RYU Gyogyoku

写真a

Affiliation Department etc.

Department of Electrical and Mechanical Engineering
Department of Electrical and Mechanical Engineering

Title

Assistant Professor

Mail Address

E-mail address

Homepage URL

http://tribo.web.nitech.ac.jp/

Research Fields, Keywords

tribology, carbonaceous hard coating, laser processing

Graduate School

  • 2012.08
    -
    2015.07

    Tsinghua University  Graduate School, Division of Engineering  Enviromental EngineeringMaster's Course  Completed

Degree

  • Nagoya University -  Doctor (Engineering)

  • Tsinghua University -  Master (Engineering)

Field of expertise (Grants-in-aid for Scientific Research classification)

  • Materials/Mechanics of materials

  • Design engineering/Machine functional elements/Tribology

  • Production engineering/Processing studies

 

Papers

  • Surface modification of metal surface using pico-second laser irradiation and investigation of its tribological properties

    Xiaoxu LIU, Yoshiki TANAKA, Sho FUJIWARA, Satoru MAEGAWA, Shingo ONO and Fumihiro ITOIGAWA

    Proceedings of International Conference on Leading Edge Manufacturing in 21st century : LEM21 ( The Japan Society of Mechanical Engineers )    2021.11  [Refereed]

    Research paper (international conference proceedings)   Single Author

  • Development of High-Performance Polycrystalline CVD Diamond-coated Cutting Tools using Femtosecond Lasers

    Xiaoxu Liu, Osamu Konda, Hiroko Furuhashi, Kohei Natsume, Satoru Maegawa, and Fumihiro Itoigawa

    International Journal of Automation Technology ( Fuji Technology Press Ltd. )  15 ( 4 ) 413 - 421   2021.07  [Refereed]  [Invited]

    Research paper (scientific journal)   Multiple Authorship

  • Improvement of crystallization in CVD diamond coating induced by femtosecond laser irradiation

    Liu, X., Natsume, K., Maegawa, S., Itoigawa, F.

    Diamond and Related Materials   107   2020.08  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

  • Micromachining of polycrystalline CVD diamond-coated cutting tool with femtosecond laser

    Xiaoxu LIU, Kohei NATSUME, Satoru MAEGAWA, Fumihiro ITOIGAWA

    Journal of Advanced Mechanical Design, Systems, and Manufacturing   14 ( 4 )   2020.05  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

  • Lubrication Effect of Smeared Oil on Workpiece Surface in Intermittent Cutting With Very Short Cutting Duration

    Yoshiki Nakamura, Fumihiro Itoigawa, Shinya Hayakawa, Satoru Maegawa, Xiaoxu Liu

    Proceedings of the JSME 2020 Conference on Leading Edge Manufacturing/Materials and Processing     2020  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

  • Development of High-performance Polycrystalline CVD Diamond Coated Cutting Tool Edge With Femtosecond Laser

    Xiaoxu Liu , Kohei Natsume, Satoru Maegawa, Fumihiro Itoigawa

    Proceedings of the JSME 2020 Conference on Leading Edge Manufacturing/Materials and Processing     2020  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

  • Tribological properties of ta-CNx coating sliding against steel and sapphire in unlubricated condition

    Xiaoxu Liu, Noritsugu Umehara, Takayuki Tokoroyama, Motoyuki Murashima

    Tribology International ( Elsevier )  131   102 - 111   2018.10  [Refereed]

    Research paper (scientific journal)   Single Author

  • Effect of oil temperature and counterpart material on the wear mechanism of ta-CNx coating under base oil lubrication

    Xiaoxu Liu, Ryo Yamaguchi, Noritsugu Umehara, Motoyuki Murashima, Takayuki Tokoroyama

    Wear ( Elsevier )  390   312 - 321   2017.09  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

    Tetrahedral amorphous carbon nitride (ta-CNx), as an emerging and promising diamond-like carbon (DLC), has better mechanical properties than amorphous carbon nitride (a-CNx) to ensure the sufficient durability, and overcomes the limit of high internal stress of tetrahedral amorphous carbon (ta-C), which makes ta-CNx coatings ofgreatworthofresearchforthetribologicalandmechanicalapplications.Inthisstudy,wepresenttheeffectsof oil temperature and counterpart material on the wear behavior of ta-CNx coatings under base-oil lubrication, andfurtherclarifythewearmechanism.ta-Candta-CNxcoatingswithN/Catomicratioof2.2%and11.0%were deposited by an ion beam assisted filtered arc deposition (IBA-FAD) system, and the tribological tests were performed using a ball-on-disk tribo-tester with ta-C and ta-CNx coated steel ball sliding against uncoated disk under base-oil lubrication. The results show that nitrogen doping tends to decrease the hardness and Young's modulus by reducing the sp3 structure. Sliding against steel disk, with increase of sliding distance ta-CNx shows obviously distinct wear behavior compared to ta-C, much more slowly increasing wear volume, exhibiting excellent wear resistance. Increasing oil temperature from room temperature to 120 °C results in rising wear rates of all the three coatings, with totally worn out ta-C and much lower wear rate of ta-CNx, which decreases by more than half than ta-C for high nitrogen content ta-CNx. However, as the counterpart material changed from steel to alumina, the wear rate presents oppositely increasing tendency with N/C ratio, probably caused by the change of deciding factor to hardness in this mechanical wear. It is found that the wear performance of ta-CNx coating has a clear dependence on the oil temperature and counterpart material. Based on the results, the better wear resistance of softer ta-CNx against steel could be attributed to the less tribo-chemical wear between carbon and iron, due to the nitrogen doping partial passivation effect.

  • Clarification of high wear resistance mechanism of ta-CNx coating under poly alpha-olefin (PAO) lubrication

    Xiaoxu Liu RyoYamaguchi NoritsuguUmehara Xingrui Deng Hiroyuki Kousaka Motoyuki Murashima

    Tribology International ( Elsevier )  105   193 - 200   2016.10  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

Presentations

  • Surface modification of metal surface using pico-second laser irradiation and investigation of its tribological properties

    Xiaoxu LIU, Yoshiki TANAKA, Sho FUJIWARA, Satoru MAEGAWA, Shingo ONO and Fumihiro ITOIGAWA

    the 10th International Conference on Leading Edge Manufacturing in 21st Century (LEM21)  (オンライン)  2021.11  -  2021.11  JSME

  • 転がり滑り接触下の摩耗係数に関する研究

    野田隆悟,劉暁旭,前川覚,糸魚川文広

    トライボロジー会議2021 秋 松江  2021.10  -  2021.10 

  • 短パルスレーザ照射による機能性表面創製とそのトライボロジー特性に関する研究

    劉暁旭,田中良樹,藤原奨,前川覚,小野晋吾,糸魚川文広

    トライボロジー会議 2021春  (オンライン)  2021.05  -  2021.05  日本トライボロジー学会

  • A Novel Method for Visualizing Oil Film Pressure Distribution on Sliding Surface Using Surface Plasmon Resonance Technology

    Tatsuya Inagaki, Xiaoxu Liu , Satoru Maegawa and Fumihiro Itoigawa

    2nd Korea-Tribology International Symposium  (Virtual Conference)  2020.11  -  2020.12 

  • Surface Roughness of Finished Surface by Processing with Short Pulse Laser

    Kosuke Hasegawa, Xiaoxu Liu, Satoru Maegawa and Fumihiro Itoigawa

    18th International Conference on Precision Engineering.  (Virtual Conference)  2020.11  -  2020.11 

  • Surface fabricating Process in Pulse Laser Grinding of PCBN Cutting Tools

    Xianlong Ni, Xiaoxu Liu, Satoru Maegawa and Fumihiro Itoigawa

    18th International Conference on Precision Engineering.  (Virtual Conference)  2020.11  -  2020.11 

  • Edge shaping and structural modification of CVD polycrystalline diamond coated tool with femtosecond laser

    Xiaoxu Liu, Satoru Maegawa, Hiroko Furuhashi, Shingo Ono and Fumihiro Itoigawa

    18th International Conference on Precision Engineering.  (Virtual Conference)  2020.11  -  2020.11 

  • Elucidation of Influencing Factors for Lubrication in Intermittent Cutting with Very Short Cutting Duration

    Yoshiki Nakmura, Shinya Hayakawa, Fumihiro itoiga, Satoru Maegawa and Xiaoxu Liu

    18th International Conference on Precision Engineering.  (Virtual Conference)  2020.11  -  2020.11 

  • Effects of double rake angle tool in low-speed cutting of high-purity iron

    Junya Sezutsu, Fumihiro Itoigawa, Shinya Hayakawa, Satoru Maegawa and Xiaoxu Liu

    18th International Conference on Precision Engineering.  (Virtual Conference)  2020.11  -  2020.11 

  • Clarification of High Wear Resistance Mechanism of ta-CNx Coating Deposited by IBA-FAD System

    Xiaoxu Liu, Noritsugu Umehara, Takayuki Tokoroyama, Motoyuki Murashima  [Invited]

    トライボロジー会議2020 秋 別府  (オンライン)  2020.11  -  2020.11 

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Other external funds procured

  • Offer organization: Private Foundations 

    Project Year: 2019.03  -  2019.09