper, the calculating method of the theoritical contact stiffness of grinding wheel in grinding operation was proposed. Comparing calculated results of the contact stiffness in grinding operation with measured it in the stationary state, the contact stiffness of the grinding wheel in grinding operation was investigated.
Machining Characteristics of Cylindrical Blasting and Application to Micro Patterning
Authors: Sogabe E. , Ohashi Kazuhito , Lu N. , Fujiwara M. , Onishi T. , Tsukamoto Shinya
Published: September 2011

Micro patterning on cylindrical surface, e.g. dynamic pressure bearings, is mainly carried out by chemical etching. However, there exist environmental problems in the waste etchant processing and safety ones in works using toxic chemical liquids. On the other hands, blasting is expected as one of micro patterning methods and comes into use for not only surface modification but also machining of hard and brittle materials. The purpose of this study is to develop the micro blasting technique for cylindrical parts. Therefore, machining characteristics in blasting of rotating workpieces are experimentally investigated, analyzing the stock removal and the surface roughness. In addition, the patterning of micro herringbone grooves are carried out on spindle surfaces based on the obtained characteristics.
A Study of the Micro-End Milling of Titanium Alloy
Authors: Tsuda Koji , Okuda Koichi , Shizuka Hiroo , Nunobiki Masayuki
Published: September 2011

This study deals with the cutting characteristics of titanium materials when milled by a small-diameter end mill, or a micro end mill. It is well known that titanium is difficult to cut by conventional means. However, its cutting characteristics have not yet been made sufficiently clear in cases where a micro end mill less than 1 mm in diameter is used. This study chiefly involves the experimental investigation of tool wear and surface roughness of micro-end milling of Ti-6Al-4V. The findings were that tool wear did not increase much when the cutting speed was increased from 50 m/min to 200 m/min. Furthermore, the cutting force required to cut decreased at high speeds and during wet cutting. In wet cutting, the surface had a roughness (Rz) of only 0.3 μm at 200 m/min in contrast to 0.6 μm at 50 m/min.
A Study of Jet Formation for Premixed Slurry Jet Nozzle Using the Discrete Phase Model
Authors: Luo Wu Sheng , Wang Cheng Yong , Wang Jun , Song Yue Xian
Published: September 2011

Abrasive jets can be used for polishing when fine slurry is used. This paper presents a model for the jet formation process, CFD simulations are carried out for the prediction of flow pattern in a nozzle with abrasive suspension slurry jets using the discrete phase model. The CFD model aids in understanding the process because of the difficulties in performing the direct measurement of the jet axial velocity and radial velocity, the model simulates the different pressure premixed slurry pass through the pipeline and the focus tube to the atmosphere. The model is able to predict the orifice efficiency and the cross sectional profiles of the jet velocity after the nozzle, the modeled results are in good agreement with both experimental and analytical data. The simulation model can be useful in studying the overall slurry jet process and for the optimization of the slurry jet parameters.
Evaluation of Surface Roughness of Quartz Glass Substrate in Fabrication Process for Neutron Focusing Mirror
Authors: Nagano Mikinori , Yamaga Fumiya , Yamasaki Kenta , Zettsu Nobuyuki , Yamazaki Dai , Maruyama Ryuji , Soyama Kazuhiko , Yamamura Kazuya
Published: September 2011

The aspherical supermirror is among the most useful optics for focusing a neutron beam with a wide wavelength range. The improvement in surface roughness is essential for increasing the focusing gain. A highly efficient and high-precision fabrication process for the substrate of the aspherical mirror combining conventional precision grinding, numerically controlled local wet etching (NC-LWE) figuring, and low-pressure polishing was developed. Using this new fabrication process, plano-elliptical neutron-focusing mirror substrates were successfully fabricated with a figure error of submicrometer order and an rms surface roughness of less than 0.3 nm. In this report, the surface roughness of a quartz glass substrate for a neutron focusing supermirror was evaluated.
Influence of Wafer Grinding and Etching Techniques on the Fracture Strength of Thin Silicon Substrates
Authors: Landesberger Christof , Paschke Christoph , Bock Karlheinz
Published: September 2011

We investigated the influence of various backside thinning techniques on the fracture strength of thinned single crystalline silicon wafers by means of ring-ball breaking tests and atomic force microscopy (AFM). In the case of wafer grinding the mean breaking force of samples depends on the surface roughness after fine grinding. Subsequently applied stress-relief processes spin-etching, CMP polishing and plasma dry etching lead to a strong increase of breaking force by a factor of 6 to 15. The three different stress-relief techniques resulted in the same maximum values of breaking force. However, the required amount of material removal is specifically different and also depends on the conditions of initial grinding step. The results will help to identify optimum wafer thinning sequences in the field of MEMS devices and future applications of ultra-thin and flexible integrated circuits.
Silicon Electrochemical Etching for 3D Microforms with High Quality Surfaces
Authors: Ivanov Alexey , Mescheder Ulrich
Published: September 2011

In this paper the process of silicon anodization as a structuring technique is discussed. 3D-structuring is achieved by 3D control of current density in an anodization process. In contrast to conventional ECM techniques electrodes as structured thin layers on the work piece are used. For the shape controlling of etch form frontside masking design and local backside doping are presented. Influences of the opening size and etch depth on the shape of the etch form is shown. The surface quality of the resulting 3D structures is investigated, with best surface quality (about 1 nm rms) being obtained for electropolishing in 7 wt.% HF at applied current densities of 100 ‑ 300 mA/cm². Application of 3D silicon forms for injection moulding is demonstrated and further implementations of the process for optical and fluidic devices are discussed.
Development of CMG Wheels for Stress Relief in Si Wafer Thinning Process
Authors: Mikami Yuki , Zhou Li Bo , Shimizu Jun , Ojima Hirotaka , Tashiro Yoshiaki , Kamiya Sumio
Published: September 2011

In recent semiconductor industry, production of ever flatter, thinner and larger Si wafer are required to fulfill the demands in high integration and cost reduction. A severe problem encountered in wafer thinning process is the warp and distortion of wafer induced by the residual stress and subsurface damage. Chemo-mechanical grinding (CMG) process is emerging process which combines the advantages of fixed abrasive machining and chemical mechanical polishing (CMP), offers a potential alternative for stress relief. This paper studies the influence of the wheel manufacturing process on the wheel physical properties. Three-factor two-level full factorial designs of experiment are employed to reveal the main effects and interacted effects of mixing method and filtration of raw materials on the bending strength and elastic modulus of CMG wheel. The difference in wheel properties is discussed by association with CMG performance including wheel wear, grinding force and surface roughness.
Influence of Y and Nb Addition on Crystallization Behavior and Mechanical Properties of Zr-Ni-Al-Cu-M Bulk Amorphous Alloys
Authors: Iqbal Muhammad , Akhter Javed Iqbal
Published: September 2011

Bulk amorphous alloys are new class of materials with excellent mechanical and thermal properties. Bulk metallic glasses (BMGs) have wide range of application such as structural materials. Minor alloying additions play beneficial role in the production and properties of BMGs. The present study was conducted to investigate the effect of Y and Nb addition on activation energy, crystallization behavior, thermal and mechanical properties of Zr64.5Ni15.5Al11.5Cu8.5. Bulk amorphous ingots and sheets of three [Zr0.645Ni0.155Al0.115Cu0.085]100-xM2 (M = Y and Nb and x = 0, 2 at. %) alloys were produced by Cu mold casting technique. The alloys were characterized by XRD, DSC, SEM, FESEM and EDS. Activation energies were calculated. The alloy containing Y shows single stage crystallization while Nb addition shows double stage crystallization. The maximum activation energy calculated is 300 kJ/mol. Parameters describing thermal stability in these systems were determined from DSC data which improved as a result of these additives. Reduced glass transition temperature Trg and thermal parameters like g, d and b were improved by Y addition. The supercooled liquid region varies between 87-100 K. Hardness and elastic moduli were also improved. It was concluded that Y and Nb addition has beneficial effect on mechanical properties. Three phases NiZr2 and CuZr2 and Cu10Zr7 were identified by XRD and confirmed by EDS in the samples annealed at 823 K while the AlNiY ternary phase was detected in the alloy containing Y.