An investigation was carried out to study the cutting forces in the deep sawing of hard granite. The maximum depth of cut was up to 120mm in the investigation. During the deep sawing of granite, the cutting power, vertical and horizontal forces were measured respectively by wattmeter and dynamometer. The tangential and normal force components acted on the saw-blade and each diamond grit were then calculated and analyzed according to the measurements. The distribution of stress in the saw-blade was also analyzed by Finite Element Method (FEM). It is hoped that this study will be of benefit to wider applications of deep sawing.

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We have tried to obtain an optimal abrasive system that can improve the quality of products or goods and the production efficiency by establishing the process system to manufacture 100micro drills and by experimenting it in various ways. This paper have decided the optimum nomenclatures of 100micro drill for the shape design by considering the important factors such as the cutting point angle, helix angle, web thickness, flute length and under cut etc through the FEM analysis and was evaluated the characteristics of it owing to getting the high quality's products by various experiments.

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In order to develop a new ELID grinding system as a surface fabrication process for metallic biomaterials such as a Ti-6Al-4V alloy, ground surfaces were analyzed by using a TEM, XPS and a Nano-Hardness Tester (NHT). Chemical stability was examined by electrochemical corrosion tests using a three-electrode electrochemical cell connected to a computer driven potentiostat. In order to investigate the tribological properties, reciprocating sliding friction tests were also carried out. Finished surfaces produced by the new ELID grinding system showed higher corrosion resistance and tribological properties as compared to those of the polished surfaces. It is believed that this new system improves corrosion resistance and tribological properties by creating a thick oxide layer with a diffused oxygen and carbon element.

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This study investigated the effects of grinding wheels on the surface modification properties in Electrolytic In-process Dressing grinding. Three specimens were ground with different abrasive grinding wheels: diamond wheel, SiO_2 wheel, and diamond+SiO_2 wheel. These three different grinding wheels produced surfaces modified by the diffusion of the abrasive elements. Adhesive strength evaluation tests between the substrate surface and the DLC film were performed using micro-scratch testing. The finished surface ground by the diamond+SiO_2 wheel showed the highest adhesive strength due to the physical and chemical properties of the diffused elements. As a result, application of this proposed grinding method to mold fabrication shows considerable promise.

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We are studying ways of recycling grinding fluid, supplying grinding fluid and electrode technology in the aim to develop Eco-friendly ELID grinding technology. As one elemental technology of this Eco-friendly ELID grinding technology, we developed a metal free electrode-conductive resinoid bonded wheel using RB ceramics as the conductive material. The prototyped grinding wheel was a #8000 RB ceramics bonded grinding wheel using diamond abrasives. Using this wheel, electrolytic dressing characteristics and grinding characteristics were investigated. Experimental results show that a non-conductive coating is formed on the wheel surface by electrolytic dressing, and this coating has greater frictional coefficient and wear amount than the bonding matrix. Grinding experiments of some hard and brittle materials were carried out using this grinding wheel, and it was found that a stable mirror surface finishing can be realized by adding ELID grinding.

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In the aim to fabricate high quality ground surfaces efficiently by ELID grinding, investigations were conducted on the grinding system, grinding wheel, grinding fluid, and electrolytic power supply system. As part of this study, we developed a conductive rubber-bond grinding wheel for ELID grinding. The grinding wheel is composed of rubber, carbon, and abrasives, and was designed to demonstrate ELID effects (continuous grinding ability) by the excellent finishing effects of rubber and conductivity ensured by carbon. The prototyped grinding wheel was a #120 conductive rubber-bond grinding wheel using Al_2O_3 abrasives. Using this wheel, the electrical dressing characteristics and grinding characteristics were investigated. The experimental results show that a non-conductive coating was formed on the wheel surface by electrical dressing, and this coating has greater frictional coefficient and wear amount than the bonding matrix. Grinding experiments of mono-crystalline silicon were also carried out using this grinding wheel, and it was found that stable grinding without loading can be realized by adding ELID grinding.

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In this research, processing of micro tools was realized by ELID grinding. However, there was a problem in productivity, that is to say: various shaped processing time is long. Under this background, in order to target high-streamline in establishment of micro tool processing, the desk-top type cylindrical grinding machine called "CYLIN" which is equipped with the ELID system was developed. In this paper, this processing system for micro tools is introduced, and basic experiments processing micro tools of hard metal were conducted. In this experiment, using a#20000 wheel a micro tool of aspect ratio 20 was successfully produced with ELID grinding. And it was suggested that the grinding wheel rotational direction affects the obtained micro tool surface quality. And, in processing of a highaspect-ratio micro tool which was ground by two wheels at the same time, there is no size difference of a root part and a tip part changing.

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In this study, The ELID micro grinding method and inclined rotational grinding by three-axis motion control (XYZ axis) was carried out on a micro aspherical mold. ELID (Electrolytic In-Process Dressing) grinding method is possible to achieve ultraprecision smooth surface of hard and brittle materials. To obtain ultra smooth surface required such as micro lens, final polishing process taken long tune after conventional grinding process was necessary. ELID grinding method using an ultraprecision grinding machine tool has been found to be effective in reducing the time required for finial polishing process in this study. Results of this grinding experiments indicated that ultraprecision surface roughness and form accuracy was achieved successfully. High profile accuracy into effective diameter within ±0.1μm p-v was successfully achieved in this grinding experiment too.

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To realize efficient grinding of a spherical lens, in this study, the authors developed an ELID grinding system by applying the CG (curb generator) method to the 4-axes desktop machine tool TRIDER-X designed based on the concept of a micro workshop. The system comprises of a 4-axes desktop machine tool mounted with a CG unit developed using micro abrasives grinding wheels above #12000 on an ELID grinding system. The grinding wheels used cast iron bond diamond abrasives #324, #2000, #4000 and metal resin bond diamond abrasives #12000. Grinding was conducted on light barium flint glass, and fundamental experiments were carried out by the CG method. As a result, it was confirmed that grinding can be carried out stably without burning in the use of grinding wheels made of micro abrasives above #12000.

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The designed form and surface quality of focusing neutron mirror is a main factor affecting the performance of the neutron optical devices. In order to improve the situation, one of the authors designed a new type of mirror for focusing neutron beams. Its form is an inside deep rotary paraboloid and the material used is quartz. To test the optical performances of the designed parameters and simplify the fabrication process, the first fabrication was to grind the 1/4 of the mirror, cut along the symmetric axis by two perpendicular planes, thus the surface to be ground is an outside symmetric paraboloid. The fabrication process was investigated in this experiment. The workpiece was first ground applying the ELID method with #325 and #1200 cast iron bonding diamond abrasive wheels. Then the ground surface was polished with CeO_2 slurry. The finished surface roughness was Ra2.0nm and rms2.4nm and the form error was about 2μm. After a coating process, its properties of focusing neutron beams were investigated. The optical properties obtained included a reflecting rate of 42%, gain 1.9 and 2.3mm×10.1mm beam focused to 1.6mm×2.1mm.

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The surface of high-speed steel M2 was treated by a 2.5-kW CW Nd:YAG laser with different power densities for achieving laser transformation hardening and laser surface melting. It was found that M2 cannot be hardened so effectively by laser transformation hardening, with the hardness increased to 415 Hv_<0.2> whereas for laser-melted M2, the hardness was increased to 612 Hv_<0.2>, which is at the same level as the conventionally hardened M2. Potentiodynamic polarization test shows that the laser-melted M2 possesses the highest corrosion resistance in 3.5% NaCl solution at 23℃. The enhancement in the surface hardness and the corrosion resistance of the laser-melted M2 is due to the combined effects of refinement and dissociation of large carbides and the dissolution of the alloying elements (Cr, Mo V and W) in the ultrafine martensitic and austenitic solid solution.

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This paper deals with the thermal deformation of a base sheet caused by cutting out a lot of products to avoid the situation that the laser cutting is interrupted by the deformation of the base sheet. In experiments, we cut several kerfs in stainless sheets by various cutting conditions. We considered the deformation to be difference between the waviness profiles which measured before and after the laser cutting. The base sheet bent upward or downward according to the cutting order. The sheet bent upward when the processing was advanced from the edge to the center. And the sheet bent downward in the case of the inverse order. It can be expected that the deformation of the base sheet can be reduced by appropriately setting the cutting order.

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Influence of wavelength and the kind of assist gas on machining characteristics of aluminum nitride using Q-switched Nd:YAG harmonics were experimentally investigated. Removal rate increases with the reduction of wavelength. Drilled depth increases proportionally with the number of laser shot at the beginning region of machining, while it stagnates after the proportional region. Drilled depth was greatly different by the kind of assist gas in the case of fundamental wavelength, while it was not influenced sensitively by the kind of assist gas in the case of harmonics because of its high photon energy. Debris was deposited remarkably except for fundamental wavelength, when blind hole is drilled using helium as the assist gas.

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The fundamental characteristics of laser cutting for thin copper plate by a Q-switched single-mode fiber laser were experimentally investigated, and the effects of the nozzle shape on cutting results were also discussed. High speed cutting of 29mm/s could be carried out with a newly designed nozzle, since high assist gas pressure could be supplied on the workpiece without MSD. Nozzle Laval 800 makes it possible to cut more efficient, since the melted material in the kerf decreases compared to a traditional convergent nozzle. Using a Q-switched single-mode fiber laser, the kerf is very fine, and color change around the kerf is hardly observed by oxidation due to little heat conduction from dross. Therefore, it proved to be available in cutting of thin metal plate.

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In recent years, demands for the precise welding with laser are increasing with aim at the high precision and high quality. Especially, for the welding of corner section, quality of the product appearance includes chamfering of edges and round-finish of materials are also prioritized besides the welding strength. However there have been only a few examinations about the comparison of various laser welding. This paper presents the welding characteristics of the YAG laser and the CO_2 laser of stainless steel, and reports the results of examinations for the quality improvement of the round-finish welding.

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The process for the fabrication of polymer based high aspect ratio arrayed microneedles by laser LIGA technology is investigated in this study. ArF excimer laser with projective mask is used to create arrayed microholes on BK7 glass. The micromolds formed by microholes are subsequently filled with epoxy resist, and then the glass substrate is etched away to obtain the arrayed microneedles. It is found that the higher laser fluence is beneficial for the formation of microneedles with a smaller tip radius. The higher repetition rate leads to stronger plasma shielding effect, and the molded microneedles with a smaller tip radius. Based on our study, the polymer based microneedles with the tip radius of less than 100nm can be obtained by the laser LIGA process.

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One of the urgent challenges of current laser material processing is the high quality and precise etching of transparent materials for, e.g., microoptical applications. Indirect laser processing techniques such as LIBWE and LESAL (laser-induced backside wet etching, laser etching at a surface adsorbed layer, respectively) allow the accurate etching of transparent materials like fused silica at low laser fluences, with etch rates in the nanometer scale and a low roughness. In combination with established laser processing techniques, e.g., mask projection, scanning contour mask technique, and direct writing, these etch techniques allow the direct machining of dielectric materials with almost optical quality. The etching of diffractive and refractive topographies for micro prism arrays, free-form surfaces, as well as periodically sub-micron structures with nanometer depth accuracy and a low roughness is demonstrated.

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Micromachinability of silicon was investigated using the fourth-harmonic wavelength (λ=266nm, t=6ns) of a pulsed YAG laser beam. The beams were irradiated onto a silicon test piece in flowing water. The drilled surfaces were then characterized using an optical microscope, a laser interference microscope and a scanning electron microscope. Compared with atmospheric machining, problems such as reattachment of debris and molten material were improved clearly and dramatically. The relationship between the irradiation parameters and the resulting shape became quantitatively clear from the experiment. Furthermore, the presumption method of the ablated shapes was realized using the NN learned by experimental data of the limited number.

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The SUS316L stainless steel is widely used as the machinery parts for chemical plant and power plant. In order to improve the wear- and corrosion-resistance quality of parts, usually, the plasma process has been adopted to clad Co-based and Ni-based alloys powder on parts surface of SUS316L stainless steel. In the present work, the CO_2 laser (CW-2.4kW) cladding of low residual stress and small distortion, and plasma cladding were investigated to deposit Ni-based alloy powder (WELPC-6) on the cylindrical prod for power plant. The smooth clad bead was obtained by CO_2 laser cladding. The phases of clad layer were investigated by an optical microscope, scanning electron microscopy (SEM), X-ray diffractometer (XRD), electron probe microanalysis (EPMA), and energy-dispersive spectrometer (EDS). The microstructures of clad layers belong to a hypereutectic structure. Primary phases consist of boride CrB and carbide Cr_7C_3. The eutectic structure consists ofγ-Ni+Cr_2B or γ-Ni+Cr_<23>C_6. Comparing with the plasma cladding, the fine microstructures, low dilutions, high Vickers hardness and excellent wear-resistance were obtained by CO_2 laser cladding.

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