Development of deep laser drilling method by forming optical fiber structure in the processing hole

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05173
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26050:Material processing and microstructure control-related
• Research Institution: University of Hyogo
• Principal Investigator: Keisuke Yoshiki 兵庫県立大学, 産学連携・研究推進機構, 非常勤研究員 (60432548)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 超臨界二酸化炭素 / レーザー加工 / 深穴加工 / 高アスペクト比 / 対流 / 切りくず排出 / 噴流

Outline of Final Research Achievements

In this study, we investigated the application of the optical fiber effect and the behavior of supercritical fluids in laser hole processing. The experiment revealed that the behavior of supercritical fluids was affected by intermittent irradiation conditions and affected the effect of laser processing. Therefore, we adjusted the processing frequency to suppress the influence of jet flow and optimized the pulse interval of laser processing. We showed basic guidelines for laser processing, and as a result, deep hole laser processing became possible more than before. In addition, we revealed through observation of internal convection in metal material processing that supercritical fluids actually convect due to laser heat. This method makes it possible to perform difficult deep hole laser processing, effectively transmit laser energy to materials, and greatly improve energy efficiency and processing capacity.

Free Research Field

レーザー加工

Academic Significance and Societal Importance of the Research Achievements

本研究では，超臨界二酸化炭素雰囲気中でのレーザー加工における噴流と対流の挙動とその影響を明らかにし，最適な加工条件を提案した．これは，従来の空気中でのレーザー加工に比べて高アスペクト比の深穴加工が可能な新しい技術を開発したことを意味する．超臨界二酸化炭素は高い流動特性により対流を生じ，切りくずの排出や集光の改善に有利である．また，二酸化炭素は有効利用や温室効果ガスの削減にも寄与する．この技術は，半導体や自動車などの分野で求められる高精度な深穴加工に応用できると期待される．本研究は，超臨界二酸化炭素雰囲気中でのレーザー加工に関する基礎的な知見を提供し，今後の応用展開に向けた重要な一歩となる．