研究者詳細 - 岡田　晃

放電加工による内部空間形状の創成に関する基礎的研究査読

その他リンク： https://link.springer.com/article/10.1007/s00170-023-11857-5/fulltext.html

Investigation on high-quality laser welding of copper and aluminum 招待査読国際誌

Yasuhiro Okamoto, Yuki Yamada, Akihiro Ochi, Akira Okada, Takeshi Yamamura, Katsutoshi Nagasaki, Kazunobu Mameno, Norio Nishi

International Conference on Processing & Manufacturing of Advanced Materials (THERMEC2023) 2023年7月

Study on Joint Characteristics in Laser Butt Welding of AMed and Wrought Ti6Al4V Plates 査読国際共著国際誌

Yasuhiro Okamoto, Togo Shinonaga, Yoshito Takemoto, Akira Okada, Akihiro Ochi, Ryuya Kishimoto, Sisa Pityana, Nana Arthur, Peter Omoniyi, Rasheedat Mahamood, Martin Maina, Esther Akinlabi

Welding in the World 67 ( 5 ) 1997 - 2005 2023年6月

Micro-welding of Glass by Multiple Spot of Picosecond Pulsed Laser with Spatial Light Modulator 査読国際誌

Ryo Takashima, Yasuhiro Okamoto, Akira Okada

Technical Digest of the 24th International Symposium on Laser Precision Microfabrication – LPM2023 R3-S15-3 2023年6月

Optimization of Dielectric Oil Resistivity on Wire EDM Characteristics 査読国際誌

Shixian Liu, Akira Okada, Tomohiko Kitamura

Proceeding of the 16th international conference of the european society for precision engineering and nanotechnology 23 2023年6月

Investigation on Laser Welding of Copper and Aluminum by Irradiation from Copper-side 招待査読国際誌

Yasuhiro Okamoto, Yuki Yamada, Akihiro Ochi, Takeshi Yamamura, Katsutoshi Nagasaki, Kazunobu Mameno, Norio Nishi, Akira Okada

Proceedings of Laser in Manufacturing 2023 176 2023年6月

Fundamental Study on High-quality Micro-shape Fabrication on Monocrystalline Diamond by Nanosecond Pulsed Laser 国際誌

Kaichi Kawata, Yasuhiro Okamoto, Akira Okada

Technical Digest of the 24th International Symposium on Laser Precision Microfabrication – LPM2023 R3-S11-2 2023年6月

Effect of scanning speed on molten metal behaviour under angled irradiation with a continuous-wave laser 査読国際誌

Tatsuhiko Sakai, Yasuhiro Okamoto, Nozomi Taura, Riku Saito, Akira Okada

Journal of Materials Processing Technology 313 117866 - 117866 2023年4月

Fundamental Study on Electrode Performance of Diamond Composite for EDM 査読国際誌

Shun-ichiro Tsuetani, Koki Yoshida, Akira Okada

International Journal of Electrical Machining ( 28 ) 26 - 31 2023年3月

Improvement in Mechanical Properties of AMed Al-Si Alloy Surface by Large-area EB Irradiation 査読国際誌

Togo Shinonaga, Hiroya Kobayashi, Atsuhi Yamaguchi, Akira Okada

International Journal of Electrical Machining ( 28 ) 20 - 25 2023年3月

Mo-rich layer formation on maraging steel and surface modification by large-area electron beam irradiation 査読国際誌

Togo Shinonaga, Shun Watanabe, Atsushi Yamaguchi, Akira Okada

Journal of Materials Processing Technology 311 117813 - 117813 2023年1月

Investigation on Mechanism of Edge Shape Change in Large-area Electron Beam Irradiation by Thermo-fluid Analysis 査読国際誌

Hibiki Tajima, Togo Shinonaga, Akira Okada

Proceedings of 4th International Conference on Machining Materials and Mechanical Technologies IC3MT2022 2022年11月

Influence of dielectric oil resistivity on wire EDM characteristics 査読国際誌

Shixian Liu, Akira Okada, Tomohiko Kitamura

Proceedings of 4th International Conference on Machining Materials and Mechanical Technologies IC3MT2022 2022年11月

Influence of Nozzle Jet Flushing in Wire EDM on Machining Characteristics 査読国際誌

Shogo KIMURA, Shixian LIU, Akira OKADA, Haruya KURIHARA

Proceedings of the 19th International Machine Tool Engineeris' Conference 2 - 3 2022年11月

Improvement in EDM Characteristics for Internal Space Shape Using Revolution Ball Electrode by Servo Control of Rotation Speed 査読国際誌

Kodai Fujieda, Atsushi Yamaguchi, Akira Okada

Proceedings of 19th International Conference on Precision Engineering C216 2022年11月

Influence of Focusing Position on Micro-groove Formation on Metal Surface by High-speed Scanning of Angled CW Laser Irradiation 査読国際誌

Riku Saito, Yasuhiro Okamoto, Akira Okada, Tatsuhiko Sakai

Proceedings of 19th International Conference on Precision Engineering 2022年11月

Fundamental Study on Laser Forming of Carbon Fiber Reinforced Thermoplastic Sheet with Low Surface Damage by Using Pulsed CO2 Laser 査読国際誌

Rina WATANABE, Ryoji KITADA, Yasuhiro OKAMOTO, Akira OKADA, Sena KIZAKI

Proceedings of 19th International Conference on Precision Engineering 2022年11月

Fabrication of High-quality Micro-shape on Monocrystalline Diamond Surface by Nanosecond Pulsed Laser and Acid Cleaning 査読国際誌

Tsubasa Okubo, Yasuhiro Okamoto, Akira Okada

Proceedings of 4th International Conference on Machining Materials and Mechanical Technologies IC3MT2022 2022年11月

Improvement of Anodic Oxide Film Characteristics of Al-Cu Alloy by Large-area Electron Beam 査読国際誌

Ikuya Miyamoto, Togo Shinonaga, Akira Okada

Proceedings of 19th International Conference on Precision Engineering 2022年11月

Influence of surface roughness of die sinking EDM on mold releasability in compression molding of thermosetting phenol resin 査読国際誌

Ryoji Kitada, Qin Wang, Shun-ichiro Tsuetani, Akira Okada

Procedia CIRP 113 238 - 243 2022年10月

Optimization of Dielectric Oil Viscosity for High-precision Wire EDM 査読国際誌

Shixian LIU, Shogo KIMURA, Akira OKADA, Tomohiko KITAMURA

Procedia CIRP 113 244 - 249 2022年10月

Influence of Nozzle Jet Flushing in Wire EDM of Workpiece with Stepped Thickness 査読国際誌

Shogo KIMURA, Hiroki IWAI, Shixian LIU, Akira OKADA, Haruya KURIHARA

Procedia CIRP 113 149 - 154 2022年10月

Study on Smoothing of Hole Wall Surface by Electron Beam Polishing under Control of Magnetic Field 査読国際誌

Togo SHINONAGA, Jiayu LU, Motohiro INOUE, Akira OKADA

Procedia CIRP 113 536 - 540 2022年10月

Synergy Effect of Abrasive Blasting and Large-area EB Irradiation on Surface Finishing of AMed Titanium Alloy 査読国際誌

Hiroya KOBAYASHI, Togo SHINONAGA, Toshiya TSUJI, Akira OKADA

Procedia CIRP 113 318 - 322 2022年10月

Fiber laser cutting of steel materials with twin spot beam-twin spot setting in kerf width direction 査読国際誌

Kota Morimoto, Atsushi Yagi, Naoto Kai, Yasuhiro Okamoto, Akira Okada, Hiroaki Ishiguro, Ryohei Ito, Akihiko Sugiyama, Hiroshi Okawa

Journal of Laser Applications 34 042009-1 - 042009-7 2022年9月

Study on Joint Characteristics in Laser Butt Welding of AMed and Bulk Ti6Al4V Plates 査読国際共著国際誌

Yasuhiro Okamoto, Togo Shinonaga, Yoshito Takemoto, Akira Okada, Akihiro Ochi, Ryuya Kishimoto, Sisa Pityana, Nana Arthur, Peter Omoniyi, Rasheedat Mahamood, Martin Maina, Esther Akinlabi

Proceedings of IIW 2022 International Conference on Welding and Joining 469 - 472 2022年7月

High-quality Micro-shape Fabrication of Monocrystalline Diamond by Nanosecond Pulsed Laser and Acid Cleaning 査読国際誌

Yasuhiro Okamoto, Tsubasa Okubo, Atsushi Kajitani, Akira Okada

International Journal of Extreme Manufacturing 4 25301 2022年3月

Improvement in Corrosion Resistance of Al-Cu Alloy by Large-area Electron Beam Irradiation 査読国際誌

Togo Shinonaga, Shun Watanabe, Akira Okada

International Journal of Electrical Machining 27 22 - 27 2022年3月

Study on Laser Drilling Process of Solid Metal on Its Liquid 査読国際誌

Yasuhiro Okamoto, Nozomi Taura, Akira Okada

International Journal of Electrical Machining 27 35 - 39 2022年3月

Effects of superposition of 532 nm and 1064 nm wavelengths in copper micro-welding by pulsed Nd:YAG laser 査読国際誌

Martin Ruthandi Maina, Yasuhiro Okamoto, Kazuki Hamada, Akira Okada, Shin-ichi Nakashiba, Norio Nishi

Journal of Materials Processing Technology 299 117388 2022年1月

Fundamental Study on Side Surface Smoothing of Hole by Large-area EB Irradiation Method 査読国際誌

Jiayu LU, Togo SHINONAGA, Motohiro INOUE, Akira OKADA

Proceedings of the 10th International Conference on Leading Edge Manufacturing in 21st Century D16 2021年11月

Fundamental Study on Factors of Mold Releasability from Milling Surface in Compression Molding of Thermosetting Phenol Resin 査読国際誌

Ryoji KITADA, Qin WANG, Kazuhiro KAWAGUCHI, Shun-ichiro TSUETANI, Akira OKADA

Proceedings of the 10th International Conference on Leading Edge Manufacturing in 21st Century C08 2021年11月

Investigation on reduction of dross height by analyzing beam intensity distribution in fiber laser cutting 査読国際誌

Naoto Kai, Yasuhiro Okamoto, Akira Okada, Hiroaki Ishiguro, Ryohei Ito, Akihiko Sugiyama, Hiroshi Okawa, Rio Fujita

Journal of Laser Applications 33 ( 4 ) 042008 - 042008 2021年11月

Fundamental Study on Laser Forming Characteristics of Carbon Fiber Reinforced Thermoplastic Sheet 査読国際誌

Ryoji KITADA, Rina WATANABE, Takashi KAWAZOE, Yasuhiro OKAMOTO, Akira OKADA

Proceedings of the 10th International Conference on Leading Edge Manufacturing in 21st Century D26 2021年11月

Fundamental Study on Surface Texturing of Alloy Steel by Ultrashort Pulsed Laser for Control of Water Repellency 査読国際誌

Kentaro MURATA, Togo SHINONAGA, Yasuhiro OKAMOTO, Akira OKADA

Proceedings of the 10th International Conference on Leading Edge Manufacturing in 21st Century D25 2021年11月

Fundamental Investigation of Working fluid Flow Formed by High-speed Wire Running in Multi-wire EDM Slicing 査読国際誌

Shusei TABUCHI, Yasuhiro OKAMOTO, Akira OKADA, Haruya KURIHARA

Proceedings of the 10th International Conference on Leading Edge Manufacturing in 21st Century G08 2021年11月

Direct Observation of Spark Locations in Fine Wire EDM Using High-speed Camera 査読国際誌

Yu MIYAZAKI, Shixian LIU, Akira OKADA

Proceedings of the 10th International Conference on Leading Edge Manufacturing in 21st Century G07 2021年11月

Possibility of Compositionally Graded Surface Formation by Electrical Discharge Machining 査読国際誌

Shun-ichiro TSUETANI, Yuki IKEUCHI, Akira OKADA, Ryoji KITADA

Proceedings of the 10th International Conference on Leading Edge Manufacturing in 21st Century G06 2021年11月

Influence of Working Oil Viscosity on Wire EDM Characteristics 査読国際誌

Shixian LIU, Hiroki IWAI, Akira OKADA

Proceedings of the 10th International Conference on Leading Edge Manufacturing in 21st Century G03 2021年11月

Fundamental Study on Calcination Method of Limestone by Using CW Laser of Near-infrared 査読国際誌

Takafumi MIYAJIMA, Yasuhiro OKAMOTO, Shuji FUJIKI, Masakazu OKA, Shunjirou SHIZUKA, Akira OKADA

Proceedings of the 10th International Conference on Leading Edge Manufacturing in 21st Century D24 2021年11月

Fundamental Study on Laser Micro-welding of Glass by Using Spatial Light Modulator 査読国際誌

Kazuki IHORIYA, Yasuhiro OKAMOTO, Akira OKADA

Proceedings of the 10th International Conference on Leading Edge Manufacturing in 21st Century D22 2021年11月

Surface Smoothing and Surface Modification of Maraging Steel by Large-area EB Irradiation 査読国際誌

Shun WATANABE, Togo SHINONAGA, Atsushi YAMAGUCHI, Akira OKADA

Proceedings of the 10th International Conference on Leading Edge Manufacturing in 21st Century D17 2021年11月

Formation and Its Mechanism of High-speed Micro-grooving on Metal Surface by Angled CW Laser Irradiation 査読国際誌

Nozomi Taura, Akiya Mitsunobu, Tatsuhiko Sakai, Yasuhiro Okamoto, Akira Okada

Journal of Laser Micro/Nanoengineering 16 ( 2 ) 2021年10月

Influence of Free-electron Density Distribution on Mechanical Strength in Micro-welding of Glass by Picosecond Pulsed Laser 査読国際誌

Zhiyong Ouyang, Yasuhiro Okamoto, Kazuki Ihoriya, Akira Okada

Journal of Smart Processing 10 ( 5 ) 294 - 300 2021年9月

Cutting performance evaluation of boron-doped and undoped diamond coatings in drilling of CFRP laminates 査読国際誌

Alexander Soldatov, Akira Okada, Hitoshi Ogawa

Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 095440542110406 - 095440542110406 2021年8月

Formation of Smooth and Flat Area for Monocrystalline Diamond by ns Pulsed Laser 査読国際誌

Yasuhiro Okamoto, Tsubasa Okubo, Atsuya Kajitani, Akira Okada

Proceedings of Laser in Manufacturing 2021 21 - 24 2021年6月

Reliable and strong micro-welding of glass by ultrashort pulsed laser 査読

Yasuhiro Okamoto, Zhiyong Ouyang, Akira Okada

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XXI 11676 116760P-1 - 116760P-7 2021年3月

Development of Cu-Zr Wire Electrode for High-performance Fine Wire EDM 査読国際誌

Shizian Liu, Masato Miyoshi, Akira Okada, Naokuni Muramatsu, Kazuhiko Nomura

International Journal of Electrical Machining ( 26 ) 40 - 45 2021年3月

Surface Profile Variation of Periodic Surface Nanostructures Produced by Ultrashort Pulsed Laser for Enhancement of Cell Orientation 査読国際誌

Togo Shinonaga, Shouno Kinoshita, Yasuhiro Okamoto, Akira Okada

International Journal of Electrical Machining 26 ( 26 ) 54 - 59 2021年3月

Clarification of Temperature Distribution for Metals with Different Thermal Conductivity in Large-area Electron Beam Irradiation 査読国際誌

Shoya Ota, Tsubasa Sakai, Togo Shinonaga, Yasuhiro Okamoto, Akira Okada

Procedia CIRP 95 960 - 965 2021年1月

Highly Efficient Surface Repairing of AMed Metal Parts by Large-area EB Irradiation 査読国際誌

Togo Shinonaga, Taisei Watanabe, Atsushi Yamaguchi, Akira Okada

Procedia CIRP 95 976 - 980 2021年1月

Fundamental Study on Internal Space Forming by EDM 査読国際誌

Yuta Inaba, Shuoxun Li, Atsushi Yamaguchi, Akira Okada

Procedia CIRP 95 215 - 219 2021年1月

Investigation on Surface Smoothing of Mold Material by Pulsed Laser Irradiation of 532 nm 査読国際誌

Kohei Umezu, Takuro Kozaki, Yasuhiro Okamoto, Akira Okada

Procedia CIRP 95 879 - 884 2021年1月

Influence of Nozzle Jet Flushing on Working Fluid Flow and Wire Electrode in Trim-cut WEDM 査読国際誌

Hiroki Iwai, Tomonori Ebisu, Akira Okada, Haruya Kurihara

Procedia CIRP 95 250 - 254 2021年1月

Strength characterization of adhesive joint surface treated by large-area EB irradiation 査読国際誌

Yuya OMIYA, Kenji TOYOTA, Ryota NAKANISHI, Togo SHINONAGA, Tadashi SHIOTA, Akira OKADA, Masahiro FUJII

Journal of Advanced Mechanical Design, Systems, and Manufacturing 15 ( 4 ) JAMDSM0052 - JAMDSM0052 2021年

Fundamental Study on High-speed Micro-grooving of Metal by Angled Irradiation of Single-mode CW Fiber Laser 査読国際誌

Tatsuhiko Sakai, Yasuhiko Okamoto, Chie Katayama, Hirofumi Imai, Akira Okada

Applied Sciences 10 ( 23 ) Jan-33 - Nov-33 2020年12月

高性能微細ワイヤ放電加工実現のための Cu-Zr ワイヤ電極の開発査読

劉世賢, 三好雅人, 岡田晃,村松尚国,野村和弘

電気加工学会誌 54 ( 137 ) 155 - 161 2020年11月

Release Resistance of Compression-molded Thermosetting Resin from EDMed Metal Mold 査読国際誌

Ryoji Kitada, Yuki Ikeuchi, Akira Okada

Proceedings of the 18th International Conference on Precision Engineering (ICPE2020) B-5-4 2020年11月

Study on High-efficiency and High-quality Micro-welding of Copper by Superposition of 532 nm and 1064 nm Lasers 査読国際誌

Shota Kawasaki, Yasuhiro Okamoto, Martin Ruthandi Maina, Akira Okada, Shin -ichi Nakashiba, Norio Nishi

Proceedings of the 18th International Conference on Precision Engineering (ICPE2020) B-6-2 2020年11月

Micro-welding Characteristics of Glass Plates with Gap by Picosecond Pulsed Laser 査読国際誌

Fujiwara Takumi, Zhiyong Ouyang, Yasuhiro Okamoto, Akira Okada

Proceedings of the 18th International Conference on Precision Engineering (ICPE2020) B-6-1 2020年11月

Development of Control Method by Variation Range of Gap Voltage in Multi-wire EDM Slicing with Group Power Supplying 査読国際誌

Tomoya Takegawa, Shusei Tabuchi, Yasuhiro Okamoto, Akira Okada, Haruya Kurihara

Proceedings of the 18th International Conference on Precision Engineering (ICPE2020) B-5-1 2020年11月

Fundamental Study on Micro-edge Filleting by Using Large-area Electron Beam Irradiation Method 査読国際誌

Zehua Zhou, Tsubasa Sakai, Togo Shinonaga, Akira Okada

Proceedings of the 18th International Conference on Precision Engineering (ICPE2020) B-6-4 2020年11月

Fundamental Study on Double-Layered Surface Formation by Electrical Discharge Machining 査読国際誌

Yuki Ikeuchi, Shun-ichiro Tsuetani, Ryoji Kitada, Akira Okada

Proceedings of the 18th International Conference on Precision Engineering (ICPE2020) B-5-5 2020年11月

Fundamental Study on High-Speed Surface Processing of Metal by Angled Irradiation of Single-Mode CW Fiber Laser 査読国際誌

Tatsuhiko Sakai, Chie Katayama, Hirofumi Imai, Yasuhiko Okamoto, Akira Okada

Proceedings of 39th International Congress on Applications of Lasers & Electro-Optics 2020 2020年10月

Fundamental Study on Reduction of Dross in Fiber Laser Cutting of Steel by Shifting Nozzle Axis 査読国際誌

Atsushi Yagi, Seigo Kadonaga, Yasuhiro Okamoto, Hiroaki Ishiguro, Ryohei Ito, Akihiko Sugiyama, Hiroshi Okawa, Rio Fujita, Akira Okada

Proceedings of 39th International Congress on Applications of Lasers & Electro-Optics 2020 2020年10月

Alumina film sputter deposition on mold steel by large-area electron beam irradiation 査読国際誌

Togo Shinonaga, Masashi Takata, Motohiro Inoue, Akira Okada

International Journal of Precision Engineering and Manufacturing-Green Technology s40684-020-00243-1 2020年7月

Evaluation of Mechanical Strength at High Energy Conditions in Micro-joining of Glass by Picosecond Pulsed Laser 査読国際誌

Zhiyong Ouyang, Takumi Fujiwara, Yasuhiro Okamoto, Akira Okada

Technical Digest of the 21st International Symposium on Laser Precision Microfabrication (LPM2020) 2020年6月

ワイヤ放電加工におけるノズルフラッシングがコーナ加工形状に及ぼす影響査読

岩井宏樹, 劉世賢, 蛭子奉紀, 岡田晃, 栗原治弥

精密工学会誌 86 ( 6 ) 480 - 485 2020年6月

因幡勇汰, LI SHUOXUN, 山口篤, 岡田晃

日本機械学会論文集 86 ( 892 ) 20 - 00205 2020年6月

γ相黄銅めっき細線ワイヤを用いた微細ワイヤ放電加工特性の基礎的検討査読

三好雅人, 劉世賢, 岡田晃, 星間昭人, 杭田勝俊

日本機械学会誌論文集 86 ( 892 ) 20 - 00213 2020年6月

Fundamental Investigation on EDM Characteristis of Lanthanum Hexaboride 査読国際誌

Yuki Ikeuchi, Keita Fujii, Akira Okada

International Journal of Electrical Machining ( 25 ) 27 - 32 2020年3月

Effect of Numerical Aperture on Molten Area Characteristics in Micro-joining of Glass by Picosecond Pulsed Laser 査読国際誌

Yasuhiro Okamoto, Zhiyong Ouyang, Takumi Fujiwara, Akira Okada

Welding in the World 64 ( 6 ) 937 - 947 2020年3月

Fundamental study on internal space forming by EDM

Yuta Inaba, Shuoxun Li, Atsushi Yamaguchi, Akira Okada

Procedia CIRP 95 215 - 219 2020年

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：Elsevier B.V.

Machining of internal space shapes inside metal through a small-diameter entrance hole is difficult by current mechanical machining methods. For such shapes, it is necessary to insert a slender cutting tool with bending or curving function from the small hole, and to remove material by the bended or curved tool in a direction different from the tool inserting direction. Since large machining force acts on the tool in mechanical machining methods, it is difficult to maintain the deformed tool attitude, and excessively large machining force may cause the tool failure. On the other hand, electrical discharge machining (EDM) has high flexibility in the electrode shape, since it is non-contact machining method and the machining force is extremely small. Therefore, it is highly expected that internal space machining would be possible by EDM if an optimum electrode structure can be designed and prepared. This study proposes a new internal space machining method by EDM using a revolution ball electrode. This electrode consists of a vertical rotation rod fixed on z-axis of machine head, a tilting rod connecting to the lower end of the rotation rod with a flexible hinge joint, and a copper tungsten ball electrode fixed to the lower end of the tilting rod. After the electrode in straight attitude is inserted into a small-diameter entrance hole, the material removal for internal space is performed, rotating the electrode. A centrifugal force acts on the ball by the electrode rotation, and the tilting angle of tilting rod may be controlled with the rotation speed, since the magnitude of centrifugal force is varied with the rotation speed. In order to confirm the controllability of tilting angle, the variation of tilting angle with the rotation speed was measured by a high-speed camera observation. It was found that the angle was well controlled by the rotation speed, which indicates that the ball can be positioned at any positions with the z coordinate of electrode and the rotating speed, if the tilting rod length is changeable during the process. Next, the EDM characteristics including surface roughness and electrode wear were experimentally investigated using the revolution ball electrode. Furthermore, machining of some axially-symmetric spacial shapes, such as cylindrical shape and spherical one were tried into a zinc alloy workpiece. The machining results show that this method has high possibility to form internal space shapes inside metal.

DOI： 10.1016/j.procir.2020.01.156

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 ―チタン合金の放電加工特性と曲がり穴加工― 査読

Fundamental study on machining of internal space shapes by EDM 査読国際誌

Shuoxun Li, Yuta Inaba, Akira Okada, Atsushi Yamaguchi

Proceedings of 8th International Conference of Asian Society for Precision Engineering and Nanotechnology 13th B22 2019年11月

Fundamental investigation on EDM characteristics of lanthanum hexaboride applied for electron emission parts 査読国際誌

Keita Fujii, Yuta Ikeuchi, Akira Okada

Proceedings of 8th International Conference of Asian Society for Precision Engineering and Nanotechnology B25 2019年11月

Fundamental study on fine wire EDM characteristics using γ-phase brass coated steel wire 査読国際誌

Masato Miyoshi, Akira Okada, Takaaki Enomoto, Yoshiki Natsumeda

Proceedings of 8th International Conference of Asian Society for Precision Engineering and Nanotechnology 86 ( 892 ) B23 - 00213 2019年11月

Investigation on Laser Drilling Process of Solid Metal on Its Liquid and Detection Method of Penetration State 査読国際誌

Chikako Kawasaki, Yasuhiro Okamoto, Nozomi Taura, Tatsuhiko Sakai, Akira Okada

Proceedings of 8th International Conference of Asian Society for Precision Engineering and Nanotechnology B02 2019年11月

Fundamental Investigation on Reduction of Surface Roughness for Mold Material by μs Pulsed Laser of 532 nm 査読国際誌

Takuro Kozaki, Yasuhiro Okamoto, Akira Okada

Proceedings of 8th International Conference of Asian Society for Precision Engineering and Nanotechnology B01 2019年11月

Change of Thickness of Removal and Modifed layers on Workpiece with Different Material Property by Larg-area EB irradiation 査読国際誌

Tsubasa Sakai, Shoya Ota, Togo Shinonaga, Akira Okada

Proceedings of 8th International Conference of Asian Society for Precision Engineering and Nanotechnology B09 2019年11月

Fundamental Study on Surface Damage Repairing of AMed Metal Parts by Large-area Electron Beam Irradiation 査読国際誌

Taisei Watanabe, Togo Shinonaga, Atsushi Yamaguchi, Akira Okada

Proceedings of 8th International Conference of Asian Society for Precision Engineering and Nanotechnology B06 2019年11月

Influence of Surface Temperature Field in Large-area Electron Beam Irradiation on Wear Resistance of Zirconia 査読国際誌

Togo Shinonaga, Tsubasa Sakai, Motohiro Inoue, Akira Okada

Proceedings of 8th International Conference of Asian Society for Precision Engineering and Nanotechnology B08 2019年11月

Influence of Initial Surface State on Shape Change of LIPSS 査読国際誌

Yuki Wada, Togo Shinonaga, Yasuhiro Okamoto, Akira Okada

Proceedings of 8th International Conference of Asian Society for Precision Engineering and Nanotechnology B06 2019年11月

Investigation of Micro-grooving of Metals by High-speed Scanning of CW Laser 査読国際誌

Chie Katayama, Yasuhiro Okamoto, Tatsuhiko Sakai, Seigo Kadonaga, Akira Okada

Proceedings of 8th International Conference of Asian Society for Precision Engineering and Nanotechnology B04 2019年11月

ワイヤ放電加工における加工粉排出向上のためのノズル噴射法の検討査読

蛭子奉紀, 岡田晃, 栗原治弥

日本機械学会論文集 85 ( 880 ) 19 - 224 2019年11月

Effective Supplying Method of Shielding Gas in Vertical-position Laser Welding of Pure Titanium 査読国際共著国際誌

Yasuhiro Okamoto, Kyo Kitagawa, Seigo Kadonaga, Akira Okada, Esther T. Akinlabi, Sisa Pityana

Proceedings of 38th International Congress on Applications of Lasers & Electro-Optics 2019 M2020 2019年10月

Influence of numerical aperture on molten area formation in fusion micro-welding of glass by picosecond pulsed laser 査読国際誌

Z. Ouyang, Y. Okamoto, Y. Ogino, T. Sakagawa, A. Okada

Applied Sciences 9 ( 7 ) 1412-1 - 1412-16 2019年7月

Creation of Smooth and Flat Surface in Micro-machining of Monocrystalline Diamond by Pulsed Laser 査読国際誌

Yasuhiro Okamoto, Takahiro Shimose, Atsuya Kajitani, Akira Okada

Proceedings of Laser in Manufacturing 2019 220 2019年6月

山口篤, 太田浩平, 李碩勛, 岡田晃

精密工学会誌 85 ( 4 ) 359 - 364 2019年4月

Surface Characteristics of Molding Die Treated by Electron Beam Irradiation 査読国際誌

Yoshihito HAGIHARA, Masaaki SANO, Akira OKADA

International Journal of Electrical Machining ( 24 ) 13 - 20 2019年3月

Investigation of Separation Method for Gallium Nitride with Internal Modified Layer by Ultrashort Pulsed Laser 査読国際誌

Yasuhiro Okamoto, Motoki Ota, Akira Okada

International Journal of Electrical Machining 24 ( 24 ) 27 - 32 2019年3月

Study on Improvement of Wear Resistance for Zirconia by Large-area Electron Beam Irradiation 査読国際誌

Togo Shinonaga, Mitsuhiro Kimura, Motohiro Inoue, Akira Okada

International Journal of Electrical Machining ( 24 ) 21 - 26 2019年3月

High surface quality micro machining of monocrystalline diamond by picosecond pulsed laser 査読国際誌

Y. Okamoto, A. Okada, A. Kajitani, T. Shinonaga

CIRP Annals - Manufacturing Technology 68 ( 1 ) 197 - 200 2019年

工作物の磁性が大面積電子ビーム照射における除去厚さおよび改質層厚さに及ぼす影響査読国際誌

酒井翼, 篠永東吾, 岡田晃

日本機械学会論文集(Web) 85 ( 880 ) 19-00227 2019年

Effects of Concave Shape on Absorption Rate and Molten Volume in Micro-welding of Copper by Pulsed Nd:YAG Laser 査読

Kazuki Hamada, Martin Maina, Reiki Inoue, Yasuhiro Okamoto, Akira Okada, Norio Nishi, Shin-ichi Nakashiba, Tomokazu Sakagawa

Proceedings of the 17th International Conference on Precision Engineering (ICPE2018) B-6-2 2018年11月

Improvement of Shape Accuracy in Multi-wire EDM Slicing of Semiconductor Ingot 査読国際誌

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

Proceedings of the 17th International Conference on Precision Engineering (ICPE2018) B-5-18 2018年11月

Influence of Surface State in Micro-Welding of Copper by Nd:YAG Laser 査読

Martin Ruthandi Maina, Yasuhiro Okamoto, Reiki Inoue, Shin-ichi Nakashiba, Akira Okada, Tomokazu Sakagawa

Applied Sciences 8 ( 12 ) Jan-64 - Mar-64 2018年11月

Investigation of Assist Gas Flow to Improve Slope Angle of Kerf in Thick Plate Cutting of Mild Steel by Fiber Laser 査読

Kyo Kitagawa, Yasuhiro Okamoto, Akira Okada, Hiroaki Ishiguro, Akihiko Sugiyama, Hironobu Miyoshi, Ryohei Ito

Proceedings of 37th International Congress on Applications of Lasers & Electro-Optics 2018 M1305 2018年10月

Improvement of Slope Angle of Kerf in Thick Plate Cutting of Mild Steel by Fiber Laser 査読

Kyo Kitagawa, Yasuhiro Okamoto, Akira Okada, Hiroaki Ishiguro, Akihiko Sugiyama, Hironobu Miyoshi, Ryohei Ito

Proceedings of 37th International Congress on Applications of Lasers & Electro-Optics 2018 P115 2018年10月

Investigation on Osteoconductivity of EDMed Titanium Alloy Surface in Deionized Water 査読

Yuta lida, Keita Fujii, Togo Shinonaga, Akira Okada

Proceedings of 2018 International Conference on Machining, Materials and Mechanical Technologies 180 - 184 2018年9月

Fundamental Study on Curved Hole by EDM Drilling Using a Suspended Ball Electrode into Practical Materials 査読

Kohei Ota, Shuoxun Li, Akira Okada, Yasuhiro Okamoto, Atsushi Yamaguchi

Proceedings of 2018 International Conference on Machining, Materials and Mechanical Technologies 283 - 287 2018年9月

Influence of Molten Area on Joining Strength in Micro-welding of Glass by Picosecond Pulsed Laser 査読

Yuta Ogino, Zhiyong Ouyang, Yasuhiro Okamoto, Togo Shinonaga, Akira Okada

Proceedings of 2018 International Conference on Machining, Materials and Mechanical Technologies 194 - 198 2018年9月

High-speed Wire EDM by Newly Developed Copper-Zirconium Wire Electrode 査読

Ayaka Kuwada, Naokuni Muramatsu, Kazuhiro Nomura, Yasuhiro Okamoto, Akira Okada

Proceedings of 2018 International Conference on Machining, Materials and Mechanical Technologies 185 - 189 2018年9月

Study on Improvement of Wear Resistance for Zirconia by Large-area EB Irradiation 査読

Togo Shinonaga, Mitsuhiro Kimura, Motohiro, Inoue, Akira Okada

Proceedings of 2018 International Conference on Machining, Materials and Mechanical Technologies 190 - 193 2018年9月

Smoothing of Hole Bottom Surface by Guiding Electron Beam with Magnet 査読

Mituhiro Kimura, Togo Shinonaga, Motohiro Inoue, Akira Okada

Proceedings of 2018 International Conference on Machining, Materials and Mechanical Technologies 26 - 30 2018年9月

High Surface Quality Welding of Aluminum Using Adjustable Ring-mode Fiber Laser 査読

Martin Ruthandi Maina, Yasuhiro Okamoto, Akira Okada, Matti N?rhi, Jarno Kangastupa, Jorma Vihinen

Journal of Materials Processing Technology 258 ( 8 ) 180 - 188 2018年8月

Stabilization of Fusion Micro-welding of Glass by Picosecond Pulsed Laser 査読

Yasuhiro Okamoto, Yuta Ogino, Togo Shinonaga, Akira Okada

International Conference on Processing and Manufacturing of Advanced Materials (THERMEC '2018) 2018年7月

Investigation of Surface Quality in High Speed Laser Welding of Aluminum Alloy using Adjustable Ring-mode Fiber Laser 査読

Martin Ruthandi Maina, Yasuhiro Okamoto, Akira Okada, Matti N?rhi, Jarno Kangastupa, Jorma Vihinen

2018 Sustainable Research and Innovation Conference 2018年5月

Influence of Intensity Distribution on Surface Quality in High Speed Laser Welding of Aluminum Alloy 査読

Martin Ruthandi Maina, Yasuhiro Okamoto, Akira Okada, Matti N?rhi, Jarno Kangastupa, Jorma Vihinen

TECHNICAL DIGEST of the Third Smart Laser Processing Conference, SLPCp8-P6, p.62 62 2018年4月

Control of Kerf Width in Multi-wire EDM Slicing of Semiconductors with Circular Section 査読

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

Procedia CIRP 68 100 - 103 2018年4月

Study on Improvement of Wear Resistance for Zirconia by Large-area Electron Beam Irradiation 査読

Togo Shinonaga, Yasuaki Kimura, Tsubasa Sakai, Akira Okada

Procedia CIRP 68 178 - 183 2018年4月

Influence of Jet Flushing on Corner Shape Accuracy in Wire EDM 査読

Tomonori Ebisu, Akiyoshi Kawata, Yasuhiro Okamoto, Akira Okada, Haruya Kurihara

Procedia CIRP 68 104 - 108 2018年4月

Magnetic fixtures for enhancement of smoothing effect by electron beam melting 査読

Togo Shinonaga, Akira Okada, Hao Liu, Mitsuhiro Kimura

Journal of Materials Processing Technology 254 229 - 237 2018年4月

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 Ltd

In large-area electron beam (EB) irradiation method developed recently, high energy density EB can be obtained without focusing the beam. Therefore, large-area EB of 60 mm in diameter can be used for instant melting and evaporation of the wide area material surface, and high efficient surface finishing is possible. However, if the workpiece has a hole shape, the EB concentrates in the entrance edge or inside wall of the hole. Thus, it is difficult to smooth the hole bottom surface. Previous study showed that the surface smoothing and micro-deburring effects for non-magnetic workpiece could be improved by setting a magnetic block under the workpiece, since the electrons tend to concentrate the magnetic block along magnetic lines. In this study, smoothing of hole bottom surface was experimentally investigated by setting a magnetic block under a workpiece in large-area EB irradiation. Expansion of smoothing area of the bottom surface was also tried by setting a through hole at the center of the magnetic block. It was clarified that wide area of hole bottom surface could be smoothed by large- area EB irradiation by setting the magnetic block under workpiece. The surface roughness decreased to less than 3.0 μmRz at the area of hole bottom surface. When the hole diameter was 20 mm and hole depth was less than 40 mm, smoothing area of 10 mm in diameter was obtained by using the magnetic block. Moreover, the smoothing area was sufficiently expanded by setting a through hole with an appropriate diameter in magnetic block.

DOI： 10.1016/j.jmatprotec.2017.11.024

Mold Releasability of EDM Finished Surface Using Powder Mixed Working Fluid 査読

Ryoji Kitada, Keita Fujii, Ruixiang Wang, Akira Okada

International Journal of Electrical Machining ( 23 ) 24 - 31 2018年3月

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 ( 23 ) 38 - 44 2018年

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 ( 23 ) 45 - 50 2018年

Influence of material property on thickness of modified layer generated by large-area electron beam 査読

Togo Shinonaga, Yasuaki Kimura, Tsubasa Sakai, Akira Okada

19TH CIRP CONFERENCE ON ELECTRO PHYSICAL AND CHEMICAL MACHINING 68 178 - 183 2018年

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：ELSEVIER SCIENCE BV

In large-area electron beam (EB) irradiation method developed recently, high energy density of EB can be obtained without focusing the beam. Therefore, the wide area of material surface can be melted instantly, and high efficient surface finishing is possible. Moreover, surface functions such as corrosion resistance and water repellency of the metal molds were improved by the large-area EB irradiation, since thin resolidified layer was formed on the metal surface. It is expected that thick modified layer is effective to maintain their surface functions for long-term. Therefore, control and prediction of the modified layer thickness are important in order to obtain appropriate modified layer thickness on metals with different material properties. In this study, variations of modified layer thickness on metals with different material property are experimentally investigated. Furthermore, electron behavior during large-area EB irradiation is simulated by using an electron track analysis, and prediction of the modified layer thickness is tried with temperature distributions by using an unsteady heat conduction analysis. Experimental results show that the modified layer thickness increases with increasing energy density. The thickness with high relative permeability is larger than that with low one. Analytical results of the modified layer thickness in unsteady heat conduction analysis show quantitative agreement with experimental ones. Furthermore, the modified layer thickness on the metals with different thermal property and density is also discussed. Then, the modified layer thickness of metals with different material property can be predicted by using our unsteady heat conduction analysis model. (C) 2018 The Authors. Published by Elsevier B.V.

DOI： 10.1016/j.procir.2017.12.043

Effects of Polarization Direction on Removal Characteristics of Silver Nanowire Transparent Conductive Film by Ultrashort Pulsed Laser 査読

T. Shimose, Y. Okamoto, M. Oshita, N. Nishi, T. Shinonaga, A. Okada

Journal of Advanced Mechanical Design, Systems, and Manufacturing 12 ( 5 ) JAMDSM0100-1 - JAMDSM0100-5 2018年

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 ) 869 - 877 2017年11月

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 45 - 50 2017年9月

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

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

A.Okada, A. Yamacuchi, K. Ota

CIRP Annals ?Manufacturing Technology 66 ( 1 ) 189 - 192 2017年

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

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

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

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

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

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

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

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

Alexander SOLDATOV, Akira OKADA, Kensuke UEMURA, Hitoshi OGAWA

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

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

Mizuna Ito, Togo Shinonaga, Yasuhiro Okamoto, Akira Okada

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

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

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 D09 2017年

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

Shono Kinoshita, Togo Shinonaga, Yasuhiro Okamoto, Akira Okada

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

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

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 M202 2017年

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

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

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

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

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

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

Togo Shinonaga, Mitsuhiro Kimura, Akira Okada

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

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

Ruixiang Wang, Yuta Iida, Ryoji Kitada, Akira Okada

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

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

Yasuhiro Okamoto, Hibiki Yamamoto and Akira Okada

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

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 and Manufacture 110 ( 110 ) 18 - 26 2016年11月

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 and Processing 122 ( 5 ) 492 2016年5月

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

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 and Processing 122 ( 4 ) 400 2016年4月

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

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

Sameh Habib, Akira Okada

Journal of Material Processing Technology 227 ( 227 ) 147 - 152 2016年1月

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

山口篤, 岡田晃, 三宅達也

精密工学会誌 82 ( 10 ) 907 - 912 2016年

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 ( 21 ) 13 - 17 2016年

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 ( 21 ) 7 - 12 2016年

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

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

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

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

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

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

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

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

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

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

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

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

Motoki Ota, Yasuhiro Okamoto, Togo Shinonaga, Akira Okada

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

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

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

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

Togo Shinonaga, Shono Kinoshita, Yasuhiro Okamoto, Akira Okada

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

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

Takuya Kamei, Akira Okada, Yasuhiro Okamoto

Procedia CIRP 42 ( 42 ) 596 - 600 2016年

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

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

Investigation of Nanocrystalline Diamond Coating on Cutting Tools for CFRP 査読

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

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

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

Formation of Periodic Nanostructures with Femtosecond Laser for Creation of New Functional Biomaterials 査読

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

Procedia CIRP 42 ( 42 ) 57 - 61 2016年

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

Ryota Toshimitsu, Akira Okada, Ryoji Kitada and Yasuhiro Okamoto

Procedia CIRP 42 ( 42 ) 231 - 235 2016年

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

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

Procedia CIRP 42 ( 42 ) 62 - 66 2016年

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

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

Procedia CIRP 42 ( 42 ) 448 - 453 2016年

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

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

Effect of Surrounding Gas Condition on Surface Integrity in Microdrilling of SiC by ns Pulsed Laser 査読

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

Applied Physics B Laser and Optics 119 ( 3 ) 509 - 517 2015年6月

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

Yasuhiro Okamoto, Satoshi Matsuoka, Tadanori Otowa and Akira Okada

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

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

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

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

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

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

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

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

Akira Okada, Takuya Konishi, Yasuhiro Okamoto, Haruki Kurihara

CIRP Annals - Manufacturing Technology 64 ( 1 ) 233 - 236 2015年

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

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

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

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

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

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

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

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

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

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

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

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

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

Proceedings of Lasers in Manufacturing Laser in Manufactring 2015 2015年

Smart Laser Micro-welding of Difficult-to-weld Materials for Electronic Industry 査読

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

Proceedings of Laser-based Micro- and Nano-Processing IX, Lasers and Application in Science and Engineering, Photonics West Conference 2015 9351 935102-1 - 935102-9 2015年

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

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 62 595 - 598 2015年

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

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

Proceedings of 2nd International Manufacturing Engineering Conference 2015 2015年

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

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

Atsushi YAMAGUCHI, Akira OKADA, Tatsuya MIYAKE, Toshiki IKESHIMA

Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, C25 4pages 2015.8 ( 0 ) _1104 - 1_ 2015年

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

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

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

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

Improvement of Surface Characteritics for Long Life of Metal Molds by Large-area EB Irradiation 査読

Akira Okada, Yasuhiro Okamoto, Yoshiyuki Uno, Kensuke Uemura

Journal of Material Processing Technology 214 ( 8 ) 1740 - 1748 2014年8月

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

Yasuhiro Okamoto, Tomohiro Takekuni and Akira Okada

Journal of Laser Micro/Nanoengineering 9 ( 1 ) 52 - 58 2014年3月

Fundamental Study on Releasability of Molded Rubber from Mold Tool Surface 査読

Akira Okada, Yasuhiro Okamoto, Adam Clare and Yoshiyuki Uno

International Journal of Advanced Manufacturing Technology 70 ( 5-8 ) 1515 - 1521 2014年2月

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

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

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

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 ( 783-786 ) 2792 - 2797 2014年

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

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

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

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

Tomoaki Miyoshi, Akira Okada, Yasuhiro Okamoto

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

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

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

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

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

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

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

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

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

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

Akira Okada, Takuro Konishi, Yasuhiro Okamoto, Haruki Kurihara

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

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

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

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

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

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

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

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

Syuhei Iwasaki, Ryoji Kitada, Akira Okada, Yasuhiro Okamoto

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

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

Shuhei Misumi, Akira Okada, Yasuhiro Okamoto

Procedia CIRP 6 487 - 492 2013年4月

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 and Muhaizad Muktar

Journal of Laser Micro/Nanoengineering 8 ( 1 ) 90 - 96 2013年1月

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

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

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

Neural Network Modeling for Prediction of Weld Bead Geometry in Laser Microwelding 査読

Mohd Idris Shah Ismail, Yasuhiro Okamoto and Akira Okada

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

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

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

Effect of Cutting Direction on Machining of Carbon Fiber Reinforced Plastic By Electrical Discharge Machining Process 査読

Sameh Habib, Akira Okada and Sho Ichii

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

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

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

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 ( 11 ) 105 - 111 2013年

Fundamental study on sputter deposition of ceramic film by large-area electron beam irradiation 査読

S. Misumi, A. Okada, Y. Okamoto, M. Inoue

PROCEEDINGS OF THE SEVENTEENTH CIRP CONFERENCE ON ELECTRO PHYSICAL AND CHEMICAL MACHINING (ISEM) 6 486 - 491 2013年

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：ELSEVIER SCIENCE BV

The sputter deposition of ceramic film on metal mold steel surface by large-area electron beam (EB) irradiation was discussed. The large-area EB has high energy density enough to generate plasma above the workpiece surface during the surface smoothing process, which causes the sputtering of target material set near the workpiece surface. The sputter deposition of target material with simultaneous surface melting and resolidification of workpiece surface by large-area EB would improve the adhesion between the deposited film and the workpiece. Short ceramic tube made of alumina or zirconia as a target was put on the substrate surface of steel, and large-area EB was irradiated to the surface. The workpiece surface component and structure after the irradiation were investigated using EDX and XRD analysis, in order to discuss the possibility of large-area EB irradiation as a new coating method. (C) 2013 The Authors. Published by Elsevier B.V.

DOI： 10.1016/j.procir.2013.03.053

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

Kazuki Kuriyama, Akira Okada, Yasuhiro Okamoto

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

Fundamental Study on Micro-deburring by Large-area EB Irradiation 査読

Akira OKADA, Hajime YONEHARA, Yasuhiro OKAMOTO

Procedia CIRP 5 ( 5 ) 19 - 24 2013年

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

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

Procedia CIRP 6 ( 6 ) 232 - 237 2013年

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

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

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

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

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

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

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

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

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

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

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

Akira Okada, Ryoji Kitada, Shuhei Iwasaki, Yasuhiro Okamoto

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

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

Yasuhiro Okamoto, Kento Shirasaya, Ryoji Kitada, Akira Okada

Proceedings of 32nd International Congress on Applications of Lasers & Electro-Optics 2013 829 - 835 2013年

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

Satoshi Matsuoka, Yasuhiro Okamoto, Akira Okada

Procedia CIRP 6 ( 6 ) 492 - 497 2013年

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

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

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

Yasuhiro Okamoto, Isamu Miyamoto, Jorma Vihinen, Akira Okada

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

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

Yasuhiro Okamoto, Atushi Kimura, Akira Okada, Jun Ohya and Toshiyuki Yamauchi

Key Engineering Materials 523-524 287 - 292 2012年11月

Study on Improvement in Surface Characteristics by Large-area EB Irraidation 査読

Akira Okada, Tomohiro Fujita, Kouki Kouyama and Yasuhiro Okamoto

Proceedings of the 15th International Machine Tool Engineers' Conference 66 - 67 2012年11月

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 and Shin-ichi Nakashiba

Key Engineering Materials 516 36 - 41 2012年6月

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

Takuya Fujimoto, Akira Okada, Yasuhiro Okamoto, Yoshiyuki Uno

Key Engineering Materials 516 73 - 78 2012年6月

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

記述言語：英語掲載種別：研究論文（学術雑誌）

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 μm thickness of FPC and a several hundreds μm 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. © KSPE and Springer 2012.

DOI： 10.1007/s12541-012-0041-3

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

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

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

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

Challenge to Development of Functional Multi-wire EDM Slicing Method using Wire Electrode with Track-shaped Section 査読

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

EMERGING TECHNOLOGY IN PRECISION ENGINEERING XIV 523-524 ( 523-524 ) 287 - + 2012年

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：TRANSACTION PUBLISHERS

A newly developed multi-wire electrical discharge machining (EDM) method would accomplish the high performance slicing of silicon and silicon carbide with a narrow kerf width under a clean process environment. However, the thinner wire is challenging process with a normal round shape wire electrode. Therefore, a new wire electrode with track-shaped section was proposed in order to satisfy both the narrow kerf width and the high wire tension even in the case of thin wire electrode. In this study, the running control of wire electrode with track-shaped section was experimentally investigated, and the possibility of proposed process was discussed. A brass coated steel wire electrode with track-shaped section of aspect ratio 1:2 could perform the smaller vibration and the stable running up to 300 m/min. The side support method with fixture plates could improve the running stability of brass coated steel wire electrode with track-shaped section and reduce the kerf width. The brass coated steel wire electrode with track-shaped section could accomplish the uniform and straight kerf shape by increasing the wire tension.

DOI： 10.4028/www.scientific.net/KEM.523-524.287

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

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

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

Velocity and Angle of Spatter in Fine Laser Processing 査読

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

Physics Procedia 39 ( 39 ) 792 - 799 2012年

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

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

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

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

Effect of Plasma Nitriding on Cutting Performance of Stainless Steel Cutlery 査読

Tsukasa Tamaoki, Akira Okada, Kensuke Uemura, Yoshiyuki Uno

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

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

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

Physics Procedia 39 ( 39 ) 577 - 584 2012年

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

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

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

Yasuhiro Okamoto, Shinichi Nakashiba, Tomokazu Sakagawa, Akira Okada

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

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

Ryuto Fujie, Akira Okada and Yoshiyuki Uno

Proceedings of 10th International Conference on Progress of Machining Technology 227 - + 2012年

High-speed Observation of Wire Movement in Fine Wire EDM 査読

Sho Ichii, Akira Okada and Yasuhiro Okamoto

Proceedings of 10th International Conference on Progress of Machining Technology 215 - 218 2012年

Surface Modification of Cemented Carbide with Nickel Binder by Large-Area Electron Beam 査読

Akira Okada, Shuhei Misumi and Yasuhiro Okamoto

Proceedings of 10th International Conference on Progress of Machining Technology 207 - 210 2012年

Thermal Deformation in Micro-welding of Thin Stainless Steel Sheet by Single-mode Fiber Laser 査読

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

Proceedings of 10th International Conference on Progress of Machining Technology 199 - 202 2012年

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

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

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

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

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

Surface modification of cemented carbide by EB polishing 査読

Akira Okada,Ryoji Kitada,Yasuhiro Okamoto,Yoshiyuki Uno

CIRP Annals - Manufacturing Technology 60 ( 1 ) 575 - 578 2011年

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

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

Improvement of Razor Blade Surface Integrity by Plasma Nitriding 査読

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

Influence of Carbon Fiber Direction on EDM Characteristics of CFRP 査読

Sho Ichii, Akira Okada, Yasuhiro Okamoto, Yoshiyuki Uno

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

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

Tomohiro Fujita, Akira Okada, Yasuhiro Okamoto, Yoshiyuki Uno

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

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

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

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

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

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

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

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

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

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

Evaluations of Spark Distribution and Wire Vibration in Wire EDM by High-speed Observation 査読

Akira OKADA, Yoshiyuki UNO, Masanori NAKAZAWA, Toshiyuki YAMAUCHI

CIRP Annals Manufacturing Technology 59 ( 1 ) 231 - 234 2010年

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

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

Akira OKADA, Takuya FUJIMOTO, Yoshiyuki UNO

Proc. of the 21st International Conference on Computer-Aided Production Engineering, (CAPE2010) Paper No. 007, CD-Rom. 1 CDROM 2010年

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

Akira OKADA, Yoshiyuki UNO, Kensuke UEMURA

Proc. of the 25th Annual Meeting of the American Society for Precision Engineering, 301-304 1 301 - 304 2010年

Unconventional Methods of Cutting of Bone and Tissue 査読

Hai Wang, Sameh Habib, Akira OKADA, Yoshiyuki UNO

Proc. of the 16th International Symposium on ElectroMachining 1 457 - 461 2010年

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

Hongge GUO, Ryoji KITADA, Akira OKADA, Yoshiyuki UNO

Proc. of the 16th International Symposium on ElectroMachining 1 451 - 454 2010年

EDM Characteristics of Carbon Fiber Reinforced Plastic 査読

Hai Wang, Sameh Habib, Akira OKADA, Yoshiyuki UNO

Proc. of the 16th International Symposium on ElectroMachining 1 65 - 68 2010年

Study on Electrical Discharge Machining Characteristics of Electrically Conductive Ceramics 査読

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

Key Engineering Materials 407-408 ( 407-408 ) 636 - + 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

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

Computational Fluid Dynamics Analysis of Working Fluid Flow and Debris 査読

Akira OKADA, Yoshiyuki UNO, Shinya ONODA and Sameh HABIB

CIRP Annals Manufacturing Technology 58 ( 1 ) 209 - 212 2009年

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

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

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

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

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

Ryoji KITADA, Akira OKADA, Yoshiyuki UNO

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

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

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

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

Fundamental Study on Releasability of Resin from EDMed Surface 査読

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

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

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

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

Study on Separation Force of Molded Resin from EDMed Surface 査読

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

Improvement of Surface Characteristics of Metal Mold by EB polishing 査読

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

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

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

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 ) 694 - 700 2008年

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 System and Manufacturing 2 ( 4 ) 735 - 741 2008年

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

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

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

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

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

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

Akira OKADA, Yoshiyuki UNO, Hironori KIMURA, Seiji IWASAKI

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

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

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

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

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

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

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

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 ( 364-366 ) 302 - 307 2007年

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

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

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

*Akira OKADA, Yoshiyuki UNO, Kensuke UEMURA, Purwadi RAHARJO and Joseph A. McGEOUGH

IMechE Journal of Engineering Manufacture 221 ( 2 ) 173 - 178 2007年

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

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

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

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

Kimihiko ARIZONO, Toshiyuki YAMAUCHI, Akira OKADA, Yoshiyuki UNO

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

Advantage of Flange Type Electrode in Deep-Hole EDM 査読

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

RF Cutting of Non and Semiconducting Materials 査読

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

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

Unconventional Method of Cutting for Orthopaedic Surgery 査読

Joseph McGeough, Akira OKADA

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

Radio Frequency Electrodischarge Machining of Silicon Wafers 査読

David McMillan, Joseph McGeough, Brian Flynn, Akira Okada

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

High Efficiency EB Polishing of Metal Mold 査読

*Akira OKADA, Yoshiyuki UNO, Yoshiaki DAICHI and Sadao SANO

Proc. of the 15th International Symposium on ElectroMachining, pp.409-414 409 - 414 2007年

Machining Characteristics of EDM by Radio-frequency Plasma 査読

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

CIRP Annals 55 ( 1 ) 167 - 170 2006年

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

放電加工面の耐食性に関する基礎的研究査読

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

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

Yoshiyuki UNO, Akira OKADA, Kensuke UEMURA, Purwadi RAHARJO

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

Newly Developed CuW Electrode for High Performance EDM 査読

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

Proc. of Progress of Machining Technology 273 - 276 2006年

High Efficiency Finishing Process for Metal Mold by Large-area Electron Beam Irradiation 査読

Yoshiyuki Uno, Akira OKADA, Kensuke UEMURA, Purwadi RAHARJO, Toshihiko FURUKAWA, Kousaku KARATO

Precision Engineering（Journal of the American Society for Precision Engineering） 29 ( 4 ) 449 - 455 2005年10月

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

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

Biomachining of Metal Using Agar Culture Medium 査読

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

Unconventional Cutting Technologies in Orthopaedic Surgery 査読

Joseph A. McGEOUGH, *Akira OKADA

Proceedings of 7th International Conference on Advanced Manufacturing Systems and Technology Processing ( 486 ) 87 - 97 2005年

Fundamental Study on Radiofrequency Machining of Metals 査読

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

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

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- 査読

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

Fundamental Study on Coating Wire Electrode for High Performance WEDM 査読

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

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

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

寒天培地を利用した金属のバイオマシニング査読

*岡田晃,宇野義幸,中西隆,金枝敏明

先端加工学会誌 23 ( 1 ) 13 - 18 2005年

Effect of debris distribution on wall concavity in deep-hole EDM 査読

S Cetin, A Okada, Y Uno

JSME INTERNATIONAL JOURNAL SERIES C-MECHANICAL SYSTEMS MACHINE ELEMENTS AND MANUFACTURING 47 ( 2 ) 553 - 559 2004年6月

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

In deep-hole electrical discharge machining, the electrode jump height and hence the movement of the machining debris inside the side gap affect the wall concavity of the machined holes. In this study, the dielectric fluid flow and the debris distribution in the machining gap caused by electrode jump is analyzed to understand the wall concavity phenomenon of the holes using a computational fluid dynamics (CFD) simulation program. Fluid flow and debris-fluid interaction under low and high electrode jumps are examined and compared. The accuracy of the predictions obtained by the numerical calculation is assessed through comparisons with experimental data.

DOI： 10.1299/jsmec.47.553

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

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

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

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 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

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査読

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 Accumulation on Machining Speed in EDM 査読

Serkan CETIN,*Akira OKADA, Yoshiyuki UNO

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

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

S Cetin, A Okada, Y Uno

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

記述言語：英語掲載種別：研究論文（学術雑誌）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

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Energy Distribution in Electrical Discharge Machining with Graphite Electrode 査読

「文鎮」から「ジャイロスコープ」へ進化した「機械工作実習」査読

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査読

*岡田晃,宇野義幸,藪下法康,植村賢介,Purwadi Raharjo

精密工学会誌 69 ( 10 ) 1464 - 1468 2003年

放電加工面の摩擦特性に関する基礎的研究査読

岡田晃, 宇野義幸, 中島洋平

電気加工学会誌 37 ( 85 ) 24 - 31 2003年

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

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

Investigation of Dielectric Flow during Electrode Jump in EDM Gap 査読

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

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

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

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査読

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

EDM Characteristics of Metal Impregnated Graphite Electrode 査読

*Akira OKADA, Yoshiyuki UNO, Takashi TAKAGI, Masatsugu YOKOTANI

Progress of Machining Technology 402 - 407 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査読

宇野義幸,*岡田晃,中聡,山本庄一,坂根豊

電気加工学会誌 36 ( 81 ) 2002年

Surface Modification of EDMed Surface with Powder Mixed Fluid 査読

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

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

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

Akira Okada*, Yoshiyuki Uno and Isao Okajima

Memoirs of the Faculty of Engineering, Okayama University 34 ( 1・219-26 ) 19 - 26 2000年

記述言語：英語出版者・発行元：Faculty of Engineering, Okayama University

In EDM, the machining characteristics greatly depend on the energy distribution. Therefore, it is very important to clarify the energy distribution for understanding various phenomena in EDM. In this paper, the energy distribution in EDM with graphite electrode is investigated by measuring the temperatures of electrode and workpiece. Experimental analysis shows that the material removal rate depends on energy density while the electrode wear greatly depends on the adhesion of heat resolved carbon from machining fluid, and the energies distributed into electrode and workpiece are almost constant regardless of pulse duration.

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Wire EDM Slicing of Monocrystalline Silicon Ingot 査読

Yoshiyuki Uno, Akira Okada*, Yasuhiro Okamoto and Tameyoshi Hirano

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

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

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

Formation of hard layer by EDM with carbon powder mixed fluid using titanium electrode 査読

A Okada, Y Uno, K Hirao, T Takagi

PROGRESS OF MACHINING TECHNOLOGY 464 - 469 2000年

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：AVIATION INDUSTRY PRESS

A new method for forming hard layer containing titanium carbide by EDM with carbon powder mixed fluid using titanium electrode is proposed, and the effects of machining conditions on characteristics of the layer are experimentally investigated. Furthermore, the wear resistance of EDMed surface was evaluated. Experimental analysis made it clear that a thick and smooth TiC layer could be formed on the machined surface by this method. It was also pointed out that the hardness of modified surface became higher with an increase of discharge duration and/or carbon powder concentration in the kerosene type machining fluid, and that the wear resistance of the modified layer was much higher than that of base material.

単結晶シリコンインゴットの放電スライシング法(共著) 査読

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

High Efficiency Fine Boring of Monocrystalline Silicon Ingot by Electrical Discharge Machining 査読

Yoshiyuki Uno, Akira Okada*, Yasuhiro Okamoto, Kazuo Yamazaki, Subhash H. Risbud and Yoshiaki Yamada

Precision Engineering(Journal of the American Society for Precision Engineering) 23 ( 2 ) 126 - 133 1999年4月

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) 査読

郭常寧,宇野義幸,岡田晃*,勝田智宣,橋川栄二,高木俊

電気加工学会誌 33 ( 72 ) 37 - 45 1999年

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) 査読

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

Internal Surface Finishing of Small Hole by Electrochemical Machining after Honing 査読

Akira Okada*, Yoshiyuki Uno, Satoshi Naka, Shoich Yamamoto and Akiyo Kinoshita

Proc. of the 3rd International Conference on Abrasive Technology 275 - 282 1999年

Surface Modification by EDM with Nickel Powder Mixed Fluid 査読

Yoshiyuki Uno, Akira Okada*, Yasuhiro Hayashi and Yoshiaki Tabuchi

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

三角形断面電極による微細複雑形状放電加工法(共著) 査読

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

EDM Characteristics of CVD-Carbon Electrode(共著) 査読

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

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

A Okada, Y Uno, Y Okamoto

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

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：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.

High Efficient Electrical Discharge Machining of Titanium Alloy 査読

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

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 65 ( 1 ) 239 - 242 1998年

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

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

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) 査読

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

単結晶シリコンの放電加工に関する基礎的研究(共著) 査読

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 fine boring of single crystalline silicon ingot by electrical discharge machining 査読

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

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) 査読

宇野義幸, 岡田晃, 岡本康寛

精密工学会誌 63 ( 12 ) 1725 - 1729 1997年

Electrical Discharge Machining of a Groove with a Rotating Disk Electrode

UNO Yoshiyuki, OKADA Akira, ITOH Mitsuru, YAMAGUCHI Tsuyoshi

International journal of electrical machining 1 13 - 20 1996年1月

CVD炭素電極の放電加工特性(共著) 査読

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

Newly Developed CVD-Carbon Electrode for Higher Performance EDM 査読

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

単結晶シリコンの微細穴放電加工に関する研究(共著) 査読

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) 査読

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) 査読

宇野義幸, 岡田晃, 亀川出

電気加工学会誌 29 ( 62 ) 9 - 17 1995年

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

Akira OKADA, Yoshiyuki UNO

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

高速極性切替放電加工に関する研究(共著) 査読

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

The effect of high speed polarity changing on EDM performance 査読

Y Uno, A Okada, M Itoh

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

A New Biological Machining Technique with Chemolithotrophic Bacteria 査読

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

銅合金(MS46)の放電加工特性(共著) 査読

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

回転円板電極による放電溝加工の研究(共著) 査読

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

Yoshiyuki UNO, Akira OKADA

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

記述言語：日本語出版者・発行元：Japan Society of Electrical Machining Engineers

The factors which make titanium alloy difficult to EDM are experimentally investigated, analyzing the shape of crater generated by a single discharge, the pile-up time of workpiece, the waveform of successive discharge current, the shape of debris and so on. Then the condition for high efficient electrical discharge machining of titanium alloy is recommended. Main conclusions obtained in this study are as follows:<br>(1) The pile-up generated by a single discharge in titanium alloy is higher than that in steel, and the pile-up time is also longer.<br>(2) The removal volume of crater generated by a single discharge in titanium alloy is larger than that in steel, which agrees with the conventional theory that the lower product of melting point and the thermal conductivity of material leads to easier EDMing.<br>(3) The metal removal rate is lower and the electrode wear is larger for titanium alloy under the conventional EDM condition as compared with those for steel, since the frequent short-circuit results in the unstability of machining.<br>(4) High efficient and low electrode wear electrical discharge machining of titanium alloy is possible by decreasing the duty factor, since the resting duration is enough for pileup of workpiece and the machining becomes stable.

DOI： 10.2526/jseme.27.56_1

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