Elucidation of mechanism for formation of high density dislocations and quenching of high density crystalline structures using laser-driven shocks and its applications

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420778
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Material processing/Microstructural control engineering
• Research Institution: Osaka University
• Principal Investigator: Sano Tomokazu 大阪大学, 工学(系)研究科(研究院), 准教授 (30314371)
• Co-Investigator(Renkei-kenkyūsha): ARAKAWA Kazuto 島根大学, 総合理工学研究科, 准教授 (30294367) ; INUBUSHI Yuichi 理化学研究所, ビームライン開発チーム, 特別研究員 (40506250) ; HOSOKAI Tomonao 大阪大学, 大学院工学研究科, 特任准教授 (80361533)
• Research Collaborator: SANO Yuji ; MATSUDA Tomoki ; KASHIWABARA Ryota ; MATSUYAMA Norihiro
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: フェムト秒レーザー / 衝撃圧縮 / レーザー衝撃法 / 準安定構造 / 格子欠陥 / ピーニング / 転位導入

Outline of Final Research Achievements

We investigated crystalline structures and mechanical properties of femtosecond laser-irradiated materials such as pure iron (bcc), pure titanium (hcp), pure silicon (diamond), aluminum (fcc), and nickel (fcc). Metastable structures, which did not exist in the initial state, were formed in pure iron, pure titanium, and pure silicon, which had polymorphs in higher temperatures or higher pressures. For all materials, high-density lattice defects were formed and hardness increased in the femtosecond laser-affected zone. We found number of pulses and pulse energy of the femtosecond laser influences the depth of the hardened zone and the increment of the hardness. We succeeded in improving fatigue properties of aluminum plates by shooting femtosecond laser pulses on the surface.

Free Research Field

レーザー加工