Development of fatigue design method of small-sized structures based on controlled nano-crystalline microstructure

• Project/Area Number: 15H03896
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Materials/Mechanics of materials
• 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: ¥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.

Research Products

• [Journal Article] 電着銅の疲労特性に及ぼす結晶粒径の影響 (2015)
  • Author(s): 田中啓介，竹下峻平，大塚一史，佐野勝基，來海博央
  • Journal Title: 材料 Volume: 64 Pages: 918-925
  • Peer Reviewed
• [Presentation] 電着ニッケル薄膜における切欠き疲労限度の予測 (2018)
  • Author(s): 江川祐二，村瀬優太，田中啓介，來海博央
  • Organizer: 日本機械学会，東海支部第67期講演会
• [Presentation] Effect of micro-notches on fatigue strength of electrodeposited nanocrystalline nickel thin films (2018)
  • Author(s): Keisuke Tanaka, Yuta Murase, Hirohisa Kimachi
  • Organizer: 12th International Fatigue Congress, Fatigue 2018
  • Int'l Joint Research
• [Presentation] 電着ニッケル薄膜切欠き試験片における疲労き裂の発生と進展 (2017)
  • Author(s): 田中啓介，永田寬茂，原口正義，村瀬優太，來海博央
  • Organizer: 日本材料学会 第66期学術講演会
• [Presentation] 電着ニッケルナノ結晶薄膜の切欠きによる疲労強度低下の予測 (2017)
  • Author(s): 田中啓介，村瀬優太，長谷光司，來海博央
  • Organizer: 日本機械学会 M&M2017材料力学カンファレンス
• [Presentation] 電着ナノ結晶バルク材の疲労特性に及ぼす結晶粒径の影響 (2017)
  • Author(s): 伊賀友一朗，小林大純，村瀬優太，田中啓介，來海博央
  • Organizer: 日本機械学会 M&M2017材料力学カンファレンス
• [Presentation] 電着ナノ結晶バルク材の疲労特性に及ぼす結晶粒径の影響 (2017)
  • Author(s): 村瀬優太，長谷光司，田中啓介，來海博央
  • Organizer: 日本材料学会主催 第18回破壊力学シンポジウム
• [Presentation] 電着ニッケル薄膜のき裂開閉口計測に基づく疲労き裂進展特性の評価” (2017)
  • Author(s): 石田幸也，田中啓介，清水憲一，村瀬優太
  • Organizer: 日本材料学会主催 第18回破壊力学シンポジウム
• [Presentation] 電着法により創製したNiナノ結晶バルク材の疲労特性に及ぼす結晶粒径の影響 (2017)
  • Author(s): 小林大純，村瀬優太，伊賀友一朗，來海博央，田中啓介
  • Organizer: 日本材料学会，東海支部，第11回学術講演会
  • Place of Presentation: 名古屋
• [Presentation] 微小欠陥が電着法により創製したニッケルナノ結晶薄膜の疲労強度に及ぼす影響 (2016)
  • Author(s): 長谷光司，村中洋昭，田中啓介，來海博央
  • Organizer: 日本材料学会，第33回疲労シンポジウム
  • Place of Presentation: 赤穂
  • Year and Date: 2016-11-11
• [Presentation] 電着法で創製したニッケルナノ結晶薄膜の非ポア特性に及ぼす結晶粒径の影響 (2016)
  • Author(s): 村瀬優太，小林大純，田中啓介，來海博央
  • Organizer: 日本材料学会，第33回疲労シンポジウム
  • Place of Presentation: 赤穂
  • Year and Date: 2016-11-11
• [Presentation] 電着法により創製したNiナノ結晶バルク材の疲労特性評価 (2016)
  • Author(s): 小林大純，村瀬優太，佐野勝基，田中啓介，來海博央
  • Organizer: 日本材料学会東海支部 第１０回学術講演会
  • Place of Presentation: 岐阜
  • Year and Date: 2016-03-09
• [Presentation] ニッケルナノ結晶薄膜の疲労強度に及ぼす微小欠陥の影響 (2016)
  • Author(s): 長谷光司，永田寬茂，田中啓介，來海博央
  • Organizer: 日本材料学会東海支部 第１０回学術講演会
  • Place of Presentation: 岐阜
  • Year and Date: 2016-03-09
• [Presentation] UV-LIGAプロセスにより創製したNi薄膜切欠き試験片に疲労特性 (2016)
  • Author(s): 永田寬茂，田中啓介，來海博央
  • Organizer: 日本材料学会東海支部 第１０回学術講演会
  • Place of Presentation: 岐阜
  • Year and Date: 2016-03-09
• [Presentation] X線・破壊力学による疲労の研究―研究の歩みと展望― (2016)
  • Author(s): 田中啓介
  • Organizer: 日本材料学会 合同公開部門委員会
  • Place of Presentation: 富山
  • Invited
• [Presentation] Fatigue properties of nano-crystalline nickel folms made by electrodeposition (2015)
  • Author(s): Kesuke Tanaka, Hirohisa Kimachi
  • Organizer: International Conference on Advanced Technology in Experimental Mechanics
  • Place of Presentation: 豊橋
  • Year and Date: 2015-10-04
  • Int'l Joint Research
• [Presentation] 電着したニッケルナノ結晶薄膜の微視構造のX線回折プロファイル解析による評価 (2015)
  • Author(s): 田中啓介，小池祐基，佐野勝基，來海博央，町屋修太郎，菖蒲敬久
  • Organizer: 日本材料学会 第49回X線材料強度に関するシンポジウム
  • Place of Presentation: 大阪
  • Year and Date: 2015-07-16