Calcium fluoride (111) single crystals for ultra violet applications were float polished to a flatness of 32 nm p-v on 90-mm-diameter samples that had a surface roughness of 0.06 nm Ra, and 0.72 nm Ry, as measured with a scanning probe microscope (SPM). By observing an area of a float-polished surface with a high resolution transmission electron microscope, it was determined that the float-polished surface had a perfect (111) lattice with small atomic steps, and no subsurface damage. The polished surface roughness depends on the mismatch between the sample surface and the (111) plane. This result was also verified by SPM observation.

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For the purposes of investigation of size effects on polishing performance and characteristics of polished surfaces as well as optimization of Four-Body Finishing process, instead of the 10μm polymer particles that have been used in general, smaller polymer particles, 2 to 4μm in diameter, were employed in polishing experiment with silicon wafers. The results showed that, at the same polymer particles concentration.in slurry, higher removal rates, much smaller edge profile PV values, lower Roughness (Ra) and Waviness (Wa) can be realized with small polymer particles than large ones. Furthermore, using small polymer particles produced higher ratios of motor torque over removal rate, which means, better power efficiency in material removal. These advantages are attributed to much more working points, smaller material removal unit by smaller particles and compacter layer structure of the polymer particles.

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Electrorheological fluid (ER fluid) is one of the functional fluids, which viscosity increases with electric field intensity. WC aspherical glass molding dies are usually manufactured by grinding process. However, the decline of the number of effective cutting edges in micro-grinding process causes coarse surface roughness. Therefore, polishing process must be done after the grinding process. In this paper. ER fluid assisted polishing method is proposed. In this polishing method, electric field is generated between a workpiece and a micro-tool, and abrasive grains are gathered around the micro tool. Gathered abrasive grains act like a micro polishing pad. And roughness of ground surface is improved by this polishing method.

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Not only the corrugation wear of railroad causes vibration and noise, but also it is mentioned as one of the factors which are connected with the derailment. Before, As this corrugation wear countermeasure, the re-profiling method by face grinding has been used. However, the problems that the grinding distance per unit time is short and that it is difficult to get a smooth plane, and that a re-profiling machine is expensive, are also being taken up in this method. Then, as the new efficiently method, a platen polishing with the ML(Multi-Layered ) belt is noticed. In this study, polishing characteristic of ML belt is developed.

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One of the most important performance indices of the machine tools is the machining accuracy in the multi-axis machining process. Therefore it is required to establish systematic analysis and design .methods of the multi-axis machine tools, from the viewpoint of the machining accuracy of the complicated .products. The objective of the research is to establish mathematical models representing the shape generation motion deviations of machine tools, on the basis of the geometric deviations of the relative motion between a pair of connecting units with respect to the priority of the geometric features. A case study on the kinematic motion deviations of the three-axis machining centre is carried out with the proposed method.

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This paper focuses drill-movement time. Drill moving time is not at all small when compared with cutting processing time. TSP was applied to determine the moving route of PWB holes arrangement. No one has attempted to quantify the effect of TSP. So, effect of applying TSP method is conformed by Fractal'index. Someone aimed at the improvement of the calculation time and accuracy of the TSP method to obtain the shortest route. However, considering the characteristic of PWB hole arrangement and feed control characteristic of machine tool the shortest route of geometrical problem TSP is not always the shortest moving time. So, feed control characteristic of machine tool is .applied to TSP method;. We researched a CAM system of PWB integrated the feed control characteristic of machine tool. However, the quality of PWB will be decreased in the section where the pitch between holes is extremely short. Then; it proposes the technique to prevent PWB being transformed by suppressing the highest temperature when processing it.

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Reducing the time cost of polishing process is one of the important problems in manufacturing industry of metallic molds. The feed-rate of a polishing robot is generally given to be small, if a workpiece has a large curvature. In this paper, we propose an advanced control for polishing robots so that the feed-rate along freeformed surface is .regulated suitably. It is known that the smaller the curvatures of the workpiece modeled by a 3D CAD are, the larger the distance between two adjacent steps of cutter location (CL) data generated by the mainprocessor of the CAM is. Accordingly, considering the curvature results in acquiring the distance between two adjacent steps of the CL data. The proposed controller can change the feed-rate in proportion to the distances. Promising results are shown through polishing experiments.

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This paper describes a technique to generate NC data for deposited forging dies. Machining deposited forging dies involves the two problems of tool breakage caused by excess machining load, and inefficient machining caused by high air-cut ratio. We propose a technique to efficient die surface machining, which utilizes the measurement of raw stocks, selection of the optimal tool path for the measured object, and machining load simulation for the measured object.

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Ceramic nanoparticles reinforced photosensitive resins are developed by the mixing ceramic nanoparticles (alumina-silica particles) into photosensitive resins uniformly to -produce micro stereolithography parts with high mechanical properties in this research. Micro Vickers hardness values are improved to 3.4 times than hardness values of photosensitive resins not reinforced due to reinforce the particles into the photosensitive resin at the mixing rate, 50wt%. Also, the continuous laminating micro stereolithography method using the grayscales at the LCD mask images is proposed in order to control surplus growth phenomena and to produce highly precise micro structures. Finally, micro bevel gears are fabricated by .the use of ceramic particles reinforced photosensitive resins.

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This paper introduces a miniature injection mold with diameter 30mm and length 38.5mm, which allows rapid heating and cooling, to optimize the solidification timing by controlling heat flux not spatially but temporally. On the surface of a box shape cavity, sub-micron grooves were machined using Focused Ion Beam. Using this mold we raised the mold temperature upon injection from 100 to 250℃ and time controlled the heal flux. This method allowed us to produce micro features of 3OOnm.

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The authors developed a micro thermocouple array to measure resin temperature distribution in the injection mold. We laser welded φ25μm Alumel and Chromel wire and assembled a micro thermocouple array with three measurement points in 1 mm. Using the micro thermocouple array, we directly measured resin temperature in the injection mold, and calculated heat flux passing through resin.

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Metal base MEMS is proposed in the aim both of high productivity and cost reduction, that utilizes the micro-press machine and the aerosol deposition method. The micro-press, which is developed based on the concept ofMicrofactory', is good at fabricating micro structure from metal sheet with easy setup and low energy consumption. The aerosol deposition method can stack ceramics layer at room temperature with high rate, so that several microns thick of high performance functional ceramics layer can be: obtained in short time rather than conventional MEMS process. Combining these techniques, the basic punching experiment has been done by using the micro-press to the sus304 metal sheet, which has PZT ceramic-coated layer. Because we consider that a great cost reduction and simple process would be realized if the sheet metal with the ceramic layer could be processed at the same time. As the result of the experiment, micro beam structure of 100μm in width and 50μm in thickness has been made in precise successfully. Then, the peel of the ceramics layer was prevented by selection of an proper direction of punching.

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Recently, creation of micro and highly functional product is demanded in many areas, and then many researchers are carrying out studies concerning about forming of those micro components. For this purpose a ballistic range by which an ultrasonic forming can be done is developed in this research. Micro piercing with high aspect can be performed in a high speed forming through various speed effects. For example material which situates in the direction of tool advancement is heated locally and adiabatically and becomes soft locally, buckling of a punch is hard to occur in order that a forming energy is transformed from a kinematical energy of a flying punch.

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Cutting processes are discussed to fabricate micro patterns on glasses in this paper. The principle of glass milling is shown to machine the crack-free surface. The cutting tests with ball end mills are performed to verify that the milling mechanism is effective to machine the glass without brittle fracture. Based on the results, a machine tool is developed to fabricate micro-scale patterns. The machine tool has seven axes to .machine materials with the tilted ball end mill. It is shown that the developed machine tool works well in some machining examples.

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This paper discusses the extension of one-axis vibration machining to multi-axes one to produce texture which is defined as the regular periodic structure on the surface. Applying two-axis vibration, 20kHz in vertical and 240Hz in horizontal, to a cylindrical tool of O.1mm in diameter, sinusoidal micro-grooves were machined on a glass plate. The workpiece material is low-melting-temperature glass, and it is already found that it can be machined in ductile mode and tool profile and motion can be well copied to the workpiece. It was found that the multi-axes vibration produce the texture effectively with fine surface quality.

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Vibration machining is applied for micromachining of brittle materials. However, shaping of the tiny tool is difficult though it has strong effect on the machining quality. This paper proposes a method of on-the-machine shaping of the tiny tool. The method is using single-crystal diamond tool, to shape the sintered-carbide tiny tool utilizing the ultrasonic vibration for the subsequent machining. Comparing the results of different vertical feeds, it was found that better tip profile and surface quality can be obtained with less vertical step feed. The importance of monitoring the vertical force and the video in the machining process is also emphasized.

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Depth-sensing nanoindentation tests were made on single-crystal InP at various loads using a sharp pyramid-type diamond indenter, and the resulting indents were examined using SEM and TEM. The results suggest that dislocations and slips dominate the deformation mechanism, where no phase transformation occurs. A high-density dislocation region was formed just beneath the indenter, below which is a low density dislocation region. The geometry and size of the high density dislocation region showed a correlation to the shape of the indenter and the indentation load. The dislocations along the <111> directions were dominant. The micro hardness of InP was also experimentally obtained.

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Nanoscale machining on Si (100) and fused quartz surfaces by a diamond tip has been performed using an atomic force microscope combined with a two-axis capacitive force/displacement transducer. A normal force F_n and a lateral force F_l under processing have been measured and evaluated. From evaluation of generated nanoscale grooves, a nanoscale scratching process is divided into an elastic deformation stage, an elastic/plastic deformation stage and a removal stage with increasing normal force, In the elastic/plastic deformation stage, a ratio offeree components F_l/F_n increases rapidly with an increase of normal force. In the removal stage, a rate of increase in F_l/F_n to normal force becomes gentle and the F_l/F_n becomes a constant value with an increase of normal force, which is about 0.4 on Si. That is, a transition of the elastic/plastic deformation stage and the removal stage is identified from a variation of the ratio offeree components.

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This paper presents characteristic of the shrinkage fit system holder, examination on the correspondence to the automation and development results for high-speed milling.

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This paper investigates how to use cylindrical shape memory alloy (SMA) as chucking part because tool holder can be simplified and miniaturized. SMA material cannot be utilized as chucking tool since it is one-way direction, but it is possible to attach and take off a tool by changing temperature in case cylindrical SMA is made combing cylinder with heat dies steel(SKD6l). It is clear that combing cylinder with cylindrical SMA could resist cutting resistance. Therefore, prototype tool holder that used combing cylinder with cylindrical SMA as chucking part is developed and trice real cutting processes.

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The ball bearing is built-in the nut of the ordinary taper collet chuck. But, the ball bearing is used for radial rotation and the thrust load when tightening the nut is absolutely no good for the ball bearing. The new mechanism of the nut is developed to sort out this problem. The TiN coated plane bearing (TiN bearing) is built-in the nut. When tightening the nut, between the nut and the upper surface of the TiN bearing is sliding and between the lower surface of the TiN bearing and the collet is not sliding, therefore the TiN bearing is pushing the collet straight down to the taper hole of the collet chuck. Thus, the run-out accuracy and the gripping torque are improved substantially.

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MQL (Minimum Quantity Lubrication) machining method attracts more and more attentions in production facilities for energy conservation and environmental protection. This innovative way of machining utilizes small amount of lubrication oil and compressed air instead of much water soluble coolant. Our "MQL Collet System" is most suitable for MQL machining method. Collet has 6 oil-jet splay nozzles in internal diameter for securing sufficient amount of lubrication oil in use of a small diameter tools and high precision aluminum machining. We introduce MQL collet system based on semi-dry actual cutting examples.

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Recent years have seen a rapid increase in the sales of turning mills. It is expected that the sales and manufacturing of turning mills will be equivalent to those of CNC lathes and machining centers. However, the interface (connecting section between the tool holder and the spindle) does not employ a common standard. Therefore, a committee (Interface Committee for Turning Mills, ICTM) was organized to design a new open standard. As a result of this committee in October 2002, ICTM-HSK standard that arranged ISOHSK was developed. This particular standard offers high accuracy positioning for turning holders and has exchangeability with ISOHSK-A system

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This paper describes a new standard of the tool-holding system to provide.double contact of the tool holder, that is "having the 7/24 tapered portion and the flange face of the tool holders simultaneously contacted with the 7/24 tapered portion and the face.of the machine spindle."

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BT toolshank, which is widely used in machining centers, is generally clamped with the force from Belleville-spring directly acted on a pull-stud. Since such clamping mechanism has a very long forceflow loop from a nose of spindle to a belleville-spring mechanism near end of spindle, it is said that the static stiffness of the tool holding system becomes lower and then the durability to chatter becomes worse. In this study, the new clamping mechanism for BT toolshank is proposed to become the forceflow loop shorter and enable to magnify clamping-force with wedge mechanism. From the FEM analysis of the clamping characteristics of proposed mechanism, it is found that the force-flow loop inclamping is restricted within the limited area, which only includes the small clamping wedge, pullstud, toolshank and spindle-end, and much shortened compared with conventional mechanisms. Furthermore, due to the design improvement for preventing the wedge inclination in clamping, the magnification ratio of clamping force becomes higher and is enabled to keep over 2.5 times even in spindle speed of 30,000 min.

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This study describes the influence of BN coating conditions on cutting performance. cBN sintered tool has good cutting performance. But this tool is extremely expensive and has configuration limitation. If carbide end-mill could be coated with c-BN; so that superior end-mill can be produced cheaply. In this paper, the better BN coating conditions that is suitable for SUS304 cutting were discussed on basis of experimental results, for example tool life, cutting force and observation of tool damage.

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Development of coated tool is activity performed in recent years for the purpose of extending tool life and application for cutting of high hardness and high toughness material in order to acquire a machined surface side by stabilizing the cutting edge. However, in case of cutting ductility-material, such as aluminum alloy, it is easy to occur cohesion of chips, and that causes chipping of cutting edge. These are causes of material chipping on cutting edge. Then, Application of the Diamond-like carbon (DLC) film was considered, DLC film has outstanding properties such as high hardness, chemical resistance and low friction coefficient under various conditions. Hardness and scratch tests of DLC films were carried out, and these results were appreciated.

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Even the various kinds of the multi-functioned reamers are developed,many user are choosing and using the reamer as conventional concept. Here, the improvement of the productivity and the accuracy are suggested to introduce the one step ahead reaming and the application.

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The relationship between L (tool overhang) and D (tool diameter) is critical for any machining operation. Especially, the larger L/D ratio makes chatter and vibratioa Therefore, the L/D ratio (nearly equal to static rigidity) of a cutting tool is conventionally used as a main criteria of processing. However, the latest cutting and holding tools, have the complicated taper form aiming at securing high static rigidity. Then, in order to compute the static rigidity value of the tooling which consists of them, "rigidity estimation software" was developed newly. In this paper, the cutting test was performed using the tooling based on the calculation result of this software, and the validity of the processing criteria by L/D was verified.

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New type of intelligent cutting tool with built-in thin film thermocouples (TFTs) was proposed. This cutting tool has many minute temperature sensors to measure the temperature distribution on the tool rake face directly. In this study, three types of cutting tools with built-in TFTs were developed. TFTs composed of Nickel and Nickel-Chrome thin films were fabricated on the rake face of the Alumina cutting insert by DC magnetron sputtering. Then Hafnium oxide film was deposited on the TFTs to insulate electrically. Finally Titanium nitride film was coated to endure cutting situation. Appropriate temperature distributions on the tool rake face including tool-chip contact area were measured by the cutting temperature experiments.

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One of the advantages of 'Repeatable On-the-Machine Cutting Edge Forming Technology' that we proposed previously is that both the material and shapes of a cutting tool can be changed without any tool removal from roughing to finishing process. In this point of view, repeatable on-the-machine grinding tool fabrication without any tool removal has been attempted in order to enable high efficient machining of hardened SKD11. Nickel Electroplated abrasive tool was immediately fabricated for high efficient finishing on the same machine after endmilling the hardened SKD11(HRC60) in the experiment. The result shows us the efficiency and great possibility of the technology.

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To facilitate a machine operator to perform a high-productivity machining by fully utilizing the potential of today's high-speed machining centers, we have developed a manufacturing system that can autonomously determine machining conditions in an intelligent manner. This paper presents the implementation of an autonomous machining process monitoring scheme and an in-process optimization scheme of tool paths into canned milling cycles. Since a tool path in a canned cycle is given as the repetition of simple paths, the implementation of such an in-process control scheme is more practical compared to the case under an arbitrary tool path. As an example, this paper particularly considers a trochoidal grooving canned cycle.

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Virtual machining simulator for ball end mill is discussed. This system consists of geometric simulator and physical simulator, and can predict instantaneous cutting force and machining error due to end mill deformation according to machining process. The predicted machining errors are-displayed in workpiece geometry, so operator can evaluate product accuracy easily and efficiently. The prediction models of cutting force and machining error are described and development status of the system is described in this paper.

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In order to level up the 3D complex shape machining for the metal mold and die, the machining simulation which can be considered the contact point or relative angle between the workpiece and machining tool is useful. In this study we has been developed the technique which calculates the interference quantity of the cutting edge and the workpiece for the ball-nosed end milling. In this report the new machining test method at any tool orientation used by 3axis controlled machine tool is presented, and the relationship between machining accuracy and the tool orientation is discussed.

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Ball end mills are widely used in machining of parts with sculptured surfaces. The properties required for ball end milling are high productivity, high machining accuracy and integrity of machined surface. In this study the machining error theory is applied to the analysis of spherical surfaces. The workpiece material used is plain carbon steel. Cutting tool is a cobalt enriched highspeed steel (Co-HSS) ball end mill. The machining errors are examined for various cutting conditions and cutting modes. The machining error in up cross-feed is lager than that in down crossfeed. Furthermore, it is seen that the influence of cross-feed on machining error is largest in the cutting mode of down cross-feed and down cut.

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In this study, the design and production of a desk-top-type, small machine tool were carried out, and the cutting performance of a small-end mill tool at high-speed condition is investigated. The size of the developed machine tool is 300×400×340mm, and the weight is 50kg. This machine could reach a cutting speed of 16.7m/s using a small end mill. As a result of high-speed milling with this machine, a surface roughness of 1.34μmRz without tear parts was obtained at cutting speed of 16.7m/s. In addition, the thickness of deformed layers produced by milling operation at a speed of 16.7m/s decreased in comparison with that of layers produced at 2.5m/s. It was confirmed that the thickness of deformed layers at 16.7m/s was0.6μm.

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This paper describes the results of experiments on high speed milling of quenched die steel using small diameter cBN ball endmills. For the experiment, three kinds of cBN ball endmills with the different cutting edge shape that it was tool radius 0.3mm, and the developed small high-speed milling machine were used. In the cutting condition of rotational speed N=170,OOOmin-1, depth of cut Ad=0.O1mm/Pf=0. 05mm, feed speed F=1000mm/min, the long tool-life machining was possible.

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This paper deal with cutting mechanism and cutting performance of machining for inclined sur&ce by an oval end mill. The cutting edge shape of the oval end mill is very complex, so we use 3D-CAD for calculation of chip area during machining. Then cutting performance is discussed using the evaluate value calculated by the multiplication of the chip area and the length from Z axis to the gravity of the chip area. And also the theoretical jvalue of surface roughness of machined surface is calculated and compared with the value by experiment.

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An approach is presented to simulate cutting processes with tilted ball end mills. An energy approach, which makes the chip flow model with pilling up orthogonal cuttings in the plane containing the cutting velocities and the chip flow velocities, is extended to apply to the operations on multi-axis machine tools: The tilted tool in the plane perpendicular to the feed direction is interpreted as machining of the inclined workpiece at a tilt angle. The tilted tool in the direction of the cutter feed is analyzed with coordinate transformation from the general coordinate system to the coordinate system inclined at a tilt angle. Based on the orthogonal cutting data, the chip flow model can be made to predict the cutting force with the chip flow direction. The comparison of the analysis results with the measured cutting forces verifies the presented model based on the energy approach.

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This study aims to improve tool life by investigating the effectiveness of the use of high oxygen atmosphere for the reduction of adhesion by generation of oxide. Titanium alloy (Ti-6Al-4V), Inconel 718 and four other kinds of coated carbide end mills were used in this experiment, and the effect of cutting atmosphere on tool wear were investigated by side cutting under the dry cutting condition. From the results obtained, because the adhesion was decreased by the oxidation, the tool life in the high oxygen atmosphere became longest under the dry cutting conditions. Moreover, when the titanium alloy was machined, (TirAl)N and TiSiN recorded the highest wear reduction in the high oxygen atmosphere. The smallest wear was recorded by TiBON. It was observed that machining under the high oxygen atmosphere was effective to demonstrate the performance of the coating tool from which lubricity was given by the oxide generation.

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Stainless steel is widely used as a popular material not only in many industries but also in the production for daily necessaries. And besides, it is also known well as one of the difficult-to-cut material. In this paper, two kinds of austenitic stainless steels, SUS 304 and SUS 316, were end milled using coated carbide end mill and non-coated carbide end mill by side cutting method. Cutting force, AE signal obtained during end milling and tool failure were investigated. Coated carbide end mill shows superior cutting performance. Austenitic stainless steel SUS 304 shows a poor machinability compared with SUS 316 and carbon steel S50C.

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This paper discusses the cutting force and the cutting area during the cutter rotation in milling of glass. It is shown that no brittle fracture occurs on the machined surface in the picture took on a SIM (Scanning Ion Microscope). Three components of the cutting force in machining of glass, then, are measured with a set of piezo dynamometers. The noise signals induced by the vibration of the fixture, the tool, the spindle and the table are removed with the filters in the frequency domain. The cutting forces measured show that the cutting processes in machining of glass are the same manner as that of machining of metals; and the cutting force also increases with the feed rate. The cutting area with the cuter rotation is analyzed to show the effect of the tilt of the tool on the machined surface and tool life in glass machining. The glass can be machined at a high cutting speed by the tilt of the milling, tool. The tilt of the tool leads to a long tool life with air cutting time.

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We have studied single discharge machining to low melting temperature(47℃) alloy. The purpose of this study is to make clear the crater generation process in single discharge machining. In this report, single discharge machining is carried out with kerosene oil and de-ionized water and air. In kerosene oil and de-ionized water, the cross section profile of the crater is near the one part of sphere shape. Under the negative electrode with over 200μs pulse duration in kerosene oil, the volume of the crater decrease. In de-ionized water and the negative electrode in kerosene oil, a lot of non-spherical debris are observed. From the observation of the craters and the debris of the low melting temperature alloy, the mechanism of the material removal is discussed.

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A new surface finishing process for biomaterial titanium alloy products by wide-area electron beam irradiation is proposed. In the wide-area EB irradiation equipment, high energy density EB can be irradiated without concentrating the beam. Therefore, wide-area EB with a maximum diameter of 60mm can be used for instantaneous melting or evaporating metal surface. Experimental results made it clear that the surface roughness becomes smaller and the glossiness becomes higher with increasing energy density of beam. Under a proper irradiating condition, the surface roughness of titanium alloy machined with end mill could be decreased from lOumRz to less than lumRz in just a few minutes. Moreover, the corrosion resistance could be improved simultaneously. Therefore, wide-area EB irradiation method has a possibility of high efficient surface smoothing and surface modification process instead of hand finishing.

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This report describes the electric discharge surface coating technology which can form the layer of metal or ceramics using electric discharge. According to this technology, thickness of micrometers to millimeters layer can be formed. The characteristic of this technology is as follows. (1)No deformation and no crack. (2)The adhesion magnitude of the layer to the workpiece is very high. (3)A uniform layer can be formed without depending on a worker's skill. (4)The suitable layer can be achieved by choosing electrode material and electrical conditions at EDM. As mentioned above,this technology can expect the application to gas turbine parts, automobile engine parts, etc.

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Aluminum is inferior in mechanical properties, such as hardness and wear resistance, compared with steel material, so various technical developments with which they are compensated is performed. In this research, the surface modification which used electrical discharge machining as one of the technology was observed. Processing liquid had high heat stability compared with the kerosene usually used by electrical discharge machining, and used silicone oil excellent in electric insulation. Stabilization of electric discharge and the increase in the thickness of EDC layer are expected by using this processing liquid. EDC layer speed was able to be raised to 378 M m/3min by optimization of pulse width, a current value, a duty factor, and a electrode gap.

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In this research, a machine tool with a tool wire has been developed for combined machining. Wire EDM for shape forming and abrasive machining for surface grinding are carried out by using the developed machine tool. Repetitive surfacing leads to 3 dimensional observation of materials distribution of a specimen. In this paper, we applied abrasive machining to cast iron and analyzed its surface by energy dispersion X-ray spectrometry (EDS). We discuss the feasibility of materials distribution of the specimen ground by wire scanning surfacing with a scanning electron microscope (SEM).

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In case of the electrical discharge machining of insulating ceramics by an assisting electrode method, since the resistance of EDMed surface is very high, it is difficult to detect the contact between a workpiece and an electrode. Therefore, after the electrode comes in contact with the workpiece, the feed of the electrode continues, and the electrode and/or the workpiece will be broken. In this study, we control the torque of the main axis in order to keep stable machining. The results of electrical discharge machining to insulating SiiNt ceramics using this equipment are described. Furthermore, in order to improve the EDMed surface, polishing process was carried on the same machine. The electrical conductive layer on the EDMed surface could be removed by rotating tool with diamond abrasive.

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Self-sharpening phenomena of thin tungsten electrodes in single, high current discharge have been studied by a stroboscopic imaging technique using a fast pulse laser. The diameter of sharpened electrodes depends on discharge duration even though the total discharge energy is kept constant. Effects of four types of machining atmosphere are examined: discharge in working-oil, discharge with working-oil film, discharge in argon gas and discharge in air. The optimal discharge conditions for self-sharpening vary with machining atmosphere. The self-sharpening in argon and air are found to be induced by discharge with higher current.

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3dimensinal products have been machined from insulating materials (Si_3N_4, ZrO_2, SiC, Al_2O_3, etc.) on electrical discharge machine by using an assisting electrode method. However, fundamental phenomenon problems related to : processing principle, such as the investigation of the forming conductive layer during machining, are still not been solved completely. In this research, EDM properties have been investigated on glass materials that are transparent and the process in a material can be checked from outside. Most of the glass materials are non-crystalline unlike ceramics that are crystalline. Specific properties of EDM on heat resistance glass were investigated in this research.

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