Development of fatigue design method of small-sized structures based on controlled nano-crystalline microstructure
Project/Area Number |
15H03896
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Materials/Mechanics of materials
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Research Institution | Nagoya Industrial Science Research Institute (2016-2017) Meijo University (2015) |
Principal Investigator |
Tanaka Keisuke 公益財団法人名古屋産業科学研究所, 研究部, 上席研究員 (80026244)
|
Co-Investigator(Kenkyū-buntansha) |
來海 博央 名城大学, 理工学部, 教授 (30324453)
清水 憲一 名城大学, 理工学部, 准教授 (50294434)
|
Project Period (FY) |
2015-04-01 – 2018-03-31
|
Project Status |
Completed (Fiscal Year 2017)
|
Budget Amount *help |
¥16,510,000 (Direct Cost: ¥12,700,000、Indirect Cost: ¥3,810,000)
Fiscal Year 2017: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Fiscal Year 2016: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2015: ¥9,750,000 (Direct Cost: ¥7,500,000、Indirect Cost: ¥2,250,000)
|
Keywords | 機械材料・材料力学 / 疲労 / 破壊力学 / 薄膜 / ナノ結晶 / き裂進展 / 結晶粒径依存性 / 微小構造体 |
Outline of Final Research Achievements |
The effect of notches on the fatigue strength reduction was studied using two types of nickel thin films were produced by electrodeposition: ultra-fine grained film (UFG) with the grain size of 384 nm and nano-crystalline grained film (NCG) with that of 17 nm. Micro-sized notches introduced by FIB. The fatigue strength decreased with increasing depth of micro-notches. NCG had much higher strength than UFG compared at the same notch depth. The fatigue limit was controlled by crack initiation. A fictitious crack model successfully predicted the reduction of the fatigue limit due to micro-notches. The characteristic crack length of NCG was much smaller than that of UFG. Macro-notched specimens produced by the UV-LIGA process also follow the fatigue strength reduction predicted by the fictitious crack model. Micro-mechanisms of fatigue crack initiation and propagation on nanocrystalline thin films were examined based on SEM and EBSD observations.
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Report
(4 results)
Research Products
(17 results)