bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of the Source Temperature on Properties of CdTe Thin Films by Close-Spaced Sublimation
Authors: Shen Xin Jie , Shi Cheng Wu , Zhan Xiao Ping , Yao Min , Zhang Yan Ru
Published: November 2012

In this paper，CdTe thin films were successfully grown at higher source temperatures of 650 °C and 700 °C using close-spaced sublimation(CSS) and characterized by energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis-NIR absorption spectra, respectively. The results indicated that the grain size of CdTe thin film increased from 1 μm to 5 μm with the increase of the source temperature from 650 °C to 700 °C. The direct band gaps of CdTe thin films prepared at different source temperatures of 650 °C and 700 °C were 1.44 and 1.43 eV, respectively.
Research on Path Planning of Automatic Parking System
Authors: Piao Chang Hao , Zhang Le , Lu Sheng , Li Yu Sheng
Published: November 2012

A non-parallel initial state path planning algorithm for the automatic parking system is presented in this paper. Automatic parking system is a hot research point in intelligent vehicle application fields, and the trajectory generation is one of its key technologies. In the actual process of parking, the initial state of vehicle is always non-parallel to the parking place, so this situation should be researched to serve automatic parking system better. According to the analysis of vehicle kinematics model and the parking process, the trajectory can be considered as the combination of some sections of tangent arc. In this article, the trajectory is composed of several period of circular arc and it is improved by combining with the actual circumstance, then a strong adaptable parking trajectory for the automatic parking system is designed. The simulation analysis is done to verify the geometry trajectory, and the method is used on our intelligent vehicle to check out the feasibility. Compared with traditional trajectory generation method, experimental results show the adaptability and success rates of the method designed in this paper is much more better, which the parking success rates is about 90%.
Fault Detection of Artillery Automatic Loading System Based on PCA
Authors: Zhang Peng Jun , Bo Yu Cheng , Wang Hui Yuan , Li Qiang
Published: November 2012

The motion process of the automatic loading system is a high overloading and intermittent motion environment will bring about motor windings loosening, transmission system wear and tear, fracture, sensor failure and other security risks or system failures. In the paper no-stationary signal analysis by wavelet transform through wavelet decomposition and non-linear threshold de-noising. And use PCA established system model for on-line monitor. By calculate and analysis four kind of result to find fault source. Finally through the experimental prove the reliability of the method.
Design of Testing System for Main Spindle Box of CNC Lathe Based on LabVIEW
Authors: Zhang Zhi Wei , Li Song , Chen Bing Bing , Song Jin Chun
Published: November 2012

According to the testing craft and requirements of CNC Lathe about main spindle box, testing system of hardware and software structure was designed in this paper. It adopts sensors, data acquisition cards, industrial control computer, frequency converter and so on as hardware, good data analysis methods, and LabVIEW as software tool, to realize real-time monitoring of main spindle box testing conditions.
Finite Element Numerical Analysis of the LGV Frame Based on ANSYS
Authors: Fan Qin Man
Published: November 2012

The frame is the main part of the force matrix of truck vehicle and the stress state is complex and difficult to design. The finite element method is more accurate for the analysis of the static and dynamic characteristics of the frame, which provide guidance for the frame structure design. Establish finite element model of the frame with the application of ANSYS. According to the mechanical analysis of the model, impose reasonable constraints and load, the most typical of the four conditions in the frame is calculated with the finite element analysis, and predicted the weak parts of the frame according to the frame stress-strain cloud, which provided a very important theoretical basis for the improvement of the frame structure of the frame and optimizing design of the frame.
Study on the Measurement Model of Knowledge Management Contribution Rate for Real Estate Enterprises
Authors: Shen Liang Feng , Song Tian Ping
Published: November 2012

Through the introduction of potential analysis method, a measurement model of enterprise knowledge management contribution rate is put forward in this paper based on the improved the method of Solow’s residual value, and is estimated by the performance measure of a real estate enterprise for implement knowledge management, then the results have shown that the model and the method have good feasibility.
Identification of Nonlinear Property of Honeycomb Paperboard through Use of Hilbert Transform
Authors: Wei Xiao Qin , Zhu Da Peng
Published: November 2012

A method is formulated to model the properties of honeycomb paperboard based on Hilbert transform, In this method, there are no assumptions on the forms of the stiffness and damping properties, this method is truly nonparametric. An experiment system is set up to record the free response of the mass loaded honeycomb paperboard system, the experiment data are used to identify the stiffness and damping properties of honeycomb paperboard. The motion equation of mass loaded honeycomb paperboard system is formulated, the transmissibility curve is simulated, the comparison of the simulated curves and the experiment data indicates the model in this paper is accurate.
Light Doping Effect on System Energy in Conjugated Polymers
Authors: Wang Yu , Shou Yuan Peng , Qiu Yu
Published: November 2012

Based on a tight binding model, we investigate impurity effect upon the stability of neutral and negatively or positively charged 1D conjugated polymer chains. Impurities are introduced by an attractive or a repulsive potential located at the lattice sites. The offsets of system energy due to light doping are calculated within adiabatic approximation. We show that doping position has significant impact upon system stability. A general picture of impurity distribution along the stretch direction of the polymer chain is obtained for both attractive and repulsive impurity potentials in neutral as well as in charged conjugated polymers. A polymer chain can generally be divided into edge, center and transition regions in terms of impurity distribution. It is found the static impurity distribution within a polymer is dominated by the strength and the sign of the impurity potential as well as whether the polymer chain is neutral or charged. Impurity distribution within the edge and the transition region is characterized by cluster and that within the center region by separation.
Shape Recovery Method for Repairing Dents on Stainless Steel Sheets by Laser Forming
Authors: Nunobiki Masayuki , Fukuoka Shinji , Okuda Koichi , Shizuka Hiroo
Published: November 2012

This research proposes the application of laser forming to repair dents made in stainless steel sheets. Stainless steel sheets are widely used for the exterior coverings of trains or automobiles. When dents are made in an exterior sheet, it is necessary to detach the panel and strike the sheet from the inside with a hammer. This research indicates that dents were repaired by irradiating them from the outside with a laser beam. It is effective to repair dents without detaching the exterior sheet from the body of the vehicle. In the proposed method, a laser was scanned along the shape of the dent under the condition that the sheet bent by the temperature gradient mechanism or upsetting mechanism. In our experiments, circular dents were made in a 1-mm-thick SUS304 sheet. The laser was scanned along several circular scan lines on the circular dent with a diameter of approximately 20 mm. The depth of approximately 1.5 mm of the dent decreased by 85% using this technique.
Fabrication and Characterization of Electrodes for Microbial Fuel Cell
Authors: Ogikubo Hidetoshi , Ohtake Naoto
Published: November 2012

Bio- Fuel Cell is promising technology to overcome global issue. However, there are many problems in Bio-fuel cell using organism catalyst because research of this type of fuel cell is started in only few years. Purpose of this research is to obtain high electric power using new type of electrode in Microbial Fuel Cell (MFC). Firstly, three types of electrodes were prepared. Those are (1) painted CNT (Carbon Nanotube) by Ag paste, (2) only Ag paste (without CNT) and (3) bare carbon thin plate. MFC with CNT painted (2) electrode generated high current density and high power in MFC, but its E.M.F (Electromotive Force) was decreased. When CNT painting was applied only to anode, high current and power densities were attained without reducing E.M.F.
Control of Built-Up Edge Behavior by Chamfered Cutting Edge Preparation and Surface Modification
Authors: Kiyota Hiroki , Itoigawa Fumihiro , Nakamura Takashi
Published: November 2012

A chamfered cutting edge, which is commonly shaped in order to strengthen an edge of a cutting tool consisting of brittle material, easily causes an enhanced adhesion and a burr formation due to high compressive stress anterior to the edge. These problems lead to a detachment of tool material and a notch wear at depth-of-cut line, which would result in unexpected tool fracture. On the other hand, the edge shape promotes formation of a built-up edge (BUE) as a dead metal and can maintain it stably. Actually, the formed BUE is plastically extruded along to the chamfered edge and can prevent formation of the notch wear. In this study, basic experiments to reveal effects of chamfered tool edge preparation, such as chamfer angle, chamfer width and rake angle, on the BUE behavior were conducted. Additionally, the results suggested that the plastic flow in the BUE extrusion can suppress the adhesion if the extrusion is arisen uniformly. Therefore, attempts to control the BUE flow by chamfer surface modification were carried out.
Cutting Experiments in Cutting Speeds of up to 200 m/s with a High-Speed Impact Cutting Tester
Authors: Higashi Tappei , Sando Masato , Shinozuka Jun
Published: November 2012

High-speed orthogonal cutting experiments with cutting speeds of up to 200 m/s with a high-speed impact cutting tester of air-gun type are attempted. In this tester, a light projectile with a small built-in cutting tool is loaded into a tube, being accelerated by a compressed gas. The projectile captures the chip that is indispensable to analyze the cutting mechanism. The projectile holding the chip is decelerated by another compressed gas just after finishing the cutting, being stopped without damage in the tube. Successful experiment can be accomplished by setting adequate values of the operation parameters for the experiment, which are the pressure of each gas and the opening and shutting time of the solenoid-controlled valve for each compressed gas. In order to determine the adequate values of these parameters, a ballistic simulator that simulates the velocity and position of the projectile traveling in the tube is developed. By setting the values of these parameters obtained by the simulator, the cutting speed of 200 m/s is achieved when the ambient pressure is set to be a vacuum and helium is used for each compressed gas. This paper describes the ballistic simulator developed and shows the experimental results of the high-speed cutting of aluminum alloy A2017.
Theoretical Investigation of an Optical Vibration Using Laser Beams from Optical Fibers Inserted at an Angle of 35 Degrees
Authors: Watanabe Nobuyuki , Taguchi Kozo
Published: November 2012

Optical trapping is a technique that is used to capture, translate, and manipulate microscopic particles, such as dielectric microspheres and cells. This cell manipulation and examination technology can be integrated on a Lab-on-a-Chip device. We have already developed an optically vibration system. The optical vibration system was formed using a temperature stabilized 1480nm cw diode laser. The output of laser light was coupled into optical fibers, which had optical connectors at these fiber ends. The fiber end had a hemispherical micro-lens with 5μm radius of curvature for focusing the laser beam emerging from the optical fiber end. These trapping fibers were attached to xyz manipulators and were inserted into a sample cell at an angle of 35 degrees. The trapped microsphere, 10μm diameter polystyrene particle (refractive index 1.59), could be optically vibrated by controlling laser power emerging from optical fibers. We theoretically analyzed the optical forces exerted on a microsphere by laser beams. Its operating principle is based upon the conservation of photon momentum carried by the incident laser light on a trapped microsphere. From these theoretical results, we verified that our proposed optical manipulation technique was useful for the manipulation of biological cells.
Surface Nitriding of Al-Mg Alloys Using a Rotary Barrel Tank
Authors: Tao Zhou , Yoshida Masashi , Okumiya Masahiro , Utsumi Noah , Tsunekawa Yoshiki
Published: November 2012

The authors developed a new nitriding process to form an aluminum nitride film on a pure aluminum surface. In this study, a rotary barrel polishing method was applied to gas nitriding in an attempt to form an aluminum nitride film on the surface of Al-Mg alloys. Nitriding was carried out at 823 K, 853 K, and 873 K for 3.6 ks to 25.2 ks. Alumina- and aluminum - 50mass% magnesium powders were used as the media that flowed in the barrel tank. An aluminum nitride film was formed on the aluminum alloy surfaces within a relatively short time. The effect of the treatment temperature on the formation and growth of the aluminum nitride was investigated. It was found that the formation and growth of the aluminum nitride film were greatly affected by differences in the Mg content in the aluminum substrate and by the treatment temperature.
Improvement of Finished Surface Integrity of High Chromium Cast Iron in Reaming
Authors: Hikiji Rikio
Published: November 2012

With the improvement of accuracy in machine tools, ultra precision final machining has been carried out by cutting instead of grinding. In addition, JIS method for cutting fluids is revised in order to consider earth environment. However, it is very difficult for workshop to extract an optimum machining condition. The results of this study contribute to extraction of an eco-friendly machining method and reduction of running cost as well as the excellent surface integrity. This time, final machining for high chromium cast iron as the turbocharger parts of the automobile was taken up as an example which acquired the good finished surface by cutting. Namely, for the purpose of reducing the running cost, instead of honing that has been used for finishing it in the hole processing, reaming was carried out for finishing, and its practicability was investigated experimentally. As a result, it was clarified that the surface integrity was improved with the oil hole reamer and the synthetic soluble oil.
Improving Anti-Adhesion in Cutting of Aluminum Alloy by Micro Stripe Texture – Considering Texture Combination
Authors: Sugihara Tatsuya , Enomoto Toshiyuki , Yukinaga Satoshi , Hirose Kenji , Satake Urara
Published: November 2012

In cutting of aluminum alloys, one of the most serious problems is chip adhesion to cutting tool surface, often leading to tool failure, above all, in dry cutting. To address this problem, we adopted surface engineering approach, namely, a functionalization of tool surfaces by textures. In our previous research, we have developed the DLC-coated cutting tool with nano/micro-textured surfaces and the cutting tool with micro stripe textured surface formed using femtosecond laser technology. Face-milling experiments on aluminum alloys showed that the nano/micro-textured surface suppresses the genesis of adhesion at the atomic level. On the other hand, it was found that micro stripe texture prevents chip adhesion from growing larger even in dry cutting conditions. In this study, a cutting tool with new textured surface combined nano/micro texture and micro stripe texture was developed in order to further improve anti-adhesiveness in cutting of aluminum alloys. As a result, it was confirmed that the combined texture brings excellent anti-adhesion compared to the previously developed tools.
Wear Characteristics of Cutting Tools in Turning of Sintered Steel under Different Lubrication Conditions
Authors: Obikawa Toshiyuki , Ohno Tatsumi , Yamaguchi Masashi , Maetani Toshio , Unami Shigeru , Ozaki Yukiko
Published: November 2012

Finish machining of sintered steel is increasingly important for near net shape technology. However, the life of a cutting tool for machining sintered steel is generally much shorter than for carbon steel and thus, finish machining increases the manufacturing cost of sintered products. For this reason, wear characteristics of several grades of cutting tools in turning sintered steel were investigated under different lubrication conditions. As a result, it is found that a P10 grade of cermet and an S01 grade of AlTiN coated carbide are recommended for dry machining. When cutting fluid is necessary for chip control and disposal, air jet assisted wet machining with a K10 uncoated cemented carbide and wet machining with a P10 cermet are recommended. It is also found that a small amount of cutting fluid remained in the workpiece during wet machining caused an intense thermal impact to a P10 uncoated cemented carbide leading to short tool life.
Investigation into Chemo-Mechanical Fixed Abrasive Polishing of Fused Silica with the Assistance of Ultrasonic Vibration
Authors: Li Ya Guo , Wu Yong Bo , Zhou Li Bo , Guo Hui Ru , Cao Jian Guo , Fujimoto Masakazu , Kemmochi Masaaki
Published: November 2012

Ultrasonic vibration assisted processing is well known for the improvement in machined surface quality and processing efficiency due to the reduced forces and tribology-generated heating when grinding hard-brittle materials. We transplanted this philosophy to chemo-mechanical fixed abrasive polishing of optical glass, namely fused silica, in an attempt to improve surface roughness and/or material removal rate. Experiments were conducted to elucidate the fundamental characteristics of chemo-mechanical fixed abrasive polishing of fused silica in the presence and absence of ultrasonic vibration on a setup with an in-house built gadget. The experimental results show that ultrasonic vibration assisted chemo-mechanical fixed abrasive polishing can yield increased material removal rate while maintaining the surface roughness of manufactured optics compared to conventional fixed abrasive polishing without ultrasonic vibration. The mechanism of material removal in fixed abrasive polishing was also delved. We found that the glass material is removed through the synergic effects of chemical and mechanical actions between abrasives and glass and the resultant grinding swarf contains ample Si element as well as Ce element, standing in stark contrast to the polisher that contains abundant Ce element and minor Si element.
Evaluation of Surface Roughness and Subsurface Damage of 4H-SiC Processed by Different Finishing Techniques
Authors: Deng Hui , Yamamura Kazuya
Published: November 2012

Single crystal SiC is one of the most attractive semiconductor materials for next generation power device applications. However, it is very difficult to be precisely machined due to its high hardness and chemical inertness. We evaluated the machining characteristics of 4H-SiC using different processes including diamond abrasives lapping, chemical mechanical polishing (CMP) and plasma assisted polishing (PAP). Scratches were introduced through diamond abrasives lapping due to the high hardness of diamond, which resulted in the worsening of surface roughness. A damage layer was observed in the cross-sectional transmission electron microscopy (XTEM) images. A scratch-free surface was obtained through CMP, but it’s not atomically flat since step/terrace structure couldn’t be clearly observed. PAP was newly proposed for the finishing of difficult to machine materials. In PAP, water vapor plasma oxidation and soft abrasive polishing were repeatedly conducted. Ceria which is much softer than SiC was used as the abrasive material. PAP was proved very effective to achieve surfaces out of scratches. Also, due to the low hardness of ceria, no damage layers were introduced. The roughness of PAP processed surface was decreased to about 0.1 nm rms. The surface was also observed by XTEM, which proved an atomically flat surface without crystallographical damage was obtained.
Investigation of Ultrasonic-Assisted Drilling of Al/SiC Metal Matrix Composite with Taguchi Method
Authors: Kadivar Mohammad Ali , Akbari Javad , Yousefi Reza
Published: November 2012

Burr in drilling plays an important role on product quality, so analysis the burr size is essential at the final production. This paper presents the application of Taguchi method for survey the burr height and burr thickness by adding ultrasonic vibration to the process. In this paper L18 orthogonal array based on Taguchi techniques was used in the design of experiments. Analysis of Variance (ANOVA) was used to determination the effect of drilling parameter on burr formation. Influence of cutting speed, feed rate and percentage of SiC particle was investigated in with and without Ultrasonic assisted drilling. Al/SiCp MMC with 5, 15 and 20 wt% of particulate SiC in dry drilling operation with TiN coated drill tools were investigated.
High Efficiency and Eco-Friendly Heat Treatment of Small Parts with a Low-Power Diode Laser Beam
Authors: Hirogaki Toshiki , Aoyama Eiichi , Ogawa Keiji , Ogawa Sachiko , Okamoto Rie , Oda Ryosuke
Published: November 2012

Demand is increasing for the manufacturing and machining of small mechanical parts. We focus on using a multi-functional desktop-sized machine tool to meet such demands because power consumption is decreased when they are machined. However, few reports have focused on heat treatment among manufacturing processes, we investigate the laser heat treatment of small parts as a highly efficient and eco-friendly method and propose in-situ heat treatment on a desktop-sized machine tool using a low-power diode laser beam. We quenched a small thin steel plate with a 30 W diode laser source. Our proposed method makes it feasible to quench a small thin steel plate and effectively reduces the power consumption of in-situ heat treatment by a desktop-sized machine tool.
Fabrication of Smooth Surface on 4H-SiC Substrate by Ultraviolet Assisted Local Polishing in Hydrogen Peroxide Solution
Authors: Kubota Akihisa , Kurihara Kazuya , Touge Mutsumi
Published: November 2012

In this study, we investigated the possibility of removing and smoothing a single-crystal silicon carbide (SiC) surface under ultraviolet (UV) irradiation in hydrogen peroxide (H2O2) solution. In this method, a SiC substrate was excited by UV irradiation that transmitted synthetic quartz, and then an oxide layer on the SiC substrate was formed by photochemical reaction. Simultaneously, hydroxyl radical (OH*) was generated by the decomposition of H2O2 solution by UV irradiation. OH* plays an important role of oxidation of SiC surface. With these chemical reactions, oxide layer was effectively formed on the SiC surface. Finally, the oxide layer generated on a SiC substrate was chemically and/or mechanically removed by synthetic quartz and solutions. The polishing characteristics of this method were investigated by controlling the process parameters. Additionally, surface quality and removal depth were measured and evaluated by a phase-shift interference microscopy. Obtained results show that the surface morphology and the removal rate are strongly dependent on the existence of the UV irradiation. Moreover, it is shown that the removal characteristics of the SiC substrate depend on the process parameters such as the process time, reciprocating speed, and contact load. The processed surface has revealed that many scratches on the preprocessed surface was completely removed. The microroughness of the processed surface was improved to 0.15 nm (Rms) and 1.62 nm (p-v), respectively. These results provide useful information for obtaining an atomically smooth SiC surface.
Thermal Conductivity of Metal Powder and Consolidated Material Fabricated via Selective Laser Melting
Authors: Alkahari Mohd Rizal , Furumoto Tatsuaki , Ueda Takashi , Hosokawa Akira , Tanaka Ryutaro , Abdul Aziz Mohd Sanusi
Published: November 2012

Selective Laser Melting (SLM) is a direct fabrication of part through layer by layer powder deposition and successive laser beam irradiation based on Computer Aided Design (CAD) data. One of the important properties in SLM is thermal conductivity of metal powder. This is because the ability of metal powder to conduct heat will affect the consolidation process during SLM. In this paper, thermal conductivity of metal powders with different particle diameters and their mixture was analysed. Other than that, thermal conductivity of consolidated materials fabricated via SLM process was also studied. In order to measure the thermal conductivity of metal powder, a theoretically verified method which was previously developed by the authors was used. Determination of thermal conductivity of consolidated material was analysed using laser flash technique. It was found that the thermal conductivity of powder metal was influenced by bulk density and particle diameter of metal powder. In this study also, metal powders of different particle diameters were mixed with various volume ratios, and its effect was discussed. Thermal conductivity of the consolidated materials was also examined, and its relation to porosity was elaborated.
Adhesion Strength of Electroless Copper Plated Layer on Fluoropolymer Surface Modified by Medium Pressure Plasma
Authors: Ooka Kento , Yamamoto Yuto , Hara Yasuhiro , Zettsu Nobuyuki , Yamamura Kazuya
Published: November 2012

We demonstrated high adhesive fluoropolymer/copper interface through combination of atmospheric pressure plasma with liquid phase self-assembly. However, there are some disadvantages in atmospheric pressure plasma technique, such as small processing area due to the localized plasma and high gas temperature. Medium pressure plasma process has some advantages over atmospheric pressure plasma systems. A large plasma volume and low gas temperature, available for surface treatment of polymer material, can be easier obtained at medium pressure than at atmospheric pressure, which can result in a higher overall productivity. In this paper, we investigated the adhesion strength of electroless copper plated layer formed on poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA) surface modified by combination of medium pressure helium plasma irradiation and aminated acrylic polymer grafting. The 90° peel test result for copper plating film formed on the treated PFA films showed the adhesion strength of 0.44 N/mm without increasing the surface roughness.
Development of Deburring Technology with Whirling EDM - Influence of the Motor Rotational Speed Control Conditions and the Electrical Conditions on the Machining Characteristics
Authors: Nakayama Atsushi , Lertphokanon V. , Ota Minoru , Egashira K. , Yamaguchi K. , Kawada N. , Kouno S.
Published: November 2012

The authors developed Whirling Electrical Discharge Machining (Whirling EDM) [1] with the feedback circuit to control gap distance between tool electrode and workpiece. It was found that the probability of discharge was increased by feedback circuit [2]. However, the motor rotational speed control conditions were not optimized and the machining characteristics were not clarified. In this paper, the rotational behavior of tool electrode in Whirling EDM was observed by high-speed camera, and it was considered that the influence of motor rotational speed control conditions on machining characteristics and the relationship between electrical conditions and machining characteristics. As a result, the discharge probability was able to be increased by decreasing range of motor rotational speed in feedback circuit. In addition, the machining characteristics of Whirling EDM which are influenced by electrical conditions were clarified.
Electrochemical Micromachining Using Electrostatic Induction Feeding Method
Authors: Koyano Tomohiro , Kunieda Masanori
Published: November 2012

This paper describes micro electrochemical machining (ECM) using the electrostatic induction feeding method. In ECM, electrolytic dissolution can be localized in the area where the gap width is narrow by using pulse durations shorter than several tens of nano-seconds. With the electrostatic induction feeding method which has been developed for micro electrical discharge machining, the current pulse of such short durations can be obtained more easily compared with the conventional pulse generators. In this study, the influences of the pulse voltage of power supply and feeding capacitance on the machining current were investigated theoretically. It was found that the current pulse duration is nearly equal to the rise time and fall time regardless of the pulse-on time of the pulse voltage. Hence, ultra-short pulses can be obtained without a need to use an expensive pulse generator. Micro-hole drilling carried out in a sodium nitrate aqueous solution with current pulse duration of 30ns showed that significantly small side gap of 2μm could be obtained.
Generation of Microelectrodes for Micro EDM
Authors: Miura Kohichi , Kohmo Shun Ichiro , Naruoka Ryuichi , Yamada Takazo , Lee Hwa Soo
Published: November 2012

A new turning method to control the thrust force to be zero has already been proposed in our laboratory, and it is shown that micro shafts which diameters are less than 1 mm can be generated stably and repeatedly by applying this turning method. As an application of this turning method, a generating method of electrodes of micro electric discharge machining, EDM, for micro holes is proposed. When drilling a micro hole by EDM using an electrode with high aspect ratio, machined chip is difficult to be exhausted. Therefore, machining time has a tendency to be long and the electrode consumption becomes large. Standing in such a viewpoint, a new method to exhaust the chip smoothly by forming the micro electrode geometry is proposed in this paper. As the results of this study, it is confirmed that the machining time of micro holes can be shorted and the consumption of electrode can also be decreased experimentally.
Nano-Micro Geometric Modeling Using Microscopic Image
Authors: Usuki Shin , Miura Kenjiro Takai
Published: November 2012

In recent years, there are a lot of active researches on nano-micro manufacturing and metrology, since not only industrial fields but also medical fields require higher accuracy with respect to miniaturizing size of the target. However, we cannot make an effective use of three dimensional measurement data for the nano-micro design and manufacturing due to a wide variety of instruments, resolutions, and noises. In fact, the nano-micro geometric modeling is at an early stage of development in spite of its importance for the next generation. In order to find a solution to this problem, we propose to combine the multi-resolution processing with the microscopic images for high speed and non-destructive geometric modeling as well as for the homogeneous modeling from micro features to macro ones. This research includes measurement data tiling between different instruments, high resolution optical microscopic imaging, focus judgment of three dimensional microscopic data, and large scale point crowd processing. These built models are potentially applied to in-line inspections and numerical simulations. Therefore, the nano-micro geometric modeling contribute to further developments of ultra precise manufacturing and the biotechnology.
Biofabrication of Biopolymer and Biocomposite Scaffolds for Bone Tissue Engineering
Authors: Chen Yo Yu , Li Hui Lin , Chen Chang Cheng , Jiang Cho-Pei
Published: November 2012

The aims of this study were to fabricate biopolymer and biocomposite scaffolds for bone tissue engineering by an air pressure-aided deposition system. A thermosensitive mPEG-PCL-mPEG triblock copolymer was synthesized as a biopolymer material. Biocomposite material was composed of synthesized biopolymer and hydroxyapatite (HA) with a mean diameter of 100 µm. The weight ratio of HA added to the synthesized biopolymer was 0.5. The experimental results show that the average compressive strength of biocomposite scaffolds with mean pore size of 410µm (porosity 81%) is 18.38 MPa which is two times stronger than that of biopolymer scaffolds.
Indexing 5-Axis Machining Process Design Support System Shortening Die Fabrication Lead Time
Authors: Yamada Yoshihiko , Okita Toshiyuki , Kuwano Yoshimasa
Published: November 2012

In recent years, due to intensified global competitiveness in die machining, further reduction of lead time, lower costs and higher accuracy are in demand. 5-axis machining is receiving attention as a means to solving these issues. However, differing to the conventional 3-axis machining, complex thinking tasks such as determining tool orientation while considering interference are required in the process design phase prior to machining, which not only places pressure on even those experienced workers, but also consumes a significantly longer amount of time than that required for the actual machining itself. Accordingly, with the aim of shortening the overall lead time from machining process design through to machining itself, we have developed a support system which makes highly efficient indexing 5-axis machining process design possible in a short time even for inexperienced workers. This report presents the algorithms contrived and calculation test results.
Generation of NC Program for Realizing High Speed Feed Rate of Cutting Tool
Authors: Sakurai Shintaro , Aoyama Hideki , Sano Noriaki
Published: November 2012

As the feed rate of cutting tools is influenced by the quality of NC programs, this causes two problems when cutting freeform surfaces using NC machine tools, one is the feed rate does not reach the specified value, and the other is the quality of the machined surface decreases due to the large acceleration and deceleration of the control axes. One reason for these problems is that the method to generate cutter location data does not take into consideration the sampling time of the NC controller. To improve these problems, the approximation of offset curves with a series of circular arcs has generally been proposed. But conventionally, circular arc interpolation algorithms are complicated and not rational. So, in this study, we proposed two simple NC program generation methods. (1) Approximate the offset form with circular arcs based on the location of the center of curvature. (2) Make the distance between the cutter location points of the NC data an integral multiple of the “feed rate command F × sampling time T”. We also confirm the effectiveness of the proposed methods by simulations and experiments.
Development of Orthros, an Evaluation System for Free Curved Plate Thickness with a Robot - Generation of the Path Considering Collision
Authors: Okugawa Yurie , Asakawa Naoki , Okada Masato
Published: November 2012

While it is important that evaluation of thickness of a product made with press working to evaluate a mold, currently, there is not an appropriate system which can measure thickness of a free curved plate. The study deals with a development of an automatic measurement and evaluation system for thickness of free curved plates, called Orthros. The system measures thickness of a plate with laser displacement gauges and an industrial robot. While the system has been capable for measurement of a relatively simple shaped workpiece, it had collisions between laser-path and workpiece for that of a complicated shape, owing to a geometrical limit about measuring posture of the gauges. In this article, a new method to detect collision and to avoid collision by changing measuring posture on the basis of CAD data is proposed. In the method, not only the geometrical characteristic of the laser-path but also the measuring error characteristic of the gauges depending on the measuring posture are considered and continuous measuring path having change in posture to avoid collision is devised. From the experiment result, it is confirmed that the proposed method has an ability to measure a thickness of a workpiece with complicated shape.
Reuse of Digital Mock-Up Data by Using Shape Matching
Authors: Ranglani Sagar , Michikawa Takashi , Suzuki Hiromasa
Published: November 2012

We present a framework for reuse of digital mock-up models. Our idea is to find reusable models in the archives by shape matching. Since the reusable models are already designed by operators in the past projects, we can easily create various types of data by using existing models. Indeed, we demonstrate this framework is efficient for surface simplification and CAE mesh generation problems.
Proposal of a Machining Test of Five-Axis Machining Centers Using a Truncated Square Pyramid
Authors: Ohta Katsunori , Li Zhi Meng , Tsutsumi Masaomi
Published: November 2012

NAS 979 has been used for over 40 years as a performance evaluation standard for five-axis machining centers. This standard provides some finishing conditions of the cone-frustum under five-axis control, and prescribes the measuring methods and permissible tolerances of geometric deviations. However, this standard cannot be applied to the tilting rotary table type five-axis machining center but to the universal spindle head type one. When the standard is applied to the tilting rotary table type, it is not clear yet that the effects of the geometric and synchronous deviations which influence the measured results. Thus, there are no methods for evaluating the accuracy of linear interpolation movement under simultaneous five-axis control. This paper proposes a machining test method using a truncated square pyramid for checking the accuracy of the tilting rotary table type five-axis machining centers. In the simulation and experiment, the bottom of the truncated square pyramid with a half apex angle of 15° is mounted on a fixture with a slope of 10° or 20°, and feed velocity of each axis is analyzed by changing the center position.
Cutting Performance of Ceramic Tools in Turning of Mild Steel
Authors: Tanaka Ryutaro , Hosokawa Akira , Furumoto Tatsuaki , Ueda Takashi
Published: November 2012

This study deals with the cutting performance of ceramic tools in turning of mild steel and BN free-machining steel based on it. The tool lives of ceramic tools in turning standard steel were less than 15 min at the cutting speed 250 m/min. On the other hand, the tool lives in turning of BN free-machining steel were obvious longer than that of standard steel. The tool life of TiC added alumina ceramic tool reached almost 10 hours in the case that the tool life criteria was set at VB=0.3mm. This tool life was twice as long as that of coated carbide tool.
Development of Pipe Structure Frame for CNC Lathe – Adaptation of Thermal Displacement Control
Authors: Suzuki Naohiko , Morimoto Yoshitaka , Kaneko Yoshiyuki , Sugino Hiroyuki , Isobe Minoru , Okazaki Yuichi
Published: November 2012

The miniaturization of many machine parts for machine tools is desired for the purpose of effective utilization of space, energy saving, and realization of desktop factory. To develop a compact and miniaturized NC machine tool, new downsized small parts such as hydraulic parts, pneumatic parts, electric parts and mechanical parts must be developed. These parts are not always satisfied for the practical usage in the present industrial level. Therefore, in spite of many requirements toward the miniaturization of the machine tool from the market, the miniaturized NC machine tool has not been put to practical use. The old-style structure of machine tools is one of the reasons of obstacle to solve this problem. We have proposed a newly developed ultra small size CNC lathe by using the pipe frame structure. The heat transfer between pipe elements and connecting block is affected strongly to the axial displacement. Therefore, the heat transfer between pipes can be insulated by the heat control on the connecting block. The thermal displacement control is realized by using the Peltier devices set on the connecting block. The results on the thermal displacement control of this structure and the effects on the cutting results are reported.
Optimization of Feed Speed and Stroke for Step Micro Hole Drilling of Printed Wiring Boards by Response Surface Method
Authors: Noguchi Naoya , Hirogaki Toshiki , Aoyama Eiichi , Ogawa Keiji , Takeda Yutaka
Published: November 2012

There have been few reports dealing with the drilling of printed wiring boards (PWBs) with micro-drills that are smaller than 0.2 mm in diameter, and super-high-speed spindles that are higher than 160,000 rpm. In these cases, preventing the micro-drill from breaking and keeping the position accuracy of the drilled hole has been difficult. We therefore focus on the high-speed step-drilling method and short stroke as a novel way of resolving these problems. On the other hand, determining the complicated combination of feed speed, rapid feed speed, and stroke length is difficult. Under these backgrounds, in this report we propose a fast-feed step cycle that use fast-feed command without the processing feed. Thus, we attempted to apply the response surface method to optimize these parameters. As a result, a proposed method was found to be effective to improve the drilled hole quality and drilling efficiency in such kinds of micro-drilling of the PWBs.
Change in Dynamic Characteristics of Spindle for Machining Centers Caused by Chucking Mechanism of Clamped Toolholders
Authors: Sakamoto Haruhisa , Maeki Yuhei , Shimizu Shinji
Published: November 2012

In this study, the effects of clamping toolholders on the dynamic characteristics of spindle systems are evaluated experimentally. In the experiments, the transfer functions are obtained by the impulse response method, and then, the dynamic characteristic parameters are identified based on the vibration model of single-degree of freedom. Two types of machining center spindles and four types of toolholders are evaluated. From the experimental results, the following are revealed: (1) the clamping toolholder enhances the vibration amplitude markedly compared with that of the spindle not clamping toolholder. (2) The different chucking mechanisms clearly change the dynamic stiffness of the spindle systems. (3) The order of magnitude of the dynamic stiffness of the spindle systems agrees well with that of the isolated toolholders. It is confirmed experimentally that clamping of the appropriate toolholder improves the dynamics stiffness of the spindle systems for machining centers.
A Thermally Stable High Speed Spindle System Equipped with Self-Cooling Function
Authors: Tamura Yuuki , Sawano Hiroshi , Yoshioka Hayato , Shinno Hidenori
Published: November 2012

Demands for high speed and high precision machining technologies have recently increased in a variety of industries. In general, a high speed spindle system can realize such high performance machining, however it generates a large amount of heat that causes thermal deformation. However, few research papers on thermal deformation-minimized spindle systems have been published so far. This paper presents a newly developed spindle system driven by a built-in air turbine. The developed spindle system has a self-cooling function with the air turbine. In addition, the spindle system has a compact and simple structure compared to the conventional spindle cooling systems. The air turbine was designed to improve the cooling and torque performances. Actual spindle rotational experiments were performed in order to evaluate rotating accuracy and thermal characteristics of the spindle system during rotating at a high speed. Experimental results confirmed that the spindle system can minimize thermal deformation of the spindle by the self-cooling function.
Hydrostatic Bearing with High Bulk Modulus Fluid
Authors: Kuze Kensuke , Sawano Hiroshi , Yoshioka Hayato , Shinno Hidenori
Published: November 2012

Hydrostatic bearing systems are used in machine tools due to the high damping capacity, the high stiffness, and the smooth motion. Demands for higher stiff bearing system have recently increased in various industrial sectors. In order to achieve higher stiffness of the bearing system, working fluid with lower compressibility should be used. High bulk modulus fluid with very low compressibility has been recently developed. This paper presents a hydrostatic bearing system using high bulk modulus fluid. The basic characteristics of the bearing are evaluated with an experimental setup for evaluating the bearing system and then compared the degassed oil with the conventional oil. Furthermore, static and dynamic characteristics of the bearing system were evaluated and compared with that of a conventional hydrostatic bearing. Experimental results confirmed that the high bulk modulus fluid enhances the performance of the hydrostatic bearing.
A Prototype MEMS Actuator Driven by Magnetic Fluid Enclosed with Polyimide Diaphragms
Authors: Okubo Yuhei , Ota Hiro , Syoji Kazuki , Imai Satomitsu
Published: November 2012

A MEMS actuator using a magnetic fluid enclosed with polyimide (PI) diaphragms is proposed. The actuator produces a large displacement and force thanks to its structure in which a magnetic fluid is confined between two thin-film PI diaphragms (diameter: 5 mm) fabricated on two silicon substrates. The two substrates with diaphragms are glued together by sandwiching a polyester sheet to form a diaphragm unit. The thickness of the diaphragms is 8.5 µm so that they can deflect greatly. The magnetic fluid inserted between the two diaphragms is composed of magnetite and isoparaffin. The diaphragm unit (containing the magnetic fluid) is deflected by applying an external magnetic field to it with a magnet coil. Response times and displacements of the diaphragms were measured when a magnetic field was applied. Under an applied voltage of 10 V, the diaphragm unit could produce displacements of 4 µm at the diaphragm center. Response time to reach 90% of the maximum diaphragm displacement was about 2 s. Under an applied voltage of 80 V, force generated by the diaphragm unit was 0.065N. It is concluded from these experimental results that the proposed actuator is applicable to MEMS devices such as micro pumps and give another example here.
Fabrication and Characterization of AFM Probe Integrated with High-Aspect-Ratio Diamond Tip
Authors: Shibata Takayuki , Maruno Kazuhiro , Nagai Moeto , Kawashima Takahiro , Mineta Takashi , Makino Eiji
Published: November 2012

In order to realize a smart nano-machining and measurement system based on atomic force microscope (AFM), we have been developing diamond probes with a high-aspect-ratio, sharpened diamond tip. In this paper, we described the most important micromachining techniques for the fabrication of the diamond probes. The high-aspect-ratio diamond microstructures were successfully fabricated by employing our proposed two-step reactive ion etching (RIE) processes. A novel bonding technique of diamond to Si at wafer level was also developed by using an inorganic-organic hybrid sol-gel film (MeSiO3/2) as an adhesive layer to prepare a diamond/SOI wafer as the starting material. Moreover, we demonstrated the applicability of a fabricated diamond probe not only to AFM measurements but also to a tool for nanomachining.