DOI Kotaro

J-GLOBAL         Last updated: Dec 17, 2018 at 14:21
 
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Name
DOI Kotaro
Affiliation
National Institute for Materials Science
ORCID ID
0000-0002-5204-1088

Published Papers

 
Kotaro Doi, Eiji Akiyama, Masao Hayakawa
{ECS} Transactions   75(29) 33-41   Jan 2017   [Refereed]
High strength steels are sensitive to hydrogen embrittlement which decreases long-term reliability.In this study, hydrogen entry in tribocorrosion environment is investigated by using modeled tribocorrosion environment. From hydrogen thermal desor...
Denki Kagaku   86(Autumn) 236-241   Sep 2018   [Refereed]
生体内におけるMg合金の腐食挙動およびその評価方法に加え、著者らが取り組んでいるMg合金表面被覆および表面被覆したMg合金の力学的変形を伴う環境での腐食挙動について概説した。
Doi K, Miyabe S, Tsuchiya H, Fujimoto S.
Journal of the Mechanical Behavior of Biomedical Materials   56 6-13   2016   [Refereed]
Fatigue has been reported as many of failures for metallic biomaterials. As most of fatigues for biomaterials are related to corrosion and/or wear, corrosion fatigue and fretting fatigue have been extensively examined. In the present work the corr...
Fatigue of metallic biomaterials
宮部さやか, 土井 康太郎, 藤本慎司
表面技術   69(8) 346-350   Aug 2018   [Refereed]
生体内は,Cl-,Na+,Mg2+,Ca2+,HxPO4n-などの無機イオンに加えアミノ酸,タンパク質,細胞などが存在するとともに,心臓の拍動,呼吸,歩行などの日常生活にともなう繰り返し応力が負荷されるので,生体内はこれら生化学的環境と力学的環境とが複合している。従って,金属インプラントは生化学と力学との複合環境で使用されるため,腐食と繰り返し応力に起因する様々な損傷が生じる。本稿では,生体環境で使用される金属インプラントに生じる疲労の概要と,表面処理が材料の疲労特性に及ぼす影響について解...
Kotaro Doi, Sachiko Hiromoto, Eiji Akiyama
MATERIALS TRANSACTIONS   59(6) 927-934   Jun 2018   [Refereed]
A novel test method which enhances oxygen supply to accelerate the corrosion of reinforcing steel in concrete has been proposed in this study.In 0.5 MPa O2 gas, Fe specimens covered with 5 mm of mortar or cement paste showed ORCD almost 25 times a...

Misc

 
P. Seenuvasaperumal, P. Seenuvasaperumal, K. Doi, Dudekula Althaf Basha, Alok Singh, A. Elayaperumal, Koichi Tsuchiya
Materials Letters   227 194-198   Sep 2018
© 2018 Elsevier B.V. Dry sliding wear behavior of ultrafine-grained (UFG) AZ31B magnesium alloy processed by high pressure torsion (HPT) has been investigated against bearing steel ball at room temperature. The HPT process progressed with formatio...
Mizuki Tenjimbayashi, Yudai Kawase, Kotaro Doi, Chen Xian Ng, Masanobu Naito
Applied Physics Letters   113    Jul 2018
© 2018 Author(s). Inspired by penguins, the formation of an air film on surfaces underwater has been well-researched for the potential reduction of drag. However, the features that contribute to drag reduction of penguins are not only the formatio...
Kotaro Doi, Sachiko Hiromoto, Hideki Katayama, Eiji Akiyama
Journal of the Electrochemical Society   165    Jan 2018
© The Author(s) 2018. The effects of oxygen pressure on the corrosion of iron embedded in mortar with various Cl− contents were examined by using a novel hyperbaric-oxygen accelerated corrosion test (HOACT). Exposure and electrochemical tests of a...
Kotaro Doi, Sachiko Hiromoto, Eiji Akiyama
Materials Transactions   59 927-934   Jan 2018
© 2018 The Japan Institute of Metals and Materials. A novel accelerated corrosion test method which enhances oxygen supply has been proposed for reinforcing steel in concrete in this study. Oxygen reduction current density (ORCD) was measured by m...
Kotaro Doi, Sachiko Hiromoto, Eiji Akiyama
Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals   82 1-7   Jan 2018
© 2017 The Japan Institute of Metals and Materials. A novel accelerated corrosion test method enhancing oxygen supply to simulate the corrosion of reinforcing steel in concrete has been proposed in this study. Oxygen reduction current density meas...

Conference Activities & Talks

 
Steel Corrosion Enhancement in Mortar by Supplying Pressurized Oxygen Gas
DOI, Kotaro, HIROMOTO, Sachiko, Eiji AKIYAMA
18th Asian Pacific Corrosion Control Conference   5 Nov 2018   
Recently, some researchers tried to accelerate the corrosion of reinforcing steel in concrete by enhancement of anodic reaction to understand the corrosion mechanism of steel corrosion in concrete. However, there is a difficulty for the effective ...
Accelerated Corrosion of Reinforcing Steel in Mortar by Supplying Pressured Oxygen Gas
DOI, Kotaro, HIROMOTO, Sachiko, Eiji AKIYAMA
EUROCORR2018   9 Sep 2018   
In this study, an accelerated corrosion test method with enhancing oxygen reduction reaction was developed to enhance the corrosion of reinforcing steel in concrete. The effect of mill scale on the corrosion of reinforcing steel mortar and the mec...
Corrosion Enhancement of iron Embedded in Mortar by Hyperbaric-oxygen Accelerated Corrosion Test
DOI, Kotaro, HIROMOTO, Sachiko, Eiji AKIYAMA
69th Annual ISE Meeting   2 Sep 2018   
Recently, in order to form rusts similar to that formed in the real environment easily and in a short time, we developed hyperbaric-oxygen accelerated corrosion test (HOAC test). In the HOAC test, pressurized oxygen gas was supplied to the iron or...
Effect of Polymers on Self-Healing Behavior of Hydroxyapatite Coating of Magnesium Alloy in Physiological Solution
DOI, Kotaro, HIROMOTO, Sachiko
69th Annual ISE Meeting   2 Sep 2018   
In this study, sodium polyacrylate (SPA) which acts as a nucleus for Ca-P deposition was combined to HAp coating. Polyethylene glycol (PEG) which can adsorb Ca-P compounds was also used. The corrosion behavior was examined by a static immersion te...
Enhancement of Reinforcing Steel Corrosion in Mortar by Hyperbaric-oxygen Accelerated Corrosion Test
DOI, Kotaro, HIROMOTO, Sachiko, Eiji AKIYAMA
MANA International Symposium 2018   5 Mar 2018   
In this study, an accelerated corrosion test method with enhancing oxygen reduction reaction was developed to enhance the corrosion of reinforcing steel in concrete. The effect of mill scale on the corrosion of reinforcing steel mortar and the mec...