Construction of scientific principles of the interrelationship between melting dynamics and solidification dynamics in metallic materials

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H00310
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 26:Materials engineering and related fields
• Research Institution: Kyushu University
• Principal Investigator: Morishita Kohei 九州大学, 工学研究院, 准教授 (00511875)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 溶解ダイナミクス / 凝固ダイナミクス / レーザー溶融 / 溶断 / Ni基超合金 / Cu粉体

Outline of Final Research Achievements

In additive manufacturing (AM) of metallic materials, the correlation between mechanical properties and process parameters has been actively studied, but what actually happens during laser or electron beam irradiation is still largely unexplored. This study aims to empirically clarify the melting and solidification dynamics and their interrelationships in a wide range of melting and solidification phenomena, from low-speed melting such as casting to rapid melting such as in AM of metallic materials. The results of this study revealed that the resolidified micro structure originating from the solid/liquid interface is strongly affected by the pre-melting micro structure and provided fundamental data for the study.

Free Research Field

凝固現象

Academic Significance and Societal Importance of the Research Achievements

本研究では，溶解組織の形成過程（溶解ダイナミクス）とその後の凝固組織の形成過程（凝固ダイナミクス）を，個々に解明するのではなく，相互に作用しあうものとして体系化した点に学術的意義があると考える．得られた知見は液相からの核生成・成長とは異なる，材料の溶解によって生じた固液界面からの凝固成長における組織制御指針を与えるものであり，すなわち，溶接やAMだけでなく鋳造プロセスにおいて再溶解が発生する特殊な操業などにも広く適用できると考える．また，本課題を通して確立したレーザー溶解の観察手法は今後の金属３Dプリント技術の理解に貢献できると考える．