Development of fatigue damage healing technology of metals by electron wind force control and elucidation of atom rearrangement and recombination mechanism

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K21925
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 18:Mechanics of materials, production engineering, design engineering, and related fields
• Research Institution: Waseda University
• Principal Investigator: Hosoi Atsushi 早稲田大学, 理工学術院, 教授 (60424800)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: 疲労き裂治癒 / 高密度電流

Outline of Final Research Achievements

Fatigue damage and crack healing of metallic materials were achieved by controlling high-density current field, and its mechanism was investigated. It was found that the growth of extrusion on the surface of metallic materials could be retarded by applying high-density current. It was shown that the current application could reduce the atomic vacancy density by acting on atomic vacancies in the channel of the PSB, and thus suppress the growth of the extrusion. It was also shown that the effect of pulsed current on fatigue cracks is to reduce the stress intensity factor by acting on the thermal compressive stress around the crack, resulting in crack closure and inter-plane bridging.

Free Research Field

材料力学、破壊力学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果により、金属材料にパルス電流を印加することで疲労き裂発生の遅延や発生したき裂の治癒の可能性が示された。電流は抵抗の低いところを選択的に流れることから微小欠陥やき裂を迂回するため、その先端に高密度電流場が形成される。つまり損傷部に選択的に電流の効果を付与することができる利点がある。