Kyushu University Academic Staff Educational and Research Activities Database
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Hiroyoshi Tanaka Last modified date:2024.04.25

Assistant Professor / Machine Design and Bionic Systems
Department of Mechanical Engineering
Faculty of Engineering

Graduate School
Undergraduate School

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 Reseacher Profiling Tool Kyushu University Pure
Academic Degree
BPh, PhD
Country of degree conferring institution (Overseas)
Field of Specialization
Total Priod of education and research career in the foreign country
Outline Activities
Based on the rolling sliding contact fatigue of mechanical rolling elements and DLC coating film, effects of hydrogen on mechanical elements have been investigated. These will help to provide practical education and activation for work with business region.
Research Interests
  • Friction and wear properties and environmental compatibility of rubber materials used in hydrogen facilities
    keyword : Hydrogen, rubber materials, environmental compatibility, friction and wear, failure
  • Durability Evaluation of Ultra-High Pressure fitting used in hydrogen facilities
    keyword : Hydrogen, CT fitting, deformation, failure
  • Friction and wear of DLC films in hydrogen
    keyword : DLC, hydrogen, friction, wear
  • Friction and wear in hydrogen gas, Rolling contact fatigue in hydrogen, peameation properties of hydrogen into materials under high pressure hydrogen.
    keyword : sliding contact, friction and wear, rolling contact, fatigue life, high pressure hydrogen, peameation properties of hydrogen, surface analysis
    1989.04In order to elucidate the performance of mechanical elements in hydrogen environment, sliding friction test and rolling fatigue test are conducted..
  • Lubrication performance of greases
    keyword : grease, friction and wear, rolling contact fatigue
Current and Past Project
  • Argonne national laboratory has contributed to the wind program funded by U.S. Department of Energy, my research was in the part of this program. Purpose of this study is rolling contact fatigue in wind turbines system, especially in micropitting on gears in wind turbines.
Academic Activities
1. Hiroyoshi Tanaka, Effect of Environmental Gas on Surface Initiated Rolling Contact Fatigue, Tribology Online, 8, 1, 90-96, 2013.01, This paper describes an exploratory study on the effects of temperature on the formation of oxide film and rolling contact fatigue life in hydrogen, argon and air. Rolling contact fatigue tests were conducted at 333 K and 363 K by using a three-ball-on-disk type apparatus. The rolling contact fatigue life in hydrogen was shorter than that in argon, and life in air was the longest. Relationship was found between fatigue life and hydrogen concentration in steel. Cross sections of the specimens show that iron oxide grew to larger grain size in the subsurface in hydrogen environment, which may have resulted in shorter fatigue life. It was also found that fatigue failure occurs on ball surface in hydrogen at 363 K..
2. Effects of Exposure to 40MPa Hydrogen on DLC Films.
1. Hiroyoshi Tanaka, Joichi Sugimura, Effects of Transition Metals on Low Friction of DLC Coatings, 2021 Hydrogenius and I2Cner Tribology Symposium, 2021.01.
2. 田中 宏昌, Effects of transition metals on low friction of DLC coatings, 2019 ITC sendai, Miyagi Japan, 2019.09, In this study, two transient metals, Titanium and Chromium, are selected and doped to the DLC coating. Sliding tests are conducted to see how the transient metals gives rise to low friction and wear..
3. 田中 宏昌, Effect of molecular structure of synthetic oils on decomposition and hydrogen generation in rolling contact, 2018 Tribology Frontiers Conference, Chicago Illinois , 2018.10, This study describes effects of additives on hydrogen permeation into bearing steel under rolling contact. Rolling contact tests were conducted under oil lubrication in hydrogen. PAO, POE, PPG were used as lubricants..
4. 田中 宏昌, Permeation of hydrogen into steel under rolling contact in various gas with additive free oils, Tribology frontier 2016, 2016.11, This study describes effects of additives on hydrogen permeation into bearing steel under rolling contact. Rolling contact tests were conducted under oil lubrication in hydrogen. PAO, POE, PPG were used as lubricants..
5. 田中 宏昌, Effects of lubricant additives on hydrogen permeation under rolling contact, Tribology frontier 2015, 2015.10, This study describes effects of additives on hydrogen permeation into bearing steel under rolling contact. Rolling contact tests were conducted under oil lubrication in hydrogen. WS2 nanoparticles, TOP, DBDS, ZDDP and MoDTC were used as lubricant additive.
6. 田中 宏昌, Hydrogen Permeation through Oxide Layer on Steels, ITC2015, 2015.09, This paper describes the surface film formation and hydrogen permeation on steel surface under hydrogen environment. Sliding tests of bearing steel AISI52100 and stainless steel AISI440C are conducted in hydrogen and vacuum with oil lubrication..
7. 田中 宏昌, Joichi Sugimura, Suguru Ikeda, Different failure modes in rolling contact of steel under grease lubrication, STLE tribology frontier 2014, 2014.10, Rolling contact fatigue test under grease lubrication is conducted for the purpose of clarifying effect of surrounding gas on rolling contact fatigue life. The influence of temperature, atmosphere, and grease types is investigated through surface analysis, hydrogen diffused in steel, the composition of surface film and the characteristics of lubrication state. The bearing life depended on environment and lubricant, and surface failure was classified into three types in terms of surface roughness and temperature change. At higher temperature, there is a tendency that roughness becomes smaller and bearing life is extended..
8. 田中 宏昌, Joichi Sugimura, Taiki komatsu, Effects of environmental gas on decomposition of lubricant and hydrogen generation at nascent iron surface, Asiatrib2014, 2014.02, Lubricated sliding tests of iron were made in a temperature controlled chamber, and the amount of hydrogen generated was determined with gas chromatography. The lubricants used included polyalphaolephine polyorester, polypropyrenglycol and dimethyl silicone oil. It was found that the amount of hydrogen generated is significantly larger when nascent surface is continuously created than under static non-sliding conditions. It was also found that hydrogen generation is retarded when the environment gas contains more oxygen. Among the oils tested, the silicone oil showed very low hydrogen generation under non-sliding condition while it generates much greater amount of hydrogen than other lubricants..
9. 田中 宏昌, EFFECTS OF HYDROGEN ON STRUCTURAL CHANGE AND ROLLING CONTACT FATIGUE OF STEEL, Asiatrib2014, 2014.02, This paper describes experimental study of rolling contact fatigue under various conditions. Ball-on-disk type rolling contact fatigue tests were conducted in hydrogen and other gasses. Some of the specimens contained extra amount of hydrogen by the pre-treatment of hydrogen exposure prior to the tests. After the rolling contact fatigue test, hydrogen content measurement with thermal desorption spectroscopy, cross section observations with SEM(Scanning electron microscope) and EsB (Energy selective back-scatter) detector were conducted..
10. 田中 宏昌, Rolling contact fatigue test with greases in hydrogen environment, WTC2013, 2013.09, This paper describes a study on grease lubrication of rolling element bearing under hydrogen environment. Rolling contact fatigue tests were conducted with greases under hydrogen and other gas environments. In order to find influences of hydrogen on several greases, relationship between RCF life and permeation of hydrogen and/or surface condition are focused on..
11. 田中 宏昌, PERMEATION OF HYDROGEN INTO STEEL IN SIMPLE CYCLIC CONTACT TESTS, ISFF7, 2013.04, This paper describes permeation of hydrogen under simple mechanical motion at tribo-interface. It has been believed that hydrogen plays an important role in degrading mechanical properties of ferrous materials in rolling contact. It is necessary to study each of the effects of elementary processes at contact and slip on hydrogen permeation into steel. An experimental apparatus was used which enabled a variety of simple contact tests with cyclic normal loading and reciprocating sliding for each in controlled environment.
12. Hiroyoshi Tanaka, Rolling Contact Fatigue under Grease Lubrication in Hydrogen, IJTC2012, 2012.10, In order to investigate the effects of greases on rolling contact fatigue life in hydrogen, we will focus on how surface film formation
Wettability or polarity of base oil, thickener of grease affects the surface initiated and/or subsurface initiated rolling contact fatigue.
13. Rolling fatigue in hydrogen gas environment.
  • Effect of Environment Gas on Surface Initiated Rolling Contact Fatigue,Tribology Online, 8,1, (2013) pp.90-96.
Educational Activities
charge of practice of experiment, graduation thesis, helping for foreign students
Other Educational Activities
  • 2004.09.
Professional and Outreach Activities
Support of post-doctral researchers for their experimental works, attending SICORP project(JST).