Conditions for the Occurrence of Novel Electromagnetic Separation Phenomena Observed in Aluminum Alloys and their Understanding

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05184
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26060:Metals production and resources production-related
• Research Institution: Chiba Institute of Technology
• Principal Investigator: Tamura Yosuke 千葉工業大学, 工学部, 教授 (40316807)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 電磁分離 / アルミニウム合金 / 過共晶 / リサイクル / 省エネルギー / 材料創製

Outline of Final Research Achievements

Electromagnetic separation phenomena of primary crystals observed in Al-10Fe and Al-25Si alloys, which were solidified while applying electromagnetic force, were investigated. Under predetermined conditions, primary crystals were segregated to the entire surface layer of the specimens by the electromagnetic force in both alloys. However, it was revealed that the electromagnetic force did not act on primary crystals that had already crystallized in the molten metal. When primary crystals segregated to the surface layer of the specimen, the central part of the specimen without them exhibited a supercooled structure with a fine eutectic structure including dendritic primary Al crystals. Additionally, a similar effect was observed in the Al-Si alloy by simply passing current through the molten metal. It appears that this novel electromagnetic separation phenomenon is triggered by the influence of electric and magnetic effects on the nucleation and growth of crystals.

Free Research Field

材料工学

Academic Significance and Societal Importance of the Research Achievements

電磁分離現象に係る当該分野においては，様々な近似・仮定に基づいたコンピュータシミュレーションが進んでいる。一方，その成果を技術として活用するには，実験事実に基づいた知見の蓄積が不可欠である。この点において，実験に基づく当該研究成果は貴重と言える。また従来報告されていない現象も発見されており，新たな学術分野の構築に繋がる可能性もある。新奇な電磁分離現象に関する理解を深めることは，リサイクルの効率化や新しい材料創製プロセスを開発することと同義である。以上より，本研究成果は学術的・社会的に有意義と言える。