2022 Fiscal Year Final Research Report

Homogenous distribution of the minor phase in immiscible Al-based alloys solidified by electromagnetic vibration processing

Research Project

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Project/Area Number	20K05186
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	National Institute of Advanced Industrial Science and Technology
Principal Investigator	Li Mingjun 国立研究開発法人産業技術総合研究所, 材料・化学領域, 主任研究員 (50392808)
Co-Investigator(Kenkyū-buntansha)	田村卓也国立研究開発法人産業技術総合研究所, 材料・化学領域, 研究チーム長 (30446588)
Project Period (FY)	2020-04-01 – 2023-03-31
Keywords	アルミニウム / 電磁振動 / 不混和性合金 / 孤立微細分散 / スズ
Outline of Final Research Achievements	The immiscible Al-Sn alloy is prone to segregate under a usual casting condition. If the Sn phase can be isolated finely and dispersed homogenously into the Al matrix, the properties will be greatly enhanced. In the present study, we solidified Al-20 wt% Sn when electromagnetic vibration (EMV) was imposed upon the solidifying liquid. The effects of electric current, vibration frequency, and magnetic flux density on the solidification microstructure were examined and characterized. It was found that when EMV was imposed at f = 100 Hz, the Sn phase could be isolated finely and dispersed homogenously in the primary Al matrix. The specimen with fine Sn dispersions had an improved elongation in tensile tests. The homogenous distribution of Sn is attributed to the uncoupled movement between the primary Al phase and the surrounding liquid, which may breakdown the Sn liquid film into discrete segments and thus form isolated particles at the final stage.
Free Research Field	金属生産工学
Academic Significance and Societal Importance of the Research Achievements	二相分離（偏晶型）合金は構成する金属間の密度差が大きく、鋳造時には軽元素は上に浮き、重元素は下に沈むため偏析しやすく、従来の鋳造技術では作製が不可能であった。これらの二相分離合金の第二相を母相中に均一に孤立微細分散させることができれば、優れた特性を有する複合材料が創製できる。我々は直流磁場中で溶湯に交流電流を印加することで発生する電磁振動プロセスを用いる事により、Al-Sn不混和性合金において第二相のSnがAl母相に均一に孤立微細分散した事に成功した。磁場強度の影響を精査した結果、Snの孤立微細分散できる原理を見出すことができた。