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UEKI Kosuke

    Department of Mechanical Engineering　Lecturer
Last Updated :2024/05/19

Researcher Information

J-Global ID

Research Interests

  • microstructure   Corrosive properties   mechanical properties   Thermomechanical treatment   Co-Cr alloy   

Research Areas

  • Nanotechnology/Materials / Structural and functional materials
  • Nanotechnology/Materials / Material fabrication and microstructure control
  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Machine materials and mechanics

Academic & Professional Experience

  • 2022/04 - Today  Kindai UniversityFaculty of Science and Engineering, Department of Mechanical Engineering講師
  • 2024/04 - 2024/09  Osaka Sangyo UniversityFaculty of Engineering Department of Mechanical Engineering for Transportation非常勤講師
  • 2019/04 - 2022/03  Kindai UniversityFaculty of Science and Engineering, Department of Mechanical Engineering助教
  • 2016/04 - 2019/03  日本学術振興会 特別研究員DC1

Education

  • 2016/04 - 2019/03  東北大学大学院  工学研究科  材料システム工学専攻 博士後期課程
  • 2014/04 - 2016/03  東北大学大学院  工学研究科  材料システム工学専攻 博士前期課程
  • 2010/04 - 2014/03  Tohoku University  Faculty of Engineering  Department of Materials Science and Engineering

Association Memberships

  • 一般社団法人 軽金属学会   Japan Society of Powder and Powder Metallurgy   日本塑性加工学会   日本機械学会   THE JAPAN INSTITUTE OF METALS AND MATERIALS   

Published Papers

  • Kai Hiyama; Kosuke Ueki; Kyosuke Ueda; Takayuki Narushima
    Materials Science and Engineering: A 899 146458  2024/05 [Refereed]
  • Kosuke Ueki; Kyosuke Ueda; Masaaki Nakai; Takayoshi Nakano; Takayuki Narushima
    Key Engineering Materials Trans Tech Publications, Ltd. 967 115 - 120 2023/12 [Refereed]
     
    The Co-20Cr-15W-10Ni (CCWN, mass%) alloy, registered as American society of testing and materials (ASTM) F90, has been widely used as a balloon-expandable stent because of its excellent balance between its mechanical properties and corrosion resistance. To realize a less invasive stent placement, the stent diameter must be reduced, which implies that the stent strut thickness must be reduced. As such, the CCWN alloy must be high in strength and ductility while maintaining a low yield stress to facilitate the expansion and suppression of stent recoil. In this study, we focus on the effects of the adding Mn/Fe on the microstructure, mechanical properties, and corrosive properties of CCWN alloys. A 6 mass% Mn-added CCWN alloy with a grain size of approximately 20 μm prepared in this study exhibits excellent balance between tensile strength and ductility. In addition, it exhibits a lower yield stress while maintaining a high tensile strength compared with the ASTM F90 alloy. Meanwhile, a 6 mass% Fe-added CCWN alloy exhibits a higher ductility compared with the ASTM F90 alloy. The addition of Mn or Fe to the CCWN alloy increases the stacking fault energy of the alloy and suppresses strain-induced martensitic transformation during plastic deformation, thus improving the ductility of the alloy. Results of polarization tests show that the 6 mass% Mn-or Fe-added CCWN alloys exhibit the same corrosion current density as the ASTM F90 alloy. Mn-added Co-Cr-W-Ni alloys are suitable for use in balloon-expandable stents.
  • Kosuke Ueki; Ryo Hirano; Masaaki Nakai
    Materials Today Communications Elsevier BV 34 105465 - 105465 2352-4928 2023/03 [Refereed]
  • Shunsei Takeda; Kosuke Ueki; Kyosuke Ueda; Masaaki Nakai; Takayoshi Nakano; Takayuki Narushima
    Materials Science and Engineering: A Elsevier BV 862 144505 - 144505 0921-5093 2023/01 [Refereed]
  • Norain Binti ABDULLAH; Daisuke MIYAZAKI; Ei YAMAMOTO; Kosuke UEKI; Masaaki NAKAI
    Mechanical Engineering Journal Japan Society of Mechanical Engineers 9 (6) 22-00282  2022/12 [Refereed]
  • Xiao Xu; Takumi Odaira; Sheng Xu; Kenji Hirata; Toshihiro Omori; Kosuke Ueki; Kyosuke Ueda; Takayuki Narushima; Makoto Nagasako; Ryosuke Kainuma; Stefanus Harjo; Takuro Kawasaki; Lucie Bodnarova; Petr Sedlak; Hanus Seiner
    ADVANCED MATERIALS & PROCESSES ASM INT 180 (7) 35 - 37 0882-7958 2022/10
  • Kazunori ASANO; Kenkichi FUJITO; Hiroyuki WATANABE; Masaya IWASAKI; Kosuke UEKI; Masaaki NAKAI
    Transactions of the JSME (in Japanese) Japan Society of Mechanical Engineers 88 (913) 22 - 00216 2022/09 [Refereed]
  • Norain Binti Abdullah; Daisuke Miyazaki; Ei Yamamoto; Kosuke Ueki; Masaaki Nakai
    Journal of Materials Research Springer Science and Business Media LLC 37 2536 - 2545 0884-2914 2022/06 [Refereed]
  • Takumi Odaira; Sheng Xu; Kenji Hirata; Xiao Xu; Toshihiro Omori; Kosuke Ueki; Kyosuke Ueda; Takayuki Narushima; Makoto Nagasako; Stefanus Harjo; Takuro Kawasaki; Lucie Bodnárová; Petr Sedlák; Hanuš Seiner; Ryosuke Kainuma
    Advanced Materials Wiley 34 (27) 2202305 - 2202305 0935-9648 2022/05 [Refereed]
     
    The demand for biomaterials has been increasing along with the increase in the population of elderly people worldwide. The mechanical properties and high wear resistance of metallic biomaterials make them well-suited for use as substitutes or as support for damaged hard tissues. However, unless these biomaterials also have a low Young's modulus similar to that of human bones, bone atrophy inevitably occurs. Because a low Young's modulus is typically associated with poor wear resistance, it is difficult to realize a low Young's modulus and high wear resistance simultaneously. Also, the superelastic property of shape-memory alloys makes them suitable for biomedical applications, like vascular stents and guide wires. However, due to the low recoverable strain of conventional biocompatible shape-memory alloys, the demand for a new alloy system is high. The novel body-centered-cubic cobalt-chromium-based alloys in this work provide a solution to both of these problems. The Young's modulus of <001>-oriented single-crystal cobalt-chromium-based alloys is 10-30 GPa, which is similar to that of human bone, and they also demonstrate high wear and corrosion resistance. They also exhibit superelasticity with a huge recoverable strain up to 17.0%. For these reasons, the novel cobalt-chromium-based alloys can be promising candidates for biomedical applications.
  • Masaaki Nakai; Takeshi Iwasaki; Kosuke Ueki
    Journal of the Mechanical Behavior of Biomedical Materials Elsevier BV 104808 - 104808 1751-6161 2021/09 [Refereed]
  • Masaaki NAKAI; Rin SAWAKI; Kosuke UEKI; Shingo KUROSU; Tomonori NAMBU
    Transaction of the JSME Japan Society of Mechanical Engineers 87 (900) 21 - 00101 2021/08 [Refereed]
  • Soh Yanagihara; Kosuke Ueki; Kyosuke Ueda; Masaaki Nakai; Takayoshi Nakano; Takayuki Narushima
    Metallurgical and Materials Transactions A Springer Science and Business Media LLC 52 (9) 4137 - 4145 1073-5623 2021/07 [Refereed]
     
    AbstractThis is the first report presenting the development of a Co–Cr–W–Ni–Mn alloy by adding 6 mass pct Mn to ASTM F90 Co–20Cr–15W–10Ni (CCWN, mass pct) alloy for use as balloon-expandable stents with an excellent balance of mechanical properties and corrosion resistance. The effects of Mn addition on the microstructures as well as the mechanical and corrosion properties were investigated after hot forging, solution treatment, swaging, and static recrystallization. The Mn-added alloy with a grain size of ~ 20 µm (recrystallization condition: 1523 K, 150 seconds) exhibited an ultimate tensile strength of 1131 MPa, 0.2 pct proof stress of 535 MPa, and plastic elongation of 66 pct. Additionally, it exhibited higher ductility and lower yield stress while maintaining high strength compared to the ASTM F90 CCWN alloy. The formation of intersecting stacking faults was suppressed by increasing the stacking fault energy (SFE) with Mn addition, resulting in a lower yield stress. The low-yield stress is effective in suppressing stent recoil. In addition, strain-induced martensitic transformation during plastic deformation was suppressed by increasing the SFE, thereby improving the ductility. The Mn-added alloys also exhibited good corrosion resistance, similar to the ASTM F90 CCWN alloy. Mn-added Co–Cr–W–Ni alloys are suitable for use as balloon-expandable stents.
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  • Kosuke Ueki; Soh Yanagihara; Kyosuke Ueda; Masaaki Nakai; Takayoshi Nakano; Takayuki Narushima
    MATERIALS TRANSACTIONS Japan Institute of Metals 62 (2) 229 - 238 1345-9678 2021/02 [Refereed]
     
    We investigated changes in the microstructure and mechanical properties of biomedical Co20Cr15W10Ni alloys (mass%) containing 8 mass% Mn and 03 mass% Si due to hot forging, solution treatment, cold swaging, and static recrystallization. The ©-phase (M XM X type cubic structure, M: metallic elements, X: C and/or N, space group: Fd-3m (227)) and CoWSi type Laves phase (C14 MgZn2 type hexagonal structure, space group: P63/mmc (194)) were confirmed as precipitates in the as-cast and as-forged alloys. To the best of our knowledge, this is the first report that reveals the formation of CoWSi type Laves phase precipitates in CoCrWNi-based alloys. The addition of Si promoted the formation of precipitates of both ©-phase and CoWSi type Laves phase. The solution-treated 8Mn+(0, 1)Si-added alloys exhibited TWIP-like plastic deformation behavior with an increasing work-hardening rate during the early to middle stages of plastic deformation. This plastic deformation behavior is effective in achieving both the low yield stress and high strength required to develop a high-performance balloon-expandable stent. The 8Mn+2Si-added alloy retained the CoWSi type Laves phase even after solution treatment, such that the ductility decreased but the strength improved. Additions of Mn and Si are effective in improving the ductility and strength of the CoCrWNi alloy, respectively. 6 12
  • Kosuke Ueki; Soh Yanagihara; Kyosuke Ueda; Masaaki Nakai; Takayoshi Nakano; Takayuki Narushima
    Materials Science Forum Trans Tech Publications, Ltd. 1016 1503 - 1509 0255-5476 2021/01 [Refereed][Invited]
     
    The Co-20Cr-15W-10Ni (CCWN, mass%) alloy has excellent corrosion resistance and strength-ductility balance and is applied in almost all balloon-expandable stent platforms. To further reduce the invasiveness of stent placement, it is necessary to reduce the diameter of the stent. That is, both high strength and high ductility should be achieved while maintaining a low yield stress. In our previous studies, it was discovered that low-temperature heat-treatment (LTHT) at 873 K improves the elongation of the CCWN alloy. In this study, we focused on the grain refinement by swaging and static recrystallization to improve the strength of the alloy. The as-swaged alloy was recrystallized at 1373–1473 K for 100–300 s, followed by LTHT. A fine grain structure with an average grain size of 3–17 μm was obtained by static recrystallization. The η-phase (M12X-M6X type precipitates, M: metallic elements, X: C and/or N) formed during the recrystallization at 1373–1448 K. The alloys recrystallized at 1448 and 1473 K had a homogeneous structure with a small variation in the grain size. On the other hand, the alloys recrystallized at 1373 and 1423 K had an inhomogeneous structure in which fine and coarse grains were mixed. Both the strength and ductility of the CCWN alloy were improved by combining high-temperature short-time recrystallization and LTHT.
  • Kosuke Ueki; Motoka Kasamatsu; Kyosuke Ueda; Yuichiro Koizumi; Daixiu Wei; Akihiko Chiba; Takayuki Narushima
    Metals 10 (1) 1 - 13 2020/01 [Refereed]
     
    © 2020 by the authors. Licensee MDPI, Basel, Switzerland. We studied the precipitates that were induced during γ-ε phase transformation in biomedical Co-28Cr-6Mo (mass%) alloys that were fabricated by electron beam melting with carbon contents of 0.184 and 0.018 mass%. In the high-C as-built alloy, M23X6-type, π-phase (M3T2X-type), and η-phase (M6X-M12X-type) precipitates were observed (M and T: metallic elements, X: C and/or N). σ-phase (Co(Cr,Mo)), π-phase, and Co3Mo2Si-type precipitates were observed in the low-C as-built alloy. This is the first report that shows the presence and chemical composition of this precipitate, as the Co3Mo2Si-type precipitate has not been detected in biomedical Co-Cr-Mo alloys before. After aging in the ε-phase stability region, the high-C and low-C alloys both contained a single ε-phase matrix, and the amount of π-phase precipitates increased. Conversely, the amount of π-phase precipitates in both alloys decreased when a reverse transformation treatment was applied in the γ-phase stability region after aging. In the low-C alloy, the amount of Co3Mo2Si-type precipitates increased after reverse transformation treatment. These results indicate that the dissolution of π-phase precipitates and the formation of Co3Mo2Si-type precipitates during reverse transformation promote the formation of fine γ-phase grains at the precipitate/ε-phase matrix interface, because the formation and dissolution of these precipitates affect the γ-phase stability of the matrix.
  • Kosuke Ueki; Soh Yanagihara; Kyosuke Ueda; Masaaki Nakai; Takayoshi Nakano; Takayuki Narushima
    Materials Science and Engineering A ELSEVIER SCIENCE SA 766 0921-5093 2019/10 [Refereed]
     
    © 2019 The Authors A process combining swaging, static recrystallization, and heat treatment at 873 K (low-temperature heat-treatment, LTHT) was developed for achieving both high ultimate strength and high ductility in Co-20Cr-15W-10Ni (mass%, CCWN) alloy for stent application. The alloys swaged to a sectional area reduction rate of 58.3% were annealed at 1373–1473 K for 30–300 s. Under annealing at 1373 K for 300 s, a fine grain structure with an average grain size of ~6 μm formed, while under annealing at 1473 K, a structure with an average grain size of 12 μm formed after 120 s. In the alloys annealed at 1373–1448 K, the formation of η-phase precipitates (M6X-M12X type, M: metallic elements, X: C and/or N) was observed, while no precipitates were observed in the alloys annealed at 1473 K. The improvement in ultimate strength by grain refinement was confirmed. Alloys annealed at 1473 K showed higher ductility compared to those annealed at 1373–1448 K even if the grain size was similar. It is considered that the η-phase precipitates deteriorated the ductility of the annealed alloys. LTHT suppressed the strain-induced martensitic γ-to-ε transformation to improve the ductility of the fine-grained as well as coarse-grained alloys. Thus, regardless of the grain size, it is newly evidenced that LTHT effectively improves ductility in CCWN alloy. By combining high-temperature short-time annealing and LTHT, both the ultimate strength and ductility of Co-20Cr-15W-10Ni (mass%) alloy improved, and it was possible to provide properties suitable for next-generation balloon-expandable stents with Co-20Cr-15W-10Ni (mass%) alloy.
  • Ueki Kosuke; Abe Mai; Ueda Kyosuke; Nakai Masaaki; Nakano Takayoshi; Narushima Takayuki
    MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING ELSEVIER SCIENCE SA 739 53 - 61 0921-5093 2019/01 [Refereed]
     
    The microstructure and tensile properties of Co-27Cr-6Mo (mass%) alloys heat-treated at 673-1373 K were studied. Lower elongation was observed after heat treatment at 1073 K due to formation of carbonitride precipitates. In contrast, when low-temperature heat treatment (LTHT) was applied at 673-873 K, both the ultimate tensile strength and elongation synchronously improved compared with the solution-treated alloy. Electron backscatter diffraction analysis for plastic-strained alloys and in situ X-ray diffraction analysis under stress induced conditions revealed that the strain-induced martensitic transformation (SIMT) of the gamma(fcc)-phase to epsilon(hcp)-phase during plastic deformation was suppressed by the LTHT. Stacking faults (thin epsilon-phase) were observed to collide in the LTHT alloys. The following mechanisms for the synchronous improvement in the tensile strength and elongation after LHTH are proposed. First, stacking faults with multiple variants were formed during LTHT. Then, the epsilon-phase of a single variant formed by SIMT during plastic deformation collides with preexisting multi-variant stacking faults formed during LTHT, increasing the tensile strength. In addition, the SIMT during plastic deformation is suppressed in the high-plastic-strain region by the collision. This decreases the total amount of epsilon-phase formed during plastic deformation, which improves the ductility. We demonstrated that LTHT of Co-Cr-Mo alloys effectively improves the performance and mechanical safety of spinal fixation implants, which often fracture because of fatigue cracking.
  • Daixiu Wei; Yuichiro Koizumi; Akihiko Chiba; Kosuke Ueki; Kyosuke Ueda; Takayuki Narushima; Yusuke Tsutsumi; Takao Hanawa
    Additive Manufacturing 24 103 - 114 2214-8604 2018/12 [Refereed]
     
    © 2018 We have investigated the spatial distribution of microstructures of a Co-Cr-Mo alloy rod fabricated by Electron Beam Melting (EBM) method along built height. The topside of the rod is rich in γ-fcc phase and consists of fine grains with high local distortion density. The bottom part has an ε-hcp single phase and consists of relatively coarser grains with low local distortion density. The middle part of the rod consisted of the mixture of both phases. The mean grain size increases from 56 μm (at the top of the rod) to 159 μm (at the bottom), and is accompanied by a decrease in the γ-fcc phase fraction. On the other hand, a large number of precipitates including the main M 23 X 6 phase and minor phases (η-phase and π-phase) were observed. The area fraction of the precipitates increases gradually from 5.26% (at the top) to 8.73% (at the bottom), and the relative proportion of each phase fluctuates at different positions. The hardness of the top side is lower than that of the bottom side. As a result, the hardness of the samples, as well as the area fraction of precipitates formed in the samples, increases gradually from top to bottom of the rod, while corrosion resistance is uniformly high throughout the rod almost independently of the location. The mechanism behind the formation of phase distribution is discussed in terms of thermodynamic phase stability and kinetics of phase transformation accompanying the thermal history during the post-solidification process.
  • Kosuke Ueki; Kyosuke Ueda; Masaaki Nakai; Takayoshi Nakano; Takayuki Narushima
    Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science Springer Boston 49 (6) 2393 - 2404 1073-5623 2018/06 [Refereed]
     
    Microstructural changes were observed during the plastic deformation of ASTM F90 Co-20Cr-15W-10Ni (mass pct) alloy heat-treated at 873 K (600 °C) for 14.4 ks, and analyzed by electron backscatter diffraction and in situ X-ray diffraction techniques. The obtained results revealed that the area fraction of the ε-phase (fε) in the as-received alloy was higher than that in the heat-treated alloy in the low-to-middle strain region (≤ 50 pct), whereas the fε of the heat-treated alloy was higher than that of the as-received alloy at the fracture point. During plastic deformation, the ε-phase was preferentially formed at the twin boundaries of the heat-treated alloy rather than at the grain boundaries. According to the transmission electron microscopy observations, the thin ε-phase layer formed due to the alloy heat treatment acted as the origin of deformation twinning, which decreased the stress concentration at the grain boundaries. The results of anodic polarization testing showed that neither the heat treatment at 873 K (600 °C) nor plastic deformation affected the alloy corrosion properties. To the best of our knowledge, this is the first study proving that the formation of a thin ε-phase layer during the low-temperature heat treatment of the studied alloy represents an effective method for the enhancement of the alloy ductility without sacrificing its strength and corrosion properties.
  • Kosuke Ueki; Kyosuke Ueda; Takayuki Narushima
    METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE SPRINGER 47A (6) 2773 - 2782 1073-5623 2016/06 [Refereed]
     
    The microstructure and mechanical properties of a heat-treated biomedical ASTM F90 Co-20Cr-15W-10Ni (mass pct) alloy were investigated. The alloy was heat-treated at temperatures of 673 K to 1623 K (400 A degrees C to 1450 A degrees C) for holding times of 0.6 to 259.2 ks. The formation of M23X6-type (M: metallic element and X: C and N) and eta-phase (M6X-M12X type) precipitates was detected in the heat-treated alloys using a combination of electrolytic extraction and X-ray diffraction. The formation of precipitates deteriorated the ductility of the heat-treated alloys. On the other hand, both the tensile strength and elongation were improved by heat treatment at low temperatures of 673 K to 873 K (400 A degrees C to 600 A degrees C). In this heat-treated alloy, the density of stacking faults was higher than that of the as-received alloy, and the formation of the epsilon-phase was detected. (C) The Minerals, Metals & Materials Society and ASM International 2016
  • Kosuke Ueki; Yuto Kurihara; Shingo Mineta; Alfirano; Kyosuke Ueda; Shigenobu Namba; Takashi Yoneda; Takayuki Narushima
    MATERIALS TRANSACTIONS JAPAN INST METALS 57 (12) 2048 - 2053 1345-9678 2016 [Refereed]
     
    Changes in the microstructure and hardness of biomedical Co-Cr-Mo forged alloys (Co-27Cr-6Mo-0.77Si-0.64Mn-0.17N-0.06C (mass%)) during aging were investigated with a focus on precipitation. After solution treatment at 1523 K for 1.8 ks, the alloys were subjected to aging at temperatures between 973 and 1373 K for up to 86.4 ks. eta-phase (M6X-M12X type), M23X6-type and pi-phase (A(2)T(3)X type) precipitates were detected after aging. The formation of pi-phase precipitates was detected in alloys aged between 1023 and 1123 K for holding times >= 21.6 ks, with a nose temperature between 1073 and 1123 K. The presence of Tr-phase precipitates in the aged Co-Cr-Mo alloy is reported for the first time; N contained within the alloy is believed to contribute to formation of the yr-phase. The formation of a hexagonal-close-packed Co-based metallic phase (epsilon-phase) was observed between 1023 and 1123 K. The Vickers hardness increased in alloys aged at 1023 and 1073 K. This increase in hardness is attributed to the presence Of pi-phase and epsilon-phase and their wide-area precipitation.
  • Kyosuke Ueda; Motoka Kasamatsu; Masanori Tanno; Kosuke Ueki; Jean Geringer; Takayuki Narushima
    MATERIALS TRANSACTIONS JAPAN INST METALS 57 (12) 2054 - 2059 1345-9678 2016 [Refereed]
     
    Pin-on-disk wear tests using Co-Cr-Mo (CCM) alloy pins and disks were conducted in 0.14 NI NaCl solutions with and without albumin. To clarify the effect of precipitates in the CCM alloys on the alloy wear behavior, as-received (having precipitates) and solution-treated (having no precipitates) CCM alloys were used as specimens. Friction coefficients during wear testing were measured. After the wear testing, the mass loss of pins and disks, wear tracks on the disks, and the wear debris were examined using scanning electron microscopy (SEM) and laser microscopy (LM). The concentration of metallic ions in solution was analyzed by inductively coupled plasma-atomic emission spectroscopy (ICPAES). In the solution without albumin, the friction coefficient increased with increasing sliding time and discontinuous wear grooves with attached and detached sections were observed, indicating that adhesive wear was dominant. On the other hand, in the solution with albumin, the friction coefficient was constant independent of the sliding distance and continuous wear grooves were observed, indicating that abrasive wear was dominant. High amounts of mass loss were detected from the as-received alloys in the albumin solution, and it is theorized that the wear debris (including precipitates) enhanced the third-body wear. The concentration of Cr ions in solution was lower than the expected values based on the alloy composition. In the solution with albumin, it was thought that the Cr ions bonded with the albumin, increasing the amount of available Cr ions in solution.
  • Microsturucture, tensile properties and corrosive properties of ASTM F90 Co-20Cr-15W-10Ni alloys
    K. Ueki; K. Ueda; T. Narushima
    Proceedings of 24thInternational Symposium of Processing and Fabrication of Advanced Materials, PFAM XXIV 50 - 58 2015/12 [Refereed]
  • Effect of heat treatment of the microstructure and mechanical properties of biomedical Co-20Cr-15W-10Ni alloy
    K. Ueki; K. Ueda; T. Narushima
    Proceedings of the Biomaterials International Conference 2015 1182  2015/06 [Refereed]
  • Kosuke Ueki; Kyosuke Ueda; Takayuki Narushima
    ADVANCED CERAMICS AND NOVEL PROCESSING TRANS TECH PUBLICATIONS LTD 616 258 - 262 1013-9826 2014 [Refereed]
     
    The precipitation behavior during heat treatment and resulting mechanical properties of ASTM F 90 Co-20Cr-15W-10Ni (mass%) alloys were investigated with regards to their biomedical applications. Heat treatment was conducted at temperatures of 873 to 1623 K, for a holding time of 259.2 ks. The precipitates produced were then electrolytically extracted from the alloys and analyzed by X-ray diffraction (XRD). This revealed that the precipitates formed were an M23X6 type and/or eta-phase (i.e., an M6X-M12X type). The M23X6-type precipitate was detected across the entire heat-treatment temperature range; however, the.-phase precipitate was only detected at 1073 to 1473 K, becoming dominant at 1173 to 1373 K. The formation of M23X6 type precipitates at 873 K is shown to improve the mechanical properties of this alloy, whereas the domination by the eta-phase precipitate at higher temperatures causes deterioration in the ductility.

Conference Activities & Talks

  • ステント用Co-Cr-W-Pt合金の加工熱処理に伴う微細組織変化  [Not invited]
    中島 知紀; 植木 洸輔; 上田 恭介; 成島 尚之
    公益社団法人 日本金属学会 2024年春期(第174回)講演大会  2024/03
  • 生体用Co-Cr-Fe-Ni-Mo系合金における加工硬化挙動の計算材料学的・実験的検討  [Not invited]
    檜山 快; 植木 洸輔; 佐原 亮二; 上田 恭介; 成島 尚之
    公益社団法人 日本金属学会 2024年春期(第174回)講演大会  2024/03
  • 植木 洸輔; 肥田 輝; 堀畑 敦史; 仲井 正昭
    公益社団法人 日本金属学会 2024年春期(第174回)講演大会  2024/03
  • 生体用Co-Cr-Fe-Ni-Mo系合金における 積層欠陥エネルギーの実験的・計算材料学的研究
    檜山快; 植木洸輔; 佐原亮二; 上田恭介; 成島尚之
    2023年度 東北大学金属材料研究所共同研究ワークショップ／日本バイオマテリアル学会東北ブロック交流会  2023/12
  • Effect of Ni and Fe content on microstructure and mechanical properties of biomedical Co-Cr-Fe-Ni-Mo alloy  [Not invited]
    Kai Hiyama; Kosuke Ueki; Kyosuke Ueda; Takayuki Narushima
    The 11th Pacific Rim International Conference on Advanced Materials and Processing  2023/11
  • 高い X 線視認性を有する ステント用 Co-Cr-W-Pt系合金の微細組織制御  [Not invited]
    中島 知紀; 伊藤 悠莉; 本田有作; 植木洸輔; 沼野智一; 上田恭介; 成島尚之
    第45回日本バイオマテリアル学会大会  2023/11
  • バルーン拡張型ステント用Co-Cr-W-Ni合金チューブ材の微細組織と力学特性
    植木 洸輔; 上田 恭介; 仲井 正昭; 中野 貴由; 成島 尚之
    日本機械学会 M&M2023 材料力学カンファレンス  2023/09
  • 弾性率の異なるTi合金プレートで固定した家兎大腿骨における仮骨形成
    宮﨑 大輔; 山本 衛; 新井 悠希; 坂田 誠一郎; 植木 洸輔; 仲井 正昭; ノルアイン アブドラ
    公益社団法人 日本金属学会 2023年秋期期(第173回)講演大会  2023/09
  • Co-Cr-Al-Si合金の高い弾性異方性と単結晶における低いヤング率
    許 皛; 大平 拓実; 許 勝; 平田 研二; 大森 俊洋; 植木 洸輔; 上田 恭介; 成島 尚之; 長迫 実; Harjo Stefanus; 川崎 卓郎; Bodnárová Lucie; Sedlák Petr; Seiner Hanuš; 貝沼 亮介
    公益社団法人 日本金属学会 2023年秋期期(第173回)講演大会  2023/09
  • 高濃度Taを含有したTi合金の溶製方法およびヤング率
    大田 尚輝; 植木 洸輔; 仲井 正昭
    公益社団法人 日本金属学会 2023年秋期期(第173回)講演大会  2023/09
  • X線透視下視認性に優れたステント用NiフリーCo-Cr基合金の開発
    肥田 輝; 植木 洸輔; 仲井 正昭
    公益社団法人 日本金属学会 2023年秋期期(第173回)講演大会  2023/09
  • バルーン拡張型ステント用Co-Cr-Ni-Pt-W系合金の機械的特性、X線視認性および磁化率アーチファクト形成評価
    上田 恭介; 本田 有作; 植木 洸輔; 沼野 智一; 成島 尚之
    公益社団法人 日本金属学会 2023年秋期期(第173回)講演大会  2023/09
  • 生体用Co-Cr-Fe-Ni-Mo合金の塑性変形に伴う微細組織変化
    檜山 快; 植木 洸輔; 上田 恭介; 成島 尚之
    公益社団法人 日本金属学会 2023年秋期期(第173回)講演大会  2023/09
  • 生体用β型Ti-Nb-Ta-Zr合金粉末を用いて粉末床溶融結合法で 作製したシングルトラックの評価
    武田 森哉; 仲井 正昭; 植木 洸輔; 京極 秀樹
    公益社団法人 日本金属学会 2023年秋期期(第173回)講演大会  2023/09
  • Kosuke Ueki; Ryo Hirano; Masaaki Nakai
    Biomaterials International 2023  2023/08
  • Wear properties of biomedical titanium alloys with dimple textured surface through laser processing  [Invited]
    Masaaki Nakai; Takeshi Iwasaki; Kosuke Ueki
    Thermec'2023 International Conference on PROCESSING & MANUFACTURING OF ADVANCED MATERIALS Processing, Fabrication, Properties, Applications  2023/07
  • Improvement of work-hardening behavior of Co-Cr-W-Ni alloy by adding Mn / Fe for balloon-expandable stents  [Invited]
    Kosuke Ueki; Kyosuke Ueda; Masaaki Nakai; Takayoshi Nakano; Takayuki Narushima
    Thermec'2023 International Conference on PROCESSING & MANUFACTURING OF ADVANCED MATERIALS Processing, Fabrication, Properties, Applications  2023/07
  • 生体用Co-Cr-W-Ni合金におけるメカニカルミリング法と放電プラズマ焼結を用いた調和組織形成による機械的特性向上  [Not invited]
    植木 洸輔; 水谷 祐太; 仲井 正昭
    公益社団法人 日本金属学会 2023年春期(第172回)講演大会  2023/03
  • 骨治癒の進行に及ぼすチタンインプラントプレートの剛性の影響  [Not invited]
    ノルアイン アブドラー; 宮崎 大輔; 山本 衛; 植木 洸輔; 仲井 正昭
    公益社団法人 日本金属学会 2023年春期(第172回)講演大会  2023/03
  • 生体用Co-Cr-Fe-Mo系合金の微細組織と機械的特性に及ぼすNi含有量の影響  [Not invited]
    檜山 快; 植木 洸輔; 上田 恭介; 成島 尚之
    公益社団法人 日本金属学会 2023年春期(第172回)講演大会  2023/03
  • 弾性率の異なるTi合金プレートで固定した家兎大腿骨に形成された仮骨の定量評価  [Not invited]
    宮﨑 大輔; ノルアイン ビンティ アブドラ; 山本 衛; 植木 洸輔; 仲井 正昭
    公益社団法人 日本金属学会 2023年春期(第172回)講演大会  2023/03
  • 低ヤング率を有するCo-Cr-Al-Si超弾性合金
    許 皛; 大平 拓実; 許 勝; 平田 研二; 大森 俊洋; 植木 洸輔; 上田 恭介; 成島 尚之; 長迫 実; Harjo Stefanus; 川崎 卓郎; odnárová Lucie; Sedlák Petr; Seiner Hanuš; 貝沼 亮介
    公益社団法人 日本金属学会 2022年秋期期(第171回)講演大会  2022/09
  • 骨治癒時の仮骨形成パターンに及ぼすインプラントプレートの剛性の影響
    ノルアイン アブドラー; 宮崎 大輔; 山本 衛; 植木 洸輔; 仲井 正昭
    公益社団法人 日本金属学会 2022年秋期期(第171回)講演大会  2022/09
  • 高いX線造影性を有するステント用Co-Cr-Ni-Pt-W系合金開発
    本田 有作; 植木 洸輔; 上田 恭介; 成島 尚之
    公益社団法人 日本金属学会 2022年秋期期(第171回)講演大会  2022/09
  • 生体用Co-Cr-W-Ni合金におけるFe添加が機械的特性および耐食性に与える影響
    肥田 輝; 植木 洸輔; 上田 恭介; 成島 尚之; 仲井 正昭
    公益社団法人 日本金属学会 2022年秋期期(第171回)講演大会  2022/09
  • 生体用Co-Cr-Fe-Ni-Mo合金の微細組織および機械的特性に及ぼす加工熱処理の影響
    檜山 快; 植木 洸輔; 上田 恭介; 成島 尚之
    公益社団法人 日本金属学会 2022年秋期期(第171回)講演大会  2022/09
  • 高濃度Taを含有するTi合金のインゴット内部のTa濃度分布と局所的ヤング率
    大田 尚輝; 植木 洸輔; 仲井 正昭
    公益社団法人 日本金属学会 2022年秋期期(第171回)講演大会  2022/09
  • 初期治癒段階における骨形成に及ぼすインプラントプレートと骨と弾性率差の影響  [Not invited]
    ノルアイン アブドラ; 宮崎 大輔; 山本 衛; 植木 洸輔; 仲井 正昭
    公益社団法人 日本金属学会 2022年春期(第170回)講演大会  2022/03
  • 高濃度Taを含有するTi合金の溶解・凝固特性  [Not invited]
    大田 尚輝; 植木 洸輔; 仲井 正昭
    公益社団法人 日本金属学会 2022年春期(第170回)講演大会  2022/03
  • 植木 洸輔; 平野 涼; 仲井 正昭
    公益社団法人 日本金属学会 2022年春期(第170回)講演大会  2022/03
  • 平野 涼; 植木 洸輔; 仲井 正昭
    公益社団法人 日本金属学会 2021年秋期第169回講演大会  2021/09
  • Kosuke Ueki; Soh Yanagihara; Kyosuke Ueda; Masaaki Nakai; Takayoshi Nakano; Takayuki Narushima
    THERMEC'2020/2021 the International Conference on Processing and Manufacturing of Advanced Materials  2021/06
  • MnおよびSiを添加したステント用Co-Cr合金の微細組織と機械的特性  [Not invited]
    柳原 創; 植木 洸輔; 上田 恭介; 仲井 正昭; 中野 貴由; 成島 尚之
    日本金属学会2020年秋期 第167回講演大会  2020/09
  • 電子ビーム積層造形法により作製した生体用Co-Cr-Mo合金の逆変態処理による結晶粒微細化と晶析出物相の関係
    植木 洸輔; 笠松 初香; 上田 恭介; 小泉 雄一郎; 魏 代修; 千葉 晶彦; 成島 尚之
    日本金属学会2020年春期 第166回講演大会  2020/03
  • 生体用Co-Cr-W-Ni合金における加工熱処理プロセスによるバイモーダル組織形成と機械的特性評価  [Not invited]
    平野 涼; 植木 洸輔; 成島 尚之; 仲井 正昭
    日本金属学会2020年春期 第166回講演大会  2020/03
  • 生体用Co-Cr-W-Ni合金における静的再結晶・低温熱処理プロセスによる強度・延性の向上  [Not invited]
    植木 洸輔; 柳原 創; 上田 恭介; 仲井 正昭; 中野 貴由; 成島 尚之
    日本金属学会2019年秋期講演大会(第165回)  2019/09
  • SLMを用いて作製したTi-6Al-4V合金三次元格子構造体の変形挙動と特性  [Not invited]
    金 泰可; 仲井 正昭; 植木 洸輔; 宮本 陸; 坂田 誠一郎; 京極 秀樹
    日本金属学会2019年秋期講演大会(第165回)  2019/09
  • レーザ積層造形によるマルテンサイト型ステンレス鋼の高耐食性化  [Not invited]
    堤 祐介; 石本 卓也; 上田 恭介; 久世 哲嗣; 丸山 晋平; 松垣 あいら; 陳 鵬; 蘆田 茉希; 植木 洸輔; 柳谷 彰彦; 片山 秀樹; 中野 貴由; 塙 隆夫
    日本金属学会2019年秋期講演大会(第165回)  2019/09
  • Effects of Young's modulus difference of titanium alloys and bone on bone formation  [Not invited]
    ノルアイン アブドラー; 仲井 正昭; 植木 洸輔; 川村 勇樹; 山本 衛; 新家 光雄
    日本金属学会2019年秋期講演大会(第165回)  2019/09
  • Effect of Laser Nitriding Process Repetition on Surface Hardening of Ti-6Al-4V ELI  [Not invited]
    FATIN NABILAH BINTI SAPARI; 仲井 正昭; 植木 洸輔; 瀧口 功大; 大津 直史
    日本金属学会2019年秋期講演大会(第165回)  2019/09
  • 生体用Co-Cr-W-Ni合金における歪み誘起マルテンサイト変態発生挙動の結晶粒径依存性  [Not invited]
    植木洸輔; 上田恭介; 仲井正昭; 中野貴由; 成島尚之
    日本金属学会2018年秋期講演大会(第163回)  2018/09
  • 生体用Co-Cr-W-Ni合金の結晶粒径が塑性変形挙動に及ぼす影響  [Not invited]
    植木洸輔; 上田恭介; 仲井正昭; 中野貴由; 成島尚之
    日本バイオマテリアル学会東北ブロック講演会  2018/08
  • 高性能インプラント創製ための生体用Co-Cr-Mo (CCM)合金の電子ビーム積層造形に関する取り組み  [Not invited]
    小泉雄一郎; 魏代修; 山中謙太; 千葉晶彦; 植木洸輔; 上田恭介; 成島尚之; 堤祐介; 塙隆夫; 黒田健介; 興戸正純
    学際・国際的高度人材育成ライフイノベーションマテリアル創製共同研究プロジェクト（6大学連携プロジェクト）第2回公開討論会  2018/03
  • 積層造形法により作製したCo-Cr-Mo合金の組織微細化と析出物  [Not invited]
    笠松初香; 植木洸輔; 上田恭介; 小泉雄一郎; 魏代修; 千葉晶彦; 成島尚之
    日本金属学会2018年春期講演大会(第162回)  2018/03
  • ステント用Co-Cr合金の塑性変形挙動に及ぼす結晶粒径の影響  [Not invited]
    植木洸輔; 上田恭介; 仲井正昭; 中野貴由; 成島尚之
    日本金属学会2018年春期講演大会(第162回)  2018/03
  • 生体用Co-Ni-Cr-Mo(ASTM F562)合金の機械的特性に及ぼす熱処理の影響  [Not invited]
    砂沢俊哉; 植木洸輔; 上田恭介; 成島尚之
    日本バイオマテリアル学会東北ブロック講演会  2017/09
  • 生体用Co-Cr-Mo合金における熱処理が微細組織および機械的特性に与える影響  [Not invited]
    植木洸輔; 阿部舞; 上田恭介; 仲井正昭; 中野貴由; 成島尚之
    日本バイオマテリアル学会東北ブロック講演会  2017/09
  • 生体用Co-Cr-Mo合金の熱処理による機械的特性変化  [Not invited]
    植木洸輔; 阿部舞; 上田恭介; 仲井正昭; 中野貴由; 成島尚之
    日本金属学会2017年秋期講演大会(第161回)  2017/09
  • 生体用Co-Ni-Cr-Mo合金の機械的特性に及ぼすTi含有量の影響  [Not invited]
    砂沢俊哉; 植木洸輔; 上田恭介; 成島尚之
    日本金属学会2017年秋期講演大会(第161回)  2017/09
  • Changes in microstructure during deformation in ASTM F90 Co-20Cr-15W-10Ni alloy for biomedical application  [Not invited]
    Kosuke Ueki; Kyosuke Ueda; Masaaki Nakai; Takayoshi Nakano; Takayuki Narushima
    2017 Joint symposium on the Materials Science and Engineering (MSE) for the 21st Century  2017/06
  • Microstructure change during deformation of biomedical Co-Cr-W-Ni alloy  [Not invited]
    K. Ueki; K. Ueda; M. Nakai; T. Narushima
    2017 Japan-Russia Joint Seminar, Advanced Materials: Synthesis, Process and Nanostructures  2017/03
  • ステント用Co-Cr合金の低温熱処理および塑性変形に伴う微細組織変化  [Not invited]
    植木洸輔; 上田恭介; 仲井正昭; 成島尚之
    日本金属学会2017年春期講演大会(第160回)  2017/03
  • 電子ビーム積層造形(EBM)した生体用Co-Cr-Mo合金の組織と晶析出物分析  [Not invited]
    小泉雄一郎; 魏代修; 山中謙太; 千葉晶彦; 植木洸輔; 上田恭介; 成島尚之
    日本金属学会2017年春期講演大会(第160回)  2017/03
  • ASTM F1058合金における熱処理が微細組織および機械的特性に与える影響  [Not invited]
    植木洸輔; 上田恭介; 成島尚之
    日本金属学会2016年秋期講演大会(第159回)  2016/09
  • Tensile properties and corrosion resistance of heat-treated Co-20Cr-15W-10Ni alloy for stent application  [Not invited]
    K. Ueki; K. Ueda; T. Narushima
    2016 Joint symposium on the Materials Science and Engineering (MSE) for the 21st Century  2016/08
  • 金属系バイオマテリアルの表面および組織制御  [Not invited]
    植木洸輔; 上田恭介; 成島尚之
    学際・国際的高度人材育成ライフイノベーションマテリアル創製共同研究プロジェクトキックオフ公開討論会  2016/07
  • Precipitates and mechanical properties of metallic biomaterials  [Invited]
    T. Narushima; K. Ueki; K. Hara; K. Ueda
    International Conference on Processing & Manufacturing of Advanced Materials (THERMEC’ 2016)  2016/05
  • ステント用Co-Cr合金熱処理材の塑性変形中微細組織変化および耐食性  [Not invited]
    植木洸輔; 上田恭介; 成島尚之
    日本金属学会2016年春期講演大会(第158回)  2016/03
  • Microstructure, tensile properties, and corrosion resistance of ASTM F90 Co-20Cr-15W-10Ni alloy heat-treated at 673 to 1623 K  [Not invited]
    K. Ueki; K. Ueda; T. Narushima
    24thInternational Symposium of Processing and Fabrication of Advanced Materials, PFAM XXIV  2015/12
  • ステント用Co-Cr合金の熱処理による微細組織変化と機械的特性および耐食性の関係  [Not invited]
    植木洸輔; 上田恭介; 成島尚之
    日本金属学会2015年秋期講演大会(第157回)  2015/09
  • Effect of heat treatment on the microstructure and mechanical properties of biomedical Co-20Cr-15W-10Ni alloy  [Not invited]
    K. Ueki; K. Ueda; T. Narushima
    Biomaterials International 2015  2015/06
  • ジルコニウムイオンプレーティングによるニッケルチタン合金の耐食性向上  [Not invited]
    金高弘恭; 布目祥子; 冨並香奈子; 高田朝; 植木洸輔; 上田恭介; 五十嵐薫; 成島尚之
    粉体粉末冶金協会平成27年度春季大会  2015/05
  • ステント用Co-Cr合金の熱処理による組織変化が機械的特性に与える影響  [Not invited]
    植木洸輔; 上田恭介; 成島尚之
    日本金属学会2015年春期講演大会(第156回)  2015/03
  • Corrosion Resistance of Zr-ion Plationg Ni-Ti Alloys in Fluoride-containing Environments  [Not invited]
    S. Nunome; H. Kanetaka; K. Ueda; K. Ueki; T. Narushima
    International Association for Dental Research General Session & Exhibition  2015/03
  • ステント用Co-Cr合金の熱処理に伴う析出物および機械的特性の変化  [Not invited]
    植木洸輔; 上田恭介; 成島尚之
    日本金属学会2014年秋期講演大会(第155回)  2014/09
  • Precipitates and mechanical properties of heat-treated Co-Cr-W-Ni alloy (L605) for stent application  [Not invited]
    K. Ueki; K. Ueda; T. Narushima
    9th International Workshop on Biomaterials in Interface Science  2014/08

MISC

  • 学会印象記 Biomaterials International 2023
    植木 洸輔  バイオマテリアルー生体材料ー  42-  (1)  2024/01
  • 思い出の教科書、この一冊 "金属組織学" 須藤一 田村今男 西澤泰二 (共著) 丸善 1972
    植木 洸輔  まてりあ  62-  (5)  2023/05
  • なし
    植木 洸輔  Journal of Japanese Society for Biomaterials  41-  (5)  145  -147  2023/05
  • 許きょう; 許きょう; 大平拓実; 大平拓実; 許勝; 平田研二; 平田研二; 大森俊洋; 植木洸輔; 植木洸輔; 上田恭介; 成島尚之; 長迫実; HARJO Stefanus; 川崎卓郎; BODNAROVA Lucie; SEDLAK Petr; SEINER Hanus; 貝沼亮介  日本金属学会講演大会(Web)  173rd-  2023
  • 謙太 山中; 祐介 堤; 誠鎬 李; 洸輔 植木; あいら 松垣; 研 趙; 直子 池尾; 昌高 袴田  Materia Japan  61-  (11)  731  -732  2022/11
  • XU Xiao; XU Xiao; 大平拓実; 大平拓実; XU Sheng; 平田研二; 平田研二; 大森俊洋; 植木洸輔; 植木洸輔; 上田恭介; 成島尚之; 長迫実; HARJO Stefanus; 川崎卓郎; BODNAROVA Lucie; SEDLAK Petr; SEINER Hanus; 貝沼亮介  材料とプロセス(CD-ROM)  35-  (2)  2022
  • 生体用Co-Cr合金の加工熱処理による組織制御
    植木 洸輔  ぷらすとす  4-  (37)  34  -39  2021/01  [Refereed]
  • 小泉雄一郎; 魏代修; 山中謙太; 千葉晶彦; 植木洸輔; 上田恭介; 成島尚之  日本金属学会講演概要(CD-ROM)  160th-  2017

Awards & Honors

  • 2023/11 The 11th Pacific Rim International Conference on Advanced Materials and Processing 2023年11月20日 Best Poster award
     Effect of Ni and Fe content on microstructure and mechanical properties of biomedical Co-Cr-Fe-Ni-Mo alloy 
    受賞者: Kai Hiyama;Kosuke Ueki;Kyosuke Ueda;Takayuki Narushima
  • 2019/09 日本バイオマテリアル学会 優秀ポスター賞
     ステント用Co-Cr-W-Ni合金の結晶粒微細化と機械的特性 
    受賞者: 柳原 創;植木 洸輔;上田恭介;仲井正昭;中野貴由;成島尚之
  • 2017/06 2017 Joint symposium on the Materials Science and Engineering (MSE) for the 21st Century Best poster award
     Changes in microstructure during deformation in ASTM F90 Co-20Cr-15W-10Ni alloy for biomedical application 
    受賞者: K. Ueki;K. Ueda;M. Nakai;T. Nakano;T. Narushima
  • 2015/09 日本金属学会 2015年秋期講演大会(第157回) 優秀ポスター賞
     ステント用Co-Cr合金の熱処理による微細組織変化と機械的特性および耐食性の関係 
    受賞者: 植木洸輔;上田恭介;成島尚之

Research Grants & Projects

  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists
    Date (from‐to) : 2021/04 -2025/03 
    Author : 植木 洸輔
     
    メカニカルアロイングおよび放電プラズマ焼結によってFe-Mn-Mg合金の創製に成功した。作製したFe-Mn-Mg合金に対し、微細組織分析、硬さ試験、圧縮試験、浸漬試験、電気化学試験を行うことで、Fe, Mn, Mgの合金化プロセス、相変態挙動、Mg添加量が機械的特性および腐食特性に与える影響を明らかにした。Mg添加量の増加に伴い、合金化に必要なメカニカルアロイングの実施時間が増加することが明らかとなった。放電プラズマ焼結時にはbcc相からfcc相+hcp相への母相の相変態が発生した。Mg添加量のみならず、焼結体の緻密性も機械的特性および腐食特性に大きな影響を及ぼすことが明らかとなった。 これらの研究成果は、2021年9月14日に日本金属学会2021年秋期(第169回)講演大会にて「メカニカルアロイングと放電プラズマ焼結による生体用Fe-Mn-Mg合金の開発」という題目にてポスター発表を、2022年3月17日に日本金属学会2022年春期(第170回)講演大会にて「メカニカルアロイングおよび放電プラズマ焼結によって作製したFe-Mn-Mg合金の相変態挙動と機械的および腐食特性」という題目にて口頭発表を行った。さらに、現在投稿論文を執筆中であり、2022年5月頃に投稿予定である。また、2022年8月に開催される国際会議「Biomaterials International 2022]にて「EFFECT OF Mg ADDITON ON MECHANICAL AND CORROSIVE PROPERTIES OF BIODEGRADABLE Fe-Mn ALLOY FABRICATED BY MECHANICAL ALLOYING AND SPARK PLASMA SINTERING」という題目にて発表予定である。
  • 一般社団法人田中貴金属財団：貴金属に関わる研究助成金 萌芽賞
    Date (from‐to) : 2022/04 -2024/03 
    Author : 植木 洸輔
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2020/04 -2023/03 
    Author : 仲井 正昭; 山本 衛; 京極 秀樹; 坂田 誠一郎; 植木 洸輔
     
    骨固定用金属製インプラントの剛性は、骨修復中とその後とで適正値が異なり、骨修復中は高剛性、骨修復完了後は低剛性のほうが適切であることが実験的に示唆されている。さらに、この骨修復状況に依存した金属製インプラントの剛性の適正値の変化は力学的負荷方向に依存し、骨修復中は骨のねじり方向、骨修復後は軸方向の剛性が重要であると考えられる。そこで、本研究では、骨のねじり方向に高剛性であり、軸方向に低剛性となるように、意図的に大きな剛性異方性を付与した金属製インプラントの作製を試みる。この実現のため、材質と形状とを同時に制御することが可能な金属積層造形技術を用いる。昨年度、市販の316Lステンレス鋼を供試材として用い、横方向には高ヤング率となり、縦方向には低ヤング率となるように、面内の直交する二方向の結晶方位を制御し、プレートのヤング率を縦方向よりも横方向に高くすることに成功した。今年度は、結晶構造が体心立方格子（BCC）からなる、市販されていないチタン合金製粉末をガスアトマイズ法およびプラズマ回転電極法を用いて試作し、粒度分布や流動性を評価するとともに、粉末内部のミクロ組織を観察・分析した。その結果、粉末製造法に依存して、各粉末のサテライトの付着状況や真球度が異なっていたが、いずれも金属積層造形に用いることが可能であることを確認した。さらに、粉末内部の気孔の存在割合やデンドライト組織形態が粉末製造法に依存して異なることを明らかにした。ただし、元素分布自体は、いずれの粉末内部においても、BCC安定化元素の濃化部とそれ以外の元素の濃化部とに分かれ、濃化の程度は粉末製造法にあまり依存しないことが明らかとなった。
  • 株式会社クボタ：クボタ若手研究者研究奨励制度(金属材料分野)
    Date (from‐to) : 2021/12 -2022/12 
    Author : 植木 洸輔
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows
    Date (from‐to) : 2016/04 -2019/03 
    Author : 植木 洸輔
     
    1. 前年度までのASTM F90 Co-20Cr-15W-10Ni(mass%)合金における加工熱処理による結晶粒微細化と低温熱処理による機械的特性の向上に関する研究を発展させ、塑性変形挙動の結晶粒径依存性を調査した。粗大結晶粒組織の場合には、塑性変形中に加工硬化率が上昇する優れた加工硬化特性を示し、低温熱処理を施すことでその傾向が促進された。一方で、微細結晶粒組織の場合には、塑性変形初期では高い加工硬化率を示すものの、歪みの増加とともに加工硬化率が減少する傾向を示した。結晶粒微細化によって歪み誘起マルテンサイト変態(SIMT)の発生が促進されていることが明らかとなった。これは、結晶粒微細化に伴い、SIMTの発生サイトになりやすい結晶粒界および双晶界面が増加したためであると考えられる。さらに、結晶粒径にかかわらず、低温熱処理によりSIMTの発生が抑制された。これらの結果から、結晶粒微細化と低温熱処理を組み合わせることで高強度、高延性、低降伏応力というバルーン拡張型ステントに適した特性を付与することが可能であることが明らかとなった。 2. ASTM F90 Co-20Cr-15W-10Ni(mass%)合金をベースとして、低降伏応力を維持したままでのさらなる高強度化、高延性化を目的として、Si, Mnを添加した新合金を作製した。Siは、固溶強化による強度向上を、Mnは延性の向上および析出物形成の抑制を目的として添加した。Si添加により(Co, Ni)WSi laves相が形成し、強度が向上したものの、延性の著しい低下が確認された。一方で、Mn添加により延性が向上し、塑性変形中に加工硬化率が上昇する優れた加工硬化特性を示した。この結果から、Mn添加は、高強度、高延性、低降伏応力を共立する合金開発において一つの有効な方法であることが示唆された。

Teaching Experience

  • Materials Engineering and ProcessingMaterials Engineering and Processing Kindai University
  • Interdisciplinary Lecture in Mechanics ⅠInterdisciplinary Lecture in Mechanics Ⅰ Kindai University
  • Materials EngineeringMaterials Engineering Osaka Sangyo University

Others

  • 2020/04 -2021/03  メカニカルアロイングによる革新的Fe基生分解性金属材料 の創製 
    近畿大学学内研究助成金 研究種目: 奨励研究助成金 課題番号: SR01

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