Ibaraki University's
Frontier Research Center for Applied Atomic Sciences

顔写真
Assistant Professor

Onuki Yusuke


Career

  1. University of Saskatchewan Department of Engineering Postdoctoral Research Fellow 2013/04/20-2014/03/31
  2. Tohoku University Institute of Multidisciplinary Research for Advanced MAterials Research Associeate 2014/05/01-2014/12/31

Academic background

  1. Yokohama National University Graduate School of Engineering システム統合工学専攻 Doctor later 2013/03/31 Completed Japan

Academic degrees

  1. Doctor of Enginnering Yokohama National University 2013/03/31

Research Areas

  1. Structural/Functional materials
  2. Material processing/Microstructural control engineering

Research keywords

  1. Texture
  2. neutron diffraction
  3. microstructure control

Subject of research

  1. 多結晶磁歪合金の高性能化をもたらす組織設計と配向制御指針の確立 2015/04/01-Present
  2. 無機・金属材料の微細組織構造階層性を指向した中性子散乱解析システムの開発 2016/04/01-Present
  3. 金属材料の集合組織・微細組織の高速高精度測定技術の確立とin situ中性子散乱解析システムの開発 2016/04/01-Present
  4. 中性子線による高温オーステナイト組織の動的微細組織変化のその場観察 2016/04/01-Present

Research Projects (Competitive Research Funds)

  1. 多結晶磁歪合金の高性能化をもたらす組織設計と配向制御指針の確立 Science research expense 若手研究(B) 2015/04/01-2018/03/31

Papers

  1. Research paper (scientific journal) Joint Quantitative phase fraction analysis of steel combined with texture analysis using time-of-flight neutron diffraction Yusuke Onuki, Akinori Hoshikawa, Shigeo Sato, Toru Ishigaki & Toshiro Tomida Journal of Materials Science 52/ 19, 11643-11658 2017/06/27 0022-2461 DOI 10.1007/s10853-017-1309-x The accuracy of the phase fraction determined by time-of-flight neutron diffraction measurement at iMATERIA was verified by preparing model samples consisting of laminations of ferritic and austenitic stainless-steel sheets. Rietveld texture analysis, based on 132 diffractograms, was employed as the analysis method. The analyzed volume fractions of austenite agree with the prepared fractions (0.61–49.3 vol%) with a maximum error of only 5%, relative to the prepared fractions. This is due to the excellent fitting quality of the multidiffractogram- based Rietveld refinement with consideration given to the textures of both the major and minor phases. Although the quality of the texture analysis for the austenite phase becomes poor, at\5 vol%, the consideration of the textures improves the accuracy of the phase fraction determination. Also described is how the textures affect the phase fractions, as determined by the conventional diffraction method. It is clearly shown that texture cannot be ignored in phase fraction analysis and, in turn, a reasonable consideration of the texture realizes precision in the analysis.
  2. 中性子を利用した結晶方位の先端的評価技術の開発と今後の展望 小貫 祐介 まてりあ 公益社団法人 日本金属学会 55/ 3, 104-107 2016 1340-2625 URL
  3. Research paper (international conference proceedings) Joint Rapid Measurement of Texture of Metals by Time-of-Flight Neutron Diffraction at iMATERIA and its Applications Y. ONuki, A. Hoshikawa, S. Sato, T. Ishigaki Materials Science Forum Trans Tech Publications 879, 1426-1430 2017 1662-9760 10.4028/www.scientific.net/MSF.879.1426 The authors have developed the texture measurement system at iMATERIA, which is the neutron diffractometers built in Materials and Life Science Experimental Facility (MLF) at J-PARC, Japan. The high flux of the incident beam and Time-Of-Flight method enabled the complete texture measurement within several minutes in case of steels. Since the neutron beam can transmit most of the materials, the measured texture represents the state of whole exposed volume. The multi-histogram analysis also enables to determine phase fractions in a multiphase material as well as the texture of each phase.
  4. Research paper (scientific journal) Joint Rapid measurement scheme for texture in cubic metallic materials using time-of-flight neutron diffraction at iMATERIA Yusuke Onuki,* Akinori Hoshikawa, Shigeo Sato, Pingguang Xu,Toru Ishigaki, Yoichi Saito, Hidekazu Todoroki and Makoto Hayashi Journal of Applied Crystallography 49, 1579-1584 2016/10 10.1107/S160057671601164X URL A rapid texture measurement system has been developed on the time-of-flight neutron diffractometer iMATERIA (beamline BL20, MLF/J-PARC, Japan). Quantitative Rietveld texture analysis with a neutron beam exposure of several minutes without sample rotation was investigated using a duplex stainless steel, and the minimum number of diffraction spectra required for the analysis was determined experimentally. The rapid measurement scheme employs 132 spectra, and by this scheme the quantitative determination of volume fractions of texture components in ferrite and austenite cubic phases in a duplex stainless steel can be made in a short time. This quantitative and rapid measurement scheme is based on the salient features of iMATERIA as a powder diffractometer, i.e. a fairly high resolution in d spacing and numerous detectors covering a wide range of scattering angle.
  5. Research paper (international conference proceedings) Joint Stress and Strain Analysis in an Fe-Ga Alloy Single Crystal T. Ikeuchi, S. Tsubaki, M. Imafuku, S. Fujieda, Y. Onuki, S. Suzuki Materials Science Forum Trans Tech Publications 879, 807-809 2017 1662-9760 10.4028/www.scientific.net/MSF.879.807

Joint / funded research

  1. 茨城県中性子ビームラインの測定手法及び解析手法に係る試験研究事業 2015/01-2016/03 Commissioned research by the investment
  2. 茨城県中性子ビームラインの特性を活かした中性子構造解析の先導的研究事業 2015/01-2016/03 Commissioned research by the investment