2021/07/12 更新

写真a

オカダ アキラ
岡田 晃
OKADA Akira
所属
自然科学学域 教授
職名
教授
外部リンク

学位

  • 修士(工学) ( 岡山大学 )

  • 博士(工学) ( 大阪大学 )

研究キーワード

  • 機械工作・生産工学

  • Workshop Processes Production Engineering

研究分野

  • ものづくり技術(機械・電気電子・化学工学) / 加工学、生産工学

経歴

  • 岡山大学   教授

    2011年 - 現在

      詳細を見る

  • 岡山大学   准教授

    2006年 - 2010年

      詳細を見る

  • - 岡山大学 講師

    1998年

      詳細を見る

  • 岡山大学

    1994年 - 1998年

      詳細を見る

所属学協会

▼全件表示

委員歴

  • 日本機械学会   部門運営委員  

    2018年 - 現在   

      詳細を見る

    団体区分:学協会

    researchmap

  • 精密工学会 代議員  

    2016年 - 現在   

      詳細を見る

    団体区分:学協会

    researchmap

  • 電気加工学会 英文誌編集委員長  

    2013年 - 現在   

      詳細を見る

    団体区分:学協会

    researchmap

  • 電気加工学会   理事  

    2000年 - 現在   

      詳細を見る

    団体区分:学協会

    電気加工学会

    researchmap

  • 精密工学会   中国四国支部幹事  

    2000年 - 現在   

      詳細を見る

    団体区分:学協会

    精密工学会

    researchmap

 

論文

  • Study on Variation of Burr Height in Micro-deburring with Large-area Electron Beam 査読

    Togo Shinonaga, Tsubasa Sakai, Yasuaki Kimura, Akira Okada

    International Journal of Electrical Machining   2018年

     詳細を見る

  • Influence of Pulse Duration on Effective Energy on Material Removal in Micro-processing of Mild Steel by Several Hundred Nanoseconds Pulsed Laser 査読

    Yasuhiro Okamoto, Mizuna Ito, Akira Okada, Togo Shinonaga

    International Journal of Electrical Machining   2018年

     詳細を見る

  • Effects of pulse duration on removal characteristics of silver nanowire transparent conductive film by nanosecond pulsed laser 査読

    Norio Nishi, Yasuhiro Okamoto, Masafumi Oshita, Akira Okada, Togo Shinonaga, Tomokazu Sakagawa

    JOURNAL OF MATERIALS PROCESSING TECHNOLOGY   240   255 - 261   2017年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE SA  

    In laser processing of silver nanowire transparent conductive film covered with an acrylic resin layer, effects of pulse duration on electrical insulation and surface quality were experimentally investigated by using nanosecond pulsed laser. The minimum laser fluence to achieve the stable electrical insulation by removal of silver nanowire became small with decreasing the pulse duration, but shorter pulse duration showed drastic change of removal trace area of silver nanowires at the boundary region of laser fluence to change conductive state to insulation one. In contrast, longer pulse duration around 200 ns indicated almost constant small removal trace area of silver nanowires, and wide processing window to perform the stable electrical insulation with small removal trace area of silver nanowires can be expected by using a proper long pulse duration in nanosecond pulsed laser processing. (C) 2016 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jmatprotec.2016.10.004

    Web of Science

    researchmap

  • Improvement of Surface Characteristics for Long Life of Metal Mold by EDM in Chromium Powder MixedWorking Fluid. 査読

    Ruixiang Wang, Ryoji Kitada, Ryota Toshimitsu, Akira Okada

    International Journal of Electrical Machining   ( 22 )   26 - 30   2017年

     詳細を見る

  • Improvement of curved hole EDM drilling performance using suspended ball electrode by workpiece vibration 査読

    A. Okada, A. Yamaguchi, K. Ota

    CIRP ANNALS-MANUFACTURING TECHNOLOGY   66 ( 1 )   189 - 192   2017年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    Small-diameter curved hole EDM drilling method using a metal ball electrode suspended with flexible thin foil has been studied using zinc alloy with low melting point as workpiece material. In order to improve the drilling performance and to extend drillable hole depth for practical materials, such as aluminium alloy and steel, curved hole drilling with workpiece vibration was proposed in this study. The influences of discharge conditions and vibration amplitude on the machining characteristics were experimentally investigated. Various types of curved holes were successfully drilled in practical materials by EDM using the suspended ball electrode with workpiece vibration. (C) 2017 Published by Elsevier Ltd on behalf of CIRP.

    DOI: 10.1016/j.cirp.2017.04.125

    Web of Science

    researchmap

  • Study on clarification of large-Area eb irradiation phenomenon by electron track analysis 査読

    Yasuaki Kimura, Togo Shinonaga, Akira Okada

    Key Engineering Materials   749 ( 749 )   118 - 123   2017年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Trans Tech Publications Ltd  

    In large-Area electron beam (EB) irradiation method, uniformly high energy density can be obtained without focusing the beam. Large-Area EB can be used for melting and evaporating metal surface instantly. It was clarified that high efficient surface finishing of metal mold steels, ceramics and cemented carbides was possible by the large-Area EB irradiation. Furthermore, the tip of convex shape was often rounded after large-Area EB irradiation with remarkable material removal at the tip. This phenomenon is probably caused due to the heat accumulation and electrons concentration at the tip. However, electrons behavior near the workpiece surface during large-Area EB irradiation has not yet been clarified. In this study, electron track analysis was conducted in order to clarify electrons behavior during large-Area EB irradiation. At first, analytical model of the large-Area EB irradiation apparatus was built. Then, the EB diameter on the workpiece surface was experimentally measured with different energy density in order to evaluate the accuracy of our analytical model. The calculated results of EB diameter were in good agreement with the experimental ones. In addition, the electrons concentration phenomenon at the tip of convex shape was clarified by calculating energy density distribution on the surface obtained with electron track analysis. The analytical results indicated that the energy density increased from edge to tip of convex shape, while the energy density was constant in the case of planar shape. Experimented results also showed that removal thickness increases with high relative permeability. These results were similar tendency to the energy density distribution. Therefore, electrons concentration on the tip could be simulated by the electron track analysis.

    DOI: 10.4028/www.scientific.net/KEM.749.118

    Scopus

    researchmap

  • Influence of nozzle jet flushing on wire breakage in 1st-cut wire edm from start hole 査読

    Akiyoshi Kawata, Akira Okada, Yasuhiro Okamoto, Haruya Kurihara

    Key Engineering Materials   749 ( 749 )   130 - 135   2017年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Trans Tech Publications Ltd  

    In wire EDM (electrical discharge machining) process, it is important to smoothly exclude debris and bubbles generated in the working gap for keeping stable performance. Much debris stagnation in the gap would cause frequent occurrence of discharge concentration and secondary discharge, which results in unstable machining performance, such as frequent wire breakage, low removal rate, and low shape accuracy. Therefore, a jet flushing of working fluid using upper and lower jet nozzles has been conventionally applied for excluding the debris and bubbles from the machined kerf. Nevertheless, it is well known that the wire often breaks when the machined kerf length is a few mm from the start hole in 1st-cut wire EDM. The influence of machined kerf length on the flow field, the debris exclusion, and the wire behavior caused with hydrodynamic force by the jet flushing should be made clear. In this study, variations of flow field in the kerf, the debris accumulation state and the wire deflection caused jet flushing with machined length were analytically investigated by CFD (computational fluid dynamics) and structural analysis when 1st-cut wire EDM was done from a small start hole. Moreover, the effects of machined kerf length on the wire deflection and wire breakage were discussed. Wire breakage frequency experiments showed that wire tended to frequently break at a certain machined kerf length, where the wire deflection rapidly increased and the debris residence time in the gap became long.

    DOI: 10.4028/www.scientific.net/KEM.749.130

    Scopus

    researchmap

  • Fundamental Study on Addition of Osteoconductivity to Titanium Alloy Surface by EDM 査読

    Togo Shinonaga, Yuta Iida, Ryota Toshimitsu, Akira Okada

    International Journal of Automation Technology   11 ( 6 )   45 - 50   2017年

  • Study on Reduction of Discoloration Area in Micro-drilling of Multi-layered Artificial Skin by Picosecond Pulsed Laser 査読

    Yasuhiro Okamoto, Akira Eguchi, Naoto Maeda, Akira Okada, Shogo Minagi, Qiuyue Pan, Keiji Jin, Goro Nishigawa

    International Journal of Electrical Machining   ( 22 )   8 - 13   2017年

     詳細を見る

  • Characteristics of spatter in micro-drilling of metal sheet by pulsed Nd: YAG laser 査読

    Yasuhiro Okamoto, Hibiki Yamamoto, Akira Okada

    International Journal of Automation Technology   10 ( 6 )   874 - 881   2016年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Fuji Technology Press  

    In laser cutting and drilling process, molten material was scattered as spatter, which deteriorates the surface integrity of a workpiece because of the thermal damage. It is expected that the control of assist gas flow can reduce the adhesion of spatter. In order to investigate the improvement method of thermal damage due to the adhesion of spatter, it is required to clarify characteristics of spatter. Therefore, a method was developed to collect and analyze spatter based on the use of high-speed video cameras in the lasermicro-drilling process, and the characteristics of spatter movement were numerically investigated by CFD analysis. The scattering velocity and angle of the spatter were investigated by recognizing and tracking spatter with the high-speed video observation. The movement of spatter was observed by using two high-speed video cameras, and analyzed by using a two-direction tracking method, in which the 3D tracking lines of spatter particles were reconstructed in the forward and backward frames, and the actual trajectory of individual spatter particle was obtained by averaging those tracking lines. These measurements revealed that the initial velocity of spatter was mainly distributed from 52 m/s to 200 m/s with an average velocity of 129 m/s. The initial angle of spatter was mainly distributed between 0 and 30 degrees from the workpiece surface in the upward direction. There was little correlation between the initial velocity and angle of spatter. The diameter of spatter was mainly distributed from 1 µm to 4 µm with an average diameter of 3.7 µm. It is important to use the processing conditions achieving the smaller spatter diameter in order to reduce the thermal damage caused by spatter. Although coaxial assist gas flow has an influence on the spatter behavior, that time period is very short. Therefore, it is important to control the spatter behavior outside of the coaxial assist gas flow by using an additional gas flow to prevent the thermal damage to the workpiece surface.

    DOI: 10.20965/ijat.2016.p0874

    Scopus

    researchmap

  • Prediction of rounding phenomenon at corner tips in large-area electron beam irradiation 査読

    Togo Shinonaga, Akira Okada, Tomoaki Miyoshi

    INTERNATIONAL JOURNAL OF MACHINE TOOLS & MANUFACTURE   110 ( 110 )   18 - 26   2016年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    In large-area electron beam (EB) irradiation method, corner tip of workpiece is generally rounded since removal of material at the tip is done preferentially. Investigation of the shape change is necessary to clarify rounding phenomenon with irradiation of EB. In this study, the shape changes of corner tips were experimentally investigated by Scanning Electron Microscope (SEM) observation of the cross sections. Then, electron track analysis in the EB irradiation was conducted to clarify an electron concentration at the tip. Unsteady heat conduction analysis at the tip was also done with considering the EB concentration at the tip and an electron penetration effect into the surface. The shape changes were estimated by simulation of temperature distribution at the tips. Experimental results show that the curvature radius increases with shot number of EB. The estimated shape changes show quantitatively good agreement with the experimental ones. These results indicate that the rounding phenomenon at the tips by large area EB irradiation can be predicted by our electron track and unsteady heat conduction analysis model. (C) 2016 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijmachtools.2016.08.002

    Web of Science

    researchmap

  • Effect of focusing condition on molten area characteristics in micro-welding of borosilicate glass by picosecond pulsed laser 査読

    I. H. W. Nordin, Y. Okamoto, A. Okada, T. Takekuni, T. Sakagawa

    APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING   122 ( 5 )   492   2016年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    The characteristics of the molten area are attributed not only by laser energy condition but also the focusing condition. In this study, a picosecond pulsed laser of 1064 nm in wavelength and 12.5 ps in pulse duration was used as a laser source for joining glass material. Influence of focusing condition on micro-welding of glasses was experimentally investigated by using an objective lens with and without spherical aberration correction, and its molten area was characterized. The usage of objective lens with spherical aberration correction led to a larger molten area inside the bulk material of glass even under the same pulse energy, which related to the efficient micro-welding of glass materials. In addition, an optical system with the spherical aberration correction led to a stable absorption of laser energy inside the bulk glass material, stabilizing the shape of molten area, which resulted in the reliable weld joint. On the other hand, breaking strength of the specimens with spherical aberration correction was higher than that without spherical aberration correction. Therefore, it is concluded that the focusing condition with spherical aberration correction led to the larger and stable molten area, which resulted in higher joining strength in micro-welding of glass materials.

    DOI: 10.1007/s00339-016-0026-7

    Web of Science

    researchmap

  • Thermo-Mechanical Analysis on Thermal Deformation of Thin Stainless Steel in Laser Micro-Welding 査読

    Mohd Idris Shah Ismail, Yasuhiro Okamoto, Akira Okada

    International Journal of Manufacturing, Materials, and Mechanical Engineering   6 ( 2 )   51 - 66   2016年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IGI Global  

    In the present study, a three-dimensional finite element model has been developed to simulate the temperature, stress and deformation fields in continuous wave (CW) laser micro-welding of thin stainless steel sheet. The welding deformation was experimentally evaluated using a single-mode fiber laser with a high-speed scanning system. Application of developed thermal model demonstrated that the laser parameters, such as laser power, scanning velocity and spot diameter have a significant effect on temperature field and the weld pool. In the case of welding deformation, numerical simulation was carried out by an uncoupled thermo-mechanical model. The welding stress and deformation are generated by plastic deformation during the heating and cooling periods. It was confirmed that the residual stress is higher than yield strength and has strongest effect upon the welding deformation. The numerical simulated results have proved that the developed finite element model is effective to predict thermal histories, thermally induced stresses and welding deformations in the thin material.

    DOI: 10.4018/IJMMME.2016040104

    Scopus

    researchmap

  • Effect of wavelength and pulse duration on laser micro-welding of monocrystalline silicon and glass 査読

    I. H. W. Nordin, Y. Okamoto, A. Okada, H. Jiang, T. Sakagawa

    APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING   122 ( 4 )   400   2016年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    Micro-welding characteristics of silicon and glass by pulsed lasers are described. In this study, four types of laser beam, which are nanosecond pulsed laser and picosecond pulsed laser of 532 and 1064 nm in wavelength, were used for joining monocrystalline silicon and glass. Influence of wavelength and pulse duration on micro-welding of monocrystalline silicon and glass was experimentally investigated under the same spot diameter, and the molten area of monocrystalline silicon and glass was characterized. Finally, the breaking strength was evaluated for the overlap weld joint with different pulse duration and wavelength. A splash area of molten silicon around the weld bead line was obvious in the nanosecond pulsed laser. On the other hand, there was no remarkable molten splash around the weld bead line in the picosecond pulsed laser. Breaking strength of specimens with 1064 nm wavelength was higher than with 532 nm wavelength in nanosecond laser, whereas breaking strength of laser-irradiated specimen by picosecond pulse duration was higher than that by nanosecond pulse duration. It is concluded that the combination of picosecond pulse duration and infrared wavelength leads to the stable molten area appearance of the weld bead and higher breaking strength in microwelding of glass and monocrystalline silicon.

    DOI: 10.1007/s00339-016-9849-5

    Web of Science

    researchmap

  • Study on the movement of wire electrode during fine wire electrical discharge machining process 査読

    Sameh Habib, Akira Okada

    JOURNAL OF MATERIALS PROCESSING TECHNOLOGY   227 ( 227 )   147 - 152   2016年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE SA  

    Wire movements and vibrations are one of the most important phenomena of wire electrical discharge machining (EDM) process. Unstable wire electrode behavior and large wire vibration amplitude during the process cause wire breakage, low shape accuracy and large machined surface roughness. In this study, direct observation using high-speed camera investigated the movements of tungsten wire electrode during fine wire EDM process. The results showed that the vibration amplitude and frequency depended mainly on the wire tension, and the amplitude direction. The amplitude in the direction parallel to the machining direction was a little larger than that in the perpendicular one. In addition, the backward deflection of wire could be confirmed even in fine wire EDM. Also, the wire vibration mode was analyzed, and it could be varied with the machining position of the thin workpiece, which possibly led to smaller wire amplitude. Furthermore the amplitude envelope of wire electrode during the process was clarified. (C) 2015 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jmatprotec.2015.08.015

    Web of Science

    researchmap

  • Influence of electrical discharge machining parameters on cutting parameters of carbon fiber-reinforced plastic 査読

    Sameh Habib, Akira Okada

    MACHINING SCIENCE AND TECHNOLOGY   20 ( 1 )   99 - 114   2016年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TAYLOR & FRANCIS INC  

    Today the use of high-strength carbon fiber-reinforced plastics (CFRP) composite as a material for many engineering applications is showing an increasing demand in the industry. These composites are replacing the traditional use of steel because they offer many advantages such as very light weight, high strength, and high stiffness associated with good corrosion-resistant properties. Unfortunately, there is little technological knowledge on the electrical discharge machining (EDM) process of high-strength composite materials, especially about the CFRP. In this work, a study has made into the possibility of using EDM process as a means of machining CFRP composite. Various cutting conditions such as peak current, pulse-on time, pulse-off time and open-circuit voltage were selected to perform electrical discharge machining. The effect of electrode rotation was also studied. Optimum cutting conditions and machine settings for EDM were chosen for machining CFRP composites.

    DOI: 10.1080/10910344.2015.1133914

    Web of Science

    researchmap

  • Control of modicied surface layer thickness in pulsed large-area EB irradiation 査読

    Akira Okada, Togo Shinonaga, Motohiro Inoue

    Electrotechnica and Electronica   51 ( 5月6日 )   215 - 220   2016年

     詳細を見る

  • つり下げ電極を用いた放電加工による曲がり穴加工法の開発-アルミニウム合金と合金工具鋼の放電加工特性と曲がり穴加工-. 査読

    山口篤, 岡田晃, 三宅達也

    精密工学会誌   82 ( 10 )   907 - 912   2016年

     詳細を見る

  • Investigation on Visibility of Drilled Hole in Laser Micro-drilling of Multi-layered Articicial Skin 査読

    Yasuhiro Okamoto, Kiichi Asako, Naoto Maeda, Akira Okada, Shogo Miyanagi, Qiuyue Pan, Keiji Jin, Goro Nishigawa

    International Journal of Electrical Machining   ( 21 )   13 - 17   2016年

     詳細を見る

  • Study on Metal Film Formation by Large-area Electron Beam Irradiation 査読

    Togo Shinonaga, Masashi Takata, Akira Okada, Sadao Sano

    International Journal of Electrical Machining   ( 21 )   7 - 12   2016年

     詳細を見る

  • Effect of surrounding gas condition on surface integrity in micro-drilling of SiC by ns pulsed laser 査読

    Yasuhiro Okamoto, Kiichi Asako, Norio Nishi, Tomokazu Sakagawa, Akira Okada

    APPLIED PHYSICS B-LASERS AND OPTICS   119 ( 3 )   509 - 517   2015年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    The influence of the surrounding gas conditions on the surface integrity in the micro-drilling of silicon carbide was experimentally investigated using ns pulsed laser of 266 nm wavelength. Moreover, micro-machining characteristics were observed using high-speed shutter and video cameras in the micro-drilling of silicon carbide. The size and intensity of the laser-induced plasma were larger, and the plasma affected area was larger and deeper in argon than that in air. Although the intensity of the plasma was lower in helium than that in other gases, the surface around the drilled hole was roughened by the spread of the plasma in the vicinity of the drilled hole. Debris was removed along the flow field generated by laser shot in the opposite direction to the laser irradiation. The gas flow behavior and the spectrum and intensity of the laser-induced plasma were influenced by the surrounding gas type and pressure. The appearance of plasma generation affected the surface integrity at the circumference of the drilled hole, and the surface integrity was improved by reducing the pressure.

    DOI: 10.1007/s00340-015-6060-x

    Web of Science

    researchmap

  • Study on surface characteristics of EDMed surface with nickel powder mixed fluid 査読

    Shuhei Iwasaki, Ryoji Kitada, Akira Okada, Yasuhiro Okamoto

    Key Engineering Materials   656-657 ( 656-657 )   375 - 380   2015年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Trans Tech Publications Ltd  

    EDM finishing techn ology has progressed recently, and very small surface roughness can be obtained by controlling the electrical discharge conditions. Also, EDM using powder mixed fluids can improve the surface characteristics. Therefore, the EDM finished surface is highly expected to be applied as a final metal mold surface. In that case, the characteristics of EDMed surface affects the molding performance and the life of metal molds. As a new surface finishing method by EDM, the characteristics of EDMed surface using a nickel powder mixed fluid was experimentally discussed in this study, since nickel coatings have been widely applied to improve the corrosion resistance and the mold releasability of metal molds. Experimental analysis clarified that the resolidified layer containing nickel content could be formed on the surface by EDM in nickel powder mixed fluid. Also, the water repellency and the releasability of molded resin from the EDM finished surface could be improved.

    DOI: 10.4028/www.scientific.net/KEM.656-657.375

    Scopus

    researchmap

  • Effect of Tilting Jet Flushing Nozzle on Wire EDM Performance 査読

    Takuro Konishi, Akira Okada, Yasuhiro Okamoto, Haruya Kurihara

    International Journal of Electrical Machining   ( 20 )   2 - 8   2015年

     詳細を見る

  • Experimental investigation on wire vibration during fine wire electrical discharge machining process 査読

    Sameh Habib, Akira Okada

    International Journal of Advanced Manufacturing Technology   ( 1433-3015 )   1 - 12   2015年

     詳細を見る

  • 矩形ファイバを用いたナノ秒パルスレーザによるZnO 膜の除去加工におけるレーザ光強度分布の影響(共著) 査読

    西則男, 岡本康寛, 横山豪人, 岡田晃, 中芝伸一, 酒川友一

    精密工学会誌   81 ( 11 )   1033 - 1038   2015年

     詳細を見る

  • つり下げ電極を用いた放電加工による曲がり穴加工法の開発-小径曲がり穴加工のための電極球質量および直径の検討- 査読

    山口篤, 岡田晃, 三宅達也, 池嶋俊貴

    精密工学会誌   81 ( 11 )   1039 - 1044   2015年

     詳細を見る

  • Study on applicability of large-area EB irradiation to micro-deburring 査読

    Tomoaki Miyoshi, Akira Okada, Yasuhiro Okamoto

    Key Engineering Materials   656-657 ( 656-657 )   369 - 374   2015年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Trans Tech Publications Ltd  

    In a large-area electron beam (EB) irradiation method developed recently, high energy EB can be obtained without focusing the beam, and large-area EB with almost uniform energy density distribution of 60mm in diameter can be used for instantly melting and evaporating metal surface. Then, the surface smoothing and surface modification of metal molds made of steel, cemented carbide and ceramics can be performed efficiently. When the large-area EB is irradiated to a sharp edge, the material removal remarkably progresses at the edge due to the heat accumulation and EB concentration there, which leads to the edge rounding. Our previous study clarified that micro-deburring was also possible by using this phenomenon. Moreover, this method would be effective for removal of discontinuous micro burrs generated by thermal machining processes, such as EDM and laser cutting. In this study, the possibility to completely remove micro burrs generated in EDM was experimentally investigated. The difference in micro-deburring characteristics with the type of workpiece material was also investigated. As a result, the EDM micro burrs with a height of about up to 50μm could be completely removed by this method. Furthermore, it was made clear that the magnetic property of workpiece materials greatly influenced the deburring characteristics, and the thermal property such as melting point and thermal conductivity also did.

    DOI: 10.4028/www.scientific.net/KEM.656-657.369

    Scopus

    researchmap

  • Wire breakage and deflection caused by nozzle jet flushing in wire EDM 査読

    A. Okada, T. Konishi, Y. Okamoto, H. Kurihara

    CIRP ANNALS-MANUFACTURING TECHNOLOGY   64 ( 1 )   233 - 236   2015年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    High flow rate in nozzle jet flushing is effective for smooth debris exclusion from the wire EDM gap, but this leads to large wire deflection and vibration, resulting in the wire breakage and low shape accuracy. In this paper, the influence of nozzle jet flushing on wire breakage was experimentally investigated with varying the machined kerf length and machining conditions. Furthermore, the flow fields and debris residence time in the kerf, hydrodynamic stress distributions acting on the wire, and wire deflections were numerically analyzed. Based on the analyzed results, the causes of wire breakage were discussed. (C) 2015 CIRP.

    DOI: 10.1016/j.cirp.2015.04.034

    Web of Science

    researchmap

  • つり下げ電極を用いた放電加工による曲がり穴加工法の開発 ?つり下げ構造の最適化と複雑曲がり穴加工の可能性? 査読

    山口 篤, 岡田 晃, 三宅 達也

    精密工学会誌   81 ( 5 )   435 - 440   2015年

     詳細を見る

  • イオンビームによるステンレス鋼ナイフエッジのバリ取りと形状制御 査読

    玉置 司, 岡田 晃, 植村 賢介, 宇野 義幸, 高木 利樹

    精密工学会誌   81 ( 5 )   446 - 451   2015年

     詳細を見る

  • Effects of focusing condition on micro-welding characteristics of borosilicate glass by picosecond pulsed laser 査読

    Tomohiro Takekuni, Yasuhiro Okamoto, Takahiro Fujiwara, Akira Okada, Isamu Miyamoto

    Key Engineering Materials   656-657 ( 626-657 )   461 - 467   2015年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Trans Tech Publications Ltd  

    Glass materials are widely used in products such as optical components and semiconductor devices. In these products, precision welding techniques of glass are required to manufacture small and complicated shape. The laser welding method can perform the joining without an intermediate layer and an adhesive agent. In addition, an ultra-short pulse laser can reduce the heat affected zone with the high space accuracy. However, heating and cooling cycles are repeated even in the case of ultra-short pulsed laser. The temperature distribution and change of molten area are influenced not only by laser energy condition but also focusing condition. Therefore in this study, effects of focusing condition of laser beam on micro-welding characteristics of glass were experimentally investigated by using a picosecond pulsed laser. A usage of object lens with the spherical aberration correction led to a large molten area even at the same pulse energy, which related to the efficient welding of glass materials. An optical system with the spherical aberration correction led to stabilizing the shape of molten area, which resulted in the reliable weld joint.

    DOI: 10.4028/www.scientific.net/KEM.656-657.461

    Scopus

    researchmap

  • Influence of Bead Geometry on Weld Distortion in Laser Micro-welding of Thin Stainless Steel Sheet with High-speed Scanning 査読

    International Journal of Electrical Machining   ( 20 )   9 - 15   2015年

     詳細を見る

  • Improvement of surface characteristics for long life of metal molds by large-area EB irradiation 査読

    Akira Okada, Yasuhiro Okamoto, Yoshiyuki Uno, Kensuke Uemura

    JOURNAL OF MATERIALS PROCESSING TECHNOLOGY   214 ( 8 )   1740 - 1748   2014年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE SA  

    This paper describes the applicability of large-area EB irradiation method to a new surface modification for metal molds. The previous papers clarified that the surface roughness on wide area uniformly decreased to less than 1 mu m Rz in a few minutes by the large-area EB irradiation. Therefore, the large-area EB irradiation method has high practicability as an efficient surface finishing process for metal molds, and then the EB irradiation equipment has already been introduced into the market for practical use. In this method called EB polishing, the surface material melts and a very thin resolidified layer is formed on the surface. In this paper, the surface structure of EB polished metal mold steel SKD11 was first observed by TEM, and also component analysis was carried out by EDX. Then it was found out that the crystal grain size became small and chromium carbide is uniformly rearranged in the layer. Next, using heat conduction analysis model considering the electron penetration on the surface, the temperature distribution was calculated. The results showed that the surface temperature rapidly raised over its melting point until the end of EB irradiation, and cooled down rapidly. As the important practical surface characteristics for long life of metal mold, resistance to corrosion, water repellency, and the releasability of molded resin from metal mold surface were evaluated. The corrosion resistance and the water repellency could be improved by EB polishing, since the surface structure changes and Cr content distributed uniformly on the surface. Also, the releasability of molded resin from the surface became better. (C) 2014 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jmatprotec.2014.02.028

    Web of Science

    researchmap

  • Formation of Internal Modified Line with High Aspect Ratio in Sapphire by Sub-nanosecond Pulsed Fiber Laser 査読

    Yasuhiro Okamoto, Tomohiro Takekuni, Akira Okada

    JOURNAL OF LASER MICRO NANOENGINEERING   9 ( 1 )   52 - 58   2014年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPAN LASER PROCESSING SOC  

    The internal modification technique for a sapphire substrate using a sub-nanosecond pulsed fiber laser of 180 ps was experimentally investigated with a normal achromatic focusing lens of 20 mm focal length, and the possibility of a singulation method with this internal modification technique was discussed. The laser beam of 1060 nm was focused in sapphire substrate of 0.4 mm thickness by passing through GaN epitaxial layer grown on the top surface of the sapphire substrate, and the internal modification zone was generated from the stain-finished surface as the bottom surface of sapphire substrate. The laser beam was absorbed from the stain-finished bottom surface, and the absorption point moved in the axis of laser irradiation without moving the focusing optics. The narrow internal modified line less than 5 mu m in width with a high aspect ratio of more than 30 was successfully obtained only by one laser scanning irradiation from the epitaxial layer side. A sapphire wafer could be broken from the internal modified line with less damage of the epitaxial layer by a stress sufficiently smaller than the tensile strength of sapphire. The breaking strength and its dispersion became smaller with increasing number of laser scans.

    DOI: 10.2961/jlmn.2014.01.0011

    Web of Science

    researchmap

  • Fundamental study on releasability of molded rubber from mold tool surface 査読

    Akira Okada, Yasuhiro Okamoto, Adam Clare, Yoshiyuki Uno

    INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY   70 ( 5-8 )   1515 - 1521   2014年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER LONDON LTD  

    In compression or injection molding of rubber products, small pieces of residual rubber often remain on the metal mold surface after releasing the product. This is caused by excessive localized adhesion to the mold surface. Therefore, cleaning of metal mold surface must be often performed, which results in longer molding cycle time, and the lifetime of metal mold is often reduced. In this study, the separation forces between molded rubber and metal mold surfaces are measured with a tensile tester to evaluate the releasability of molded rubber from the metal mold surface. Mold surfaces treated by various surface coatings and surface modification methods including EB polishing were tested and compared. Experimental results show that the separation force between molded rubber and metal mold surfaces depends on the true contact area between them and the chemical composition of the metal mold surface. The separation force decreases with a decrease in contact area. The chromium content at the metal mold surface significantly reduces the separation force. EB polishing is one of the most effective surface treatments for metal molds since the real contact area can be decreased while also decreasing the surface roughness of the tool surface in a short time. Electron beam melting is also shown to be an effective method of distributing chromium uniformly on the metal mold surface.

    DOI: 10.1007/s00170-013-5415-x

    Web of Science

    researchmap

  • Singulation Characteristics of Semiconductor Package Using Pulse Fiber Laser and SHG:YAG Laser 査読

    Yasuhiro Okamoto, Ryoji Kitada, Akira Okada, Yoshiyuki Uno

    International Journal of Electrical Machining   ( 19 )   28 - 33   2014年

     詳細を見る

  • 連続発振半導体レーザ重畳パルスNd:YAGレーザを用いたアルミ合金の微細溶接におけるキーホール発現境界 査読

    中芝 伸一, 岡本 康寛, 酒川 友一, 原田 昌宜, 岡田 晃

    精密工学会誌   80 ( 4 )   419 - 424   2014年

     詳細を見る

  • Novel Micro-welding of Silicon and Glass by Ultrashort Pulsed Laser 査読

    Yasuhiro OKAMOTO, Isamu MIYAMOTO, Jorma VIHINEN, Akira OKADA

    Materials Science Forum   ( 783-786 )   2792 - 2797   2014年

  • Study on Possibility of Micro-deburring by Large-area Electron Beam Irradiation 査読

    Hajime Yonehara, Akira Okada, Yasuhiro Okamoto

    International Journal of Electrical Machining   ( 19 )   22 - 27   2014年

     詳細を見る

  • Micro-welding of High Thermal Conductive Material Aluminum-Graphite Composite by Pulsed Nd:YAG Laser 査読

    Mohd Idris Shah Ismail, Yasuhiro Okamoto, Akira Okada, Yoshiyuki Uno, Muhaizad Mukhtar

    JOURNAL OF LASER MICRO NANOENGINEERING   8 ( 1 )   90 - 96   2013年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPAN LASER PROCESSING SOC  

    The development of advanced materials with superior high thermal properties and high specific strength has led to new metal matrix composites (MMCs) as a great attractive material in electrical and electronic industries. In order to manufacture more practical component from MMCs, a technique for joining MMCs to other similar composites or monolithic materials is strongly required. Therefore, the reliable and economic joining technique is investigated to increase the applications of MMCs. In this study, the overlap welding of pure aluminum and super thermal conductive (STC) aluminum-graphite composite was experimentally and numerically investigated by using a pulsed Nd: YAG laser. In order to discuss the welding of dissimilar materials with different thermophysical properties, the temporal change of heat input was controlled by arranging the laser pulse waveform. The porosities and bumps were observed as the remarkable weld defects in the welding process without a pulse control. On the other hand, the weld bead was largely free of defects, and a size of bump was relatively small with the appropriate controlled pulse waveform. It was clarified that the laser welded joint of an aluminum and a STC aluminum-graphite composite could be successfully achieved with the better weld penetration stability by the appropriate controlled pulse waveform.

    DOI: 10.2961/jlmn.2013.01.0018

    Web of Science

    researchmap

  • IMPROVING THE PRODUCTIVITY OF ELECTRICAL DISCHARGE MACHINING PROCESS BY USING MULTI-THIN ELECTRODES 査読

    Habib Sameh, Akira Okada, Yoshiyuki Uno

    MACHINING SCIENCE AND TECHNOLOGY   17 ( 1 )   110 - 128   2013年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TAYLOR & FRANCIS INC  

    In the electrical discharge machining (EDM) process, thin tool-electrodes are constantly gaining much importance due to the growing demand for manufactured parts with more functional characteristics and with small geometrical dimensions for applications in many work fields. This article highlights the utilization of the EDM process using multi-thin tool-electrodes with diameters of 0.3, 0.5 and 1.0 mm and different lateral spaces (3.0 to 0.8 mm). This machining technology requires using more than one tool-electrode in the same time for fabrication of microholes with high process performance and productivity. One of the principal aims of the experimental investigations of this article is to determine the minimum lateral spacing required between tool-electrodes for reducing process costs under acceptable conditions related to the surface of the machined workpiece. Tool-electrode wear and material removal rate are investigated as result of these experiments under adjustment of different process parameters. The beneficial effects of this machining process are also highlighted. The first experimental results of EDM with multi-thin tool-electrodes indicate some technical and economical advantages as a machining process.

    DOI: 10.1080/10910344.2012.747916

    Web of Science

    researchmap

  • Evaluation of molten zone in micro-welding of glass by picosecond pulsed laser 査読

    Yasuhiro Okamoto, Isamu Miyamoto, Kristian Cvecek, Akira Okada, Kenta Takahashi, Michael Schmidt

    Journal of Laser Micro Nanoengineering   8 ( 1 )   65 - 69   2013年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Glass materials have been widely used in optics, MEMS, electronics and biomedical applica-tions because of their excellent optical, mechanical and chemical properties. Fusion welding by ul-trashort pulsed laser has been proposed as a promising technique for glass joining, since joining can be accomplished without an intermediate layer and mechanical contact. However, to apply a fusion welding technique by ultrashort pulsed laser as a reliable joining method, it is important to under-stand the mechanical properties of the weld seam since glass materials are very sensitive to tempera-ture gradients. Therefore, a method of evaluating the weld seam in the fusion welding of glass by picosecond pulsed laser was discussed, and its mechanical strength was investigated. A larger opti-cal contact area had a great influence on the shear load of the weld seam, while a smaller optical contact area could reduce the influence of the contact area on the measurement of shear load. There-fore, it was important to reduce the optical contact area to accurately evaluate the shearing strength of weld seam. The mechanical strength of the weld seam reduced at a low pulse repetition rate. High bending strength and shear stress could be obtained at a proper pulse repetition rate.

    DOI: 10.2961/jlmn.2013.01.0013

    Scopus

    researchmap

  • Neural network modeling for prediction of weld bead geometry in laser microwelding 査読

    Mohd Idris Shah Ismail, Yasuhiro Okamoto, Akira Okada

    Advances in Optical Technologies   ( 11 )   105 - 111   2013年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Laser microwelding has been an essential tool with a reputation of rapidity and precision for joining miniaturized metal parts. In industrial applications, an accurate prediction of weld bead geometry is required in automation systems to enhance productivity of laser microwelding. The present work was conducted to establish an intelligent algorithm to build a simplified relationship between process parameters and weld bead geometry that can be easily used to predict the weld bead geometry with a wide range of process parameters through an artificial neural network (ANN) in laser microwelding of thin steel sheet. The backpropagation with the Levenberg-Marquardt training algorithm was used to train the neural network model. The accuracy of neural network model has been tested by comparing the simulated data with actual data from the laser microwelding experiments. The predictions of the neural network model showed excellent agreement with the experimental results, indicating that the neural network model is a viable means for predicting weld bead geometry. Furthermore, a comparison was made between the neural network and mathematical model. It was found that the developed neural network model has better prediction capability compared to the regression analysis model. © 2013 Mohd Idris Shah Ismail et al.

    DOI: 10.1155/2013/415837

    Scopus

    researchmap

  • Investigation of Wire Movement in Fine Wire EDM by High Speed Observation 査読

    Akira OKADA, Sho ICHII, Yasuhiro OKAMOTO

    International Journal of Electrical Machining   ( 18 )   43 - 48   2013年

     詳細を見る

  • Influence of Polarization Plane on Groove Shape in Scribing of Sapphire by THG: YAG Laser 査読

    Yasuhiro OKAMOTO, Shin-ichi NAKASHIBA, Tomokazu SAKAGAWA, Akira OKADA, Yoshiyuki UNO

    International Journal of Electrical Machining   ( 18 )   49 - 54   2013年

     詳細を見る

  • Effect of cutting direction on machining of carbon fibre reinforced plastic by electrical discharge machining process 査読

    Sameh Habib, Akira Okada, Sho Ichii

    International Journal of Machining and Machinability of Materials   13 ( 4 )   414 - 427   2013年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In this study, the electrical discharge machining (EDM) characteristics and its removal mechanism for one and two directional carbon fibre reinforced plastic (CFRP) composite was evaluated. Also, an investigation about the influence of carbon fibre direction to machining direction was discussed to attain high performance of EDM process. Then EDM characteristics with two different combinations of machining direction and carbon fibre direction were compared. EDM machining characteristics such as material removal rate, electrode wear rate, surface roughness and SEM images were determined. Experimental results clarified that the material removal mechanism in the EDM for one directional CFRP when the machining direction is perpendicular to the fibre direction is different from that in parallel machining. Also, the EDM machining for two directional CFRP is different from that for one direction. Therefore, efficient EDM for CFRP is possible by selecting appropriate machining direction to fibre direction and the type of CFRP according to its fibre direction. Copyright © 2013 Inderscience Enterprises Ltd.

    DOI: 10.1504/IJMMM.2013.054272

    Scopus

    researchmap

  • 電子ビーム照射面に窒化処理を適用した金型綱の熱疲労特性について 査読

    萩原義人, 佐野正明, 岡田 晃

    電気加工学会誌   47 ( 115 )   88 - 96   2013年

     詳細を見る

  • プラズマ窒化処理がステンレス刃物の切断性能に及ぼす影響 査読

    玉置 司, 岡田 晃, 植村賢介, 宇野義幸

    精密工学会誌   79 ( 10 )   950 - 955   2013年

     詳細を見る

  • Micro-welding of Aluminium Alloy by Superposition of Pulsed Nd:YAG Laser and Continuous Diode Laser 査読

    Yasuhiro Okamoto, Shin-ichi Nakashiba, Tomokazu Sakagawa, Akira Okada

    The Paton Welding Journal   ( 11 )   105 - 111   2013年

     詳細を見る

  • Direct Micro-joining of Flexible Printed Circuit and Metal Electrode by Pulsed Nd:YAG Laser 査読

    Mohd Idris Shah Ismail, Yasuhiro Okamoto, Akira Okada, Yoshiyuki Uno, Kentaro Ueoka

    INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING   13 ( 3 )   321 - 329   2012年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:KOREAN SOC PRECISION ENG  

    Laser micro-welding has proven to be a very successful tool for micro-joining in the electrical and electronic industries, where the miniaturization, the high strength and the high heat resistance are constantly requested. Recently, a flexible printed circuit (FPC) is expected as a new connection technology between electrical conductors according to the improvements of reliability and controllability with the diversification of the design concept. In this technology, it is required to weld a several tens mu m thickness of FPC and a several hundreds mu m thickness of metal electrode. This material combination accompanies the difficulty to control the welding phenomenon due to the differences of thermal property and heat capacity. As a good alternative, laser micro-welding has advantages of non-contact tool, low heat distortion and consistent weld integrity In this study, the overlap welding of thin copper circuit on a polyimide film and a thick brass electrode was experimentally and numerically investigated by using a pulsed Nd:YAG laser. In addition, the shearing stress of overlap welding was evaluated with and without the control of pulse waveform, which can provide a well-directed controlling of the heat input with high energy density The results showed that a porosity was observed as the major weld defect in the welding process without a pulse control. However, the appropriate controlled laser pulse configuration of micro-welding could remove the weld defects in the molten zone, improve the weld penetration stability and increase the weld strength. The potential benefits of controlled pulse waveform were discussed for the direct laser micro-welding process. It is clarified that the direct laser micro-welding of a thin copper circuit on a polyimide film and a thick brass electrode could be successfully achieved by appropriate controlled pulse waveform and heat input.

    DOI: 10.1007/s12541-012-0041-3

    Web of Science

    researchmap

  • Investigation on Micro-machining Characteristics and Phenomenon of Semiconductor Materials by Harmonics of Nd:YAG Laser 査読

    Takayuki Hirano, Yasuhiro Okamoto, Akira Okada, Yoshiyuki Uno, Tomokazu Sakagawa, Shin-ichi Nakashiba

    PROCEEDINGS OF PRECISION ENGINEERING AND NANOTECHNOLOGY (ASPEN2011)   516 ( 516 )   36 - +   2012年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:TRANS TECH PUBLICATIONS LTD  

    Precision micro-machining without crack and heat affected zones is required in order to use high-performance materials such as silicon and silicon carbide, and it is expected that the higher harmonics of the Nd:YAG laser can perform precision micro-machining due to its high photon energy. However, even by using the harmonics of the Nd:YAG laser, a heat affected zone is inevitable due to the plasma generation. In order to reduce the influence of plasma on the processing results, it is important to understand the generation mechanism of plasma. Therefore, the laser induced plasma in micro-drilling of silicon carbide was observed by a high-speed shutter camera, and the influence of laser wavelength and surrounding conditions on the machining characteristics were experimentally investigated. The removal depth increased with decreasing wavelength and the surrounding gas pressure. The surface integrity was improved by the combination of shorter wavelength and reduced pressure conditions. The behavior of laser induced plasma was different from the wavelength of the laser beam and the surrounding gas pressure. Under atmospheric pressure conditions, the plasma grew greatly and affected the wider surface around the drilled hole with increasing wavelength. Under reduced pressure conditions, there was little difference in plasma size by wavelength, and the affected zone around the drilled hole became relatively smaller. It became clear. that a low surrounding gas pressure and shorter wavelength were important to obtain better surface integrity and highly efficient processing.

    DOI: 10.4028/www.scientific.net/KEM.516.36

    Web of Science

    researchmap

  • Optimization of Nozzle Flushing Method for Smooth Debris Exclusion in Wire EDM 査読

    Takuya Fujimoto, Akira Okada, Yasuhiro OKamoto, Yoshiyuki Uno

    PROCEEDINGS OF PRECISION ENGINEERING AND NANOTECHNOLOGY (ASPEN2011)   516 ( 516 )   73 - +   2012年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:TRANS TECH PUBLICATIONS LTD  

    In a wire EDM using a thin wire electrode, better exclusion of debris from the machined kerf is important in order to maintain stable machining performance, since the area of spark generation is along a line and very small. When large amounts of debris stagnate in the gap, secondary discharges possibly occur and these discharges easily concentrate on the same location, which leads to unstable machining performance, wire breakage, low machining rate and a low shape accuracy.
    Conventionally, the exclusion of debris is carried out by jet flushing with an upper and lower nozzle. However, the flow field of machining fluid in the kerf due to the jet flushing and the effect of jet flushing conditions from the nozzles on debris exclusion have not yet been sufficiently examined. This study aims to clarify the flow field in the machined kerf by computational fluid dynamics (CM) and to propose new jet flushing methods for smooth debris exclusion in the wire EDM. The effects of workpiece thickness and machined kerf length on the flow field of working fluid in the kerf under conventional jet flushing conditions are discussed. Then, jet flushing with a tilting nozzle is proposed in order to decrease the debris stagnation area near the wire electrode. As a result, by using the tilting nozzle, removal rate can be improved because of the smooth debris exclusion.

    DOI: 10.4028/www.scientific.net/KEM.516.73

    Web of Science

    researchmap

  • Challenge to Development of Functional Multi-wire EDM Slicing Method 査読

    Yasuhiro Okamoto, Atushi Kimura, Akira Okada, Jun Ohya, Toshiyuki Yamauchi, Toyo, Advanced Technologies Co, Ltd, Tokusen Kogyo

    Key Engineering Materials   ( 523-524 )   287 - 292   2012年

  • プラズマ窒化処理がステンレス刃物鋼の表面性状に及ぼす影響 査読

    玉置,植村, 岡田,宇野

    精密工学会誌   78 ( 1 )   72 - 76   2012年

     詳細を見る

  • ワイヤ放電加工用高性能ワイヤ電極の開発に関する研究(第4報)-ワイヤ表面の高抵抗層が放電加工特性に及ぼす影響− 査読

    岡田 晃, 山内俊之, 中澤正典, 清水敏明, 宇野義幸

    電気加工学会誌   45 ( 109 )   64 - 70   2011年

     詳細を見る

  • Effects of Wire Surface Roughness on Wire EDM Characteristics 査読

    Akira OKADA Toshiyuki YAMAUCH, Masayuki HIGASHI, Masanori NAKAZAWA, Toshiaki SHIMIZU, Yoshiyuki UNO

    International Journal of Electrical Machining   ( 16 )   1 - 7   2011年

     詳細を見る

  • Experimental Investigation on Micro-Welding of Thin Stainless Steel Sheet by Fiber Laser 査読

    Mohd Idris Shah Ismail, Yasuhiro Okamoto, Akira Okada, Yoshiyuki Uno

    American Journal of Engineering and Applied Sciences   4 ( 3 )   306 - 312   2011年

     詳細を見る

  • Surface modification of cemented carbide by EB polishing 査読

    A. Okada, R. Kitada, Y. Okamoto, Y. Uno

    CIRP ANNALS-MANUFACTURING TECHNOLOGY   60 ( 1 )   575 - 578   2011年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    Cemented carbide has many excellent properties. However, it is sometimes difficult to apply conventional surface finishing or surface modification methods for the cemented carbide. The possibility of surface modification by large-area electron beam irradiation, namely EB polishing was discussed. The surface structure of the EB polished cemented carbide was observed by TEM. The hardness and the water repellency were tested. Also, the separation force of molded resin from the surface was measured for evaluating the releasability of the resin. The water repellency and the releasability of the molded resin could be improved by EB polishing, because the surface structure changed. (C) 2011 CIRP.

    DOI: 10.1016/j.cirp.2011.03.107

    Web of Science

    researchmap

  • 大面積電子ビーム照射による超微粒子超硬合金の表面処理 査読

    北田良二, 岡田 晃, 宇野義幸, 郭 洪閣

    精密工学会誌   76 ( 12 )   1393 - 1397   2010年

     詳細を見る

  • 型彫り放電加工面の離型性に関する基礎的研究 -離型性に及ぼす要因の解明- 査読

    北田良二, 日置裕彦, 岡田 晃, 宇野義幸

    電気加工学会誌   44 ( 106 )   52 - 59   2010年

     詳細を見る

  • Evaluations of spark distribution and wire vibration in wire EDM by high-speed observation 査読

    A. Okada, Y. Uno, M. Nakazawa, T. Yamauchi

    CIRP ANNALS-MANUFACTURING TECHNOLOGY   59 ( 1 )   231 - 234   2010年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TECHNISCHE RUNDSCHAU EDITION COLIBRI LTD  

    In fine wire EDM using thin wire electrode, uniform distribution of spark location is necessary to achieve stable machining performance. However, it is difficult to precisely evaluate the distribution of spark location by the conventional branched electric current method when the workpiece is thin. A new evaluation method by using a high-speed video camera is proposed. The locations of spark are measured by analyzing the recorded images. Then the effects of machining parameters, such as servo voltage, pulse interval time, wire running speed and others on the distribution of spark location are investigated. The possibility of evaluating the wire vibration is also discussed. (C) 2010 CIRP.

    DOI: 10.1016/j.cirp.2010.03.073

    Web of Science

    researchmap

  • ワイヤ放電加工用高性能ワイヤ電極の開発に関する研究(第3報)-ワイヤ表面の凹凸が放電加工特性に及ぼす影響− 査読

    岡田 晃, 山内俊之, 東昌幸, 清水敏明, 宇野義幸

    電気加工学会誌   43 ( 104 )   179 - 186   2009年

     詳細を見る

  • Study on Electrical Discharge Machining Characteristics of Electrically Conductive Ceramics 査読

    Hai Wang, Akira Okada, Takafumi Uwano, Yoshiyuki Uno, Habib Sameh

    Key Engineering Materials   ( 407-408 )   636 - 639   2009年

  • Newly Developed CuW Electrode for High Performance EDM 査読

    Akira OKADA, Shingo OUE, Yoshiyuki UNO, Takayuki SHOJI, Takahiro FUKUSHIMA, Osamu TERADA

    International Journal of Electrical Machining   ( 14 )   23 - 28   2009年

     詳細を見る

  • 大面積電子ビーム照射による手術器具用ステンレス鋼の高能率表面仕上げ 査読

    岡田晃, 宇野義幸, 渡辺洋明, 藤原邦彦, 土居憲司

    先端加工学会誌   27 ( 1 )   48 - 55   2009年

     詳細を見る

  • Computational fluid dynamics analysis of working fluid flow and debris movement in wire EDMed kerf 査読

    A. Okada, Y. Uno, S. Onoda, S. Habib

    CIRP ANNALS-MANUFACTURING TECHNOLOGY   58 ( 1 )   209 - 212   2009年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TECHNISCHE RUNDSCHAU EDITION COLIBRI LTD  

    In wire EDM, better exclusion of debris from the machined kerf is very important to obtain a stable machining performance. The purpose of this study is to investigate the fluid flow in the kerf and better jet flushing conditions of working fluid from the nozzles. The flow field and the debris motion in the kerf were analyzed by computational fluid dynamics (CFD) simulation, comparing with the observation by high-speed video camera. The influence of flow rate of working fluid from nozzles and the nozzle standoff distance on flow field in the kerf and debris particle motion were discussed. (C) 2009 CIRP.

    DOI: 10.1016/j.cirp.2009.03.003

    Web of Science

    researchmap

  • Surface Modification of Stainless Steel for Surgical Tool by EB-polishing 査読

    Akira Okada, Yoshiyuki Uno, Hiroaki Watanabe, Kunihiko Fujiwara, Kenji Doi

    Key Engineering Materials   ( 407-408 )   339 - 342   2009年

  • New Surface Modification Method of Bio-titanium Alloy by EB Polishing 査読

    Akira OKADA, Yoshiyuki UNO, Atsuo IIO, Kunihiko FUJIWARA, Kenji DOI

    Journal of Advanced Mechanical Design System and Manufacturing   2 ( 4 )   735 - 741   2008年

     詳細を見る

  • Effect of Surface Quality of Brass Coating Wire on Wire EDM Characteristics 査読

    Akira Okada, Toshiyuki Yamauchi, Kimihiko Arizono, Yoshiyuki Uno

    JOURNAL OF ADVANCED MECHANICAL DESIGN SYSTEMS AND MANUFACTURING   2 ( 4 )   735 - 741   2008年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPAN SOC MECHANICAL ENGINEERS  

    The purpose of this study is to develop a new type of wire electrode, in which piano wire with very high tensile strength is coated with electrically conductive layer, such as brass or zinc, in order to attain high speed and high precision wire EDM. In this report, using a trial-made thin wire of 50 mu m in diameter, the optimum thickness and quality of brass layer were experimentally investigated for higher performance fine wire EDM. Furthermore, the influence of the tensile strength of piano wire used as a core wire was discussed. As a result, the coated brass with copper content of 60-70% is effective and the thickness of coated brass is needed to be more than 1.45 mu m for high removal rate.

    DOI: 10.1299/jamdsm.2.735

    Web of Science

    researchmap

  • 段付き電極による深穴放電加工特性の向上 査読

    岡田 晃, 安田竜一, 宇野義幸

    電気加工学会誌   42 ( 101 )   122 - 129   2008年

     詳細を見る

  • ワイヤ放電加工用高性能ワイヤ電極の開発に関する研究(第2報) 査読

    岡田 晃, 山内俊之, 有園公彦, 清水敏明, 宇野義幸

    電気加工学会誌   42 ( 99 )   12 - 19   2008年

     詳細を見る

  • 大面積電子ビームによる金型加工面の高能率仕上げに関する研究(第3報) 査読

    岡田 晃, 虞 戦波, 近藤 温, 宇野義幸, 佐野定男, 植村賢介

    精密工学会誌   74 ( 4 )   385 - 389   2008年

     詳細を見る

  • Surface finishing of stainless steels for orthopedic surgical tools by large-area electron beam irradiation 査読

    A. Okada, Y. Uno, J. A. McGeough, K. Fujiwara, K. Doi, K. Uemura, S. Sano

    CIRP ANNALS-MANUFACTURING TECHNOLOGY   57 ( 1 )   223 - 226   2008年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TECHNISCHE RUNDSCHAU EDITION COLIBRI LTD  

    Surgical tools and jigs are initially machined by multi-axis milling. Then surface finishing is carried out mainly by hand lapping. As these tools undergo repeated use, the removal of burrs, scratches and rust from the surfaces is also performed manually after each operation. These finishing processes are time-consuming and costly. In this study, a new finishing method by large-area electron beam irradiation is proposed. Electron beam (EB) with high energy density can be obtained without focusing the beam, and large-area EB can be used for instantly melting or evaporating the metal surface. Stainless steel for surgical tools and jigs was treated by the large-area EB irradiation method. The experimental results show that highly efficient surface smoothing of stainless steels by large-area EB irradiation may be achieved. In addition, the resistance to corrosion and blood repellency can be improved simultaneously with surface smoothing. (c) 2008 CIRP.

    DOI: 10.1016/j.cirp.2008.03.062

    Web of Science

    researchmap

  • A new polishing method of metal mold with large-area electron beam irradiation 査読

    Y. Uno, A. Okada, K. Uemura, P. Raharjo, S. Sano, Z. Yu, S. Mishima

    JOURNAL OF MATERIALS PROCESSING TECHNOLOGY   187 ( 187-188 )   77 - 80   2007年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE SA  

    A new polishing method by large-area electron beam (EB) irradiation is proposed in this study. In the large-area EB irradiation equipment used here, an EB with high energy density is irradiated without focusing the beam. An EB irradiation in a few microseconds with a maximum diameter of 60 mm can be used for melting metal surface instantly. The experimental results made it clear that the surface roughness decreases from 6 mu mRz to less than 1 mu mRz in a just few minutes under a proper machining condition. The corrosion resistance of metal mold surface also could be greatly improved by large-area EB irradiation. Furthermore it is clarified that even the surface roughness of tilting surface close to 90 degrees could be well improved. Therefore, large-area EB irradiation method has a high possibility to become a high-efficiency polishing method of metal mold. (c) 2007 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jmatprotec.2006.11.080

    Web of Science

    researchmap

  • Surface modification for orthopaedic titanium alloy by wide-area electron beam 査読

    A. Okada, Y. Uno, K. Uemura, P. Raharjo, J. A. McGeough

    PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART B-JOURNAL OF ENGINEERING MANUFACTURE   221 ( 2 )   173 - 178   2007年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PROFESSIONAL ENGINEERING PUBLISHING LTD  

    Wide-area electron beam (WAEB) irradiation was proposed as a new surface-finishing process for orthopaedic titanium alloy products. The surface roughness could be reduced from R-z = 10 mu m to R-z = 0.7 mu m all over the wide circular surface within a diameter of 60 mrn in just a few minutes under optimum electron beam conditions. In this paper, the surface structure and the surface characteristics of WAEB-irradiated surface are discussed. The crystal grain size becomes small and the microstructure in the surface vicinity changes under WAEB irradiation. The corrosion resistance and the repellency can be improved simultaneously with the surface smoothing. Therefore, the WAEB irradiation method enables highly efficient surface smoothing and surface modification of orthopaedic titanium alloy.

    DOI: 10.1243/09544054JEM574

    Web of Science

    researchmap

  • 放電加工用高性能銅タングステン電極の開発 査読

    岡田 晃, 大上真吾, 宇野義幸, 庄司隆行, 福島崇洋, 寺田修

    電気加工学会誌   41 ( 97 )   69 - 76   2007年

     詳細を見る

  • Surface Finishing of SKD 11 Tool Steel via Plasma-based Electron Beam Irradiation 査読

    Yoshiaki Daichi, Sadao Sano, Yoshiyuki Uno, Akira Okada

    Journal of Key Engineering Materials   ( 364-366 )   302 - 307   2007年

     詳細を見る

  • 放電加工面の耐食性に関する基礎的研究

    岡田 晃, 田中 智, 三田耕司, 宇野義幸

    電気加工学会誌   40 ( 94 )   66 - 73   2006年

     詳細を見る

  • Machining characteristics of EDM by radio-frequency plasma

    A. Okada, J. A. McGeough, D. MacMillan, B. Flynn

    CIRP ANNALS-MANUFACTURING TECHNOLOGY   55 ( 1 )   167 - 170   2006年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    An extension to the electrical discharge machining method by introduction of radio-frequency plasma is proposed. Sparking with the radio-frequency plasma can be generated in paraffin oil by simple electrical circuitry. In this paper, experimental investigations are described on the fundamental effects of the resonant frequency, type of electrode and workpiece materials on machining characteristics for high performance radio-frequency machining in paraffin oil. The results show that the removal rate and the electrode wear vary with the resonant frequency and type of electrode materials. The surface roughness can be reduced to less than 1 mu m Rz under suitable experimental conditions.

    DOI: 10.1016/S0007-8506(07)60390-4

    Web of Science

    researchmap

  • ホーニング加工用水溶性切削油を用いた電解による小径円筒内面仕上げ(第2報)―砥石による不働態膜除去と高能率表面仕上げ― 査読

    岡田 晃, 橋本敦史, 宇野義幸, 山本庄一, 田中正司, 佃 昭

    電気加工学会誌   40 ( 95 )   169 - 176   2006年

     詳細を見る

  • 大面積電子ビームによる金型加工面の高能率仕上げに関する研究(第2報) 査読

    岡田 晃, 宇野義幸, 仁科圭太, 植村賢介, Purwadi RAHARJO, 佐野定男, 虞 戦波, 株)ソディック

    精密工学会誌   71 ( 11 )   1399 - 1403   2005年

     詳細を見る

  • ワイヤ放電加工用高性能ワイヤ電極の開発に関する研究(第1報) 査読

    山内俊之, 岡田 晃, 森田真人, 清水敏明, 宇野義幸, トクセン工

    電気加工学会誌   39 ( 92 )   28 - 35   2005年

     詳細を見る

  • Effect of Debris Distribution on Wall Concavity in Deep Hole EDM

    International Journal of the Japan Society of Mechanical Machining, Series C,   47 ( 2 )   553 - 559   2004年

     詳細を見る

  • バイオマシニングにおける加工メカニズムの解明および加工速度向上に関する試み

    岡田 晃, 宇野 義幸, 久野 智之, 金枝 敏明

    精密工学誌   68 ( 12 )   1585 - 1589   2002年

     詳細を見る

▼全件表示

MISC

  • Low-visibility Processing of Silver Nanowire Transparent Conductive Film by Pulsed Laser

    Yasuhiro Okamoto, Norio Nishi, Masafumi Oshita Takahiro, Shimose,Togo Shinonaga, Akira Okada, Tomokazu Sakagawa

    Proceedings of 36th International Congress on Applications of Lasers & Electro-Optics 2017, M202   2017年

     詳細を見る

  • Formation of Chromium Carbide on Carbon Tool Steel by EDM in Powder Mixed Working Fluid

    Ruixiang Wang, Yuta Iida, Ryoji Kitada, Akira Okada

    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century (LEM21), D31   2017年

     詳細を見る

  • Expansion of Smoothed Area on Hole Bottom Surface by Setting Magnetic Block in Large-area Electron Beam Irradiation

    Togo Shinonaga, Mitsuhiro Kimura, Akira Okada

    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century (LEM21), D33   2017年

     詳細を見る

  • Study on Shape Variation of Periodic Surface Nanostructures Produced with Ultrashort Pulse Laser for Control of Cell Spreading Direction

    Shono Kinoshita, Togo Shinonaga, Yasuhiro Okamoto, Akira Okada

    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century (LEM21), D07   2017年

     詳細を見る

  • Effects of Polarization Directionon Removal Characteristics of Silver Nanowire Transparent Conductive Film by fs Pulsed Laser

    Takahiro Shimose, Yasuhiro Okamoto, Masafumi Oshita, Norio Nishi, Togo Shinonaga, Akira Okada

    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century (LEM21), D09   2017年

     詳細を見る

  • Influence of Pulse Duration on Effective Energy on Material in Nanosecond Pulsed Laser Processing of Mild Steel

    Mizuna Ito, Togo Shinonaga, Yasuhiro Okamoto, Akira Okada

    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century (LEM21), D10   2017年

     詳細を見る

  • Cutting Performance of Boron-doped Diamond Coated Tools in Drilling of CFRP

    Alexander SOLDATOV, Akira OKADA, Kensuke UEMURA, Hitoshi OGAWA

    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century (LEM21), B13   2017年

     詳細を見る

  • Multi-wire EDM slicing of semiconductors with group power supplying method

    Yasuhiro Okamoto, Takayuki Ikeda, Haruya Kurihara, Akira Okada, Masataka Kido

    Proceedings of euspen's 17th International Conference, 183-184   183 - 184   2017年

     詳細を見る

  • Fundamental Study on Slicing Method of Gallium Nitride by Ultrashort Pulsed Laser

    Togo Shinonaga, Motoki Ota, Yasuhiro Okamoto, Akira Okada

    The 18th International Symposium on Laser Precision Microfabrication Prpgram & Techunical digest, We1-O-9, p.132   132   2017年

     詳細を見る

  • Effect of focusing condition on molten area characteristics in micro-welding of borosilicate glass by picosecond pulsed laser

    I. H. W. Nordin, Y. Okamoto, A. Okada, T. Takekuni, T. Sakagawa

    APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING   122 ( 5 )   2016年5月

     詳細を見る

    記述言語:英語   出版者・発行元:SPRINGER  

    The characteristics of the molten area are attributed not only by laser energy condition but also the focusing condition. In this study, a picosecond pulsed laser of 1064 nm in wavelength and 12.5 ps in pulse duration was used as a laser source for joining glass material. Influence of focusing condition on micro-welding of glasses was experimentally investigated by using an objective lens with and without spherical aberration correction, and its molten area was characterized. The usage of objective lens with spherical aberration correction led to a larger molten area inside the bulk material of glass even under the same pulse energy, which related to the efficient micro-welding of glass materials. In addition, an optical system with the spherical aberration correction led to a stable absorption of laser energy inside the bulk glass material, stabilizing the shape of molten area, which resulted in the reliable weld joint. On the other hand, breaking strength of the specimens with spherical aberration correction was higher than that without spherical aberration correction. Therefore, it is concluded that the focusing condition with spherical aberration correction led to the larger and stable molten area, which resulted in higher joining strength in micro-welding of glass materials.

    DOI: 10.1007/s00339-016-0026-7

    Web of Science

    researchmap

  • Study on Clarification of Large-area EB IrradiationPhenomenon by ElectronTrack Analysis

    Yasuaki Kimura, Togo Shinonaga, Akira Okada

    Proceedings of the International Conference on Machining, Materials and Mechanical Technologies IC3MT 2016 paper#P.107   107   2016年

     詳細を見る

  • Insulation Characteristics and Visibility of Transparent Conductive Film Containing Silver Nanowires by Nanosecond Pulsed Laser

    Masafumi Oshita, Norio Nishi, Yasuhiro Okamoto, Togo Shinonaga, Akira Okada

    TECHNICAL DIGEST of the Second Smart Laser Processing Conference Paper#82   82   2016年

     詳細を見る

  • Influence of Pulse duration on Processing Characteristics of Transparent Conductive Film Containing Silver Nanowires by ns Pulsed Fiber Laser

    Masafumi Oshita, Norio Nishi, Yasuhiro Okamoto, Akira Okada, Togo Shinonaga, Tomokazu Sakagawa

    18TH CIRP CONFERENCE ON ELECTRO PHYSICAL AND CHEMICAL MACHINING (ISEM XVIII)   42   62 - 66   2016年

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Processing characteristics of transparent conductive film containing silver nanowires by ns pulsed fiber lasers with various pulse duration were experimentally investigated in the view-points of insulating state and surface quality. The laser fluence achieving the insulation state became smaller with decreasing the pulse duration. Appearance of removed trace area of silver nanowires was varied by the pulse duration, and the removal area ratio of removed trace area to the whole one was evaluated to discuss the surface quality. Small removal area ratio and good insulation state could be performed at a wide processing window at long pulse duration of 200ns. (C) 2016 The Authors. Published by Elsevier B.V.

    DOI: 10.1016/j.procir.2016.02.189

    Web of Science

    researchmap

  • Improvement in Surface Characteristics by EDM with Chromium Powder Mixed Fluid

    Ryota Toshimitsu, Akira Okada, Ryoji Kitada, Yasuhiro Okamoto

    18TH CIRP CONFERENCE ON ELECTRO PHYSICAL AND CHEMICAL MACHINING (ISEM XVIII)   42   231 - 235   2016年

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Surface finishing technology by EDM has recently progressed, and very small surface roughness can be readily obtained by controlling the electrical discharge conditions, or by using metal powder mixed working fluids. In addition, it was reported that EDMed surface using metal powder mixed fluids sometimes has high surface functions, such as high hardness, high corrosion resistance and so on. Therefore, the high functional EDM finished surface is well expected to be applied as a final metal mold surface. In this study, formation of chromium containing layer on the EDMed surface was tried by using chromium powder mixed fluid. Furthermore, the EDMed surface characteristics with chromium powder mixed fluid were experimentally evaluated. (C) 2016 The Authors. Published by Elsevier B.V.

    DOI: 10.1016/j.procir.2016.02.277

    Web of Science

    researchmap

  • Investigation of Shielding Gas Supplying Method in Vertical-position Laser Welding of Pure Titanium

    Kazuo Yokohara, Yasuhiro Okamoto, Akira Okada, Hikotaro Ochiai, Ryosuke Kimura, Shozo Ono, Masayuki Akase

    18TH CIRP CONFERENCE ON ELECTRO PHYSICAL AND CHEMICAL MACHINING (ISEM XVIII)   42   448 - 453   2016年

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Effective shielding method for a wide area is required in the vertical-position remote laser welding of pure titanium. Therefore, shielding effects of ring-type nozzles with two layers for a wide area were numerically and experimentally investigated in the vertical-position setup of workpiece with argon gas. Prevention of incoming air flow outside a ring-type nozzle is effective to increase mass fraction of argon gas. Mass fraction of argon gas could be increased using a ring-type nozzle, in which shielding gas is supplied by open-side injection ports of proper angle at a proper flow ratio of two jetting layers. (C) 2016 The Authors. Published by Elsevier B.V.

    DOI: 10.1016/j.procir.2016.02.230

    Web of Science

    researchmap

  • High-speed Observation of Thin Wire Movement in Fine Wire EDM

    Takuya Kamei, Akira Okada, Yasuhiro Okamoto

    18TH CIRP CONFERENCE ON ELECTRO PHYSICAL AND CHEMICAL MACHINING (ISEM XVIII)   42   596 - 600   2016年

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    In this study, the movements of thin tungsten wire electrode during fine wire EDM were investigated by direct observation using a high-speed camera. The results showed that the amplitude in the direction parallel to the machining direction was a little larger than that in the perpendicular one. Also, the backward wire deflection could be confirmed even in fine wire EDM. Furthermore, the wire vibration mode was found out by frequency analysis and the vibration amplitude could be reduced by adjusting the workpiece position to the 3rd order node of the vibration. In addition, the amplitude envelope of wire electrode during the process was clarified. (C) 2016 The Authors. Published by Elsevier B.V.

    DOI: 10.1016/j.procir.2016.02.266

    Web of Science

    researchmap

  • Effects of Surface States on Light Absorption Characteristics in Micro-welding of Copper by Pulsed Nd:YAG laser

    Reiki Inoue, Takuya Wada, Yasuhiro Okamoto, Akira Okada

    Proceedings of the International Conference on Machining, Materials and Mechanical Technologies IC3MT 2016 paper#P.66   66   2016年

     詳細を見る

  • Formation of periodic nanostructures with femtosecond laser for creation of new functional biomaterials

    Togo Shinonaga, Shono Kinoshita, Yasuhiro Okamoto, Masahiro Tsukamoto, Akira Okada

    18TH CIRP CONFERENCE ON ELECTRO PHYSICAL AND CHEMICAL MACHINING (ISEM XVIII)   42   57 - 61   2016年

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Pure Titanium (Ti) and Ti alloys are the most used biomaterials. However, they have problem for bioactivity because metals have no biofunction. Therefore, adding new function to Ti and Ti alloys are necessary. One method to add new function is the creation of periodic structures on the biomaterial surfaces, which can control cell spreading. Femtosecond laser is one of the useful tools for creating periodic nanostructures, which can be created on metals and semiconductors by self-organizing in the laser focusing spot. In our previous study, the nanostructures could be formed on the Ti plate by using the femtosecond laser with fundamental wavelength of 775 nm. The periodicities of the nanostructures on the Ti plate was approximately 590 nm, which was shorter than the laser wavelength. Cells tests indicated that cell spreading clearly occurs along the grooves of the nanostructures. However, the influence of the periods of the nanostructure on cell spreading has not yet been investigated. It is expected that the periods can be varied by changing laser parameters, such as pulse widths, laser wavelengths, laser fluences, and number of shots. In this study, the periodic nanostructures are created on the Ti plate surface by using the femtosecond laser with fundamental wavelength of 790 nm. Then, influence of the pulse width and number of shots on the periods is investigated. In the experiments, laser beam is focused and scanned on the Ti plate surfaces. The laser irradiated areas are analysed by using a scanning electron microscope (SEM).

    DOI: 10.1016/j.procir.2016.02.188

    Web of Science

    researchmap

  • Investigation of Nanocrystalline Diamond Coating on Cutting Tools for CFRP

    Alexander SOLDATOV, Akira OKADA, Kensuke UEMURA

    Proceedings of the International Conference on Machining, Materials and Mechanical Technologies IC3MT 2016 paper#P.102   102   2016年

     詳細を見る

  • Control of Surface Profile in Periodic Nanostructures Produced with Ultrashort Pulsed Laser

    Togo Shinonaga, Shouno Kinoshita, Yasuhiro Okamoto, Akira Okada

    Proceedings of 35th International Congress on Applications of Lasers & Electro-Optics 2016 Paper#M601   601   2016年

     詳細を見る

  • Reduction of Discoloration Zone in Micro-drilling of Multi-layered Artificial Skin by Picosecond Pulsed Laser

    Yasuhiro Okamoto, Togo Shinonaga, Akira Eguchi, Kiichi Asako, Naoto Maeda, Akira Okada, Shogo Minagi

    Proceedings of 35th International Congress on Applications of Lasers & Electro-Optics 2016 Paper#M701   701   2016年

     詳細を見る

  • Developement of Curved Hole Drilling Method by EDM with Suspended Ball Electrode.

    Tatsuya MIYAKE, Kohei OTA, Akira OKADA, Atsushi YAMAGUCHI

    Proc. of the 17th International Machine Tool Engineers Conference,(2016), 66-67   66 - 67   2016年

     詳細を見る

  • High-speed Observation of Molten Area Formation in Microwelding of Glass by Picosecond Pulsed Laser

    Motoki Ota, Yasuhiro Okamoto, Imaduddin Helmi Wan Nordin, Togo Shinonaga, Akira Okada

    Proceedings of the International Conference on Machining, Materials and Mechanical Technologies IC3MT 2016 paper#P.67   67   2016年

     詳細を見る

  • Fundamental Study onSmoothing of Hole BottomSurface by Large-area Electron Beam Irradiation

    Hao Liu, Togo Shinonaga, Akira Okada, Motohiro Inoue

    Proceedings of the International Conference on Machining, Materials and Mechanical Technologies IC3MT 2016 paper#P.71   71   2016年

     詳細を見る

  • Influence of Nozzle Jet Flushing on Wire Breakage in 1st-cut Wire EDM from Start Hole

    Akiyoshi Kawata, Akira Okada, Yasuhiro Okamoto, Haruya Kurihara

    Proceedings of the International Conference on Machining, Materials and Mechanical Technologies IC3MT 2016 paper#P.106   106   2016年

     詳細を見る

  • Fundamental Study on Separation Method of Gallium Nitride with Internal Modified Layer by Ultrashort Pulsed Laser

    Motoki Ota, Yasuhiro Okamoto, Togo Shinonaga, Akira Okada

    TECHNICAL DIGEST of the Second Smart Laser Processing Conference Paper#81   81   2016年

     詳細を見る

  • Investigation of Spatter Behavior in Micro-processing of Metal Sheet by Pulsed Laser

    Yasuhiro Okamoto, Akira Okada, Hibiki Yamamoto, Kento Shirasaya, Jari Kolehmainen, Togo Shinonaga

    Technical Digest of the 17th International Symposium on Laser Precision Microfabrication (LPM2016)Paper#82   82   2016年

     詳細を見る

  • Study on high efferent micro-deburring by large-area EB irradiation

    Togo Shinonaga, Yasuaki Kimura, Akira Okada, Tomoaki Miyoshi

    Proceeding of the 16th international conference of the european society for precision engineering and nanotechnology paper#P.7.20   7   2016年

     詳細を見る

  • Shape Change of Periodic Nanostructures Produced with Ultrashort Pulsed Laser on Titanium Surface

    Togo Shinonaga, Shono Kinoshita, Yasuhiro Okamoto, Akira Okada

    TECHNICAL DIGEST of the Second Smart Laser Processing Conference Paper#52   52   2016年

     詳細を見る

  • Effective Shielding Gas Supplying Method of Wide Area in Vertical-Position Laser Welding of Pure Titanium

    Kazuo Yokohara, Yasuhiro Okamoto, Akira Okada, Hikotaro Ochiai, Ryosuke Kimura, Shozo Ono, Masayuki Akase

    TECHNICAL DIGEST of the Second Smart Laser Processing Conference Paper#67   67   2016年

     詳細を見る

  • Investigation of Laser Microdrilling Method for Multi-Layered Arti cial Skin

    Kiichi Asako, Yasuhiro Okamoto, Akira Okada, Shogo Minagi, Naoto Maeda, Qiuyue Pan, Keiji Jin, Goro Nishigawa

    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century   2015年

  • Evaluation of Molten Area in Micro-welding of Monocrystalline Silicon and Glass

    Imaduddin Helmi Wan Nordin, Yasuhiro Okamoto, Isamu Miyamoto, Akira Okada

    Proceedings of 2nd International Manufacturing Engineering Conference 2015   2015年

     詳細を見る

  • Fundamental Study on Metal Film Coating by Large-area EB Irradiation

    Masashi Takata, Togo Shinonaga, Akira Okada, Motohiro Inoue, Sadao Sano

    Proceedings of 30th Annual Meeting of the American Society for Precision Engineering, Vol.62, pp.595-598   595 - 598   2015年

     詳細を見る

  • High-quality and Reliable Removal Method of ZnO by ns Pulsed Fiber Laser with Square Core Optical Fiber

    Norio Nishi, Yasuhiro Okamoto, Akira Okada, Shin-ichi Nakashiba, Tomokazu Sakagawa

    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century   2015年

  • Investigation of Machining Con- trollabil lity in Multi-wire EDM Slicing with Group Power Supply- ing Method

    Akitoshi Suzuki, Yasuhiro, Okamoto, Akira Okada, Haruya Kurihara, Masataka Kido

    Proceedings of the 8th International Conference on Leading Edge Manufac- turing in 21st Century   2015年

  • Fundamental Study on Curved Hole Drilling Method by EDM with Suspended Ball Electrode

    Atsushi YAMAGUCHI, Akira OKADA, Tatsuya MIYAKE, Toshiki IKESHIMA

    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, C25 4pages   2015年

  • Film Formation Mechanism in Alumina Coating by Large-area Electron Beam Irradiation

    Masashi Takata, Togo Shinonaga, Yasuhiro Okamoto, Akira Okada, Motohiro Inoue, Sadao Sano

    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century   595 - 598   2015年

  • Laser Micro-drilling of Multi-layered Arti cial Skin

    Yasuhiro Okamoto, Norio Nishi, Shin-ichi Nakashiba, Tomokazu Sakagawa, Akira Okada

    Proceedings of Lasers in Manufacturing Laser in Manufactring 2015   2015年

     詳細を見る

  • Effect of Focusing Condition on Micro-Welding Characteristic of Glass by ps Pulsed Laser

    Yasuhiro Okamoto, Imaduddin Helmi Wan Nordin, Togo Shinonaga, Tomohiro Takekuni, Tomokazu Sakagawa, Akira Okada

    Proceedings of 34th International Congress on Applications of Lasers &Electro-Optics 2015, pp.244-249   244 - 249   2015年

     詳細を見る

  • Smart laser micro-welding of difficult-to-weld materials for electronic industry

    Y. Okamoto, N. Nishi, S. Nakashiba, T. Sakagawa, A. Okada

    LASER-BASED MICRO- AND NANOPROCESSING IX   9351   2015年

     詳細を見る

    記述言語:英語   出版者・発行元:SPIE-INT SOC OPTICAL ENGINEERING  

    It has been known that wavelength, power density, interaction time and material properties have great influence on processing characteristics in laser material processing, in which materials with higher reflectivity classify into difficult-to-weld materials. In electronic industry, aluminum alloy is widely used as structural components due to its high specific strength, and copper became an important material because of its excellent electrical conductivity. These materials have high reflectivity and high thermal conductivity, which results in instability of energy absorption and processing results. Therefore, welding defects might be noticed in the micro-joining of aluminum alloy and copper. In this paper, the smart laser micro-welding of difficult-to-weld materials such as aluminum alloy and copper were discussed. The combination of a pulsed Nd:YAG laser and a continuous diode laser could perform high-performance micro-welding of aluminum alloy. A pulsed Nd:YAG laser was absorbed effectively from the beginning of laser scanning by pre-heating Nd:YAG laser pulse with the superposition of continuous diode laser, and wide and deep weld bead could be obtained with better surface integrity. As for micro-welding of copper material, stable absorption state could be achieved using a pulsed green Nd:YAG laser, since its absorptivity showed almost constant values with change of power density. A longer pulse duration was effective to achieve not only high absorptivity but also low deviation of absorptivity. The pulse waveform with maximum peak at the early period and a long pulse duration led to stabilizing the penetration depth with less porosity.

    DOI: 10.1117/12.2076232

    Web of Science

    researchmap

  • Study on Applicability of Large-area EB Irradiation to Micro-deburring

    Tomoaki Miyoshi, Akira Okada, Yasuhiro Okamoto

    Proceedings of the International Conference on Machining, Materials and Mechanical Technologies IC3MT 174   2014年

     詳細を見る

  • Investigation of Micro-welding Characteristics of Si and Glass by Picosecond Pulsed Laser

    I. H, W. Nordin, Y. Okamoto, I. Miyamoto, A. Okada

    Proceedings of the First Smart Laser Processing Conference 2014 (SLPC2014) in Electro Proceedings   2014年

     詳細を見る

  • Effect of Wavelength and Pulse Duration in Laser Micro-welding of Glass and Monocrystalline Silicon

    I. H, W. Nordin, Y. Okamoto, I. Miyamoto, A. Okada

    Proceedings of the 15th International Symposium on Laser Precision Microfabrication (LPM2014)   2014年

     詳細を見る

  • Characterization of Absorptivity in Micro-welding of Copper by Pulsed Green Nd:YAG Laser

    Yasuhiro Okamoto, Shin-ichi Nakashiba, Takuya Wada, Tomokazu Sakagawa, Norio Nishi, Akira Okada

    Proceedings of 33rd International Congress on Applications of Lasers & Electro-Optics 2014 M805 In USB   2014年

     詳細を見る

  • Effect of Surrounding Gas Condition on Surface Integrity in Micro-drilling of SiC by ns Pulsed Laser

    Yasuhiro Okamoto, Kiichi Asako, Norio Nishi, Tomokazu Sakagawa, Akira Okada

    Technical Digest of 9th International Conference on Photo-Excited Processes and Applications、A107   2014年

     詳細を見る

  • Development of Simple Power Supplying System in Multi-wire EDM Slicing Method

    Yasuhiro Okamoto, Akitoshi Suzuki, Atsushi Kimura, Akira Okada, Haruya Kurihara, Masataka Kido

    Proceedings of 29th Annual Meeting of the American Society for Precision Engineering 251-254   251 - 254   2014年

     詳細を見る

  • Effects of Focusing Condition on Micro-welding Characteristics of Borosilicate Glass by Picosecond Pulsed Laser

    Tomohiro Tekekuni, Yasuhiro Okamoto, Takahiro Fujiwara, Akira Okada, Isam Miyamoto

    Proceedings of the International Conference on Machining, Materials and Mechanical Technologies IC3MT 176   2014年

     詳細を見る

  • Study on Surface Characteristics of EDMed Surface with Nickel Powder Mixed Fluid

    Syuhei Iwasaki, Ryoji Kitada, Akira Okada, Yasuhiro Okamoto

    Proceedings of the International Conference on Machining, Materials and Mechanical Technologies IC3MT 177   2014年

     詳細を見る

  • Influence of Nozzle Jet Flushing on Wire Deflection and Breakage in Wire EDM

    Takuro Konishi, Sameh Habib, Akira Okada, Yasuhiro Okamoto, Haruya Kurihara

    Proceedings of the International Conference on Machining, Materials and Mechanical Technologies IC3MT 178   2014年

     詳細を見る

  • Improvement of Gas Shielding Effect in Vertical-position Laser Micro-welding of Titanium Alloy

    Kento Shirasaya, Yasuhiro Okamoto, Kazuo Yokohara, Shozou Ono, Ryousuke Kimura, Hikotaro Ochiai, Akira Okada

    Proceedings of 33rd International Congress on Applications of Lasers & Electro-Optics 2014 P154 In USB   2014年

     詳細を見る

  • Effect of Jet Flushing with Tilting Nozzle in Wire Electrical Discharge Machining

    Akira Okada, Takuro Konishi, Yasuhiro Okamoto, Haruki Kurihara

    Proceedings of the 14th euspen International Conference, Vol.2, pp.446-452   ( 2 )   446 - 452   2014年

     詳細を見る

  • Investigation of Micro-drilling Characteristics for SiC by Harmonics of YAG Laser

    Shin URUSHIBATA, Yasuhiro OKAMOTO, Akira OKADA, Shin-ichi NAKASHIBA, Tomokazu SAKAGAWA

    Proceedings of the 7th International Conference on Leading Edge Manufacturing in 21st Century, pp.39-42.   39 - 42   2013年

     詳細を見る

  • Fundamental Characteristics of Spatter in Micro-drilling of Metal Sheet by Pulsed Nd:YAG Laser

    Kento SHIRASAYA, Yasuhiro OKAMOTO, Akira OKADA

    Proceedings of the 7th International Conference on Leading Edge Manufacturing in 21st Century, pp.43-46.   43 - 46   2013年

     詳細を見る

  • Fundamental Study on Micro-welding of Copper by Green Pulsed YAG Laser

    Sunao TAKAI, Shin-ichi NAKASHIBA, Yasuhiro OKAMOTO, Akira OKADA, Tomokazu SAKAGAWA

    Proceedings of the 7th International Conference on Leading Edge Manufacturing in 21st Century, pp.35-38.   35 - 38   2013年

     詳細を見る

  • Fundamental study on micro-deburring by large-area EB irradiation

    Akira Okada, Hajime Yonehara, Yasuhiro Okamoto

    FIRST CIRP CONFERENCE ON BIOMANUFACTURING   5 ( 5 )   19 - 24   2013年

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    In a large-area electron beam (EB) irradiation method developed recently, high energy EB can be obtained without focusing the beam. Then the large-area EB of 60mm in diameter with uniform energy distribution can be used for instant melting of metal surface. The previous studies clarified that the surface smoothing of metal mold made of steel, cemented carbide and ceramics can be performed efficiently. Also this method can be applied to the surface finishing of biomaterials, such as stainless steel and titanium alloy. In this method, the sharp edge is rounded to about half hundred microns in radius under relatively high energy density conditions, since the material removal remarkably progresses there due to the electron concentration and heat accumulation at the edge. In this study, the possibility of micro deburring was investigated by using the preferential edge removal effect in the large-area EB irradiation. Experimental results showed that the micro-deburring was possible by large-area EB irradiation, and the burr height decreased with increasing the energy density of EB and the number of irradiation. The burr of about 10 mu m generated in EDM could be removed completely. Furthermore, micro-burrs at the edge of several small holes could be removed at once. (C) 2013 The Authors. Published by Elsevier B. V.

    DOI: 10.1016/j.procir.2013.01.004

    Web of Science

    researchmap

  • Fundamental Study on Sputter Deposition of Ceramic Film by Large-area EB Irradiation

    Shuhei Misumi, Akira Okada, Yasuhiro Okamoto

    Procedia CIRP, No.6, pp.487-492   ( 6 )   487 - 492   2013年

  • Study on Releasability of Molded Resin from EDM Finished Surface with Metal Powder Mixed Fluid

    Akira Okada, Ryoji Kitada, Shuhei Iwasaki, Yasuhiro Okamoto

    Proceedings of 28th Annual Meeting of the American Society for Precision Engineering   2013年

     詳細を見る

  • Fundamental Study on Multi-Wire EDM Slicing of SiC by Wire Electrode with Track-shaped Section

    Atsushi Kimura, Yasuhiro Okamoto, Akira Okada, Jun Ohya, Toshiyuki Yamauchi

    Procedia CIRP, No.6, pp.233-238.   ( 6 )   233 - 238   2013年

  • Influence of Weld Bead Geometry on Thermal Deformation in Laser Micro-welding

    Satoshi Matsuoka, Yasuhiro Okamoto, Akira Okada

    Procedia CIRP, No.6, pp.493-498   ( 6 )   493 - 498   2013年

  • Singulation of Semiconductor Package by Superposition of Pulsed Fiber Laser and Green YAG Laser

    Yasuhiro Okamoto, Kento Shirasaya, Ryoji Kitada, Akira Okada

    Proceedings of 32nd International Congress on Applications of Lasers & Electro-Optics 2013   2013年

     詳細を見る

  • Precise Prediction of Shape Change at Convex Corner by Large-area EB Irradiation

    Koki KOYAMA, Akira OKADA, Yasuhiro OKAMOTO, Koji TABUCHI

    Proceedings of the 7th International Conference on Leading Edge Manufacturing in 21st Century, pp.358-365   358 - 365   2013年

     詳細を見る

  • Study on Movement of Thin Tungsten Wire Electrode during Fine Wire EDM

    Naoki WATANABE, Akira OKADA, Yasuhiro OKAMOTO

    Proceedings of the 7th International Conference on Leading Edge Manufacturing in 21st Century, pp.369-372   369 - 372   2013年

     詳細を見る

  • Investigation of Phenomenon in Removal Processing of TCO Film by ns Pulsed Fiber Laser

    Takehito Yokoyama, Yasuhiro Okamoto, Shin-ichi Nakashiba, Tomokazu Sakagawa, Akira Okada

    Proceedings of 5th International Conference on Asian Society for Precision Engineering and Nanotechnology,   2013年

     詳細を見る

  • Numerical Study on Wire Deflection by Jet Flushing in Wire EDM

    Kazuki Kuriyama, Akira Okada, Yasuhiro Okamoto

    Proceedings of 5th International Conference on Asian Society for Precision Engineering and Nanotechnology,   2013年

     詳細を見る

  • Novel Micro-welding of Silicon and Glass by Ultrashort Pulsed Laser

    Yasuhiro Okamoto, Isamu Miyamoto, Jorma Vihinen, Akira Okada

    Proceedings of 8th International Conference on Processing and Manufacturing of Advanced Materials   2013年

  • Influence of Surrounding Gas Type and Pressure Condition on Micro-drilling Characteristics of Silicon Carbide by Harmonices of Nd:YAG Laser

    Yasuhiro Okamoto, Shin Urushibata, Akira Okada, Shin-ich Nakashiba Tomokazu Sakagawa

    Proc. of 31st International Congress on Applications of Lasers & Electro-Optics 2012, pp.1269-1276   1269 - 1276   2012年

     詳細を見る

  • THERMAL DEFORMATION IN MICRO-WELDING OF THIN STAINLESS STEEL SHEET BY SINGLE-MODE FIBER LASER

    Yasuhiro Okamoto, Satoshi Matsuoka, Mohd Idris Shah Ismail, Akira Okada

    PROGRESS OF MACHINING TECHNOLOGY   199 - 202   2012年

     詳細を見る

    記述言語:英語   出版者・発行元:JAPAN SOC PRECISION ENGINEERING-JSPE  

    In this study, the thermal deformation of thin stainless steel sheet in laser micro-welding were experimentally and numerically investigated. The welding deformation was experimentally evaluated using a single-mode CW fiber laser with a high-speed scanning system. The numerical simulation was developed to calculate the temperature, stress and deformation fields. It was clarified that the laser irradiation condition has a significant effect on the welding mode and stress field. In addition, the thermal deformation was influenced by the weld bead geometry and residual stress distributions, and the final deformation was formed by residual stress and plastic deformation. It was found that the tensile stress was generated around the molten zone and balanced by the compressive stress in the base material.

    Web of Science

    researchmap

  • SURFACE MODIFICATION OF CEMENTED TUNGSTEN CARBIDE WITH NICKEL BINDER BY LARGE-AREA ELECTRON BEAM

    Akira Okada, Shuhei Misumi, Yasuhiro Okamoto

    PROGRESS OF MACHINING TECHNOLOGY   207 - 210   2012年

     詳細を見る

    記述言語:英語   出版者・発行元:JAPAN SOC PRECISION ENGINEERING-JSPE  

    Cemented tungsten carbide with nickel binder is often applied to the metal mold for electronic parts due to its non-magnetic feature. However, it is difficult to use conventional methods applied to metal molds made of steel for the surface finishing or modification of cemented tungsten carbides in some cases. The large-area EB irradiation for conventional cemented tungsten carbide with cobalt binder was studied in our previous papers. In this paper, surface finishing and modification of cemented tungsten carbide with nickel binder were investigated, and the effects of EB conditions on the surface characteristics were discussed. The experimental results indicated that the surface roughness decreased and the surface glossiness increased by the large-area EB irradiation. Also, the water repellency and the releasability of molded resin from the surface could be improved under proper EB conditions.

    Web of Science

    researchmap

  • HIGHT-SPEED OBSERVATION OF WIRE MOVEMENT IN FINE WIRE EDM

    Sho Ichii, Akira Okada, Yasuhiro Okamoto

    PROGRESS OF MACHINING TECHNOLOGY   215 - 218   2012年

     詳細を見る

    記述言語:英語   出版者・発行元:JAPAN SOC PRECISION ENGINEERING-JSPE  

    In the wire EDM using a thin wire electrode, the reduction of wire vibration is important to achieve a high-precision machining, since large amplitude of wire vibration leads to large kerf width, low shape accuracy, rough machined surface and high risk of wire breakage. In this study, the movements of wire electrode are directly observed by using a high-speed video camera in order to clarify the wire vibration in fine wire EDM for thin workpiece. The results shows that the wire vibration amplitude during the process increases with wire running speed and flow rate of jet flushing but decreases with wire tension. Also, the wire behavior during process is almost 1st order string vibration. Furthermore, the wire vibration frequency increases with not only the wire tension but also the discharge pulse frequency.

    Web of Science

    researchmap

  • Micro-welding of Copper Plate by Frequency Doubled Diode Pumped Pulsed Nd:YAG Laser

    Shin-ichi Nakashiba, Yasuhiro Okamoto, Tomokazu, Sakagawa, SunaoTakai, Akira Okada

    Physics Procedia, Vol.39, pp.577-584   ( 39 )   577 - 584   2012年

     詳細を見る

  • Velocity and Angle of Spatter in Fine Laser Processing

    Yasuhiro Okamoto, Hibiki Yamamoto, Akira Okada, Kento Shirasaya, Jari Tapanni Kolehmainen

    Physics Procedia, Vol.39, pp.792-799   ( 39 )   792 - 799   2012年

     詳細を見る

  • Applicability of Reactive Ion Etching to Fabrication of Micro-Prism Array for Dioptrics System

    Ryuto Fujie, Akira Okada, Yoshiyuki Uno

    Proceedings of 10th International Conference on Progress of Machining Technology, pp.227-230.   227 - 230   2012年

     詳細を見る

  • High-performance Micro-welding of Aluminum Alloy by Combination of Pulsed Nd:YAG Laser And Continuous Diode Laser

    Yasuhiro Okamoto, Shinichi Nakashiba, Tomokazu Sakagawa, Akira Okada

    Proceedings of Materials Science & Technology 2012 Conference, pp.332-339   332 - 339   2012年

     詳細を見る

  • Novel Approach for Slicing of Silicon Carbide by Multi-wire EDM using Wire Electrode with Trackshaped Section

    Yasuhiro Okamoto, Atsushi Kimura, Akira Okada, Jun Ohya, Toshiyuki Yamauchi

    Proceedings of American Society for Precision Engineering 2012 Annual Meeting, pp.331-334   331 - 334   2012年

     詳細を見る

  • Investigation on Micro-machining Characteristics and Phenomenon of Semiconductor Materials by Harmonics of Nd:YAG Laser

    Takayuki Hirano, Yasuhiro Okamoto, Akira Okada, Yoshiyuki Uno, Tomokazu Sakagawa, Shin-ichi Nakashiba

    PROCEEDINGS OF PRECISION ENGINEERING AND NANOTECHNOLOGY (ASPEN2011)   516   36 - +   2012年

     詳細を見る

    記述言語:英語   出版者・発行元:TRANS TECH PUBLICATIONS LTD  

    Precision micro-machining without crack and heat affected zones is required in order to use high-performance materials such as silicon and silicon carbide, and it is expected that the higher harmonics of the Nd:YAG laser can perform precision micro-machining due to its high photon energy. However, even by using the harmonics of the Nd:YAG laser, a heat affected zone is inevitable due to the plasma generation. In order to reduce the influence of plasma on the processing results, it is important to understand the generation mechanism of plasma. Therefore, the laser induced plasma in micro-drilling of silicon carbide was observed by a high-speed shutter camera, and the influence of laser wavelength and surrounding conditions on the machining characteristics were experimentally investigated. The removal depth increased with decreasing wavelength and the surrounding gas pressure. The surface integrity was improved by the combination of shorter wavelength and reduced pressure conditions. The behavior of laser induced plasma was different from the wavelength of the laser beam and the surrounding gas pressure. Under atmospheric pressure conditions, the plasma grew greatly and affected the wider surface around the drilled hole with increasing wavelength. Under reduced pressure conditions, there was little difference in plasma size by wavelength, and the affected zone around the drilled hole became relatively smaller. It became clear. that a low surrounding gas pressure and shorter wavelength were important to obtain better surface integrity and highly efficient processing.

    DOI: 10.4028/www.scientific.net/KEM.516.36

    Web of Science

    researchmap

  • Optimization of Nozzle Flushing Method for Smooth Debris Exclusion in Wire EDM

    Takuya Fujimoto, Akira Okada, Yasuhiro OKamoto, Yoshiyuki Uno

    PROCEEDINGS OF PRECISION ENGINEERING AND NANOTECHNOLOGY (ASPEN2011)   516   73 - +   2012年

     詳細を見る

    記述言語:英語   出版者・発行元:TRANS TECH PUBLICATIONS LTD  

    In a wire EDM using a thin wire electrode, better exclusion of debris from the machined kerf is important in order to maintain stable machining performance, since the area of spark generation is along a line and very small. When large amounts of debris stagnate in the gap, secondary discharges possibly occur and these discharges easily concentrate on the same location, which leads to unstable machining performance, wire breakage, low machining rate and a low shape accuracy.
    Conventionally, the exclusion of debris is carried out by jet flushing with an upper and lower nozzle. However, the flow field of machining fluid in the kerf due to the jet flushing and the effect of jet flushing conditions from the nozzles on debris exclusion have not yet been sufficiently examined. This study aims to clarify the flow field in the machined kerf by computational fluid dynamics (CM) and to propose new jet flushing methods for smooth debris exclusion in the wire EDM. The effects of workpiece thickness and machined kerf length on the flow field of working fluid in the kerf under conventional jet flushing conditions are discussed. Then, jet flushing with a tilting nozzle is proposed in order to decrease the debris stagnation area near the wire electrode. As a result, by using the tilting nozzle, removal rate can be improved because of the smooth debris exclusion.

    DOI: 10.4028/www.scientific.net/KEM.516.73

    Web of Science

    researchmap

  • Evaluation of Molten Zone in Micro-welding of Glass by Picosecond Pulsed Laser

    Yasuhiro Okamoto, Isamu Miyamoto, Kristian Cvecek, Akira Okada, Kenta Takahashi, Michael Schmidt

    Proceedings of the 13th International Symposium on Laser Precision Microfabrication (LPM2012), On-line, #12-63   2012年

     詳細を見る

  • Effect of lasma Nitriding on Cutting Performance of Staninless Steel Cutlery

    Tsukasa Tamaoki, Akira Okada, Kensuke Uemura, Yoshiyuki Uno

    Proc. Of 12th International Conference of euspen, Vol.2, pp.266-270   ( 2 )   266 - 270   2012年

     詳細を見る

  • Singulation of Sapphire Substrate with High Aspect Ration Internal Modification by Sub-nanosecond Pulsed Fiber Laser

    Yasuhiro Okamoto, Kenta Takahashi, Akira Okada

    Proc. of 31st International Congress on Applications of Lasers & Electro-Optics 2012, pp.813-819   813 - 819   2012年

     詳細を見る

  • Evaluation of Damaged Region at the Groove Edge of TCO Filim in Pulsed Fiber Laser Processing

    Yasuhiro Okamoto, Naoya Tkahashi, Shin-ichi Nakashiba, Tomokazu Sakagawa, Akira Okada

    Proc. of 31st International Congress on Applications of Lasers & Electro-Optics 2012, pp.860-865   860 - 865   2012年

     詳細を見る

  • Micro-welding of high thermal conductive material aluminum-graphite composite by pulsed Nd:YAG laser

    Mohd Idris Shah Ismail, Yasuhiro Okamoto, Akira Okada, Yoshiyuki Uno, Muhaizad Mukhtar

    Proceedings of the 12th International Symposium on Laser Precision Microfabrication (LPM2011), On-line, #11-056   2011年

     詳細を見る

  • Clarification of Surface Layer Temperature in EB Polishing by Unsteady Heat Conduction Analysis

    Tomohiro Fujita, Akira Okada, Yasuhiro Okamoto, Yoshiyuki Uno

    Proceedings of International Conference on Leading Edge Manufacturing in 21st Centur, in CD-ROM   2011年

     詳細を見る

  • Welding Characteristics of Aluminum Alloy by Pulsed Nd:YAG Laser with Pre- and Post-irradiation of Superposed Continuous Diode Laser

    Shin-ichi Nakashiba, Yasuhiro Okamoto, Tomokazu Sakagawa, Kazuhiro Miura, Akira Okada, Yoshiyuki Uno, Kataoka Corpora

    Proceedings of 28th International Congress on Applications of Lasers & Electro-Optics 2011, pp.825-832   825 - 832   2011年

     詳細を見る

  • Effect of Continuous Diode Laser on Crack Generation in Pulsed Nd:YAG Laser Welding of Aluminum Alloy

    Kazuya Miura, Yasuhiro Okamoto, Shin-ichi Nakashiba, Tomokazu Sakagawa, Akira Okada, Yoshiyuki Uno, Kataoka Corpora

    Proceedings of International Conference on Leading Edge Manufacturing in 21st Century, in CD-ROM   2011年

     詳細を見る

  • Effects of Laser Wavelength and Intensity Distribution on Removal Characteristics of TCO Film

    Naoya Takahashi, Yasuhiro Okamoto, Shin-ichi Nakashiba, Tomokazu Sakagawa, Akira Okada, Yoshiyuki Uno, Kataoka Corpora

    Proceedings of International Conference on Leading Edge Manufacturing in 21st Centur, in CD-ROM   2011年

     詳細を見る

  • High-quality Dicing of Semiconductor Package by Superposition of Pulsed Fiber Laser and SHG:YAG Laser

    Hibiki Yamamoto, Yasuhiro Okamoto, Muhamad Fahmi, bin Mohd Noor, Ryouji Kitada, Akira Okada

    Proceedings of International Conference on Leading Edge Manufacturing in 21st Centur, in CD-ROM   2011年

     詳細を見る

  • Influence of Carbon Fiber Direction on EDM Characteristics of CFRP

    Sho Ichii, Akira Okada, Yasuhiro Okamoto, Yoshiyuki Uno

    Proceedings of International Conference on Leading Edge Manufacturing in 21st Centur, in CD-ROM   2011年

     詳細を見る

  • Improvement of Razor Blade Surface Integrity by Plasma Nitriding

    Tsukasa Tamaoki, Kensuke Uemura, Akira Okada, Yoshiyuki Uno(Kai, ustries Co, Ltd, Nagata SeikiCo

    Proceedings of International Conference on Leading Edge Manufacturing in 21st Centur, in CD-ROM   2011年

     詳細を見る

  • EDM Characteristics of Carbon Fiber Reinforced Plastic

    Hai Wang, Sameh Habib, Akira Okada, Yoshiyuki Uno

    PROCEEDINGS OF THE 16TH INTERNATIONAL SYMPOSIUM ON ELECTROMACHINING, 2010   65 - 68   2010年

     詳細を見る

    記述言語:英語   出版者・発行元:SHANGHAI JIAO TONG UNIV PRESS  

    Carbon fiber reinforced plastic (CFRP) is a very strong and light composite material, and it has many applications in aerospace and automotive fields. However conventional mechanical machining methods, such as cutting and grinding have some problems; delaminating, splintering, burrs of machined surface and short tool life. Electrical discharge machining (EDM) is an effective alternative 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 discharge peak current and pulse duration.

    Web of Science

    researchmap

  • CFD Analysis of Jet Flushing Effect on Debris Exclusion in Wire EDM

    Akira OKADA, Takuya FUJIMOTO, Yoshiyuki UNO

    Proc. of the 21st International Conference on Computer-Aided Production Engineering, (CAPE2010) Paper No. 007, CD-Rom.   2010年

     詳細を見る

  • Surface Finishing of Cemented Carbide by Large-area EB Irradiation

    Hongge Guo, Ryoji Kitada, Akira Okada, Yoshiyuki Uno

    PROCEEDINGS OF THE 16TH INTERNATIONAL SYMPOSIUM ON ELECTROMACHINING, 2010   451 - 454   2010年

     詳細を見る

    記述言語:英語   出版者・発行元:SHANGHAI JIAO TONG UNIV PRESS  

    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 paper, a new surface finishing by large-area electron beam (EB) irradiation is proposed, and the possibility of surface smoothing and surface modification was discussed. The experimental results clarified that high-efficient surface smoothing was possible under the proper EB conditions. The repellency and the releasability of molded resin could be improved by large-area EB irradiation.

    Web of Science

    researchmap

  • Unconventional Methods of Cutting of Bone and Tissue

    J. A. McGeough, A. Okada

    PROCEEDINGS OF THE 16TH INTERNATIONAL SYMPOSIUM ON ELECTROMACHINING, 2010   457 - 461   2010年

     詳細を見る

    記述言語:英語   出版者・発行元:SHANGHAI JIAO TONG UNIV PRESS  

    Unconventional methods of cutting based on ultrasonics, laser, and water jet mechanisms that might be used in orthopaedic surgery are discussed. Their advantages include no or little contact with bone or tissue that is to be cut, the application of less mechanical force compared to traditional techniques, and reduction in localised heat effect in the region undergoing surgical cutting. Their limitations and merits are identified.

    Web of Science

    researchmap

  • Increase in Corrosion Resistance and Water Repellency of Metal Mold Surface by EB Polishing

    Akira OKADA, Yoshiyuki UNO, Kensuke UEMURA

    Proc. of the 25th Annual Meeting of the American Society for Precision Engineering, 301-304   301 - 304   2010年

     詳細を見る

  • Study on Separation Force of Molded Resin from EDMed Surface

    Hirohiko HIOKI, Ryoji KITADA, Akira OKADA, Yoshiyuki UNO

    Proc. of the 5th International Conference on Leading Edge Manufacturing in 21st Century, pp.815-818.   815 - 818   2009年

     詳細を見る

  • Fundamental Study on Releasability of Resin from EDMed Surface

    Ryoji KITADA, Akira OKADA, Yoshiyuki UNO, Yu, YANG, Hirohiko HIOKI

    Proc. of the 9th International conference of Euspen, Vol.1, pp.117-121.   ( 1 )   117 - 121   2009年

     詳細を見る

  • Investigation on Multi-wire EDM Slicing Method for Polycrystalline Silicon Ingot

    Hirokazu TAKAHASHI, Yasuhiro OKAMOTA, Yoshiyuki UNO, Akira OKADA, Yoshihiro ABE, Shiro TAKATA

    Proc. of the 3rd International Conference on ASPEN, 1C15   2009年

     詳細を見る

  • Evaluation of Spark Location Distribution in Wire EDM by High-speed Observation

    Masanori NAKAZAWA, Akira OKADA, Toshiyuki YAMAUCHI, Yoshiyuki UNO

    Proc. of the 5th International Conference on Leading Edge Manufacturing in 21st Century, pp.841-844.   841 - 844   2009年

     詳細を見る

  • Improvement of Surface Characteristics of Cemeted Carbide by Large-area Electron Beam Irradiation

    Ryoji KITADA, Akira OKADA, Yoshiyuki UNO

    Proc. of the 3rd International Conference on ASPEN, 1P2-8   2009年

     詳細を見る

  • Addition of Surface Functions to Orthopedic Surgical Tools and Jigsby Large-area Electron Beam Irradiation

    Hiroaki WATANABE, Akira OKADA, Yoshiyuki UNO, Kunihiko FUJIWARA, Kenji DOI

    Proc. of the 5th International Conference on Leading Edge Manufacturing in 21st Century, pp.797-800.   797 - 800   2009年

     詳細を見る

  • Improvement of Surface Characteristics of Metal Mold by EB polishing

    Haruhisa BAMBA, Akira OKADA, Yoshiyuki UNO, Yuji KANEKO, Itaru MATSUMOTO

    Proc. of the 5th International Conference on Leading Edge Manufacturing in 21st Century, pp.801-804.   801 - 804   2009年

     詳細を見る

  • Development of Multi-wire EDM Slicing Mehod for Silicon Ingot

    Y.Okamoto, Y.Uno, A.Okada, S.Ohshita, T.Hirano, S.Takata

    Proc.of the 23th American Society for Precision Engineering Annual Meeting, pp530-533.   530 - 533   2008年

     詳細を見る

  • Effect of Electrostatic Cleaning of Dielectric Working Fluid on Electrical Discharge Machining Characteristics

    Akira OKADA, Yoshiyuki UNO, Hironori KIMURA, Seiji IWASAKI

    Proc. of 10th International conference of Euspen, pp.222-225.   222 - 225   2008年

     詳細を見る

  • Surface Finishing of Stainless Steels for Orthopedic Surgical Tools by Large-are Electron Beam Irradiation, (2008) CIRPAnnals Vol.57, No.1, pp.223-226.

    Akira OKADA, Yoshiyuki UNO, Joseph. A. McGEOUGH, Kunihiko FUJIWARA, Kenji DOI, Kensuke UEMURA, Sadao SANO

    CIRP Annals Vol.57, No.1 , pp.223-226   157 ( 1 )   223 - 226   2008年

     詳細を見る

  • A new polishing method of metal mold with large-area electron beam irradiation

    Y. Uno, A. Okada, K. Uemura, P. Raharjo, S. Sano, Z. Yu, S. Mishima

    JOURNAL OF MATERIALS PROCESSING TECHNOLOGY   187   77 - 80   2007年6月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE SA  

    A new polishing method by large-area electron beam (EB) irradiation is proposed in this study. In the large-area EB irradiation equipment used here, an EB with high energy density is irradiated without focusing the beam. An EB irradiation in a few microseconds with a maximum diameter of 60 mm can be used for melting metal surface instantly. The experimental results made it clear that the surface roughness decreases from 6 mu mRz to less than 1 mu mRz in a just few minutes under a proper machining condition. The corrosion resistance of metal mold surface also could be greatly improved by large-area EB irradiation. Furthermore it is clarified that even the surface roughness of tilting surface close to 90 degrees could be well improved. Therefore, large-area EB irradiation method has a high possibility to become a high-efficiency polishing method of metal mold. (c) 2007 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jmatprotec.2006.11.080

    Web of Science

    researchmap

  • Radio Frequency Electrodischarge Machining of Silicon Wafers

    David McMillan, Joseph McGeough, Brian Flynn, Akira Okada

    The 20th International Conference on Computer-Aided Production Engineering, 167-171.   167 - 171   2007年

     詳細を見る

  • New Surface Modification Method of Bio-titanium Alloy by EB Polishing

    Atsuo IIO, Akira OKADA, Yoshiyuki UNO, Kunihiko FUJIWARA, Kenji DOI

    Proc. of the 4th International Conference on Leading Edge Manufacturing in 21st Century, pp.557-560   557 - 560   2007年

     詳細を見る

  • Multi-wire Slicing Method for Silicon Ingot with Electrical Discharge Machining

    Satoru OHSHITA, Yoshiyuki UNO, Akira OKADA, Yasuhiro OKAMOTO, Tameyoshi HIRANO, Shiro TAKATA

    Proc. of Asian Electrical Machining Symposium '07, E21, pp.126-129   126 - 129   2007年

     詳細を見る

  • Unconventional Method of Cutting for Orthopaedic Surgery

    Joseph McGeough, Akira OKADA

    Keynote adress The 20th International Conference on Computer-Aided Production Engineering, 167-171.   167 - 171   2007年

     詳細を見る

  • RF Cutting of Non and Semiconducting Materials

    D.M.Macmillan, B.W. Flynn, J. McGeough, A. Okada

    CIRP Annuals 2007 - Manufacturing Technology, 56/2   2007年

     詳細を見る

  • Advantage of Flange Type Electrode in Deep-Hole EDM

    Ryuichi YASUDA, Akira OKADA, Yoshiyuki UNO

    Proc. of the 4th International Conference on Leading Edge Manufacturing in 21st Century, pp.529-532   529 - 532   2007年

     詳細を見る

  • Effect of Surface Quality of Brass Coating Wire on Wire EDM Characteristics

    Kimihiko ARIZONO, Toshiyuki YAMAUCHI, Akira OKADA, Yoshiyuki UNO

    Proc. of the 4th International Conference on Leading Edge Manufacturing in 21st Century, pp.533-536   533 - 536   2007年

     詳細を見る

  • High efficiency EB polishing of metal mold

    Akira Okada, Yoshiyuki Uno, Yoshiaki Daichi, Sadao Sano

    PROCEEDINGS OF THE 15TH INTERNATIONAL SYMPOSIUM ON ELECTROMACHINING   409 - 414   2007年

     詳細を見る

    記述言語:英語   出版者・発行元:UNIV NEBRASKA-LINCOLN  

    A new polishing method by large-area electron beam (EB polishing) is proposed. In the EB polishing, an EB with high energy density is irradiated without focusing the beam. An EB with a maximum diameter of 60 mm can be used for melting metal surface instantly. The experimental results made it clear that the surface roughness decreased from 6 mu m Rz to less than 1 mu m in just a few minutes under a proper condition. In addition, even the tilting surface could be polished very well. Furthermore, the corrosion resistance of metal surface also could be greatly improved.

    Web of Science

    researchmap

  • Newly developed CuW electrode for high performance EDM

    Shingo Oue, Akira Okada, Yoshiyuki Uno, Takayuki Shoji, Takahiro Fukushima, Osamu Terada

    Progress of Machining Technology, Proceedings   273 - 276   2006年

     詳細を見る

    記述言語:英語   出版者・発行元:JAPAN SOC PRECISION ENGINEERING-JSPE  

    This paper introduces a newly developed CuW electrode for high performance electrical discharge machining (EDM). Conventional CuW electrode used widely for high precision EDM is generally made by melting method, and the mixture ratio of Cu and W is restricted within narrow limits. On the other hand, it can be changed extensively in the case of a new CuW electrode made by powder sintering method. In order to obtain the higher metal removal rate with smaller electrode wear rate, the optimum mixture ratio of Cu and W was investigated. Experimental results show that the EDM characteristics such as, metal removal rate, electrode wear rate and the surface finish for metal mold steel greatly depend on the mixture ratio of CuW electrode. The electrode wear rate could be reduced by using the new CuW electrode with proper mixture ratios, compared with the conventional one, since workpiece material adhered to the electrode end surface during machining and prevented the electrode from wearing with high temperature. Also, better machining stability and better surface finish could be attained under proper mixture ratios of Cu and W Therefore, the new CuW electrode made by powder sintering method has high possibility for higher performance EDM.

    Web of Science

    researchmap

  • A Newly Developed Polishing Method by Large-area Electron Beam Irradiation

    Yoshiyuki UNO, Akira OKADA, Kensuke UEMURA, Purwadi RAHARJO

    Proceedings of 6th Euspen International Conference, Vol2,132-135.   ( 2 )   132 - 135   2006年

     詳細を見る

  • Unconventional Cutting Technologies in Orthopaedic Surgery

    Joseph. A. McGEOUGH, Akira. OKADA, David. MacMILLAN, Brian. FLYNN

    Keynote adress International Conference on Manufacturing Science and Technology 2006, 9-12.   ( 9月2日 )   2006年

     詳細を見る

  • High-efficiency finishing process for metal mold by large-area electron beam irradiation

    Y Uno, A Okada, K Uemura, P Raharjo, T Furukawa, K Karato

    PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY   29 ( 4 )   449 - 455   2005年10月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE INC  

    A new finishing process for metal molds by large-area electron beam (EB) irradiation is proposed in this study. In the large-area EB irradiation equipment used here, an EB with high-energy density is irradiated without focusing the beam, and so the EB with a maximum diameter of 60mm can be used for melting or evaporating metal surface instantly. Experimental results show that the surface roughness decreases from 6 mu mRz to less than 1 mu mRz in just a few minutes under proper machining conditions. The corrosion resistance of metal mold surface also could be greatly improved by large-area EB irradiation. Furthermore, the surface roughness of tilting surface close to 90 degrees could be well improved. Therefore, large-area EB irradiation method has a possibility to become a high-efficiency finishing process for metal molds. (c) 2005 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.precisioneng.2004.12.005

    Web of Science

    CiNii Article

    researchmap

  • High-efficiency finishing process for metal mold by large-area electron beam irradiation

    Y Uno, A Okada, K Uemura, P Raharjo, T Furukawa, K Karato

    PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY   29 ( 4 )   449 - 455   2005年10月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE INC  

    A new finishing process for metal molds by large-area electron beam (EB) irradiation is proposed in this study. In the large-area EB irradiation equipment used here, an EB with high-energy density is irradiated without focusing the beam, and so the EB with a maximum diameter of 60mm can be used for melting or evaporating metal surface instantly. Experimental results show that the surface roughness decreases from 6 mu mRz to less than 1 mu mRz in just a few minutes under proper machining conditions. The corrosion resistance of metal mold surface also could be greatly improved by large-area EB irradiation. Furthermore, the surface roughness of tilting surface close to 90 degrees could be well improved. Therefore, large-area EB irradiation method has a possibility to become a high-efficiency finishing process for metal molds. (c) 2005 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.precisioneng.2004.12.005

    Web of Science

    CiNii Article

    researchmap

  • 寒天培地を利用した金属のバイオマシニング

    先端加工学会誌   23 ( 1 )   13 - 18   2005年

     詳細を見る

  • A New Surface Modification Method of Metal Moldby Large-area Electron Beam Irradiation

    Akira OKADA, Yoshiyuki UNO, Keita NISHINA, Kensuke UEMURA, Purwadi?RAHARJO, Sadao SANO, Yu ZHANBO

    Proceedings of the 3rd International Conference on Leading Edge Manufacturing in 21st Century, pp.739-744   739 - 744   2005年

     詳細を見る

  • Unconventional cutting technologies in orthopaedic surgery

    JA McGeough, A Okada

    AMST '05: Advanced Manufacturing Systems and Technology, Proceedings   ( 486 )   87 - 97   2005年

     詳細を見る

    記述言語:英語   出版者・発行元:SPRINGER-VERLAG WIEN  

    In this paper, unconventional methods of cutting based on ultrasonics, laser, and water jet mechanisms that might be used in orthopaedic surgery are discussed. Their advantages include no or little contact with bone,or tissue that is to be cut, the application of much less mechanical force compared to traditional techniques, and reduction in localised heat effect in the region undergoing surgical cutting. A critical analysis is performed to identify their limitations and merits.

    Web of Science

    researchmap

  • Fundamental Study on Coating Wire Electrode for High Performance WEDM

    Masato. MORITA, Toshiyuki. YAMAUCHI, Akira. OKADA, Yoshiyuki. UNO, Toshiaki. SHIMIZU

    Proceedings of the 3rd International Conference on Leading Edge Manufacturing in 21st Century, pp.779-782   779 - 782   2005年

     詳細を見る

  • Fundamental Study on Multi-wire EDM Slicing Method for Monocrystalline Silicon Ingot-Effects of Supply Method of Working Fluid and Wire Speed on Machining Characteristics-

    Yoshiyuki UNO, Akira OKADA, Yasuhiro OKAMOTO, Katsutomo Suzuki, Satoshi HIROTA, Tameyoshi HIRANO, Shiro TAKATA, Kzuhiko ISHIKAWA

    Proceedings of the 3rd International Conference on Leading Edge Manufacturing in 21st Century, pp.783-786   783 - 786   2005年

     詳細を見る

  • Fundamental Study on Radiofrequency Machining of Metals

    Akira OKADA, Joseph, A. McGEOUGH, David MacMILLAN, dinburgh University

    Proceedings of the 19th International Conference on Computer Aided Production Engineering, (CD-ROM)   2005年

     詳細を見る

  • Surface Modification for Orthopaedic Titanium Alloy by Wide-area Electron Beam

    Akira OKADA, Yoshiyuki UNO, Kensuke UEMURA, Purwadi RAHARJO, Nagata Seiki Co

    Proceedings of the 19th International Conference on Computer Aided Production Engineering, (CD-ROM)   2005年

     詳細を見る

  • Biomachining of Metal Using Agar Culture Medium

    Journal of the Japan Society of Advanced Production Technology   23 ( 1 )   13 - 18   2005年

     詳細を見る

  • High efficient surface finishing of bio-titanium alloy by large-area electron beam irradiation

    A Okada, Y Uno, N Yabushita, K Uemura, P Raharjo

    JOURNAL OF MATERIALS PROCESSING TECHNOLOGY   149 ( 1-3 )   506 - 511   2004年6月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE SA  

    A new surface finishing process for bio-titanium alloy products by large-area electron beam (LAEB) irradiation is proposed. In the LAEB irradiation equipment, high energy density EB can be irradiated without concentrating the beam. Therefore, LAEB with a maximum diameter of 60 mm can be used for instantaneous melting or evaporating metal surface. Experimental results made it clear that the surface roughness becomes smaller with increasing energy density of beam. Under a proper irradiating condition, the surface roughness of titanium alloy machined with end mill decreases from 10 to 0.8 mum R-z in a few minutes. Moreover, the corrosion resistance can be greatly improved. (C) 2004 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jmatprotec.2004.02.017

    Web of Science

    researchmap

  • High efficient surface finishing of bio-titanium alloy by large-area electron beam irradiation

    A Okada, Y Uno, N Yabushita, K Uemura, P Raharjo

    JOURNAL OF MATERIALS PROCESSING TECHNOLOGY   149 ( 1-3 )   506 - 511   2004年6月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE SA  

    A new surface finishing process for bio-titanium alloy products by large-area electron beam (LAEB) irradiation is proposed. In the LAEB irradiation equipment, high energy density EB can be irradiated without concentrating the beam. Therefore, LAEB with a maximum diameter of 60 mm can be used for instantaneous melting or evaporating metal surface. Experimental results made it clear that the surface roughness becomes smaller with increasing energy density of beam. Under a proper irradiating condition, the surface roughness of titanium alloy machined with end mill decreases from 10 to 0.8 mum R-z in a few minutes. Moreover, the corrosion resistance can be greatly improved. (C) 2004 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jmatprotec.2004.02.017

    Web of Science

    researchmap

  • High efficient surface finishing of bio-titanium alloy by large-area electron beam irradiation

    A Okada, Y Uno, N Yabushita, K Uemura, P Raharjo

    JOURNAL OF MATERIALS PROCESSING TECHNOLOGY   149 ( 1-3 )   506 - 511   2004年6月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE SA  

    A new surface finishing process for bio-titanium alloy products by large-area electron beam (LAEB) irradiation is proposed. In the LAEB irradiation equipment, high energy density EB can be irradiated without concentrating the beam. Therefore, LAEB with a maximum diameter of 60 mm can be used for instantaneous melting or evaporating metal surface. Experimental results made it clear that the surface roughness becomes smaller with increasing energy density of beam. Under a proper irradiating condition, the surface roughness of titanium alloy machined with end mill decreases from 10 to 0.8 mum R-z in a few minutes. Moreover, the corrosion resistance can be greatly improved. (C) 2004 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jmatprotec.2004.02.017

    Web of Science

    researchmap

  • Effect of Debris Distribution on Wall Concavity in Deep Hole EDM

    International Journal of the Japan Society of Mechanical Machining, Series C,   47 ( 2 )   553 - 559   2004年

  • Effect of Debris Accumulation on Machining Speed in EDM

    International Journal of Electrical Machining   No.9, 9-14   2004年

     詳細を見る

  • Effect of Debris Accumulation on Machining Speed in EDM

    International Journal of Electrical Machining   ( 9 )   9 - 14   2004年

     詳細を見る

  • 大面積パルス電子ビーム照射によるチタン合金製生体部品の高能率表面仕上げ

    岡田 晃, 宇野 義幸, 佐藤 公亮, 八野田 健, 植村 賢介

    電気加工学会誌   38 ( 89 )   27 - 34   2004年

  • Effect of Debris Distribution on Wall Concavity in Deep Hole EDM

    Serkan CETIN, Akira OKADA, Yoshiyuki UNO

    International Journal of the Japan Society of Mechanical Machining, Series C,   47 ( 2 )   553 - 559   2004年

  • Electrode jump motion in linear motor equipped die-sinking EDM

    S Cetin, A Okada, Y Uno

    JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME   125 ( 4 )   809 - 815   2003年11月

     詳細を見る

    記述言語:英語   出版者・発行元:ASME-AMER SOC MECHANICAL ENG  

    The effects of electrode jump parameters on machining speed and depth were experimentally investigated in linear motor equipped electrical discharge machining. A new definition named "Machining speed breakpoint" is introduced, theoretically calculated from a proposed electrode jump and debris exclusion model, and compared with the experimental results. Additionally, an algorithm is developed to calculate the accumulation of debris in machining gap. The algorithm showed that the debris concentration in gap rises suddenly before the machining speed break point.

    DOI: 10.1115/1.1615793

    Web of Science

    CiNii Article

    researchmap

  • Electrode jump motion in linear motor equipped die-sinking EDM

    S Cetin, A Okada, Y Uno

    JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME   125 ( 4 )   809 - 815   2003年11月

     詳細を見る

    記述言語:英語   出版者・発行元:ASME-AMER SOC MECHANICAL ENG  

    The effects of electrode jump parameters on machining speed and depth were experimentally investigated in linear motor equipped electrical discharge machining. A new definition named "Machining speed breakpoint" is introduced, theoretically calculated from a proposed electrode jump and debris exclusion model, and compared with the experimental results. Additionally, an algorithm is developed to calculate the accumulation of debris in machining gap. The algorithm showed that the debris concentration in gap rises suddenly before the machining speed break point.

    DOI: 10.1115/1.1615793

    Web of Science

    CiNii Article

    researchmap

  • 「文鎮」から「ジャイロスコープ」へ進化した「機械工作実習」

    宇野 義幸, 岡田 晃, 岡本 康寛

    工学教育   51 ( 5 )   58 - 61   2003年

  • 大面積電子ビームによる金型加工面の高能率仕上げに関する研究

    精密工学会誌   69 ( 10 )   1464 - 1468   2003年

     詳細を見る

  • 大面積電子ビームによる金型加工面の高能率仕上げに関する研究(第1報)

    岡田 晃, 宇野 義幸, 藪下 法康, 植村 賢介

    精密工学会誌   69 ( 10 )   1464 - 1468   2003年

  • Fundamental Study on Friction Characteristics of EDMed Surface

    Journal of The Japan Society of Electrical Machining Engineers   37 ( 85 )   24 - 31   2003年

     詳細を見る

  • 放電加工面の摩擦特性に関する基礎的研究

    岡田晃, 宇野義幸, 中島洋平

    電気加工学会誌   37 ( 85 )   24 - 31   2003年

  • 放電加工面の摩擦特性に関する基礎的研究

    岡田晃, 宇野義幸, 中島洋平

    電気加工学会誌   37 ( 85 )   24 - 31   2003年

  • High Efficiency Surface Finishing of Metal Mold by Large-area Electron Beam Irradiation

    Journa of the Japan Society for Precision Engineering   69 ( 10 )   1464 - 1468   2003年

  • Investigation of Dielectric Flow during Electrode Jump in EDM Gap

    Serkan. CETIN, Akira OKADA, Yoshiyuki UNO, Yoshifumi KAWAZOE

    Proc. of the International Conference on Leading Edge Manufacturing in 21st Century, pp939-942   939 - 942   2003年

     詳細を見る

  • Study on Surface Finishing of Metal Mold by Large-area Electron Beam Irradiation

    Akira OKADA, Yoshiyuki UNO, Noriyasu YABUSHITA, Kensuke UEMURA, Purwadi RAHARJO

    Proc. of the International Conference on Leading Edge Manufacturing in 21st Century, pp1023-1028   1023 - 1028   2003年

     詳細を見る

  • Surface Modification of EDMed Surface by Wide-area Electron Beam Irradiation

    Akira OKADA, Yoshiyuki UNO, Kensuke UEMURA, Purwadi RAHARJO, Toshihiko FURUKAWA

    Proc.of the 18th American Society for Precision Engineering Annual Meeting, pp172-175.   CD-ROM   172 - 175   2003年

     詳細を見る

  • バイオマシニングにおける加工メカニズムの解明および加工速度向上に関する試み

    岡田 晃, 宇野 義幸, 久野 智之, 金枝 敏明

    精密工学誌   68 ( 12 )   1585 - 1589   2002年

  • ホーニング用水溶性切削油を用いた電解加工による小径円筒内面仕上げ

    電気加工学会誌   36 ( 81 )   2002年

     詳細を見る

  • EDM characteristics of metal impregnated graphite electrode

    A Okada, Y Uno, T Takagi, M Yokotani

    PROGRESS OF MACHINING TECHNOLOGY   402 - 407   2002年

     詳細を見る

    記述言語:英語   出版者・発行元:AVIATION INDUSTRY PRESS  

    In EDM process, graphite is widely used as an electrode. However, in EDM with graphite electrode under finish condition, the electrode wear is larger, and it is difficult to form thin and fine shapes by mechanical machining, because of its high brittleness. Therefore, graphite electrode cannot be applied to EDM with fine complicated shapes. In order to achieve high precision EDM with graphite electrode, graphite electrodes impregnated with metal were newly developed in this study. That is, copper or aluminum was impregnated into pore parts of graphite-grains-sintered electrode for improving its strength and heat conductivity. Next, the EDM characteristics were investigated. Experimental results indicated that the machined surface roughness in the case for metal impregnated graphite electrode became much smaller, compared with normal graphite electrode, while there was no difference in the electrode wear and removal rate among them. Additionally, the reasons for smaller machined surface roughness were analyzed, and it was made clear that small surface roughness obtained by using metal impregnated electrodes was caused by small roughness of electrode end surface and the effect of metal powder mixed machining fluid.

    Web of Science

    researchmap

  • Internal Surface Finishing of Small Hole by Electrochemical Processing Using Soluble Fluid for Honing

    Yoshiyuki UNO, Akira OKADA, Satoshi NAKA, Shoichi YAMAMOTO, Yutaka SAKANE

    Journal of the Japan Society of Electrical Machining Engineers   36 ( 81 )   31 - 38   2002年

     詳細を見る

  • A New Micro EDM Technique of Monocrystalline Silicon using Fine Trianglar Electrode

    Proc. of the 13th International Symposium for Electromachining   2001年

     詳細を見る

  • 放電加工技術の最近の動向

    機械の研究   53 ( 6 )   2001年

     詳細を見る

  • A New Micro EDM Technique of Monocrystalline Silicon Using Fine Triangular Section Electrode

    Akira OKADA, Yoshiyuki UNO, Yasuhiro OKAMOTO, Hiroshi NAKASHIMA, Hidetou TANAKA, Saburo OKADA

    Proc.of the13th International Symposium for ElectroMachining, pp.381-389.   381 - 389   2001年

     詳細を見る

  • High performance slicing method of monocrystalline silicon ingot by wire EDM

    Y Uno, A Okada, Y Okamoto, T Hirano

    INITIATIVES OF PRECISION ENGINEERING AT THE BEGINNING OF A MILLENNIUM   219 - 223   2001年

     詳細を見る

    記述言語:英語   出版者・発行元:SPRINGER  

    In this study, the slicing of silicon ingot by wire EDM is discussed, and the machining properties are experimentally investigated. Also, the accuracy of sliced wafer and the contamination on the machined surface are evaluated. Experimental results made it clear that the accuracy of wafer by this slicing method is almost the same as that by the conventional methods, and even higher slicing speeds are possible when multi type wire EDM slicing can be realized. Additionally, the contamination due to the adhesion and diffusion of wire electrode material into the sliced surface can be reduced by wire EDM under the condition of low current and long discharge duration. Therefore, wire EDM has a high potential as a new slicing method for monocrystalline silicon ingot.

    Web of Science

    researchmap

  • バクテリアの金属加工への応用

    高温学会誌   27 ( 1 )   2001年

     詳細を見る

  • Surface Modification of EDMed Surface with Powder Mixed Fluid

    Yoshiyuki UNO, Akira OKADA, Serkan. CETIN

    Proc.of the 2nd International Conference and Exhibition on Design and Production of Dies and Molds(CD-ROM)   2001年

     詳細を見る

  • High Performance Slicing Method of Monocryastalline Silicon Ingot by Wire EDM

    Proc. of 10th International Conference on Precision Engineering   2001年

     詳細を見る

  • 単結晶シリコンインゴットの放電スライシング法(共著)

    岡田 晃, 宇野 義幸, 岡本 康寛, 伊藤 久, 平野 爲義

    電気加工学会誌   34 ( 75 )   14 - 21   2000年

  • A New Micro EDM Technique of Monocrystalline Silicon Using Fine Triangular Section Electrode(共著)

    Proceedings of the 13th International Symposium for Electro machining   381 - 389   2000年

     詳細を見る

  • Surface Modification of EDMed Surface with Powder Mixed Fluid(共著)

    2nd International Conference and Exhibition on Design and Production of Dies and Molds(CD-Rom)   2000年

     詳細を見る

  • High Performance Slicing Method of Monocrystalline Silicon Ingot by Wire EDM(共著)

    Initiatines of Precision Engineering at the Beginning of a Millennium   219 - 223   2000年

     詳細を見る

  • A New Slicing Method of Monocrystalline Silicon lngot by Wire EDM

    Akira OKADA, Yoshiyuki UNO, Yasuhiro OKAMOTO, Hisashi ITOH, Tameyoshi HIRANO

    Journal of the Japan Society of Electrical Machining Engineers   34 ( 75 )   14 - 21   2000年

     詳細を見る

  • Wire EDM slicing of monocrystalline silicon ingot

    Y Uno, A Okada, Y Okamoto, T Hirano

    PROCEEDINGS OF THE FIFTEENTH ANNUAL MEETING OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING   172 - 175   2000年

     詳細を見る

    記述言語:英語   出版者・発行元:AMER SOC PRECISION ENGINEERING  

    Web of Science

    researchmap

  • Energy Distribution in Electrical Discharge Machining with Graphite Electrode(共著)

    Memoirs of the Faculty of Engineering,Okayama University   34 ( 1・219-26 )   2000年

     詳細を見る

  • Formation of Hard Layer by EDM with Carbon Powder Mixed Fluid(共著)

    Progress of Machining Technology   464 - 469   2000年

     詳細を見る

  • Wire EDM Slicing of Monocrystalline Silicon Ingot(共著)

    Proceedings of the 15th American Society for Precision Engineering Annual Meeting   172 - 175   2000年

     詳細を見る

  • Formation of Hard Layer by EDM with Carbon Powder Mixed Fluid

    Akira OKADA, Yoshiyuki UNO, Kazuhisa HIRAO, Takashi TAKAGI

    Progress of Machining Technology (Proc. of the 5th International Conference on Progress of Machining Technology) pp.464-469.   464 - 469   2000年

     詳細を見る

  • Internal Surface Finishing of Small Hole by Electrochemical Machining after Honing(共著)

    Proceedings of the 3rd International Conference on Abtasive Technology   275 - 282   1999年

     詳細を見る

  • Surface Modification by EDM with Carbon Power Mixed Fluid Using Titanium Electrode

    Journal of the Japan Society of Electrical Machining Engineers   33 ( 73 )   31 - 37   1999年

     詳細を見る

  • チタン電極を用いた炭素粉末混入放電加工による表面改質(共著)

    岡田 晃, 宇野 義幸, 平尾 和久, 高木 俊

    電気加工学会誌   33 ( 73 )   31 - 37   1999年

  • A New Micro EDM Technique for Fine Complicated Hole with Triangular Section Electrode

    Akira OKADA, Yasuhiro OKAMOTO, Yoshiyuki UNO, Koji WATANABE, Hidetou TANAKA, Saburo OKADA

    Journal of the Japan Society for Precision Engineering   65 ( 1 )   155 - 159   1999年

     詳細を見る

  • 三角形断面電極による微細複雑形状放電加工法(共著)

    岡田 晃, 岡本 康寛, 宇野 義幸, 渡部 晃次, 田中 英登, 岡田 三郎

    精密工学会誌   65 ( 1 )   155 - 159   1999年

  • High Efficiency Electrical Discharge Machining with Graphite Electrode

    Journal of the Japan Society of Electrical Machining Engineers   33 ( 72 )   37 - 45   1999年

     詳細を見る

  • グラファイト電極を用いた高効率放電加工法に関する研究(共著)

    電気加工学会誌   33 ( 72 )   37 - 45   1999年

     詳細を見る

  • Internal surface finishing of small hole by electrochemical machining after honing

    A Okada, Y Uno, T Furukawa, S Naka, S Yamamoto, A Kinoshita

    ABRASIVE TECHNOLOGY: CURRENT DEVELOPMENT AND APPLICATIONS I   275 - 282   1999年

     詳細を見る

    記述言語:英語   出版者・発行元:WORLD SCIENTIFIC PUBL CO PTE LTD  

    A new internal surface finishing method of small holes by ECM using a honing machine was proposed, and the machining properties were experimentally investigated. Experimental analysis made it clear that a suitable electrolytic current density condition existed for improving the surface roughness, and the generation of passive film on the machined surface could be prevented by mixing inverse electrolytic current into the normal one. Then, it was pointed out that the surface roughness could be reduced to approximately a half because only protruding parts were selectively. removed under a proper condition. This method has the possibility to be a high efficiency internal surface finishing operation of small holes after honing.

    Web of Science

    researchmap

  • Surface Modification by EDM with Nickel Powder Mixed Fluid(共著)

    International Journal of Electrical Machining   ( 4 )   47 - 52   1999年

     詳細を見る

  • A new slicing method of monocrystalline silicon ingot by wire EDM

    A Okada, Y Uno, Y Okamoto

    12TH INTERNATIONAL SYMPOSIUM FOR ELECTROMACHINING (ISEM)   1405   417 - 424   1998年

     詳細を見る

    記述言語:英語   出版者・発行元:V D I-V D E - VERLAG GMBH  

    This paper deals with a new slicing method of monocrystalline silicon ingot by wire EDM. In manufacturing process of silicon wafer, ID blade and multi wire saw have conventionally been used for slicing of ingot. However, it is difficult to apply these methods for larger ingot such as 12(R) or 16 " expected to be used in the near future, since there are some problems in efficiency, accuracy, slurry treatment, contamination and so on. Therefore, a new slicing method is required as soon as possible. In this study, the possibility of slicing by WEDM was proposed and the machining properties as well as surface integrity were experimentally investigated. It was made clear that WEDM had the possibility as a new slicing method and that contamination due to adhesion and diffusion of wire electrode material to machined surface could be reduced by using the reversed polarity WEDM.

    Web of Science

    researchmap

  • A new micro EDM technique for fine complicated hole with triangular section electrode

    Y Uno, A Okada, Y Okamoto, K Watanabe, S Okada, Y Yamada

    PROCEEDINGS OF THE THIRTEENTH ANNUAL MEETING OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING   239 - 242   1998年

     詳細を見る

    記述言語:英語   出版者・発行元:AMER SOC PRECISION ENGINEERING  

    Web of Science

    researchmap

  • A new micro EDM technique for fine complicated hole with triangular section electrode

    Y Uno, A Okada, Y Okamoto, K Watanabe, S Okada, Y Yamada

    PROCEEDINGS OF THE THIRTEENTH ANNUAL MEETING OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING   239 - 242   1998年

     詳細を見る

    記述言語:英語   出版者・発行元:AMER SOC PRECISION ENGINEERING  

    Web of Science

    researchmap

  • EDM Characteristics of CVD-Carbon Electrode(共著)

    International Journal of Electrical Machining   ( 3 )   19 - 24   1998年

     詳細を見る

  • Study on Electrical Discharge Machining Characteristics of Coated Electrodes(共著)

    Memoirs of the Faculty of Enggineering. , Okayama University   32 ( 1・2 )   1 - 6   1998年

     詳細を見る

  • A New Slicing Method of Monocrystalline Silicon Ingot by Wire EDM(共著)

    Proceedings. of the 12th International Symposium for ElectroMachining   417 - 424   1998年

     詳細を見る

  • 単結晶シリコンの放電加工(共著)

    精密工学会誌   64 ( 12 )   1739 - 1742   1998年

     詳細を見る

  • Surface Integrity in EDM of Aluminum Bronze with Nickel Powder Mixed Fluid

    Yoshiyuki UNO, Akira OKADA, Tomohiko YAMADA, Yasuhiro HAYASHI, Yoshiaki TABUCHI

    Journal of the Japan Society of Electrical Mochining Engineers   32 ( 70 )   24 - 31   1998年

     詳細を見る

  • ニッケル粉未混入放電加工におけるアルミニウム青銅の表面特性(共著)

    宇野 義幸, 岡田 晃, 山田 知彦, 林 泰弘, 田渕 義晨

    電気加工学会誌   32 ( 70 )   24 - 31   1998年

  • Electrical Discharge Machining of Monocrystalline Silicon

    Journal of the Japan Society for Precision Engineering   64 ( 12 )   1739 - 1742   1998年

     詳細を見る

  • High efficiency fine boring of single crystalline silicon ingot by electrical discharge machining

    Y Uno, A Okada, Y Okamoto, Y Yamada

    PROCEEDINGS OF THE TWELFTH ANNUAL MEETING OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING   525 - 528   1997年

     詳細を見る

    記述言語:英語   出版者・発行元:AMER SOC PRECISION ENGINEERING  

    Web of Science

    researchmap

  • 単結晶シリコンインゴットの高能率貫通穴放電加工に関する研究(共著)

    宇野 義幸, 岡田 晃, 岡本 康寛

    精密工学会誌   63 ( 12 )   1725 - 1729   1997年

  • High Efficiency Fine Boring of Single Crystalline Silicon Ingot by Electrical Discharge Machining(共著)

    Proceedings of the 12th American Society for Precision Engineering Annual Meeting   525 - 528   1997年

     詳細を見る

  • Fundamental Study on Electrical Discharge Machining of Single Crystalline Silicon

    Journal of the Japan Society for Precision Engineering   63 ( 10 )   1459 - 1463   1997年

     詳細を見る

  • 単結晶シリコンの放電加工に関する基礎的研究(共著)

    宇野義幸, 岡田晃, 中西洋人, 岡本康寛

    精密工学会誌   63 ( 10 )   1459 - 1463   1997年

  • High Efficiency Penetration Boring of Single Crystalline Silicon Ingot by EDM

    Yoshiyuki UNO, Akira OKADA, Yasuhiro OKAMOTO

    Journal of th Japan Society for Precision Engineering   63 ( 12 )   1725 - 1729   1997年

     詳細を見る

  • EDM Characteristics of CVD-Carbon Electrode

    Yoshiyuki UNO, Akira OKADA, Hirohito NAKANISHI, Changning GUO, Yasuhiro OKAMOTO, Takashi TAKAGI

    Journal of the Japan Society of Electrical-Machining Engineers   30 ( 65 )   1 - 8   1996年

     詳細を見る

  • Electrical Discharge Machining Performance of Aluminium Alloy for Plastic Injection Molding

    Yoshiyuki UNO, Akira OKADA, Takeshi MORITA, Takashi TAKAGI

    Journal of the Japan Society of Electrical-Machining Engineers   30 ( 63 )   11 - 21   1996年

     詳細を見る

  • Newly Developed CVD-Carbon Electrode for Higher Performance EDM

    Yoshiyuki UNO, Akira OKADA, Changning GUO, Takashi TAKAGI

    Progress of Cutting and Grinding, Vol.3 (Proc.of the 3rd International Conference on Progress of Cutting and Grinding), pp.386-391   ( 3 )   386 - 391   1996年

     詳細を見る

  • Electrical Discharge Machining of a Groove with a Rotating Disk Electrode(共著)

    International Journal of Electrical Machining   ( 1 )   13 - 20   1996年

     詳細を見る

  • Newly Developed CVD-Carbon Electrode for Higher Performance EDM(共著)

    Progress of Cutting and Grinding   3,386-391   1996年

     詳細を見る

  • CVD炭素電極の放電加工特性(共著)

    宇野 義幸, 岡田 晃, 中西 洋人, 郭 常寧, 岡本 康寛, 高木 俊

    電気加工学会誌   30 ( 65 )   1 - 8   1996年

     詳細を見る

  • Study on Fine Boring of Single Crystalline Silicon by EDM

    Yoshiyuki UNO, Shin-ichiro KUBOTA, Seiichi YOKOMIZO, Akira OKADA, Hideto TANAKA

    Journal of the Japan Society of Electrical-Machining Engineers   30 ( 65 )   9 - 16   1996年

     詳細を見る

  • 単結晶シリコンの微細穴放電加工に関する研究(共著)

    宇野 義幸, 窪田 真一郎, 横溝 精一, 岡田 晃, 田中 英登

    電気加工学会誌   30 ( 65 )   9 - 16   1996年

  • プラスチック金型用アルミニウム合金の放電加工特性(共著)

    宇野 義幸, 岡田 晃, 森田 剛, 高木 俊

    電気加工学会誌   30 ( 63 )   11 - 21   1996年

  • 粉未混入放電加工における表面生成機構の研究(共著)

    宇野 義幸, 岡田 晃, 亀川 出

    電気加工学会誌   29 ( 62 )   9 - 17   1995年

  • The Effect of High Speed Polarity Changing on EDM Performance (共著)

    Proceedings of 11th International Symposium for Electro Machining   241 - 249   1995年

     詳細を見る

  • Surface Generation Mechanism in Electrical Discharge Machining with Silicon Powder Mixed Fluid

    Akira OKADA, Yoshiyuki UNO

    Proc.of International Conference on Precision Engineering'95, pp.537-540.   537 - 540   1995年

     詳細を見る

  • Surface Generation Mechanism in Electrical Discharge Machining with Silicon Powder Mixed Fluid(共著)

    Proceedings of International Conference on Precision Engineering '95   537 - 540   1995年

     詳細を見る

  • The effect of high speed polarity changing on EDM performance

    Y Uno, A Okada, M Itoh

    INTERNATIONAL SYMPOSIUM FOR ELECTROMACHINING, PROCEEDINGS   29 ( 60 )   241 - 249   1995年

     詳細を見る

    記述言語:英語   出版者・発行元:PRESSES POLYTECHNIQUES ET UNIVERSITAIRES ROMANDES  

    DOI: 10.2526/jseme.29.22

    Web of Science

    researchmap

  • 高速極性切替放電加工に関する研究(共著)

    宇野 義幸, 岡田 晃, 伊藤 満, 高木 俊

    電気加工学会誌   29 ( 60 )   22 - 30   1995年

  • Surface Generation Mechanism in EDM with Silicon Powder Mixed Fluid

    Yoshiyuki UNO, Akira OKADA, Izuru KAMEKAWA

    Journal of the Japan Society of Electrical-Machining Engineers   29 ( 62 )   9 - 17   1995年

     詳細を見る

  • A New Biological Machining Technique with Chemolithotrophic Bacteria

    Yoshiyuki UNO, Toshiaki KANEEDA, Seiichi YOKOMIZO, Akira OKADA, Takahiko YOSHIMURA

    Proc.of the 9th American Society for Precision Engineering Annual Meeting, pp.457-460.   457 - 460   1994年

     詳細を見る

  • 回転円板電極による放電溝加工の研究(共著)

    宇野 義幸, 岡田 晃, 伊藤 満, 山口 毅

    電気加工学会誌   28 ( 58 )   24 - 37   1994年

  • A New Biological Technique with Chemolichotrophic Bacteria (共著)

    Proceedings of the 9th Annual Meeting of the American Society for Precision Engineering   457 - 460   1994年

     詳細を見る

  • Study on Electrical Discharge Machining of Copper Alloy MS46

    Yoshiyuki UNO, Akira OKADA, Takashi TAKAGI, Yoshiaki TABUCHI

    Journal of the Japan Society of Electrical Machining Engineers   28 ( 57 )   1 - 10   1994年

     詳細を見る

  • 銅合金(MS46)の放電加工特性(共著)

    宇野 義幸, 岡田 晃, 高木 俊, 田渕 義晨

    電気加工学会誌   28 ( 57 )   1 - 10   1994年

     詳細を見る

  • Electrical Discharge Machining of Groove with a Rotating Disk Electrode

    Yoshiyuki UNO, Akira OKADA, Mitsuru ITOH, Tsuyoshi YAMAGUCHI

    Journal of the Japan Society of Electrical Machining Engineers   28 ( 58 )   24 - 37   1994年

     詳細を見る

  • チタン合金の高能率放電加工に関する研究(共著)

    宇野義幸, 岡田晃, 中島利勝, 高木俊

    電気加工学会誌   27 ( 56 )   1 - 11   1993年

  • High Efficiency Electrical Discharge Machining of Titanium Alloy (共著)

    Proceedings of 8th Annual Meeting of the American Society for Precision Engineering   313 - 316   1993年

     詳細を見る

  • High Efficient Electrical Discharge Machining of Titanium Alloy

    Yoshiyuki UNO, Akira OKADA

    Proc.of the 8th American Society for Precision Engineering Annual Meeting, pp.313-316.   27 ( 56 )   313 - 316   1993年

     詳細を見る

▼全件表示

Works(作品等)

  • Development of High-Efficiency and High-Accuracy Slicing Method for Monocrystalline Silicon Ingot Using Electrical Discharge

    2000年

     詳細を見る

  • 放電を利用した単結晶シリコンインゴットの高能率・高精度スライシング法の開発

    2000年

     詳細を見る

受賞

  • 型技術協会 奨励賞

    2018年  

    岡田 晃

     詳細を見る

  • 電気加工学会論文賞

    2018年  

    岡田 晃

     詳細を見る

  • 17th International Machine Tool Engineers’ Conf. (IMEC), Excellent Poster Award

    2016年  

    岡田 晃

     詳細を見る

  • 精密工学会高城賞

    2015年  

    岡田 晃

     詳細を見る

  • 型技術協会 奨励賞

    2014年  

    岡田 晃

     詳細を見る

  • 21th Int. Conf. on Computer Aided Production Engineering, First Paper Prize

    2010年  

    岡田 晃

     詳細を見る

  • 9th Int. Conf. on Progress of Machining Technology, JSPE, Best Presentation Award

    2009年  

    岡田 晃

     詳細を見る

  • 電気加工学会論文賞

    2008年  

    岡田 晃

     詳細を見る

  • JSME International Conference LEM21 Best Paper Award

    2007年  

    岡田 晃

     詳細を見る

  • Japan Society of Mechanical Engineers International Conference LEM21, Outstanding Young Researcher Award

    2005年  

     詳細を見る

  • 先端加工学会論文賞

    2005年  

     詳細を見る

    受賞国:日本国

    researchmap

  • JSME LEM21 The Outstanding Young Researcher Award

    2005年  

     詳細を見る

  • Japan Society of Advanced Production Technology, Paper Award

    2005年  

     詳細を見る

  • Japan Society of Die and Mold Technology, Technology Award

    2004年  

     詳細を見る

  • 型技術協会技術賞

    2004年  

     詳細を見る

    受賞国:日本国

    researchmap

  • 電気加工学会全国大会賞

    2003年  

     詳細を見る

    受賞国:日本国

    researchmap

  • 電気加工学会全国大会賞

    2002年  

     詳細を見る

    受賞国:日本国

    researchmap

  • 電気加工学会論文賞

    2001年  

     詳細を見る

    受賞国:日本国

    researchmap

  • Japan Society of Electrical Machining Engineers,Paper Award

    2000年  

     詳細を見る

  • 岡山工学振興会科学技術賞

    1998年  

     詳細を見る

    受賞国:日本国

    researchmap

  • Japan Society of Electrical Machining Engineers,Paper Award

    1997年  

     詳細を見る

  • 電気加工学会論文賞

    1997年  

     詳細を見る

    受賞国:日本国

    researchmap

  • Japan Society of Electrical Machining Engineers,Paper Award

    1994年  

     詳細を見る

  • 電気加工学会論文賞

    1994年  

     詳細を見る

    受賞国:日本国

    researchmap

  • 電気加工学会全国大会賞

    1992年  

     詳細を見る

    受賞国:日本国

    researchmap

▼全件表示

共同研究・競争的資金等の研究

  • Surface Finishing by Wide-area Electron Beam Irradiation

    2001年

      詳細を見る

    資金種別:競争的資金

    researchmap

  • 大面積電子ビーム照射による高能率表面処理法の開発

    2001年

      詳細を見る

    資金種別:競争的資金

    researchmap

  • 電解加工による小径穴の内面仕上げ

    1996年

      詳細を見る

    資金種別:競争的資金

    researchmap

  • シリコンのマルチ放電スライシング法の開発

    1996年

      詳細を見る

    資金種別:競争的資金

    researchmap

  • 放電加工の高性能化に関する研究

    1994年

      詳細を見る

    資金種別:競争的資金

    researchmap

  • バイオマシニングに関する基礎的研究

    1994年

      詳細を見る

    資金種別:競争的資金

    researchmap

  • Internal Surface Finishing by Electrochemical Machining

      詳細を見る

    資金種別:競争的資金

    researchmap

  • Fundamental Study on Biomachining

      詳細を見る

    資金種別:競争的資金

    researchmap

  • Study on High Performance Electrical Discharge Machining

      詳細を見る

    資金種別:競争的資金

    researchmap

  • Study on High Performance Electrical Discharge Machining

      詳細を見る

    資金種別:競争的資金

    researchmap

▼全件表示

 

担当授業科目

  • 専門英語 (2021年度) 第1学期  - 火1,火2,金3,金4

  • 専門英語 (2021年度) 第1学期  - 火1,火2,金3,金4

  • 機械システム工学演習1 (2021年度) 前期  - その他

  • 機械システム工学演習2 (2021年度) 後期  - その他

  • 機械システム系入門 (2021年度) 第1学期  - 金1~2

  • 機械システム系概論 (2021年度) 特別  - その他

  • 機械システム系概論 (2021年度) 特別  - その他

  • 機械工作実習 (2021年度) 1~4学期  - 水5,水6,水7,水8

  • 機械工作実習 (2021年度) 1~4学期  - [第1学期]木5,木6,木7,木8, [第2学期]木5,木6,木7,木8, [第3学期]水5,水6,水7,水8, [第4学期]水5,水6,水7,水8

  • 機械工作実習Ⅱ (2021年度) 3・4学期  - 水5,水6,水7,水8

  • 機械工作実習I (2021年度) 1・2学期  - 水5,水6,水7,水8

  • 機械工作実習I (2021年度) 1・2学期  - 木5,木6,木7,木8

  • 機械工作法 (2021年度) 第1学期  - 月5,月6,木3,木4

  • 機械工作法 (2021年度) 第1学期  - 月5,月6,木3,木4

  • 特殊加工学 (2021年度) 第2学期  - 水3,水4,金3,金4

  • 特殊加工学演習 (2021年度) 通年  - その他

  • 特殊精密加工論 (2021年度) 後期  - 月1,月2,水1,水2

  • 産業技術実践 (2021年度) 後期  - 水5,水6,水7,水8

  • 高エネルギービーム加工学 (2021年度) 後期  - その他

  • 専門英語 (2020年度) 第1学期  - 火1,火2,金3,金4

  • 専門英語 (2020年度) 第1学期  - 火1,火2,金3,金4

  • 機械システム工学概論 (2020年度) 前期  - 金1,金2

  • 機械システム工学演習1 (2020年度) 前期  - その他

  • 機械システム工学演習2 (2020年度) 後期  - その他

  • 機械工作実習 (2020年度) 1~4学期  - 水5,水6,水7,水8

  • 機械工作実習 (2020年度) 1~4学期  - 木5,木6,木7,木8

  • 機械工作実習Ⅱ (2020年度) 3・4学期  - 水5,水6,水7,水8

  • 機械工作実習I (2020年度) 1・2学期  - 水5,水6,水7,水8

  • 機械工作実習I (2020年度) 1・2学期  - 木5,木6,木7,木8

  • 機械工作法 (2020年度) 第1学期  - 月5,月6,木3,木4

  • 機械工作法 (2020年度) 第1学期  - 月5,月6,木3,木4

  • 特殊加工学 (2020年度) 第2学期  - 水3,水4,金3,金4

  • 特殊加工学 (2020年度) 第2学期  - 水3,水4,金3,金4

  • 特殊加工学演習 (2020年度) 前期

  • 特殊加工学演習 (2020年度) 通年  - その他

  • 特殊精密加工論 (2020年度) 後期  - 月1,月2,水1,水2

  • 産業技術実践 (2020年度) 後期  - 水5,水6,水7,水8

  • 高エネルギービーム加工学 (2020年度) 後期  - その他

▼全件表示