| Project/Area Number |
16K06061
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Design engineering/Machine functional elements/Tribology
|
|---|
| Research Institution | Fukui National College of Technology |
|---|
Principal Investigator |
Kato Hirotaka 福井工業高等専門学校, 機械工学科, 教授 (30311020)
|
|---|
| Project Period (FY) |
2016-04-01 – 2019-03-31
|
| Project Status |
Completed (Fiscal Year 2018)
|
| Budget Amount *help |
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2016: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
|
|---|
| Keywords | トライボロジー / 超強加工 / 高圧ねじり加工 / バニシング / 微細結晶粒材料 / バルクナノメタル / 耐摩耗性 / 凝着性 / バニシング加工 / 凝着力 / 摩擦係数 / 摩擦加工 / 結晶粒微細化 / 高機能表層 |
|---|
| Outline of Final Research Achievements |
Ultra-fine grained (UFG) and nanostructured metallic materials produced by severe plastic deformation (SPD) have attracted growing interest owing to their superior mechanical properties without alloying. In this study, we focused on high-pressure torsion (HPT) as a bulk SPD and burnishing as a surface SPD, and the tribological properties of UFG carbon steels produced by HPT and burnishing process were investigated in detail.
It was found that the wear rate of HPT increased with increasing the hardness, which was an abnormal wear behavior. The high wear rate of HPT steels were due to the high coefficient of friction as a result of the high adhesion force, which was caused by the high density of the grain boundaries in the UFG materials. Nanostructure in the 30 - 50 nm grain size range was formed in the burnished sub-surface layer, and the hardness significantly increased due to the grain refinement. Moreover the burnishing process reduced the specific wear rates by a factor of six.
|
| Academic Significance and Societal Importance of the Research Achievements |
極めて大きな塑性ひずみを金属材料に与える超強加工により作製が可能となったナノ／サブミクロン微細結晶粒材料は、合金元素を添加せずに高強度を示すという画期的材料であるために、環境問題の観点から次世代の構造材料候補として注目を集めている。一方、摩耗は疲労・腐食と並んで構造材料の性能・寿命を決定づける重要な要因と言われており、構造材料として使用する場合そのトライボロジー特性を明らかにすることは極めて重要である。したがって、本研究で得られたバルク超強加工と摩擦表層加工により作製した微細結晶粒材料の特異な摩擦摩耗特性に関する成果は、微細組織構造材料をトライボロジー分野に応用展開する上で大きな意義がある。
|
