研究者業績
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  2. 蘆田 茉希

蘆田 茉希

アシダ マキ  (Maki Ashida)

基本情報

所属
成蹊大学 理工学部 理工学科 助教
学位
博士（工学）
J-GLOBAL ID
201801006443704147
researchmap会員ID
7000025465

研究キーワード

 1

研究分野

 1

経歴

 8
もっとみる

受賞

 24
もっとみる

論文

 51
  • Taichi Akutsu, Maki Ashida, Shotaro Hisano, Chie Ashida, Eric Des Marias, Shizuka Sutani
    Arts & Communication 2(2) 1782-1782 2024年5月6日  査読有り
    Despite the existing research on flow in music education, there remains a lack of researches in understanding children’s flow experiences in the context of playing musical instrument, electronic technological instruments, and other traditional instruments. This study investigates the observable flow experience among young children during their interactions with musical instrument digital interface instruments, violins, and bell-like instruments. The research employed a case study approach, with 20 children aged two to nine (11 females and nine males) participating in the study. In the study, we, as practitioner-researchers, offered workshops for children to experience a variety of traditional and non-traditional musical instruments. Throughout the study, researchers collected 89 video clips for analysis, using four cameras operated by four assistants who were trained to capture children’s flow in a musical context. These monthly sessions, each lasting an average of 60 min, began with the first session dedicated to capturing the very first encounter of children with various musical devices, instruments, and materials. Custodero’s Flow Indicators in Musical Activities captured children’s flow experiences during workshops. The findings included interpretations of the children’s flow experiences as they explored different devices, instruments, and materials, with a particular emphasis on accessibility and developmental considerations within the social context of children’s musical flow.
  • Kaveh Edalati, Anwar Q. Ahmed, Saeid Akrami, Kei Ameyama, Valery Aptukov, Rashid N. Asfandiyarov, Maki Ashida, Vasily Astanin, Andrea Bachmaier, Victor Beloshenko, Elena V. Bobruk, Krzysztof Bryła, José María Cabrera, Amanda P. Carvalho, Nguyen Q. Chinh, In-Chul Choi, Robert Chulist, Jorge M. Cubero-Sesin, Gregory Davdian, Muhammet Demirtas, Sergiy Divinski, Karsten Durst, Jiri Dvorak, Parisa Edalati, Satoshi Emura, Nariman A. Enikeev, Ghader Faraji, Roberto B. Figueiredo, Ricardo Floriano, Marjan Fouladvind, Daniel Fruchart, Masayoshi Fuji, Hiroshi Fujiwara, Marcell Gajdics, Diana Gheorghe, Łukasz Gondek, Joaquín E. González-Hernández, Alena Gornakova, Thierry Grosdidier, Jen Gubicza, Dmitry Gunderov, Liqing He, Oscar Fabian Higuera, Shoichi Hirosawa, Anton Hohenwarter, Zenji Horita, Jelena Horky, Yi Huang, Jacques Huot, Yoshifumi Ikoma, Tatsumi Ishihara, Yulia Ivanisenko, Jae-il Jang, Alberto M. Jorge, Mie Kawabata-Ota, Megumi Kawasaki, Tarek Khelfa, Junya Kobayashi, Lembit Kommel, Anna Korneva, Petr Kral, Natalia Kudriashova, Shigeru Kuramoto, Terence G. Langdon, Dong-Hyun Lee, Valery I. Levitas, Cong Li, Hai-Wen Li, Yongtao Li, Zheng Li, Huai-Jun Lin, Klaus-Dieter Liss, Ying Liu, Diana Maritza Marulanda Cardona, Kenji Matsuda, Andrey Mazilkin, Yoji Mine, Hiroyuki Miyamoto, Suk-Chun Moon, MullerTimo Müller, Jairo Alberto Muñoz, Maxim Yu. Murashkin, Muhammad Naeem, Marc Novelli, Dániel Olasz, Reinhard Pippan, Vladimir V. Popov, Elena N. Popova, Gencaga Purcek, Patricia de Rango, Oliver Renk, Delphine Retraint, Ádám Révész, Virginie Roche, Pablo Rodriguez-Calvillo, Liliana Romero-Resendiz, Xavier Sauvage, Takahiro Sawaguchi, Hadi Sena, Hamed Shahmir, Xiaobin Shi, Vaclav Sklenicka, Werner Skrotzki, Nataliya Skryabina, Franziska Staab, Boris Straumal, Zhidan Sun, Maciej Szczerba, Yoichi Takizawa, Yongpeng Tang, Ruslan Z. Valiev, Alina Vozniak, Andrei Voznyak, Bo Wang, Jing Tao Wang, Gerhard Wilde, Fan Zhang, Meng Zhang, Peng Zhang, Jianqiang Zhou, Xinkun Zhu, Yuntian T. Zhu
    Journal of Alloys and Compounds 174667-174667 2024年5月  査読有り
  • Maki Ashida
    Materials Transactions 64(8) 1784-1790 2023年7月  査読有り筆頭著者責任著者
    Ti6Al7Nb alloys have been widely used in the medical field, particularly in artificial hip joints, spinal fixators, and dental implants, owing to their light weight, low toxicity, and superior corrosion resistance. Grain refinement through a severe plastic deformation process under high pressure, such as high-pressure torsion (HPT) or high-pressure sliding, is widely employed for strengthening metallic materials. This overview presents the recent advances in the effect of HPT on the mechanical properties of the Ti6Al7Nb alloy. This alloy was grain-refined through HPT under applied pressures of 2 and 6 GPa, and the results revealed that the alloy subjected to HPT processing at 6 GPa exhibited a higher strength. To inhibit the decrease in the total elongation of the alloy, the number of revolutions in the HPT process was set to moderate. The tensile properties achieved after HPT processing were found to be dependent on the initial microstructure before the HPT treatment. Furthermore, an alloy with a bimodal equiaxed and acicular structure was subjected to grain refinement via the HPT process. The results revealed that fragmentation of the acicular structure during HPT further increased the strength. Moreover, the HPT-processed Ti6Al7Nb alloy exhibited superplasticity. It was thus confirmed that grain refinement by HPT is an effective method for strengthening the Ti6Al7Nb alloy, which is advantageous for medical applications.
  • Yusuke Tsutsumi, Harumi Tsutsumi, Tomoyo Manaka, Peng Chen, Maki Ashida, Hideki Katayama, Takao Hanawa
    COATINGS 13(3) 627 2023年3月  査読有り
    A customized micro-arc oxidation (MAO) treatment technique was developed to obtain antibacterial properties with no toxicity on Ti surfaces. A two-step MAO treatment was used to fabricate a specimen containing both Ag and Zn in its surface oxide layer, and the optimal incorporation conditions were determined. Surface characterization by EDS was performed followed by the antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) and osteogenic cell compatibility evaluations. In addition, metal ion release tests were performed to evaluate the contents of Ag and Zn and the ion release behavior in order to simulate practical usage. MAO-treated specimens prepared using proper concentrations of Ag and Zn (0.5Ag-5Zn: 0.5 mM AgNO3 and 5.0 mM ZnCl, respectively) exhibited excellent antibacterial properties against E. coli and S. aureus and no toxicity to MC3T3-E1 in antibacterial and cytotoxic evaluations, respectively. The antibacterial property of 0.5Ag-5Zn against S. aureus was sustained even after two months of immersion in physiological saline, simulating the in vivo environment.
  • Tomoyo Manaka, Yusuke Tsutsumi, Yukyo Takada, Peng Chen, Maki Ashida, Kotaro Doi, Hideki Katayama, Takao Hanawa
    MATERIALS TRANSACTIONS 64(1) 131-137 2023年1月  査読有り
    In orthopedics, occasionally, different types of metals are used in applications in which they are in contact with each other. However, few studies have electrochemically investigated the galvanic corrosion of orthopedic implants formed of different metals. In this study, galvanic corrosion of Ti-6Al-4V ELI alloy, Co-Cr-Mo alloy, and 316L type stainless steel, which are used in orthopedics, and a newly developed Zr-1Mo alloy as a low-magnetic susceptibility material was evaluated in saline. Coupling of the Ti-6Al-4V ELI and Co-Cr-Mo alloys did not exhibit localized corrosion and maintained highly stable passive films. Coupling of the 316L type stainless steel and Co-Cr-Mo alloy, temporary localized corrosion occurred. Similarly, coupling of the Zr-1Mo and Co-Cr-Mo alloys, temporary localized corrosion occurred. However, both of 316L type stainless steel and Zr-1Mo alloy were finally repassivated spontaneously with the immersion time. The degree of the localized corrosion of the Zr-1Mo alloy was smaller than that of 316L type stainless steel. No galvanic current was observed when the Ti-6Al-4V ELI and Co-Cr-Mo alloys were coupled. A slight galvanic current flowed when 316L type stainless steel or the Zr-1Mo alloy was coupled with the other alloys; however, the galvanic current with the Zr-1Mo alloy coupling recovered to zero after a certain period owing to repassivation. No metal ions were detected from the couplings with Zr-1Mo
  • Yuzuki Eda, Tomoyo Manaka, Takao Hanawa, Peng Chen, Maki Ashida, Kazuhiko Noda
    Surface and Interface Analysis 54(8) 892-898 2022年8月  査読有り
    Titanium (Ti) is always covered by thin passive films. Thus, valence band (VB) spectra, obtained using X-ray photoelectron spectroscopy (XPS), are superpositions of the VB spectra of passive films and that of the metallic Ti substrate. In this study, to obtain the VB spectra only of passive films, angular resolution (for eliminating the substrate Ti contribution) and argon ion sputtering (for removing passive films) were used along with XPS. The passive film on Ti was determined to consist of a very thin TiO2 layer with small amounts of Ti2O3, TiO, hydroxyl groups, and water with a thickness of 5.9 nm. The VB spectra of Ti were deconvoluted into four peak components: a peak at similar to 1 eV, attributed to the Ti metal substrate; a broad peak in the 3-10 eV range, mainly attributed to O 2p (similar to 6 eV) and O 2p-Ti 3d hybridized states (similar to 8 eV), owing to the pi (non-bonding) and sigma (bonding) orbitals in the passive oxide film; and a peak at similar to 13 eV, attributed to the 3 sigma orbital of O 2p as OH- or H2O. The VB region spectrum between approximately 3 and 14 eV from Ti is originating from the passive film on Ti. In particular, characterization of VB spectrum obtained with a takeoff angle of less than 24 degrees is effective to obtain VB spectrum only from the passive film on Ti. The property as n-type semiconductor of the passive film on Ti is probably higher than that of rutile TiO2 ceramics.
  • Maki Ashida, Minami Hanai, Peng Chen, Takao Hanawa
    MATERIALS TRANSACTIONS 63(6) 948-956 2022年6月1日  査読有り筆頭著者責任著者
  • Hiromitsu SATO, Peng CHEN, Maki ASHIDA, Yusuke TSUTSUMI, Hiroyuki HARADA, Takao HANAWA
    Dental Materials Journal 41(3) 421-428 2022年5月25日  査読有り
  • Tomoyo Manaka, Yusuke Tsutsumi, Peng Chen, Maki Ashida, Hideki Katayama, Takao Hanawa
    Journal of The Electrochemical Society 168(12) 121505-121505 2021年12月1日  査読有り
    An electrochemical surface treatment was developed to visualize the corrosion-inducing inclusions of Zr in chloride environments. Pure Zr and Zr alloy (Zr–0.5O–0.5C) were evaluated in this study. The electrochemical surface treatment consisted of repeated galvanostatic anodic polarization and potentiostatic cathodic polarization. After the electrochemical surface treatment, only one brittle and non-conductive shell of Zr oxide was observed at the corrosion initiation site on the tested surface. The corrosion-inducing inclusions were found inside the corrosion pit under the optimum polarization conditions. At the corrosion initiation site on pure Zr, the area inside the corrosion pit contained larger amounts of O, C, and Si than the surrounding matrix. In the case of the Zr-0.5O–0.5C alloy, relatively larger inclusions were observed after the treatment. Extremely large amounts of Si, together with O and C, were present in the inclusions. The inclusions that induced localized corrosion on the pure Zr and Zr-0.5O–0.5C specimens were found to be precipitated, involving the specific aggregation of Si. The surface treatment developed in this study is expected to be utilized as a powerful tool to elucidate the localized corrosion mechanism of Zr in chloride environments.
  • Tsutsumi Y, Ishimoto T, Oishi T, Manaka T, Chen P, Ashida M, Doi K, Katayama H, Hanawa T, Nakano T
    Additive Manufact 45 102066 2021年9月  査読有り
  • Masaya Shimabukuro, Tomoyo Manaka, Yusuke Tsutsumi, Kosuke Nozaki, Chen Peng, Maki Ashida, Akiko Nagai, Takao Hanawa
    Zairyo-to-Kankyo 70(8) 265-270 2021年8月10日  査読有り
  • Tsutsumi H, Tsutsumi Y, Shimabukuro M, Manaka T, Chen P, Ashida M, Ishikawa K, Katayama H, Hanawa T
    Coatings 11(7) 798-798 2021年7月  査読有り
  • Manaka T, Tsutsumi Y, Ashida M, Chen P, Katayama H, Hanawa T
    Mater Trans 62(6) 788-796 2021年6月  査読有り
  • Shimabukuro M, Tsutsumi H, Tsutsumi Y, Manaka T, Chen P, Ashida M, Ishikawa K, Katayama H, Hanawa T
    Dent Mater J 40(3) 592-598 2021年5月  査読有り
  • Hiji A, Hanawa T, Yokoi T, Chen P, Ashida M, Kawashita M
    Langmuir 37(12) 3597-3604 2021年3月  査読有り
  • Tomoyo Manaka, Yusuke Tsutsumi, Maki Ashida, Peng Chen, Hideki Katayama, Takao Hanawa
    Zairyo-to-Kankyo 69(11) 307-314 2020年11月10日  
  • Tsutsumi Y, Muto I, Nakano S, Tsukada J, Manaka T, Chen P, Ashida M, Sugawara Y, Shimojo M, Hara N, Katayama H, Hanawa T
    J Electrochem Soc 167(14) 141507-141507 2020年11月  査読有り
  • 真中智世, 堤 祐介, 蘆田茉希, 陳 鵬, 片山英樹, 塙 隆夫
    材料と環境 69(11) 307-314 2020年11月  査読有り
  • Hiji A, Hanawa T, Shimabukuro M, Chen P, Ashida M, Ishikawa K
    Surf Interface Anal 53(2) 185-193 2020年10月  査読有り
  • Shimabukuro M, Tsutsumi Y, Nozaki K, Chen P, Yamada R, Ashida M, Doi H, Nagai A, Hanawa T
    Dent Materi J 39(4) 639-647 2020年8月  査読有り
  • Shimabukuro M, Hiji A, Manaka T, Nozaki K, Chen P, Ashida M, Tsutusmi Y, Nagai A, Hanawa T
    J Funct Biomater 11(2) 44-44 2020年6月  査読有り
  • Shimabukuro M, Manaka T, Tsutsumi Y, Nozaki K, Chen P, Ashida M, Nagai A, Hanawa T
    Mater Trans 61(6) 1143-1148 2020年6月  査読有り
  • Ashida M, Tsutsumi Y, Homma K, Chen P, Shimojo M, Hanawa T
    Mater Trans 61(4) 776-781 2020年3月  査読有り筆頭著者
  • Masaya Shimabukuro, Yusuke Tsutsumi, Risa Yamada, Maki Ashida, Peng Chen, Hisashi Doi, Kosuke Nozaki, Akiko Nagai, Takao Hanawa
    ACS BIOMATERIALS SCIENCE & ENGINEERING 5(11) 5623-5630 2019年11月  査読有り
    Recently, the problem of infection on implanted devices caused by the formation of biofilms has been recognized. Surface treatment to prevent the initial stages of bacterial adhesion and subsequent bacterial growth is the only possible solution against such infection. In this study, simple electrochemical treatment was used for introducing silver, an antibiotic agent, on the titanium surface. A porous oxide layer containing small amounts of silver was formed on the metal of the substrate. This was done by microarc oxidation using the electrolyte with silver nitrate. The porous oxide layer was almost amorphous with a small fraction of anatase phase. The samples prepared using the electrolyte containing 0.04 mM or a higher concentration of silver nitrate showed an excellent antibacterial effect against both E. coli and S. aureus. However, the proliferation of osteoblast-like cells in the samples was not affected when a concentration of 0.5 mM or lower was used. Moreover, samples containing silver showed no harmful effects on the process of bone differentiation. Furthermore, the calcification process of the cells on the samples treated with and without silver were more promoted than that on untreated Ti. Thus, we found that it is possible to use this optimum concentration of silver to realize the conflicting biofunctions: its antibacterial property and osteogenic cell compatibility.
  • Masaya Shimabukuro, Yusuke Tsutsumi, Kosuke Nozaki, Peng Chen, Risa Yamada, Maki Ashida, Hisashi Doi, Akiko Nagai, Takao Hanawa
    Coatings 9(11) 705-705 2019年10月29日  査読有り
    This study investigated the time transient effect of zinc (Zn) in the porous titanium dioxide formed by micro-arc oxidation (MAO) treatment routinely performed for Zn-containing electrolytes. The aim of our analysis was to understand the changes in both the chemical and biological properties of Zn in physiological saline. The morphology of the Zn-incorporated MAO surface did not change, and a small amount of Zn ions were released at early stages of incubation in saline. We observed a decrease in Zn concentration in the oxide layer because its release and chemical state (Zn2+ compound to ZnO) changed over time during incubation in saline. In addition, the antibacterial property of the Zn-incorporated MAO surface developed at late periods after the incubation process over a course of 28 days. Furthermore, osteogenic cells were able to proliferate and were calcified on the specimens with Zn. The changes related to Zn in saline had non-toxic effects on the osteogenic cells. In conclusion, the time transient effect of Zn in a porous titanium dioxide layer was beneficial to realize dual functions, namely the antibacterial property and osteogenic cell compatibility. Our study suggests the importance of the chemical state changes of Zn to control its chemical and biological properties.
  • Shimabukuro M, Ito H, Tsutsumi Y, Nozaki K, Chen P, Yamada R, Ashida M, Nagai A, Hanawa T
    Metals 9(11) 1145-1145 2019年10月  査読有り
  • Iku KAWABATA, Haruki IMAI, Zuisei KANNO, Akemi TETSUMURA, Yusuke TSUTSUMI, Hisashi DOI, Maki ASHIDA, Tohru KURABAYASHI, Takao HANAWA, Toru YAMAMOTO, Takashi ONO
    Dental Materials Journal 38(4) 638-645 2019年7月26日  査読有り
    Differences in the volumes of artifacts caused by variously shaped titanium objects on magnetic resonance imaging (MRI) were evaluated. Spherical-, square cubic-, and regular tetrahedron-shaped isotropic, and elongated spherical-, elongated cubic-, and elongated tetrahedron-shaped anisotropic objects, with identical volumes, were prepared. Samples were placed on a nickel-doped agarose gel phantom and covered with nickel-nitrate hexahydrate solution. Three-Tesla MR images were obtained using turbo spin echo and gradient echo sequences. Areas with ±30% of the signal intensity of the standard background value were considered artifacts. Sample volumes were deducted from these volumes to calculate the total artifact volumes. Isotropic samples had similar artifact volumes. For anisotropic samples, the artifact volume increased in proportion with the normalized projection area. MRI artifact size can be reduced by high anisotropic designs, and by positioning the long axis of the metal device as parallel as possible to the magnetic field axis.
  • Watanabe K, Ashida M, Masuda T, Kral P, Takizawa Y, Yumoto M, Otagiri Y, Sklenicka V, Hanawa T, Horita Z
    Mater Trans 60(9) 1785-1791 2019年7月  査読有り責任著者
  • Oishi M, Tsutsumi Y, Chen P, Nakaishi M, Ashida M, Doi H, Hanawa T
    Dent. Mater. J. 38(3) 496-504 2019年6月  査読有り
  • Chen P, Aso T, Sasaki R, Ashida M, Tsutsumi Y, Doi H, Hanawa T
    J. Biomed. Mater. Res. A 2018年7月  査読有り
  • Ashida M, Morita M, Tsutsumi Y, Nomura N, Doi H, Chen P, Hanawa T
    Metals 8(6) 454 2018年6月  査読有り筆頭著者
  • Oishi M, Tsutsumi Y, Chen P, Ashida M, Doi H, Hanawa T
    Surf Interface Anal 50(5) 587-591 2018年5月  査読有り
  • 渡部恭平, 蘆田茉希, 増田高大, Petr Kral, 瀧沢陽一, 湯本 学, 小田切吉治, Vaclav Sklenicka, 塙 隆夫, 堀田善治
    軽金属 68(1) 9-15 2018年1月  査読有り
  • Chen P, Aso T, Sasaki R, Tsutsumi Y, Ashida M, Doi H, Hanawa T
    J Biomed Nanotechnol 13(3) 324-336 2017年3月  査読有り
  • Tsustumi Y, Doi H, Nomura N, Ashida M, Chen P, Kawasaki A, Hanawa T
    Mater. Trans. 57(12) 2033-2040 2016年12月  査読有り
    <p>Air-formed surface oxide films on four types of Co-Cr- alloys were characterized using X-ray photoelectron spectroscopy (XPS) and five types of Co-Cr alloys were anodically polarized, to identify the effects of the addition of N, Mo, and W to Co-Cr alloys containing high Cr on the surface composition and corrosion resistance. Co-20Cr-15W-10Ni (ASTM F90), Co-30Cr-6Mo, Co-33Cr-5Mo-0.3N, and Co-33Cr-9W-0.3N were employed for XPS and the above four alloys and another Co-30Cr-6Mo (ASTM F75) were employed for anodic polarization. The surface oxide film on the Co-Cr alloys consisted of oxide species of Co, Cr, Mo, W and/or Ni contains a large amount of OH− with a thickness of 2.6–3.2 nm. Cations existed in the oxide as Co2+, Cr3+, Mo4+, Mo5+, Mo6+, W6+ and Ni2+. Cr and Mo are enriched and Co and Ni are depleted in the surface oxide film. W was enriched in the case of Co-20Cr-15W-10Ni but depleted in the case of Co-33Cr-9W-0.3N. On the other hand, Cr, Mo, W and Ni were enriched and Co was depleted in the substrate alloy just under the surface oxide film in the polished alloy. During rapid formation of the surface oxide film, Cr was preferentially oxidized and the oxidation of Co and Ni delayed, according to the oxidation and reduction potentials of these elements. The Co-Cr alloys essentially have high localized corrosion resistance that is not easily affected by a small change of composition. Co-33Cr-5Mo-0.3N shows higher corrosion resistance compare than conventional Co-Cr alloys.</p>
  • Tsutsumi Y, Ashida M, Nakahara K, Serizawa A, Doi H, Grandini CR, Rocha LA, Hanawa T
    Mater. Trans. 57(12) 2015-2019 2016年12月  査読有り
  • Chen P, Ashida M, Doi H, Tsutsumi Y, Horita Z, Hanawa T
    Mater Trans 57(12) 2020-2025 2016年11月  査読有り
    <p>In this study, we evaluated the cytocompatibility of high-pressure torsion (HPT)-processed Ti-6Al-7Nb alloys. Grain size of titanium (Ti) alloys decreased from 5 µm (without HPT processing, HPT-0) to ～100 nm (at 2 GPa, HPT-2) or ～70 nm (at 6 GPa, HPT-6) through HPT processing. Cell adhesion, proliferation, and differentiation were evaluated with mouse preosteoblast (MC3T3-E1). A locomotion trend was presented by cells cultured on HPT-2 to compare with other specimens, while, an immobilization trend was presented by cells cultured on HPT-6 to compare with other specimens. Akp2 (alkaline phosphatase 2) expression was higher in cells cultured on HPT-2 than that on HPT-0 and HPT-6, indicating enhanced osteogenic differentiation. Our results demonstrate that HPT-processed Ti-6Al-7Nb alloys offer good cytocompatibility.</p>
  • Kajima Y, Takaichi A, Nakamoto T, Kimura T, Yogo Y, Ashida M, Doi H, Nomura N, Takahashi H, Hanawa T, Wakabayashi N
    J. Mech. Behav. Biomed. Mater. 59 446-458 2016年6月  査読有り
  • 土居 壽, 蘆田茉希, 堤 祐介, 野村直之, 塙 隆夫
    歯科・材料器械 35(3) 217-225 2016年5月  査読有り
    <p>Co-Cr-Mo合金は，強度および耐食性に優れていることから，生体用金属材料として広く応用されている．また，歯科用合金として古くから使用されており，特に歯科鋳造用合金として様々な種類のコバルトクロム合金が実用化されている．この合金のN濃度を増加させることにより，機械的性質が向上することが著者らの研究によりわかった．さらに，Crの濃度を増加させた時の諸性質についても詳細な検討が必要と考えられる．そこで，Co-Cr-Mo合金のN濃度とCr濃度を変化させた時の機械的性質と耐食性について，引張試験と1％乳酸中での溶出試験により検討した．その結果，N濃度が0.2〜0.4 mass％の合金において延性が向上することがわかった．また，Cr濃度は32 mass％から増加するに従って強度が増加するが，36％より多くなると脆くなることがわかった．耐食性に関しては，N，Cr濃度を変化させても影響がないことがわかった．</p>
  • Chen P, Nagai A, Tsutsumi Y, Ashida M, Doi H, Hanawa T
    J Biomed Mater Res A 104(3) 639-651 2016年3月  査読有り
  • Tsutsumi Y, Niinomi M, Nakai M, Shimabukuro M, Ashida M, Chen P, Doi H, Hanawa T
    Metals 6(4) 76 2016年3月  査読有り招待有り
  • Okamoto H, Tsutsumi Y, Watanabe M, Yamakage K, Ashida M, Chen P, Doi H, Miura H, Matsumura M, Hanawa T
    Electrochemistry 83(12) 1048-1052 2015年12月  査読有り
  • Tsutsumi Y, Nishisaka T, Doi H, Ashida M, Chen P, Hanawa T
    Surf Iinterface anal 47(13) 1148-1154 2015年12月  査読有り
  • Umezawa T, Chen P, Tsutsumi Y, Doi H, Ashida M, Suzuki S, Moriyama K, Hanawa T
    Dental Materials Journal 34(5) 713-718 2015年10月  
    To confirm similarity of hard tissue compatibility between titanium and zirconium, calcification of MC3T3-E1 cells on titanium and zirconium was evaluated in this study. Mirror-polished titanium (Ti) and zirconium (Zr) disks and zirconium-sputter deposited titanium (Zr/Ti) were employed in this study. The surface of specimens were characterized using scanning electron microscopy and X-ray diffraction. Then, the cellular proliferation, differentiation and calcification of MC3T3-E1 cells on specimens were investigated. The surface of Zr/Ti was much smoother and cleaner than those of Ti and Zr. The proliferation of the cell was the same among three specimens, while the differentiation and calcification on Zr/Ti were faster than those on Ti and Zr. Therefore, Ti and Zr showed the identical hard tissue compatibility according to the evaluation with MC3T3-E1 cells. Sputter deposition may improve cytocompatibility.
  • Ashida M, Sugimoto T, Nomura N, Tsutsumi Y, Chen P, Doi H, Hanawa T
    Mater. Trans. 56(9) 1544-1548 2015年7月  査読有り筆頭著者責任著者
    A large-scale ingot of Zr-1Mo alloy was produced for industrial manufacturing to investigate whether it is possible to produce an ingot with homogeneity. The homogeneous ingot with a chemical composition of Zr-1 mass%Mo was prepared successfully. The microstructure, mechanical properties, and magnetic susceptibility were evaluated. The microstructure showed a coarse colony structure of a plate-like α phase and a thin β phase. An ω phase precipitation was observed in the β phase. Elongation of 23% and magnetic susceptibility of 12.4 × 10−9 m3 kg−1 (0.98 × 10−6 cm3 g−1) were achieved. We found that it is possible to produce a homogeneous large-scale ingot of Zr-1Mo with high elongation and low magnetic susceptibility.
  • Ashida M, Chen P, Doi H, Tsutsumi Y, Hanawa T, Horita Z
    Mater. Sci. Eng. A 640 449-453 2015年6月  査読有り筆頭著者責任著者
  • Yu M, Chen P, Tsutsumi Y, Doi H, Ashida M, Kasugai S, Hanawa T
    Dent. Mater. J. 33 490-498 2014年8月  査読有り
  • Edalati K, Ashida M, Horita Z, Matsui T, Kato H
    Wear 310 83-89 2014年2月  査読有り
  • Maki Ashida, Peng Chen, Hisashi Doi, Yusuke Tsutsumi, Takao Hanawa, Zenji Horita
    11TH INTERNATIONAL CONFERENCE ON TECHNOLOGY OF PLASTICITY, ICTP 2014 81 1523-1528 2014年  査読有り筆頭著者責任著者
    Ti-6Al-7Nb was deformed by high-pressure torsion to improve the mechanical properties of the alloy. high-pressure torsion was conducted at room temperature under pressures of 2 and 6 GPa for disk-shaped specimens. Microstructure was characterized by transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). Mechanical properties were evaluated by tensile test and Vickers microhardness measurement. The grain size was refined to about 100 nm after high-pressure torsion processing under 6 GPa through 5 revolutions. Hardness increased with straining by high-pressure torsion and the values after high-pressure torsion processing under 6 GPa were higher than those under 2 GPa. Tensile strength after high-pressure torsion processing of all conditions was higher than that before high-pressure torsion processing. It was found that microstructure and mechanical properties were improved by high-pressure torsion processing. (C) 2014 Published by Elsevier Ltd.
  • Maki Ashida, Zenji Horita
    JOURNAL OF MATERIALS SCIENCE 47(22) 7821-7827 2012年11月  査読有り筆頭著者責任著者
    Pure Al powders were mixed with a 30 % volume fraction of Al2O3 powders having particle sizes of similar to 30 nm. The mixed powders were first subjected to ball milling (BM) and thereafter consolidated by high-pressure torsion (HPT) at room temperature under a pressure of 3 GPa for 10 turns. The Al-Al2O3 composite produced by BM and HPT (BM + HPT) had a more uniform dispersion of the nano-sized Al2O3 particles in the Al matrix. Hardness values of the BM + HPT composites were higher than those of the composites without BM. It is shown that the use of BM powders for HPT is more effective in achieving a uniform dispersion of the nano-sized Al2O3 particles and in improving mechanical properties of the Al-Al2O3 nanocomposites.

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