Investigation of cracking mechanism during additive manufacturing process and the prevention method

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05096
• 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: Osaka University
• Principal Investigator: Kadoi Kota 大阪大学, 接合科学研究所, 准教授 (40454029)
• Co-Investigator(Kenkyū-buntansha): 濱崎 洋 中部大学, 工学部, 准教授 (30437579) ; 千葉 浩行 地方独立行政法人東京都立産業技術研究センター, 事業化支援本部技術開発支援部製品化技術グループ, 副主任研究員 (30757373)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 積層造形 / 凝固割れ / その場観察

Outline of Final Research Achievements

Additive manufacturing (AM) has been an attractive process for industrial practical use in various fields in recent years. However, the occurrence of crack defects during the AM process becomes problem for reliability. In this study, a new evaluation test method of crack susceptibility optimized for the AM process, and the influential factors on the cracking behavior were investigated by experiments and numerical simulations. The new test method could reveal that the critical initial stress for the crack initiation strongly depended on AM process conditions such as laser power. Besides, numerical simulation results indicated that the higher laser power induced the higher the critical strain rate even if the initial applied stress was low.

Free Research Field

材料科学，溶接冶金

Academic Significance and Societal Importance of the Research Achievements

新たにAM過程に適した割れ感受性の評価手法を構築し，割れ発生の影響因子を精度高く評価することで，割れ現象を理解することができる．加えて，数値解析モデルの構築により，製造時のAM条件から割れ発生の予測の可能性を示すことできた．これにより，近年工業的な利用が急速に拡大しているAMの割れ発生防止を学理に基づいて管理することができ，AM技術のさらなる適用拡大や高品質化，信頼性向上に寄与できると考えられる．