High fatigue resistance of adhesive bonded material by using ethanol jet peening process

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K22395
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0301:Mechanics of materials, production engineering, design engineering, fluid engineering, thermal engineering, mechanical dynamics, robotics, aerospace engineering, marine and maritime engineering, and related fields
• Research Institution: Hiroshima University
• Principal Investigator: Arakawa Jinta 広島大学, デジタルものづくり教育研究センター, 特任助教 (80882018)
• Project Period (FY): 2020-09-11 – 2022-03-31
• Keywords: 接着接合 / 金属疲労 / 表面処理

Outline of Final Research Achievements

In this study, we aimed to improve the adhesive bonding strength associated with the surface treatment of ethanol injection type jet peening, but there were many unknown points regarding the durability strength and fracture mechanism of adhesive joint in the first place, and the fracture mechanism of adhesive joint was examined in relation to this problem.
As a result, it was found that the fatigue strength of adhesive joints using SPCC material as the base material greatly decreased by applying water immersion. On the other hand, adhesive joints made of SUS material as the base material did not tend to decrease the fatigue strength greatly by water immersion. Therefore, it became clear that the fatigue strength decreased in SPCC adhesive joints due to the decrease in the interface strength associated with water immersion.

Free Research Field

金属疲労

Academic Significance and Societal Importance of the Research Achievements

接着接合継手はマルチマテリアル化が期待される工業界において，今後の応用が多分に期待される．その中で，本研究にて明らかとした「接着接合継手の水劣化に伴う疲労強度低下」とその要因が「界面強度に低下によるものであること」を示唆した結果は，接着接合継手をあらゆる工業製品にて適用する上で，信頼性確保の観点から極めて貴重である．
また，DCB試験によって疲労き裂進展速度を定量的に求めた結果，水浸漬ををこなうことで，劇的に同指標が低下すること示した．これは，接着接合継手をあらゆる環境下において使用する中で，き裂が少しでも入った場合，非常に危険側の結果を招くことを示唆するもので設計上重要な指針となる．