Papers - Komotori, Jun

Effect of pre-treatment with fine particle peening on surface properties and wear resistance of gas blow induction heating nitrided titanium alloy

S. Takesue, S. Kikuchi, H. Akebono, Y. Misaka, J. Komotori

Surface and Coatings Technology (Surface and Coatings Technology)  359   476 - 484 2019

Research paper (scientific journal), Joint Work,  ISSN  02578972

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© 2018 Elsevier B.V. In order to develop a rapid nitriding process for titanium alloy at a low temperature, fine particle peening (FPP) was performed prior to gas blow induction heating (GBIH) nitriding. The surface microstructures of a Ti-6Al-4V alloy treated by FPP and GBIH nitriding were characterized using X-ray diffraction, optical microscopy, scanning electron microscopy, laser microscopy and micro-Vickers hardness testing. The results indicate that nitrogen diffusion into titanium during GBIH nitriding was accelerated by the pre-treatment with FPP, and a nitrided layer was formed on the surface of the Ti-6Al-4V alloy at a relatively low temperature (923 K), which grain coarsening and phase transformation did not occur and a nitrided layer was not formed only by GBIH nitriding. This is because a fine-grained surface layer was generated by the pre-treatment with FPP. Reciprocating ball-on-disk wear tests were carried out to examine the wear resistance of the prepared specimens. GBIH nitriding at a low temperature improved the wear resistance of the Ti-6Al-4V alloy following the pre-treatment with FPP, due to the formation of a hard nitrogen compound layer at the surface. The results show that the proposed surface treatment process was effective at modifying the surface properties of a titanium alloy at a low temperature and within a short span of time while avoiding grain coarsening and phase transformation.

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Effect of hydroxy groups and microtopography generated by a nanosecond-pulsed laser on pure Ti surfaces

Y. Kurashina, A. Ezura, R. Murakami, M. Mizutani, J. Komotori

Journal of Materials Science: Materials in Medicine (Journal of Materials Science: Materials in Medicine)  30 ( 5 )  2019

Research paper (scientific journal), Joint Work,  ISSN  09574530

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© 2019, Springer Science+Business Media, LLC, part of Springer Nature. In this paper, we study a process for modifying the surface microtopography of the Ti oxide layer using a nanosecond-pulsed laser (NPL). Even now, the mechanism by which hydroxyl groups are generated on the titanium surface treated by NPL is not clear. Hence, we evaluated the surface properties of the NPL defocus distances on pure titanium surfaces, and investigated the relationship between the generation of hydroxyapatites/cell viability and the titanium surface characteristics. The NPL defocus distance was varied from 0 to 4 mm. Defocus distances of 0 and 2 mm generated microtopographical features on the titanium surface, and the resulting surfaces exhibited a greater density of OH groups than the surface treated with a defocus distance of 4 mm. The surfaces treated using defocus distances of 0 and 2 mm were found to be coated with microspherical hydroxyapatite composed of coexisting plate- and needle-like crystals after immersion in simulated body fluid, and alkaline phosphatase activity assays indicated improved cell compatibility. The improvements in biocompatibility and cell compatibility were due to the pocket-like microtopographical structures formed along the processing trace. These pockets contained a large amount of OH groups, and promoted the growth of hydroxyapatite. [Figure not available: see fulltext.].

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Functionalisation of titanium alloy surface through oxygen gas jet-assisted gliding arc discharge plasma

K. Katahira, N. Mifune, J. Komotori

CIRP Annals - Manufacturing Technology (CIRP Annals)  69 ( 1 ) 201 - 204 2019

Research paper (scientific journal),  ISSN  00078506

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© 2019 A modified surface layer was fabricated on Ti–6Al–4V samples by gliding arc discharge plasma assisted with an oxygen jet gas under atmospheric conditions. The oxidation reaction on the sample surface was promoted by active species with strong oxidising performance, such as oxygen and hydroxyl radicals. An amorphous titanium oxide layer was detected on the generated surface. The oxygen diffusion layer penetrated the substrate to an approximate depth of 500 nm. The generated surface exhibited higher biological cell adhesiveness and a lower elution amount of metal ions than the untreated sample surface.

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Rapid surface nitriding of titanium alloy by a nanosecond fiber laser under atmospheric conditions

Katahira K., Tanida Y., Takesue S., Komotori J.

CIRP Annals (CIRP Annals)  67 ( 1 ) 563 - 566 2018.01

ISSN  00078506

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© 2018 CIRP A modified surface layer using a Yb nanosecond fiber laser beam under atmospheric conditions was fabricated by applying a surface nitriding process on disc-shaped Ti–6Al–4V samples. On the generated surface, a melt layer comprising a TiN dendrite structure and a heat affected zone containing a needle-like α phase were detected. The modified layer exhibited optimal characteristics with the treatment at a laser output power of 12 W, resulting in a hardness of 12 GPa. The results of friction wear evaluation tests revealed that the layer exhibited superior abrasion resistance compared with an untreated Ti–6Al–4V substrate.

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Effect of atmospheric-controlled induction-heating fine particle peening on electrochemical characteristics of austenitic stainless steel

K.Kikuchi, S.Iwamae, H.Akebono, J.Komotori, K.Kadota

Surface and Coatings Technology (Surface and Coatings Technology)  334   189 - 195 2018

Research paper (scientific journal), Joint Work,  ISSN  02578972

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© 2017 Atmospheric-controlled induction-heating fine particle peening (AIH-FPP) using Cr and Mo shot particles in a N2 atmosphere was introduced to improve the electrochemical characteristics of AISI 316 austenitic stainless steel. The surface microstructure of the AIH-FPP-treated specimen was characterized using scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX). AIH-FPP can be used to form transferred and diffused layers of shot particles on the surface of austenitic stainless steel. The thickness of the diffusion layers of Cr shot particles tended to increase with the heating time in the AIH-FPP process, whereas the Cr concentration at the surface tended to decrease. Electrochemical polarization tests were performed in 3 wt% NaCl + H2SO4 and 20 wt% NaCl environments at 343 K using a three-electrode electrochemical cell connected to a computer driven potentiostat to examine the corrosion resistance of austenitic stainless steel treated with AIH-FPP. The pitting potential of the AIH-FPP-treated specimen was higher than that of the untreated specimen. In particular, there was clear improvement in the pitting potential of austenitic stainless steel by AIH-FPP with Cr shot particles following peening with Mo shot particles. AIH-FPP using Cr and Mo shot particles in a N2 atmosphere is an effective method of improving the electrochemical characteristics of austenitic stainless steel.

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Ti合金にAIH-FPP（雰囲気制御高周波誘導加熱微粒子ピーニング）を用いて創成した金属間化合物被膜の表面特性

武末翔吾，齋藤周也，小茂鳥潤，三阪佳孝，川嵜一博

熱処理 58 ( 1 ) 11 - 16 2018

Research paper (scientific journal), Joint Work

Effect of Cr Diffused Layer Formed by AIH-FPP Treatment on Adhesion of DLC Films to a Carbon Steel Substrate

S. Takesue, H. Akebono, M. Furukawa, S. Kikuchi, J. Komotori, H. Nomura

Materials Transactions (Materials Transactions)  59 ( 4 ) 642 - 647 2018

Research paper (scientific journal), Joint Work,  ISSN  13459678

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© 2018 The Japan Institute of Metals and Materials. In this study, a diffusion layer of Cr was formed on the surface of a carbon steel by atmospheric-controlled induction heating fine particle peening (AIH-FPP) treatment, followed by coating of a diamond-like carbon (DLC) film in an attempt to provide a less expensive and facile method for the production of DLC-coated steels with superior adhesion to conventional methods. Frictional wear tests and indentation tests with Vickers indenter were conducted on these DLC-coated steel specimens, and adhesion to the substrate was investigated experimentally. It was revealed that the formation of a Cr diffused layer on the surface of the substrate by AIH-FPP treatment significantly improved the adhesion of the DLC film to the substrate under a sliding load and a large plastic deformation. In addition, frictional wear tests revealed that the thickness of the Cr diffused layer formed by AIH-FPP treatment has a significant influence on the adhesion of the DLC film to the substrate. A thicker Cr diffused layer with a thickness of about 100 µm imparted better adhesion of the DLC film to the base material, and the superior friction and wear characteristics of the DLC film were sustained up to 49000 wear cycles while the specimens with a Cr diffused layer thickness of about 40 µm and without a Cr diffused layer maintained low friction coefficients up to 36000 and 8000 wear cycles, respectively. These results suggest that the proposed film forming method with a Cr diffused layer formed by AIH-FPP treatment is superior to the conventional method and is very efficient as a technique to improve the adhesion of DLC films to a carbon steel substrate.

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Dynamic recrystallization of Fe-Cr alloys by atmospheric-controlled induction-heating fine particle peening

S. Kikuchi, I. Tanaka, S. Takesue, J. Komotori, K. Matsumoto

Surface and Coatings Technology (Surface and Coatings Technology)  344   410 - 417 2018

Research paper (scientific journal), Joint Work,  ISSN  02578972

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© 2018 Atmospheric-controlled induction-heating fine particle peening (AIH-FPP) was conducted in a N2 atmosphere to form ultrafine grains on the surface of Fe-Cr alloys. The surface microstructure of Fe-2%Cr alloy and Fe-10%Cr alloy treated with AIH-FPP at 973 K and 1073 K was characterized using optical microscopy, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). AIH-FPP can be used as a thermomechanical process to form ultrafine grains on the surface of Fe-Cr alloys because strain is induced by AIH-FPP at a high rate and high temperature during dynamic recrystallization. In particular, the grain size of Fe-Cr alloys tends to decrease with increasing AIH-FPP treatment time. This is attributed to the increase in the strain induced by AIH-FPP with increasing AIH-FPP treatment time during dynamic recrystallization. Thus, the AIH-FPP-induced stratification structure composed of fine grains becomes more pronounced with increasing treatment time. Furthermore, the AIH-FPP treatment temperature at which fine grains are formed depends on the Cr concentration of the Fe-Cr alloys.

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Rapid surface nitriding of titanium alloy by a nanosecond fiber laserunder atmospheric conditions"

K. Katahira , Y. Tanida , S. Takesue , J. Komotori

CIRP Annals - Manufacturing Technology 67   563 - 566 2018

Research paper (scientific journal), Joint Work

放電プラズマ焼結によるチタン／ジルコニア複合生体材料の創製

菊池将一，片平和俊，小茂鳥潤

日本金属学会誌 82   341 - 348 2018

Research paper (scientific journal), Joint Work

Surface Properties of Intermetallic Compound Layer Formed on Titanium Alloy by AIH-FPP (Atmospheric Controlled Induction Heating Fine Particle Peening) Treatment

S. Takesue, S. Saito, J. Komotori, Y. Misaka, K. Kawasaki

Materials Transactions 59 ( 9 ) 1452 - 1457 2018

Research paper (scientific journal), Joint Work

Improvement of the electrochemical characteristics of medium carbon steel using atmospheric-controlled induction-heating fine particle peening

S. Kikuchi, S. Iwamae, H. Akebono, J. Komotori, Y. Misaka

Surface and Coatings Technology (Surface and Coatings Technology)  354   76 - 82 2018

Research paper (scientific journal), Joint Work,  ISSN  02578972

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© 2018 Elsevier B.V. Atmospheric-controlled induction-heating fine particle peening (AIH-FPP) using Cr and Mo shot particles was introduced to improve the electrochemical characteristics of AISI 1045 medium carbon steel in NaCl solution. AIH-FPP can form transferred and diffused layers of shot particles on the surface of carbon steel. The corrosion potential of the AIH-FPP-treated steel was higher than that of the untreated steel in a NaCl environment. Furthermore, a passivation region was observed in the carbon steel treated with AIH-FPP using Cr shot particles after peening with Mo shot particles through the formation of a surface-modified layer with high Cr and Mo concentrations in 20% NaCl solution.

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Formation of titanium/zirconia based biomaterial fabricated by spark plasma sintering

Kikuchi S., Katahira K., Komotori J.

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals (Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals)  82 ( 9 ) 341 - 348 2018

ISSN  00214876

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© 2018 The Japan Institute of Metals and Materials New biomaterials were fabricated by sintering powders of commercially pure titanium（CP-Ti）and partially-stabilized zirconia （PSZ）. The Ti/PSZ composites with different mass fraction of PSZ were consolidated by spark plasma sintering（SPS）at 1173 K and 1373 K. The microstructures of composites were characterized using a scanning electron microscope（SEM）, an energy dispersive X-ray spectrometer（EDS）, X-ray photoelectron spectroscopy（XPS）and an X-ray diffraction（XRD）. Vickers hardness tests, reciprocating wear tests, fracture toughness measurements, cell culture tests and electrochemical polarization tests were conducted to discuss their capability for biomaterials as a slide member. The composites with high wear resistance were achieved by sintering at 1373 K with high mass fraction of PSZ; however, fracture toughness showed low value. In contrast, the composites sintered at relatively low temperature of 1173 K with low mass fraction of PSZ showed high wear resistance and fracture toughness. Furthermore, electrochemical characteristics and biocompatibility of composites sintered at 1173 K tended to improve as the mass fraction of PSZ decreased.

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Surface properties of intermetallic compound layer formed on titanium alloy by AIH-FPP (Atmospheric controlled induction heating fine particle peening) treatment⁺1

Takesue S., Saito S., Komotori J., Misaka Y., Kawasaki K.

Materials Transactions (Materials Transactions)  59 ( 9 ) 1452 - 1457 2018

ISSN  13459678

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© 2018 The Japan Society for Heat Treatment. The effect of the intermetallic compound layer formed by atmospheric controlled induction heating fine particle peening (AIH-FPP) treatment on the wear resistance and high-temperature oxidation resistance of titanium alloy was investigated. To form an intermetallic compound layer on a titanium alloy by AIH-FPP treatment, pure titanium, aluminum and nickel particles were mechanically milled using a planetary ball mill, and the prepared particles were used as shot particles in the AIH-FPP treatment. The results showed that intermetallic compound layers, consisted of Ti3Al and Ti2NiAl3, were formed on titanium alloy by AIH-FPP treatment using the prepared particles. The wear resistance and high-temperature oxidation resistance of the AIH-FPP treated specimen were higher than those of the untreated ones.

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硝酸アルミニウム溶液を用いたレーザ誘起湿式改質法によるSUS316L鋼の表面改質

江面篤志,良峰皓,片平和俊,小茂鳥潤

精密工学会誌 83 ( 1 ) 72 - 77 2017.01

Research paper (scientific journal), Joint Work

Efficient subculture process for adherent cells by selective collection using cultivation substrate vibration

Y.Kurashina,K.Takemura,　J.Friend,S.Miyata,J.Komotori

IEEE Transactions on Biomedical Engineering 64 ( 3 ) 580 - 587 2017

Research paper (scientific journal), Joint Work

AIH-FPP処理によるチタン合金表面のTi-Al金属間化合物化プロセスの検討

齋藤周也，武末翔吾，小茂鳥潤，深沢剣吾，三阪佳孝

砥粒加工学会誌 61 ( 3 ) 145 - 150 2017

Research paper (scientific journal), Joint Work

ガスブローIH窒化を施したTi-6Al-4V合金の表面特性に及ぼすガス流速の影響

武末翔吾,菊池将一,曙紘之,小茂鳥潤,深沢剣吾,三阪佳孝

日本金属学会誌 81 ( 5 ) 288 - 293 2017

Research paper (scientific journal), Joint Work

ミスト状硝酸アルミニウム溶液を用いたSUS316L鋼のレーザ誘起湿式表面改質

江面篤志,大川弘暉,片平和俊,小茂鳥潤

砥粒加工学会誌 61 ( 5 ) 269 - 274 2017

Research paper (scientific journal), Joint Work

メカニカルミリングにより作製した粒子を用いたAIH-FPP処理による TiAl3被膜の創成と耐摩耗性の評価

齋藤周也,武末翔吾,小茂鳥潤,深沢剣吾,三阪佳孝

日本金属学会誌 81 ( 6 ) 295 - 300 2017

Research paper (scientific journal), Joint Work