Our mission is to manufacture the optimum products using provided design data. Thanks to analysis tools brought in recently, designing of more efficient propellers have become possible. To manufacture the propeller, which can bring out designed efficiency at maximum, high level manufacturing technology is essential. Our Tamashima Factory is the specialized facility for manufacturing large-sized fixed pitch propellers. Sizing range manufacture is from 5 meters up to maximum 12 meters in diameter, weight up to 150 tons. Here, we succeeded in developing special "one-in-the-world" facilities, such as the blade milling machine which can control 5 axis at same time, the balancing machine, and the propeller overturning facility. These special facilities brought us higher machining accuracy. We would like to present the improvement of productive efficiency and quality we have achieved in last 4 years with introduction of our facilities.

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Waste treatment of used water-soluble coolant causes environmental load and the increase of manufacturing cost in machining. To reduce the environmental load by water-soluble coolant, we have developed a metabolic system for water-soluble coolant which dissevers and extracts water resource from used water-soluble coolant and reuse it. In this report, we have experimentally examined the possibility of recycling use of amine-free coolant. As a result, amine-free coolant has shown a similar aspect change compared with common water-soluble coolant.

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In the cold rolling of aluminum, coolants made with nonaromatic base oils provide poor lubricity compared with coolants made with conventional base oils. But there is not a clear difference in lubricity between nonaromatic and conventional base oils in the case of the rolling of aluminum. In experimental rolling, the lubrication performance of coolants using nonaromatic base oils can be improved with the addition of water. The addition of few % of water into a nonaromatic coolant is sufficient for practical lubrication performance in the cold rolling of aluminum.

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Fluid ability of food additive solutions is experimentally examined through the lapping of S45C with 1 wt% solution of oligosaccharide, monosodium glutamate, citric acid, glucose and L-ascorbic acid. Each food additive solution has its own pH and ORP and shows an unique fluid ability. The lapping force is strongly rerated with ORP; the less ORP the less lapping force, while it is difficult to find a certain relation between pH and lapping force.

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A slicing method of multi-wire saw is classified roughly into a loose grain method and a bonded abrasive method. Because there is a little kerf loss, a loose grain method is profitable to slicing of expensive work material. Additionally, precision slicing is possible because this method is a little damage to sliced surface, and there is comparatively a low cost. Therefore a loose grain method is adopted in slicing of wafer from a single crystal silicon ingot. However, as for a large quantity of used slurry, processing as the industrial waste is necessary. In addition to a problem for processing cost as industrial waste, consideration to environment is necessary in future. A main purpose of this study is large reduction of a quantity of use of slurry. Therefore the new slicing method is proposed which uses only slurry of the minimum quantity to be necessary for slicing. In this report, fundamental slicing performance of a proposed method is made clear. The main results obtained are as follows. The slicing in minimum quantity slurry is possible, but its precision is not so good generally.

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Applying materials on the precut surface in ductile metal cuttings can greatly improve the machinability, due to a reduction in friction between the lamella of the chip. We define this effect as the lubricant applying effect (called as LAE hereafter). This paper dealt with the influence of the LAE on the cutting of difficult-to-cut material the Ni-base superalloy Inconel 718. The experimental results demonstrate that the LAE played an important role in lubrication of the Inconel 718 cutting.

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In this paper, the influence of fullerene as an additive on flank wear and crater wear of TiN and (Al,Ti)N-coated tools, and finished surface roughness were investigated with minimal quantity lubrication (MQL) system in hobbing when changing the cutting speed. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The following results were clarified; (1) Fullerene decreases the flank wear compared with dry cutting even if the cutting speed was changed. The flank wear obtained with the(Al,Ti)-coated tool is smaller than that obtained with the TiN-coated tool. (2) Even if the cutting speed was changed, fullerene is effective for the crater wear and the finished surface roughness compared with dry cutting.

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This paper describes the results in a fundamental experiment on Near-Dry deep hole drilling with BTA tool. On the experiment, the cutting chips could not be discharged from cutting region and deposited metal occurred on the cutting edge under Near-Dry condition. Therefore, the chip thickness was measured and the shear angle and the net rake angle were calculated by applying the orthogonal cutting theory partially. In addition, the development of the deposited metal was observed. As the result, the guidelines for discharging the chips from cutting region were obtained.

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In machining of aluminum and its alloys, since they have highly adhesive characteristics compared with steels, more effective lubrication is often necessary. This paper therefore investigated the optimal lubricant and its supply method in MQL machining of aluminum alloy based on the reactivity of water which has high polarity. The experimental facts demonstrated that humidified atmospheric air could provide the excellent cutting performance for the synthetic ester of a MQL lubricant and, further, the micro water droplet treatment could improve the cutting performance of the lubricant. The method could become a powerful tool to solve the problems encountered in near-dry machining of aluminum alloys.

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An MQL method can realize ecologically-friendly machining by suppression of amount of supplied coolant. However, we must consider alternative chip control method because the MQL method has only a poor chip disposal performance. Authors proposed a novel machine tool with chip-suctioning system by use of hollow cutting tool. In this study, a prototype drill suitable for the chip-suctioning system was developed. From some experiments, the developed drill successfully functioned as chip-suctioning tool in practical drilling condition.

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In recent years, sustainable materials using natural resources have been developed to alleviate environmental problems. This research produces products that use only bamboo fiber. I propose a high quality bamboo fiber extraction method with a machining center. By using machining center I extract fiber. And extracted fibers are molded in high temperature and high pressure. And it keeps about 10 minutes. After that bamboo products are made. This product's ingredient is only bamboo fiber.

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It is expected that driven rotary tool with multi-tasking lathe provides high-speed machining and long tool life for super-heat-resistant alloy. In this paper, tool wear of driven rotary tool with textured surface was investigated. Machining S45C steel was carried out. Experimental results show that averaged flank wear V_B under the clockwise tool rotation is smaller than that under the counterclockwise tool rotation. However, there is no significant effect of textured surface in tool wear.

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Carbon fiber reinforced plastic (CFRP) is a very strong and light composite material, and it has many applications in aerospace and automotive fields. However, in conventional mechanical machining methods, such as cutting and grinding, there are some problems; delaminating, splintering, burrs of machined surface and short tool life. Electrical discharge machining (EDM) is an effective alternative methed for machining difficult-to-cut materials. In this paper, the EDM characteristics, such as material removal rate, electrode wear rate and surface roughness for CFRP were experimentally investigated with varying pulse duration. Also, the effect of the fiber orientation on the machining characteristics was discussed.

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This paper deals with the short circuiting in electrical discharge machining (EDM) of carbon fiber reinforced plastics (CFRP) in order to discuss the material removal in EDM of CFRP. Sinking EDM of CFRP using deionized water was carried out, and the relationship between short circuit ratio and material removal rate was investigated. Potential drop and temperature rise in the CFRP workpiece caused by the short circuit current were also estimated and compared with the experimental results. It is found that short circuiting contributes to the material removal in EDM of CFRP, whereas it cannot contribute to material removal in EDM of metal.

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To improve the machining properties of sinking electrical discharge machining on the cemented carbide material, the ultrasonic vibration apparatus was added on the EDM system. The designed ultrasonic vibration system was produced for this experimented. In this machine, the longitudinal and transverse direction movement could be added separately or compounded. The effect of vibration direction on the removal rate, surface roughness and wear ratio of electrode were investigated. As the results, using the compound movement, the removal rate and the surface roughness were improved than the normal, separately machining.

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Cemented carbide has many excellent properties, such as high strength, high hardness and so on. However, it is difficult to apply conventional surface finishing or surface modification methods for the cemented carbide. In this study, a new surface modification method by large-area electron beam irradiation (EB polishing) was proposed. The surface structure of the EB polished cemented carbide was observed by TEM. Then the surface characteristics, such as hardness, water repellency and releasability of molded resin were evaluated. The experimental results clarified that the water repellency and the releasability of the molded resin could be improved because the surface structure changed by EB polishing.

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Few studies have been carried out on the effect of electrical discharge machining (EDM) conditions on the strength of workpieces processed by micro-EDM. The bending strength of cemented tungsten carbide 5-μm-diameter micropins fabricated by micro-EDM was therefore investigated. Although the bending strength increased with a decrease in the electrical discharge energy at the finish machining of micropins, it decreased at smaller discharge energy. The result of the bending strength test was then applied for the EDM fabrication of cemented tungsten carbide ultrasmall-diameter cutting tools. Tools with a long tool life were successfully fabricated.

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An electroplated diamond tool is widely used for grinding, because of its high grinding efficiency. However, the height of the grain protrusion of the electroplated diamond tool is not uniform such that surface roughness deteriorates. Therefore, it is necessary to make the height of diamond grains uniform. In this paper, we propose a new electrical discharge truing (ED truing) method for the electroplated diamond tool. This ED truing method can be applied in a conventional electroplated diamond tool whose grains (diamond) have no electrical conductivity. As a result, it is shown that it is possible to truncate only the tips of diamond grains directly by this new ED truing method and to obtain an electroplated diamond tool with a uniform grain height. Moreover, it is confirmed that ground surface roughness is improved by using the ED-trued electroplated diamond tool.

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This study deals with the development of a new CAD/CAM system for fabricating the holes whose cross sections are changing variously. Hole shapes which can be achieved by machining is generally limited. As a typical example, a cross section of a machined hole is constant. To solve this problem, the authors have developed a new device which can machine holes with changing cross sections by means of electrical discharge machining. However, it was impossible to put the device into practical use since the software system for the device did not exist which can make the device machine the cross section's changing hole set as a target. Accordingly, this study aims at the development of the new CAD/CAM system to realize such machinings. Since the postprocessor constituting the CAD/CAM system has been made which is used for machining with simultaneous 2-axis control, the postprocessor for simultaneous 3-axis control machining is created as a next step.

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When an ultrashort pulse laser is focused and irradiated into the inside of permeable medium, the refractive index changes dependently on the electric field strength. As a result, a self-focusing phenomenon occurs and self-focusing can lead to a filamentation. In the light absorption medium, the absorbed light energy changes to the thermal energy after ultrashort pulse laser irradiation. Then melting or partial ablation phenomena occur near the focusing area in the medium. In this study, a paraxial wave equation in the Kerr medium which absorbs the laser beam was derived. By numerical calculation by the split-step Fourier method with the fast Fourier transform, light absorption energy distribution in a fused silica irradiated by an ultrashort pulse laser was obtained. Using the absorbed energy distribution as the initial condition, heat transfer analysis in the material was conducted. The influences of the absorption coefficient on the intensity distribution and the temperature distribution in the material were investigated.

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Fusion welding is well known as the most promising technique in glass joining, since joining can be accomplished without any intermediate layer and mechanical contact. High precision, small heat-affected zone (HAZ) and small shock-affected zone (SAZ) by ultra-short pulsed laser make it possible to perform the joining process with minimal damages to the surrounding area. However, there still remained a lot of things to be clarified in this process, since glass materials are very sensitive to temperature gradients. In this study, molten zones created by ultra-short pulsed laser in a fused silica glass were experimentally investigated. Laser irradiation was carried out inside the glass under various processing conditions. Molten zone was observed visually, and its mechanical strength was measured using three points bending test. The strength of molten zone was almost equal to the base material, and high strength could be obtained at low velocity and high pulse repetition rate condition.

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Micro-holes of some hundreds micrometer diameter were drilled on cemented tungsten carbide plates of 0.5 to 1mm thick by ultrashort laser pulses. Effects of laser light polarization, circular vs. linear, have been examined. Circularly polarized laser results in spherical shape holes while linearly polarized light results in elliptic shape hole exits. Laser induced periodic surface structures(LIPSSs) with size of 260 to 300 nm interval were found on the side of drilled hole. Effect of polarization on LIPSSs formation was also examined

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In this paper, ablation of sapphire by femtosecond laser pulses under static irradiation and line-scanning experiment was carried out. Under static irradiation, for single laser pulse irradiation, two ablation phases were observed and the threshold fluences of the two ablation phases were calculated. In line-scanning experiment, microgroove was fabricated under different experimental conditions. The relation between the width and depth of the groove and key parameters of femtosecond laser was obtained. The surface quality of the fabricated microgrooves could be improved through increasing the number of laser scans. The width and depth of the groove was not affected by the number of laser scans. Several samples of the parallel microgrooves and microstructures were fabricated by femtosecond laser pulses.

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In the cut process of glass, laser scribing is applied in which a crack grows stably in being quenched down immediately following CO_2 laser beam irradiation. Because the scanning velocity can be higher as the laser power is heightened, the laser power should be more than tens of watts in practical application. Therefore pulsed CO_2 laser is generally applied. In this research, we aimed to investigate the influence of the laser frequency in the laser scribing of glass. We conducted two dimensional thermal stress analyses in which the laser frequency and the pulse waveform are configurable, and considered the crack growth phenomenon by comparing the results with those of laser scribing experiment. The obtained conclusions are as follows: At a depth of more than 40 μm from the heated plane, the laser frequency does not influence the stress or the stress intensity factor. As a result, the crack depth is not influenced by the laser frequency because a crack grows to where the oscillation of the stress field is small enough. Therefore the crack growth phenomenon can be simply considered by analyses in which the laser oscillation is set to be continuous wave at the same power.

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This paper deals with the reduction of residual stress induced during the selective laser melting. The residual stress within the consolidated structure is calculated by the strain measurement attached on the bottom face of the substrate when the consolidated structure is cut with an end mill. The influences of base plate thickness and structure height on the residual stresses are investigated. In addition, the effect of post heating by a laser beam irradiation is evaluated. The result showed that the deformation of the substrate increased with increasing of the consolidated layer and decreasing of base plate thickness. The residual stress distribution within the consolidated structure was extremely large at the top layer of the structure and the boundary between the base plate and structure. The residual stress decreased when the top layer of the consolidated structure was heated by laser beam irradiation, and resulted in the reduction of the deformation of base plate.

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Monocrystalline silicon has played an important role as semiconductors in the electronical and the electrical industries. High efficiency and high quality manufacturing process of silicon is required for the continuous development of these fields. However, debris and cracks remained on machined surface by the traditional mechanical processing because of its high brittleness. On the other hand, laser beam machining could realize the high-speed processing. However, heat affected zone and dross remained in the case of fundamental wavelength of Nd:YAG laser. In comparison, it is expected that harmonics of Nd:YAG laser make it possible to perform the high precision micro-machining with small heat affected zone and crack because of its high photon energy. In this study, the influence of wavelength and surrounding pressure was investigated with observing process behavior using a high-speed shutter camera in micro-machining of monocrystalline silicon by fundamental wavelength and harmonics of Nd:YAG laser.

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Recently, one of the medical device "stent" is widely used for intravascular surgery and the performance improvement has been required. In this study, laser-cutting process, which is one of the important processes for development of high performance stent was investigated. The laser cutting processing is used for the manufacture of micro mesh structure. Therefore there are many points to be considered for fine cutting. In this study, the effect of the tool pass on the finished quality is described.

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Used in the production of semiconductors and solar panels, the demand for silicon wafers is increasing. However, in the current state of manufacturing process, 50% from the cutting process goes to waste. To reduce processing waste and to cut the silicon wafer thinly, a new laser cutting method was developed. A YAG laser's beam slightly penetrates silicones. By using this property, cracks in a plane parallel to the inner surface of silicon wafers are made, cutting the wafer as a whole. In this paper, experimental laboratory equipment was made and from the basic experimental results, we would like to report the successful separation of the silicon wafer.

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Cutting point temperature and tool wear during a driven rotary tool was examined in this paper. Dry and MQL tests of stainless steel (SUS304) were carried out. We measured the cutting point temperature by using tool-work-thermocouple method and tool wear. Then, the cutting speed was varied. Cutting point temperature tends to increase with the increase of cutting speed. At high speed cutting (500m/min), cutting point temperature was over 1200℃ in non-rotation tool. However, by using driven rotary cutting, cutting point temperature was 1000℃. In addition, by using driven rotary cutting with MQL, cutting point temperature was decreased to 900℃. The magnitude of tool wear almost corresponds to the cutting point temperature.

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In machining, the twist drill is one of the most common tools. But, the conventional twist drilling often lead to distorted holes that have triangle-shape or pentagon-shape because of "Walking phenomenon" and "Chatter vibration." Therefore the roundness becomes worse. In order to improve roundness, the drill with two asymmetric cutting edges has been developed. In previous researches, it is known that the roundness is improved by using the asymmetric cutting edge drill regardless of drill diameter. Especially, in the case of the drill has low rigidity, the improvement of roundness is large. In this study, we have investigated straightness and surface roughness of inner wall of holes empirically. As a result, even the drilling depth was deeper than previous researches, the roundness of drilled hole was smaller than that of conventional drilling and also the straightness was improved by using the asymmetric cutting edge drill.

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High cutting efficiency, high accuracy, and low cutting temperature are important during the machining of bone. However, there is no tool to satisfy all these requirements simultaneously. Therefore, a bone cutting tool was proposed in this paper. Especially a milling tool was designed, because it was easy to achieve high efficiency. The proposed tool has two kinds of cutting edges. One of the edges has slightly shorter diameter, and realizes rough machining. The other edge finishes the surface with small depth of cut. Thus it would be possible to perform rough and fine processes at a time with the proposed tool. Some experiments were conducted, and the cutting performances were evaluated under the following three points: efficiency, accuracy and temperature.

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In this paper, we propose the measurement method of bending stiffness characteristics concerning the starting position l_0 of actual chucking-force action in the tool hole of chucks. The bending stiffness of chucks is not determined by only spring constant k at the chucking region. Therefore, it is necessary to express the displacement at the tool point in tool chucking determined based on the bending stiffness characteristics, such as k and l_0, and tool chucking condition, such as E, I, etc. From the comparison of influence on bending stiffness between k and lo, it is found out that k is much effective on the stiffness. However, it is also confirmed that lo has a potential to change the stiffness widely. Because of above mentioned applications, it can be said that the proposed method is useful for both user and designer of milling chucks.

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Single-phase (binderless) nano-polycrystalline diamond synthesized by direct conversion of graphite under high pressure and high temperature has a very fine texture consisting of small diamond grains (several tens of nanometers in size), having extremely high hardness, no cleavage and high thermal stability. In order to clarify its potentiality for industrial uses in cutting tools, the mechanical properties of nano-polycrystalline diamond were systematically investigated. In addition, the cutting performances of the nano-polycrystalline diamond tool for some materials were evaluated. These results revealed that the nanopolycrystalline diamond has significantly higher cutting performance than conventional sintered diamond tools or mono-crystal diamond tools.

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A Frictional Stir Burnishing (FSB) is applied to the shaft materials of 0.45%C steel by using a multi-tasking machine in this paper. FSB is a process where the burnishing tool rotates at high revolution speed. Then the thin surface layer is rubbed and stirred with a temperature elevation and reduction. By FSB process on double helical path, both high hardness and compressive residual stress are achieved. However, when the FSB process using sphere tip shape tool is applied surface roughness becomes large (Ra20μm). Therefore, FSB process using flat tip shape tool is applied. As a result, both high hardness (600 HV) and compressive residual stress (-350 MPa) are achieved and surface roughness becomes small(Ra3μm).

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In recent years, in consideration of issues such as environmental protection, reducing manufacturing costs, ensuring the safety and health of workers, it has been much researched on semi-dry machining and dry machining. Then, by applying oil impregnated cutting tools, it is possible to improve the cutting performance, despite the dry cutting. In this study, we conducted experiments using oil impregnated cutting tools, and verified its performance. We got the following results. (1) Oil-impregnated tools are effective to inhibit wear. (2) Chip evacuation is improved. (3)The field environment was comfortable.

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When cutting titanium alloy, the temperature of a cutting tool edge is easy to rise and the tool edge is tend to be worn away quickly because the titanium alloy has the characteristics of low thermal conductivity and high chemical activity. Therefore, it is difficult to achieve a balance between the productivity and the tool life in cutting the titanium alloy, namely, low-speed cutting must be carried out at present. To examine the possibility of the improvement in the cutting efficiency, a PCD (polycrystalline diamond) tool having high thermal conductivity was adopted to the cutting of titanium alloy and its cutting performance was investigated. The PCD tool was found to have excellent flank wear resistance compared with conventional cemented carbide tools. It was also revealed that unprecedented high speed cutting become possible by use of PCD tool with an application of high pressure coolant.

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This paper reports analyses of stress and temperature on cutting tools made of functionally graded materials considering of layer angle. At first, we measured the cutting resistance under high-speed dry cutting test to determine the layer angle. Next, we modeled the FGM tools with the layer on a FEM software to analyze stress and thermal property. The analyses were conducted in case of layer angle is 0° and 27° for comparison. From the result of the simulation, it was found that the layer angle gave large effect to stress property while it gave small effect to thermal property.

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In the present study, depth information is extracted from two or more images by photometric stereo method. However, it is considered to obtain the accurate data from the lustrous on color changing surface object by this method. In the present report, we propose new processes to improve these problems. One technique is to use the Gauss filter. The other is to use four kinds of color light sources.

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